![[dr. bob]](/dr-bob-sm.gif)
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 7 of 7. This is the beginning of the thread.
Posted by sdb on June 27, 2006, at 23:57:49
There are many studies that prove hypericum effective as an antidepressant with anxiolitic properties. It remains controversial and for me I can not come to a final point. I am pretty sure that the drug industry had influence to play down positive effects. It is sad that there are only very limited studies about specific disorders, so you could be able to paint a clearer picture.
Maybe I will post some more studies because I think
it is positive to discuss this under experienced users and what other pbabblers say.
I will listen carefully.Take care
sdb
See Maze study below
Effects of Hypericum perforatum and paroxetine on rat performance in the elevated T-maze
Venessa Beijamini and Roberto AndreatiniCorresponding Author Contact Information, E-mail The Corresponding Author
Departamento de Farmacologia, Laboratório de Fisiologia e Farmacologia do Sistema Nervoso Central, Setor de Ciências Biológicas, Centro Politécnico, Universidade Federal do Paraná, P.O. Box 19031, Curitiba 81531-990, PR, Brazil
Accepted 7 March 2003. ; Available online 21 May 2003.
AbstractHypericum perforatum extract exhibits an antidepressant effect and since several antidepressant drugs are also effective on generalised anxiety disorder (GAD) and panic disorders (PD), H. perforatum may possess some anxiolytic/antipanic effect. Thus, the aim of the present study was to evaluate the putative antipanic/anxiolytic effect of standardised H. perforatum extract (LI 160) on rats tested in the elevated T-maze, an animal model of innate (panic) and learned (generalised) anxiety, at doses that exhibit antidepressant-like activity. H. perforatum (150, 300 and 500 mg/kg, administered orally 24, 18 and 1 h before the test) decreased the immobility time in the forced swim test. Rats were treated orally with H. perforatum (150 or 300 mg/kg) or paroxetine (5 mg/kg) 24, 18, and 1 h before being tested in the elevated T-maze (subacute treatment). Immediately after this test, the animals were submitted to the open field to evaluate locomotor activity. Paroxetine was used as a positive control, since it was clinically effective in GAD and PD. Other groups of animals were submitted to the same drug treatment for 7 days (subchronic treatment). Paroxetine (5 mg/kg) impaired inhibitory avoidance after subacute treatment, while subchronic administration increased one-way escape latency. Subacute treatment with H. perforatum (300 mg/kg) exerts a partial anxiolytic-like effect in the inhibitory avoidance task. Repeated administration of H. perforatum (300 mg/kg) induced an anxiolytic effect (decreased inhibitory avoidance) and an antipanic effect (increased one-way escape). No effect on locomotor activity was found with any treatment. Thus, the results suggest that H. perforatum extract could exert an anxiolytic and antipanic effect.
Author Keywords: Animal model; Anxiety; Antidepressant; Forced swim; Panic; Paroxetine; Phytotherapy
Article Outline
1. Introduction
2. Material and methods2.1. Animals
2.2. Drugs
2.3. Apparatus
2.4. Procedures2.4.1. Experiment 1—effects of H. perforatum on the forced swimming test
2.4.2. Experiment 2—effects of subacute (three times over 24 h) H. perforatum or paroxetine treatment on the elevated T-maze test
2.4.3. Experiment 3—effects of subchronic (7-day) treatment with H. perforatum or paroxetine on the elevated T-maze2.5. Statistical analysis
3. Results
3.1. Experiment 1—effects of H. perforatum on the forced swimming test
3.2. Experiment 2—effects of subacute (three times over 24 h) H. perforatum or paroxetine treatment on the elevated T-maze test
3.3. Experiment 3—effects of subchronic (7-day) treatment with H. perforatum or paroxetine on the elevated T-maze
3.4. Open-field results4. Discussion
Acknowledgements
References1. Introduction
Pathological anxiety comprises several kinds of disorders such as generalised anxiety disorder, panic disorder and obsessive-compulsive disorder, although for a long time animal models of anxiety considered anxiety as a single disorder. However, in the last few years, some investigators have developed animal models that try to separate these different types of anxiety. For example, the elevated T-maze, which was derived from the elevated plus-maze by suppression of one closed arm, has been proposed to evaluate two types of anxiety in the same animal, i.e. learned (or conditioned) anxiety, represented by inhibitory avoidance behaviour, and innate (or unconditioned) fear, represented by one-way escape [1, 2 and 3]. Inhibitory avoidance is the increased latency to leave a closed arm along three successive trials. This task was impaired by treatment with diazepam, ipsapirone, buspirone, ritanserin and chronic imipramine [4 and 5], treatments that were effective in generalised anxiety disorder (GAD) [6]. Thus, the learned nature and its pharmacological sensitivity suggest that this behaviour is related to GAD [5, 6 and 7]. On the other hand, one-way escape, which is tested by measuring the latency of the animal to flee from one open arm, was increased by chronic treatment with imipramine and fluoxetine ( [5], Poltronieri et al., personal communication), treatments that were effective on PD. On the other hand, anxiolytic drugs that were ineffective on PD (e.g. low to moderate dose of diazepam, buspirone, ipsapirone) did not impair one-way escape [4 and 6]. Thus, based on the assumption that innate fear is related to PD [5] and on the pharmacological sensitivity of PD, one-way escape is supposed to represent panic anxiety [1, 2, 3 and 5].
The extract of Hypericum perforatum L. (H. perforatum), popularly called St John’s Wort, has been used in folk medicine to treat depressive disorders [8]. Many clinical studies have suggested that the H. perforatum extract is effective in the treatment of mild to moderate depression (for review, see [7, 9, 10, 11 and 12]; but see also [13]). Moreover, the antidepressive effects of H. perforatum and its underlying mechanisms have been widely studied using animal models of depression [14, 15 and 16]. St John’s Wort has numerous biologically active constituents, including naphthodianthrones (e.g. hipericin), phloroglucinols (e.g. hyperforin) and flavonoids (e.g. biapigenin). Among these, the most important seems to be hyperforin, which is able to inhibit in vitro the uptake of monoamines, glutamate and γ-aminobutyric acid—GABA [17 and 18]. Chronic treatment with H. perforatum extract leads to adaptive changes in β-adrenoceptors in the frontal cortex [19], as observed with conventional antidepressive drugs.
However, few recent studies have shown that H. perforatum may also exert an anxiolytic effect. Considering clinical studies, H. perforatum treatment reduced the number of panic attacks in a patient with a possible panic disorder diagnosis [20] and three case reports suggest an anxiolytic effect of the extract [21]. Moreover, H. perforatum extract exerted a beneficial effect on patients with obsessive-compulsive disorder in an open study [22] and reduced anxiety and depression scores in the Hospital Anxiety and Depression Scale in patients with fatigue of unexplained origin [23]. Studies with animal models of anxiety strengthen the suggestion of an anxiolytic effect of this extract. It was found that H. perforatum extract without hyperforin increases the time spent in the open arms of the elevated plus-maze, suggesting an anxiolytic-like effect [24], although pure hyperforin also induces an anxiolytic effect on the elevated plus-maze [25]. Our group observed that acute treatment with H. perforatum extract decreased the marble-burying behaviour of mice but did not increase locomotor activity (Skalisz et al., unpublished results). Furthermore, H. perforatum impaired the acquisition of inhibitory avoidance in the light–dark test [26], an effect that is blocked by pre-treatment with flumazenil, a benzodiazepine receptor antagonist. H. perforatum extract also increases locomotor activity in the open field [26]. Moreover, chronic treatment with H. perforatum increased the time spent in the light compartment in the light/dark test [27]. Acute, but not chronic, H. perforatum treatment impaired inhibitory avoidance in the elevated T-maze [27]. Furthermore, Indian H. perforatum Linn extract (administered once daily for 3 days) also showed an anxiolytic-like effect on elevated plus-maze, elevated zero-maze, novelty-induced suppressed feeding latency and social interaction [28]. On the other hand, chronic treatment with H. perforatum extract reduced some flight behaviours in the Mouse Defense Test Battery, which has been suggested to be primarily sensitive to anti-panic agents [29].
Since (a) antidepressant drugs (ADs) were the main drug treatment for PD, (b) AD were also effective on GAD, and (c) H. perforatum exhibits an antidepressive effect, it was hypothesized that H. perforatum might posses antipanic and/or anxiolytic effect. Thus, the aim of the present study was to evaluate the effect of subacute and subchronic treatment with H. perforatum extract on rats tested in the elevated T-maze at the dose that exhibited antidepressive-like effect (determined in the forced swimming test) but did not change locomotor activity.
2. Material and methods
2.1. AnimalsThe subjects were adult male albino Wistar rats (250–320 g) from our own breed. They were housed in groups of five in polypropylene cages with wood shavings as bedding under controlled conditions of light (12 h light–dark cycle, light on at 7.00 a.m.) and temperature (22±1 °C). Tap water and food pellets were available ad libitum throughout the experiment.
2.2. DrugsThe dry standardized extract of aerial parts of H. perforatum (LI 160) was supplied by Eurofarma (coming from Indena, Milan, Italy; extraction solvent: methanol; herb-extract ratio 7:1). The amount of hypericin (0.3%) and hyperforin (3.3%) was quantified by high performance liquid chromatography and fluorescence detection by Indena. The H. perforatum extract was suspended in distilled water and sonicated for 20 min before oral administration. Paroxetine (Eurofarma, São Paulo, Brazil) was dissolved in distilled water. Both drugs were prepared on the same day of the experiment. The control group received physiological saline. All drugs were administered orally by gavage in a final volume of 2 ml/kg body weight.
2.3. ApparatusThe elevated T-maze was made of black painted wood and had three arms of equal dimensions (50 cm×10 cm). One arm, enclosed by 40 cm high walls, was perpendicular to two opposed open arms. To prevent the rats from falling down, the open arms were surrounded by a wood rim 1 cm high. The whole apparatus was elevated 50 cm above the floor. The experiments were performed with an observer inside the experimental room.
The open-field apparatus was a circular metal arena (1 m in diameter), divided into 6 central and 12 peripheral units (20 cm×20 cm), positioned under a bright light.
2.4. Procedures
2.4.1. Experiment 1—effects of H. perforatum on the forced swimming testThe procedure was a modification of the Porsolt et al. method, as described in a previous report [30 and 31]. Briefly, the rat was placed in a glass aquarium (20 cm×20 cm×40 cm) containing 15 cm deep cold water (24±1 °C) for 15 min followed by a 5-min retest (test session) 24 h later. Immobility time was recorded during the test session: the rat was judged immobile whenever it stopped swimming and remained floating in the water, with its head just above water level. The water was changed after each rat. Following the test, the animals were dried in a heated enclosure. The vehicle (control group) or H. perforatum extract (150, 300 and 500 mg/kg, p.o.) was administered three times (24, 18 and 1 h) before a test session. This test was performed to determine the antidepressive-like doses of H. perforatum used in the subsequent experiments.
2.4.2. Experiment 2—effects of subacute (three times over 24 h) H. perforatum or paroxetine treatment on the elevated T-maze testOne day before the elevated T-maze test, all animals were exposed to one of the open arms of the elevated T-maze for 30 min [5]. Wood barriers mounted on the border of the maze central area isolated the arms of the elevated T-maze.
In the elevated T-maze test, the rat was placed at the end of the enclosed arm facing the intersection of the arms. The latency to leave the enclosed arm with the four paws in three successive trials was recorded (standard measure proposed by Graeff et al. [1]). Additionally, the latency to enter one of the open arms was also recorded (modified measure proposed by our group). This procedure adds to the latency measured, the time spent by the rat in the junction area and in additional entries into the closed arm before the entry into any open arm. The first trial was designated as basal latency (baseline) and represented the learning inhibitory avoidance behaviour. The other trials were designated avoidance 1 and 2, respectively. The interval between trials was 30 s, during which the animal was placed in a Plexiglas box identical to its home cage. Thirty seconds after the last trial of inhibitory avoidance, the rat was placed at the end of one open arm and the latency to leave this arm with its four paws (one-way escape form open arm, standard measure proposed by Graeff et al. [1]) and the latency to enter the enclosed arm (one-way escape into enclosed arm, modified measure proposed by our group) were recorded (Escape 1). The same measurement was repeated after 30 s (Escape 2). This modification adds to the escape latency the time spent in the junction area and in other entries into open arms before entry into the closed arm. A cut-off time of 300 s was established for both measures (inhibitory avoidance and one-way escape).
Immediately after the elevated T-maze test, each rat was placed in the middle of the open field and its behaviour was evaluated for 5 min. Peripheral and central locomotion (number of units crossed) and rearing, time spent in grooming and immobility, and number of faecal boli were recorded [32].
The open field and the elevated T-maze were washed with a water–alcohol solution (5%) after each animal was tested. The experiments were performed at the same time of day (8:00–13:00 h).
The vehicle, paroxetine (5 mg/kg, p.o., positive control) and H. perforatum extract (150 or 300 mg/kg, p.o.) were administered as in experiment 1, three times (24, 18 and 1 h) before the test session.
2.4.3. Experiment 3—effects of subchronic (7-day) treatment with H. perforatum or paroxetine on the elevated T-mazeFor the subchronic study, animals were injected with vehicle, paroxetine (5 mg/kg, p.o.) or H. perforatum extract (150 or 300 mg/kg, p.o.) for 7 days, once a day. On the 6th day, all rats were exposed to one of the open arms of the elevated T-maze for 30 min. On this day, either drugs or vehicle were administered 30 min after pre-exposure. On the 7th day, rats were tested in the elevated T-maze 1 h after the last injection treatment. As in the experiment 2, the animals were submitted to the open-field test immediately after the elevated T-maze test.
2.5. Statistical analysisData were represented as mean±standard error of mean (S.E.M.) or as median±semi-inter-quartile range (SIR) as indicated in figures and table. One-way analysis of variance (ANOVA) was used to analyse the forced swimming test data. Significantly different data were further analysed by the post hoc Newman–Keuls test for individual group comparisons. The elevated T-maze data were analysed by non-parametric tests, i.e. Friedman ANOVA followed by the Wilcoxon matched pair test when appropriate for inhibitory avoidance results, and Kruskal–Wallis ANOVA followed by the Mann–Whitney U-test when appropriate for one-way escape results. The open-field parameters were evaluated by one-way ANOVA followed by the Newman–Keuls test for individual group comparisons (locomotor activity and immobility time) or by Kruskal–Wallis ANOVA followed by the Mann–Whitney U-test when appropriate (rearing, grooming and faecal boli). Differences were considered statistically significant when P≤0.05.
3. Results
3.1. Experiment 1—effects of H. perforatum on the forced swimming testThe effect of subacute treatment with H. perforatum extract on behavioural despair is illustrated in Fig. 1. ANOVA showed that there was a statistically significant effect of treatment (F3,42=6.089, P<0.002). Post hoc analysis revealed that all doses of H. perforatum extract (150, 300 and 500 mg/kg) significantly decreased immobility time when compared to the control group (P<0.05).
Enlarge Image (21K)Fig. 1. Effects of subacute administration (24, 18, and 1 h before the test) of H. perforatum extract 150 mg/kg (Hype 150, n=11), 300 mg/kg (Hype 300, n=12), 500 mg/kg (Hype 500, n=9) and vehicle (n=14) on the immobility time of rats submitted to the forced swimming test. Data represent mean±S.E.M. *P≤0.02 compared with the vehicle group.
3.2. Experiment 2—effects of subacute (three times over 24 h) H. perforatum or paroxetine treatment on the elevated T-maze test
Since we did not found statistically significant difference between groups on the latency to enter the open arm (modified procedure) in the inhibitory avoidance, these data will not be shown.
The results of the latency to leave enclosed arm (standard procedure) are showed in Fig. 2. Acute treatment did not affect the baseline latency (first withdrawal) in the inhibitory avoidance task (H3,48=5.38, P>0.10). As illustrated in Fig. 2, the control group showed inhibitory avoidance acquisition (χ2r=18.65, P<0.001) when evaluated by the latency to leave enclosed arm. The Wilcoxon matched pair test revealed that there were statistically significant differences between baseline and avoidance 1 (T=18.5, P<0.05), baseline and avoidance 2 (T=0.0, P<0.001) and between avoidance 1 and 2 (T=2.0, P<0.01). A similar profile was found for H. perforatum 150 (χ2r=15.82, P<0.001): statistically significant differences between baseline and avoidance 1 (T=1.5, P<0.01), baseline and avoidance 2 (T=1.0, P<0.01) and between avoidance 1 and 2 (T=1.0, P<0.01). The treatment with H. perforatum 300 and paroxetine 5 changed this profile: H. perforatum 300 (χ2r=14.11, P<0.001): statistically significant differences between baseline and avoidance 1 (T=2.0, P<0.01) and baseline and avoidance 2 (T=0.0, P<0.01), but not between avoidance 1 and 2 (T=1.5, 0.06>P>0.05); and paroxetine 5 (χ2r=16.05, P<0.001): statistically significant differences between baseline and avoidance 2 (T=0.0, P<0.01) and between avoidance 1 and 2 (T=0.0, P<0.01), but not between baseline and avoidance 1 (T=10.0, 0.07>P>0.05).
Enlarge Image (12K)Fig. 2. Effects of subacute administration (24, 18, and 1 h before the test) of H. perforatum extract 150 mg/kg (Hype 150, n=13) and 300 mg/kg (Hype 300, n=10), paroxetine 5 mg/kg (Paro 5, n=10), and vehicle (n=15) on the latency to leave the enclosed arm in the elevated T-maze. Data represent the mean±S.E.M. *P≤0.05 compared with baseline latency within the group; **P≤0.05 compared with avoidance 1 latency within the group.
In contrast to inhibitory avoidance, one-way escape was not affected by the treatments. Kruskal–Wallis ANOVA showed that there were no statistically significant differences between treatment groups in Escape 1A [vehicle: 30±12, Hype 150: 14±3, Hype 300: 43±29, Paro 5: 25±6, mean±S.E.M.; H(3,48)=2.24, NS], Escape 1B [vehicle: 43±12, Hype 150: 43±22, Hype 300: 69±28, Paro 5: 25±6; H(3,48)=3.00, NS], Escape 2A [vehicle: 32±10, Hype 150: 15±3, Hype 300: 22±11, Paro 5: 20±4; H(3,48)=1.81, NS] and Escape 2B [vehicle: 76±16, Hype 150: 60±20, Hype 300: 48±13, Paro 5: 91±27; H(3,48)=3.03, NS].
3.3. Experiment 3—effects of subchronic (7-day) treatment with H. perforatum or paroxetine on the elevated T-mazeSince we did not found statistically significant difference between groups on the latency to enter the open arm (modified procedure) for inhibitory avoidance, these data will not be shown.
Fig. 3 (top) shows the results of subchronic treatment on the latency to leave the enclosed arm (standard procedure). Like in the acute experiment, 7-day treatment did not affect the baseline latency in the inhibitory avoidance task (H3,48=2.49, P>0.10). Friedman ANOVA revealed an increasing latency of inhibitory avoidance along trials in the control group (χ2r=18.56, P<0.001), in the group treated with H. perforatum 150 (χ2r=9.7, P<0.01) and in the paroxetine 5 group (χ2r=15.82, P<0.001). Post hoc analysis showed statistically significant differences in the control group: between baseline and avoidance 1 (T=1.0, P<0.01), baseline and avoidance 2 (T=0.0, P<0.01) and avoidance 1 and 2 (T=1.0, P<0.05); in the H. perforatum 150 group: between baseline and avoidance 1 (T=14.0, P<0.05), baseline and avoidance 2 (T=1.0, P<0.01) and avoidance 1 and 2 (T=4.0, P<0.05); and in the paroxetine 5 group: between baseline and avoidance 1 (T=6.5, P<0.01), baseline and avoidance 2 (T=1.0, P<0.01) and between avoidance 1 and 2 (T=0.0, P<0.01). On the other hand, the H. perforatum 300 group did not acquire inhibitory avoidance learning (χ2r=4.66, NS).
Enlarge Image (21K)Fig. 3. Effects of subchronic (7 days) administration of H. perforatum extract 150 mg/kg (Hype 150, n=13) and 300 mg/kg (Hype 300, n=11), paroxetine 5 mg/kg (Paro 5, n=12) and vehicle (n=12) on rat behaviour in the elevated T-maze. Data represent mean±S.E.M. Top: Latency to leave enclosed arm. *P≤0.05 compared with baseline latency within the group; **P≤0.05 compared with avoidance 1 latency within the group. Bottom: one-way escape from the open arm (Escape 1A and 2A) and one-way escape into the enclosed arm (Escape 1B and 2B). #P≤0.05 compared with the vehicle group.
Results of one-way escape are shown in Fig. 3 (bottom; A: one-way escape from open arm, B: one-way escape into the enclosed arm). The subchronic treatment changed Escape 1A [H(3,48)=9.3, P<0.05], Escape 1B [H(3,48)=14.58, P<0.01] and Escape 2B [H(3,48)=12.35, P<0.01], but did not affect Escape 2A [H(3,48)=4.38, NS], as indicated by Kruskal–Wallis ANOVA. The one-way escape from open arm (standard measure) showed a statistically significant effect of paroxetine 5 when compared to vehicle on Escape 1A (U=24.5, P<0.01). The one-way escape into enclosed arm (modified measure) detected that H. perforatum 300 and paroxetine 5 increased the escape latency when compared to the control group in Escape 1B (U=30.5, P<0.05; U=13, P<0.001, respectively). Moreover, there was a statistically significant difference between paroxetine 5 and vehicle in Escape 2B (U=17, P<0.01).
3.4. Open-field resultsTable 1 summarises the open-field behaviour results. The subacute treatment did not change the central locomotor activity [F(3,44)=0.152, NS], peripheral locomotor activity [F(3,44)=0.675, NS], immobility time [F(3,44)=0.354, NS], grooming [H(3,48)=1.510, NS], rearing [H(3,48)=15.019, P<0.01] or faecal boli [H(3,48)=1.978, NS].
Table 1. Effects of subacute and subchronic treatment with H. perforatum extract, paroxetine or vehicle on parameters for rats tested in the open field
Full Size TableHype 150 and Hype 300: H. perforatum extract 150 mg/kg (n=13) and 300 mg/kg (n=10), Paro 5: paroxetine 5 mg/kg (n=10), and vehicle (n=15).
In the same way as the subacute treatment, no statistically significant differences were found with subchronic treatment in central locomotor activity [F(3,44)=2.61, 0.07>P>0.05], peripheral locomotor activity [F(3,44)=0912, NS], immobility time [F(3,44)=1.119, NS] or faecal boli [H(4,58)=4.12, NS]. Additionally, rearing was not affected by the treatment [H(3,48)=4.540, NS], but there was a statistically significant effect on grooming [H(4,58)=8.015, P<0.05]. A posteriori analysis revealed a statistically significant difference between H. perforatum 300 and paroxetine 5 (U=27, P<0.05) and between H. perforatum 300 and H. perforatum 150 (U=22, P<0.01).
4. DiscussionTreatment with three doses of H. perforatum extract significantly reduced the immobility time of rats submitted to the forced swimming test, suggesting an antidepressive-like effect. This result is in accordance with the antidepressive-like activity of H. perforatum in animal models [14, 15, 16, 33, 34 and 35]. Particularly in studies on rats submitted to the forced swimming test, H. perforatum exerted an anti-immobility time effect at doses (per oral) between 125 and 1000 mg/kg [15 and 35]. Thus, the results obtained in the present study for the effect of H. perforatum on FST agree with literature data and the extract doses of 150 and 300 mg/kg were chosen for use in the subsequent experiments.
Regarding the results of inhibitory avoidance in the elevated T-maze, subacute treatment with H. perforatum extract 300 mg/kg and paroxetine 5 mg/kg impaired avoidance 2 and avoidance 1 performance, respectively. These results suggest a partial anxiolytic effect (partial blockade of inhibitory avoidance acquisition) at doses that did not affect locomotor activity since did not affect square crossing in the open field and baseline latency in the elevated T-maze. However, the results with H. perforatum could be due to a higher avoidance behaviour exhibited in avoidance 1 plus a greater variability of data. On the other hand, paroxetine 5 mg data could be viewed as a delay in inhibitory avoidance acquisition, which would be an indication of anxiolytic-like effect. After subchronic administration (7 days), only the highest dose of extract impaired the development of inhibitory avoidance but did not impair the locomotor activity, which is interpreted as an anxiolytic-like effect.
Pre-clinical studies with paroxetine on animal models of anxiety have presented variable results. In the four-plate test, acute paroxetine administration induced an anxiolytic effect that was increased by buspirone pre-treatment [36 and 37]. An anxiolytic effect of acute paroxetine administration was also seen on the ultrasonic isolation calls of rat pups [38] and shock-induced ultrasonic vocalization [39]. In the social interaction test, acute treatment with paroxetine did not change animal behaviour while chronic treatment increased significantly the time spent in social interaction [40 and 41]. On the other hand, paroxetine induced an anxiogenic effect in the elevated plus-maze after acute administration [42, 43, 44 and 45] but an anxiolytic effect after repeated administration [42]. However, there is a suggestion that this acute effect of paroxetine could be due to an anti-exploratory action rather than to a true anxiogenic effect [45]. Thus, contradictory results were found with acute treatment, but a consistent anxiolytic-like effect was seen with repeated treatment. These last results correlate with clinical evidence showing that generalised anxiety disorder is improved by repeated treatment with paroxetine [46 and 47]. In the present study, we also observed this variable effect of paroxetine, but additional studies (with wide range dose and longer treatment) are need to evaluate the sensitivity of this procedure to paroxetine treatment.
Our results with H. perforatum extract agree with some clinical studies that indicated a putative anxiolytic effect for this phytomedicine [20, 21, 22 and 23], although the cited studies did not address directly this matter and had methodological flaws. However, animal studies with the light–dark test [26 and 27], elevated T-maze [27], elevated plus-maze [24 and 48] and marble-burying behaviour test [Skalisz et al., unpublished data] indicated an anxiolytic-like effect for H. perforatum, supporting the hypothesis of a putative anxiolytic clinical effect. Moreover, pure hyperforin exerted a clear anxiolytic-like effect on rat behaviour in the elevated plus-maze [25].
Regarding one-way escape, a measure related to innate anxiety, subacute H. perforatum and paroxetine administration did not change escape latency from the open arms in the elevated T-maze. However, subchronic treatment with paroxetine increased Escape 1A, 1B and 2B at a dose that did not change locomotor activity. Our data agree with clinical studies that showed an antipanic effect of paroxetine only after repeated administration [49, 50 and 51]. Chronic treatment with fluoxetine and imipramine, effective drugs for panic disorder, also increases the one-way escape latency in the elevated T-maze ( [5], Poltronieri et al., personal communication). On the other hand, benzodiazepines, 5-HT1A agonists and 5-HT2 antagonists, drugs with an anxiolytic effect but ineffective in panic disorder, did not modify this parameter [4]. These results lead to the suggestion that one-way escape could be a useful measure of antipanic drugs [4 and 5]. Thus, the present results with paroxetine provide additional data for the predictive validity of one-way escape as a model of panic anxiety.
H. perforatum extract only increased one-way escape into enclosed arm (Escape 1B), showing the possibility of an antipanic effect. In regard to H. perforatum, there is a case report that suggests this effect [20]. The reduction of flight behaviours in the Mouse Defense Test Battery is a further indication that H. perforatum may possess a potential antipanic effect [29]. Nevertheless, chronic treatment (21 days) with H. perforatum extract did not increase the escape latency from the open arms in the same model [27]. However, it is worth to note that Flausino et al. evaluated one-way escape from open arm (named A in the present study—Escape 1A and 2A), which was not influenced by H. perforatum treatment in the present study (Fig. 3, bottom). Results from our laboratory with clonazepam, a clinically antipanic drug, suggested that the one-way escape into enclosed arm (modified method) can be more sensitive to antipanic drugs than one-way escape from open arm, which can explain the contradiction between our data and Flausino et al. [27]. However, by permitting the animal to explore the apparatus a bit more (e.g. central platform), it could be said that the additional procedure used in the present study introduces a behavioural change that alters the results and validity of the model. However, data from our laboratory [Bazzi et al., unpublished data] have shown that, at least in numerical terms, there is no difference between undrugged animals tested only by the standard method and animals tested by the modified method.
Both paroxetine and H. perforatum extract, like fluoxetine and imipramine, inhibit serotonin reuptake, a fact that might explain in part their similar profile observed in elevated T-maze. However, as described before, the H. perforatum extract has many actions on neurotransmitter systems that could explain its effects on rats tested in the elevated T-maze. Thus, additional studies are needed to delineate its anxiolytic/antipanic effects.
In conclusion, the present results suggest an anxiolytic and antipanic effect of H. perforatum extract on rats tested in the elevated T-maze at doses that induce an antidepressive effect in the forced swimming test and do not change locomotor activity. However, since the results of the present study could be seen as smaller than observed in previous studies, further research is needed to corroborate the putative antipanic effect of H. perforatum. In addition, the present data supports the one-way escape as a model of panic anxiety and provide additional evidence that the modified method used to record latency escape from the open arm can be more sensitive to the antipanic effect of drugs than the standard method.
Acknowledgements
This study was supported by CAPES and CNPq, Brazil. We wish to thank Eurofarma (Brazil) for the supply of the H. perforatum extract and paroxetine. Silvia Nardi Cordazzo Genari and Cezar Augusto Harres for their technical assistance.
References
1. F.G. Graeff, M.B. Viana and C. Tomaz, The elevated T-maze, a new experimental model of anxiety and memory: effect of diazepam. Braz. J. Med. Biol. Res. 26 (1993), pp. 67–70. Abstract-MEDLINE | Abstract-EMBASE | Order Document
2. M.B. Viana, C. Tomaz and F.G. Graeff, The elevated T-maze: a new animal model of anxiety and memory. Pharmacol. Biochem. Behav. 49 (1994), pp. 549–554. Abstract | Abstract References | PDF (572 K)
3. H. Zangrossi and F.G. Graeff, Behavioral validation of the elevated T-maze, a new animal model of anxiety. Brain Res. Bull. 44 (1997), pp. 1–5. SummaryPlus | Full Text Links | PDF (248 K)
4. F.G. Graeff, C. Ferreiro Netto and H. Zangrossi, Jr., The elevated T-maze as an experimental model of anxiety. Neurosci. Biobehav. Rev. 23 (1998), pp. 237–246. SummaryPlus | Full Text Links | PDF (152 K)
5. R.C. Custódio Teixeira, H. Zangrossi, Jr. and F.G. Graeff, Behavioral effects of acute and chronic imipramine in the elevated T-maze model of anxiety. Pharmacol. Biochem. Behav. 65 (2000), pp. 571–576.
6. S.V. Argyropoulos, J.J. Sandford and D.J. Nutt, The psychobiology of anxiolytic drugs. Part 2. Pharmacological treatments of anxiety. Pharmacol. Ther. 88 (2000), pp. 213–227. SummaryPlus | Full Text Links | PDF (176 K)
7. J.F.W. Deakin and F.G. Graeff, 5-HT and mechanisms of defense. J. Psychopharmacol. 5 (1991), pp. 305–315.
8. S. Kasper, Hypericum perforatum—a review of clinical studies. Pharmacopsychiatry 34 Suppl. 1 (2001), pp. S51–S55. Abstract-EMBASE | Abstract-MEDLINE | Order Document
9. K. Linde, G. Ramirez, C.D. Murlow, A. Pauls, W. Weidenhammer and D. Melchart, St. John’s Wort for depression—an overview and meta-analysis of randomized clinical trials. Br. Med. J. 313 (1996), pp. 253–258. Abstract-MEDLINE | Abstract-Elsevier BIOBASE | Order Document
10. H.L. Kim, J. Streltzer and D. Goebert, St. John’s Wort for depression: a meta-analysis of well-defined clinical trials. J. Nerv. Ment. Dis. 187 (1999), pp. 532–539.
11. Linde K, Mulrow CD. St. John’s Wort for depression (Cochrane Review). The Cochrane library, No. 1. Oxford: Update Software; 2001.
12. G. Di Carlo, F. Borrelli, E. Ernest and A.A. Izzo, St. John’s Wort: prozac from the plant kingdom. Trends Pharmacol. Sci. 22 (2001), pp. 292–297. SummaryPlus | Full Text Links | PDF (67 K)
13. R.C. Shelton, M.B. Keller, A. Gelemberg, D.L. Dunner, R. Hirschfeld, M.E. Thase et al., Effectiveness of St. John’s Wort in major depression: a randomised controlled trial. JAMA 285 (2001), pp. 1978–1986. Abstract-Elsevier BIOBASE | Abstract-MEDLINE | Abstract-EMBASE | Order Document | Full Text via CrossRef
14. C. Gambarana, O. Ghiglieri, P. Tolu, M.G. De Montis, D. Giachetti, E. Bombardelli et al., Efficacy of a H. perforatum (St. John’s Wort) extract in preventing and reverting a condition of escape deficit in rats. Neuropsychopharmacology 21 (1999), pp. 247–257. SummaryPlus | Full Text Links | PDF (249 K) | Full Text via CrossRef
15. V. Butterweck, A. Wall, U. Liefländer-Wulf, H. Winterhoff and A. Nahstedt, Effects of total extract and fractions of Hypericum perforatum in animal assays for antidepressant activity. Pharmacopsychiatry 30 (1997), pp. 117–124. Abstract-MEDLINE | Abstract-EMBASE | Order Document
16. S.S. Chatterjee, S.K. Bhattacharya, M. Wonnemann, A. Singer and W.E. Müller, Hyperforin as a possible antidepressant component of Hypericum extracts. Life Sci. 63 (1998), pp. 499–510. SummaryPlus | Full Text Links | PDF (942 K)
17. W.E. Muller, A. Singer, M. Wonnemann, U. Hafner, M. Rolli and C. Schafer, Hyperforin represents the neurotransmitter reuptake inhibiting constituent of Hypericum extract. Pharmacopsychiatry 3 Suppl. 1 (1998), pp. 16–21. Abstract-MEDLINE | Abstract-EMBASE | Order Document
18. M. Wonneman, A. Singer, B. Siebert and W.E. Muller, Evaluation of synaptosomal uptake inhibition of most relevant constituents of St. John’s Wort. Pharmacopsychiatry 34 Suppl. 1 (2001), pp. S148–S151.
19. W.E. Muller, M. Rolli and U. Hafner, The effects of Hypericum extract (LI 160) in biochemical models of antidepressant activity. Pharmacopsychiatry 30 (1997), pp. 102–107. Abstract-MEDLINE | Abstract-EMBASE | Order Document
20. J. Yager, L. Susan, M.D. Siegfreid and T.L. Di Matteo, Use of alternative remedies by psychiatric patients: illustrative vignettes and a discussion of the issues. Am. J. Psychiatr. 156 (1999), pp. 1432–1438. Abstract-EMBASE | Abstract-MEDLINE | Order Document
21. J.R.T. Davison and K.M. Connor, St. John’s Wort in generalized anxiety disorder: three case reports. J. Clin. Psychopharmacol. 21 (2001), pp. 635–636.
22. L.H. Taylor and K.A. Kobak, An open-label trial of St. John’s Wort (Hypericum perforatum) in obsessive-compulsive disorder. J. Clin. Psychiatr. 61 (2000), pp. 575–578. Abstract-MEDLINE | Abstract-EMBASE | Order Document
23. C. Stevinson, M. Dixon and E. Ernst, Hypericum for fatigue—a pilot study. Phytomedicine 5 (1998), pp. 443–447.
24. M. Coleta, M.G. Campos, M.D. Cotrim and A. Proença da Cunha, Comparative evaluation of Melissa officinalis L., Tilia europaea, Passiflora edulis Sims. and Hypericum perforatum L. in the elevated plus maze anxiety test. Pharmacopsychiatry 34 Suppl. 1 (2001), pp. S20–S21. Abstract-EMBASE | Abstract-MEDLINE | Order Document
25. S.S. Chatterjee, E. Noldner, E. Koch and C. Erdelmeier, Antidepressant activity of Hypericum perforatum and hyperforin: the neglected possibility. Pharmacopsychiatry 31 Suppl. 1 (1998), pp. 7–15. Abstract-MEDLINE | Abstract-EMBASE | Order Document
26. A. Vanderbogaerde, P. Zanoli, G. Puia, C. Truzzi, A. Kamuhabwa, P. De Witte et al., Evidence that total extract of Hypericum perforatum affects exploratory behavior and exerts anxiolytic effects in rats. Pharmacol. Biochem. Behav. 65 (2000), pp. 627–633.
27. O.A. Flausino, Jr., H. Zangrossi, Jr., J.V. Salgado and M.B. Viana, Effects of acute and chronic treatment with Hypericum perforatum L. (LI 160) on different anxiety-related responses in rats. Pharmacol. Biochem. Behav. 71 (2002), pp. 259–265. Abstract-EMBASE | Abstract-Elsevier BIOBASE | Order Document
28. V. Kumar, A.K. Jaiswal, P.N. Singh and S.K. Bhattacharya, Anxiolytic activity of Indian Hypericum perforatum Linn: an experimental study. Indian J. Exp. Biol. 38 (2000), pp. 36–41. Abstract-Elsevier BIOBASE | Abstract-MEDLINE | Order Document
29. V. Beijamini and R. Andreatini, Effects of Hypericum perforatum and paroxetine in the Mouse Defense Test Battery. Pharmacol Biochem Behav 74 (2003), pp. 1015–1024. SummaryPlus | Full Text Links | PDF (273 K)
30. R.D. Porsolt, G. Anton, N. Blavet and M. Jalfre, Behavioural despair in rats: a new model sensitive to antidepressant treatments. Eur. J. Pharmacol. 47 (1978), pp. 379–391. Abstract | Abstract References | PDF (1006 K)
31. V. Beijamini, L.L. Skalisz, S.R.L. Joca and R. Andreatini, The effect of oxcarbazepine on behavioural despair and learned helplessness. Eur. J. Pharmacol. 347 (1998), pp. 23–27. SummaryPlus | Full Text Links | PDF (158 K)
32. Kelly AE. Locomotor activity and exploration. In: Sahgal A, editor. Behavioural neuroscience: a practical approach, vol. II. Oxford: Oxford University Press; 1993. p. 1–21.
33. V. Butterweck, F. Petereit, H. Winterhoff and A. Nahstedt, Solubilized hypericin and pseudohypericin from Hypericum perforatum exert antidepressant activity in the forced swimming test. Planta Med. 64 (1998), pp. 291–294. Abstract-MEDLINE | Abstract-Elsevier BIOBASE | Abstract-EMBASE | Order Document
34. J. De Vry, S. Maurel, R. Schreiber, R. de Beun and K.R. Jentzsch, Comparison of Hypericum extracts with imipramine and fluoxetine in animal models of depression and alcoholism. Eur. Neuropsychopharmacol. 9 (1999), pp. 461–468. SummaryPlus | Full Text Links | PDF (156 K)
35. I. Panocka, M. Perfumi, S. Angeletti, R. Ciccopioppo and M. Massi, Effects of Hypericum perforatum extract on ethanol intake, and on behavioral despair: a search for the neurochemical systems involved. Pharmacol. Biochem. Behav. 66 1 (2000), pp. 105–111. SummaryPlus | Full Text Links | PDF (166 K)
36. M. Hascoet, M. Bourin, M.C. Colombel, A.J. Fiocco and G.B. Baker, Anxiolytic-like effects of antidepressants after acute administration in a four-plate test in mice. Pharmacol. Biochem. Behav. 65 (2000), pp. 339–344. SummaryPlus | Full Text Links | PDF (574 K)
37. M. Hascoet, M. Bourin and B.A.N. Dhonnchadha, The influence of buspirone, and its metabolite 1-PP, on the activity of paroxetine in the mouse light/dark paradigm and four-plate test. Pharmacol. Biochem. Behav. 67 (2000), pp. 44–53.
38. J.T. Winslow and T.R. Insel, Serotonergic and catecholinergic reuptake inhibitors have opposite effects on the ultrasonic isolation calls of rat pups. Neuropsychopharmacology 3 (1990), pp. 51–59. Abstract-MEDLINE | Abstract-EMBASE | Order Document
39. R. Schreiber, C. Melon and J. De Vry, The role of 5-HT receptor subtypes in the anxiolytic effects of selective serotonin reuptake inhibitors in the rat ultrasonic vocalization test. Psychopharmacology 135 (1998), pp. 383–931.
40. S. Lightowler, G.A. Kennet, I.J.R. Williamson, T.P. Blackburn and I.F. Tulloch, Anxiolytic-like effect of paroxetine in a rat social interaction test. Pharmacolol. Biochem. Behav. 49 (1994), pp. 281–285. Abstract | Abstract References | PDF (496 K)
41. M.S. Duxon, K.R. Starr and N. Upton, Latency to paroxetine-induced anxiolysis in the rat is reduced by co-adminsitration of the 5-HT1A receptor antagonist WAY100635. Br. J. Pharmacol. 130 (2000), pp. 1713–1719. Abstract-MEDLINE | Abstract-EMBASE | Abstract-Elsevier BIOBASE | Order Document | Full Text via CrossRef
42. A.K. Cadogan, I.K. Wright, I. Coombs, C.A. Marsden, D.A. Kendall and I. Tulloch, Repeated paroxetine administration in the rat produces a decreased [3H]-ketanserin binding and an anxiolytic profile in the elevated x-maze. Br. J. Pharmacol. 107 (1992), p. 108.
43. C. Sanchez and E. Meier, Behavioral profiles of SSRIs in animal models of depression. Are they all alike?. Psychopharmacology 129 (1997), pp. 197–205. Abstract-EMBASE | Abstract-MEDLINE | Order Document
44. S. Koks, S. Beljajev, I. Koovit, U. Abramov, M. Bourin and E. Vasar, 8-OH-DPAT, but not deramciclane, antagonizes the anxiogenic-like action of paroxetine in an elevated plus-maze. Psychopharmacology 153 (2001), pp. 365–372. Abstract-MEDLINE | Order Document
45. S. Koks, M. Bourin, V. Vöikar, A. Soosaar and E. Vasar, Role of CCK in anti-exploratory action of paroxetine, 5-HT reuptake inhibitor. Int. J. Neuropsychopharmacol. 2 (1999), pp. 9–16. Full Text via CrossRef
46. P. Rocca, V. Fonzo, M. Scotta, E. Zanalda and L. Ravizza, Paroxetine efficacy in the treatment of generalised anxiety disorder. Acta Psychiatr. Scand. 95 (1997), pp. 444–450. Abstract-MEDLINE | Abstract-EMBASE | Order Document
47. C. Allgulander, C.R. Cloninger, T.R. Przybeck and L. Brandt, Changes on the temperament and character inventory after paroxetine treatment in volunteers with generalised anxiety disorder. Psychopharmacol. Bull. 34 (1998), pp. 165–166. Abstract-MEDLINE | Abstract-EMBASE | Order Document
48. S.K. Bhattacharya, A. Chakrabarti and S.S. Chatterjee, Activity profiles of two hyperforin-containing Hypericum extracts in behavioural models. Pharmacopsychiatry 31 Suppl. 1 (1998), pp. 22–29. Abstract-MEDLINE | Abstract-EMBASE | Order Document
49. J.C. Ballenger, D.E. Wheadon, M. Steiner, W. Bushnell and I.P. Gergel, Double-blind, fixed-dose, placebo-controlled study of paroxetine in the treatment of panic disorder. Am. J. Psychiatr. 155 (1998), pp. 36–42. Abstract-MEDLINE | Abstract-EMBASE | Order Document
50. Y. Lecrubier, A. Bakker, G. Dunbar and R. Judge, A comparison of paroxetine, clomipramine and placebo in the treatment of panic disorder. Acta Psychiatr. Scand. 95 (1997), pp. 145–152. Abstract-MEDLINE | Abstract-EMBASE | Order Document
51. Y. Lecrubier and R. Judge, Long-term evaluation of paroxetine, clomipramine and placebo in panic disorder. Acta Psychiatr. Scand. 95 (1997), pp. 153–160. Abstract-MEDLINE | Abstract-EMBASE | Order Document
Posted by sdb on June 27, 2006, at 23:57:49
In reply to hypericum - paroxetine panic maze study (long), posted by sdb on June 27, 2006, at 17:24:57
there's another one. Interesting for example is the flumazenil. Whereas human studies are controversial small studies from other animals will maybe give more clarity.
sdb
Articles
Evidence That Total Extract of Hypericum perforatum Affects Exploratory Behavior and Exerts Anxiolytic Effects in Rats
A. Vandenbogaerde*, P. Zanoli†, G. Puia†, C. Truzzi†, A. Kamuhabwa*, P. De Witte*, W. Merlevede‡ and M. BaraldiCorresponding Author Contact Information, †
* Laboratorium voor Farmaceutische Biologie & Fytofarmacologie, Faculteit Farmaceutische Wetenschappen, K.U.Leuven, Van Evenstraat 4, B-3000 Leuven, Belgium
† Department of Pharmaceutical Sciences, Chair of Pharmacology and Pharmacognosy, University of Modena and Reggio Emilia, Via Campi 183, I-41100 Modena, Italy
‡ Afdeling Biochemie, Faculteit Geneeskunde, K.U. Leuven, Herestraat 49, B-3000 Leuven, BelgiumReceived 26 April 1999; revised 27 September 1999; accepted 4 October 1999. Available online 10 April 2000.
AbstractClinical trials have extensively reported the ability of Hypericum perforatum extracts to exert a significant antidepressant activity. Hypericin, the main constituent of H. perforatum extract, is no more regarded as the active principle of the antidepressant activity of the drug. Hence, the question of which constituents are involved in the basic activity of the total extract, is still waiting for an answer. In the present study we focused our attention on the potential anxiolytic activity of H. perforatum total extract, and of some pure components such as protohypericin and a fraction containing hypericin and pseudohypericin. Herein we report that the total extract of H. perforatum increases the locomotor activity in the open field and exerts anxiolytic activity in the light–dark test, whereas the single components did not show any effect. Interestingly, the anxiolytic activity of the total extract was blocked by pretreatment of rats with the benzodiazepine antagonist Flumazenil, hence suggesting an implication of benzodiazepine receptor activation in the anxiolytic effect of H. perforatum extract. Electrophysiological studies, performed to gain more information on the mechanism of action, showed that hypericin reduced the GABA-activated chloride currents, while pseudohypericin did an opposite effect. Furthermore, both hypericin and pseudohypericin inhibited the activation of NMDA receptors.
Author Keywords: Anxiolytic effect; Locomotor behavior; Hypericin; Hypericum; Protohypericin; Pseudohypericin; GABA–benzodiazepine receptor; Glutamate receptor
Article Outline
• Methods
• Preparation of Total Extract of Hypericum perforatum
• Preparation of Hypericin, Protohypericin, and Pseudohypericin
• Animals
• Administration of Test Substances
• Locomotor Behavior
• Light–Dark Model of Anxiety
• Statistical Analysis
• Primary Cultures of Cerebellar Granule Cells
• Electrophysiological Recordings• Solutions and drugs
• Drug application• Data Analysis
• Results
• Locomotor Behavior
• Anxiolytic Effect
• Electrophysiological Studies• Discussion
• ReferencesIN the 16th century, Paracelsus recommended Hypericum plant extracts as medicine against general depression and related conditions [13]. Meanwhile, many clinical studies have been conducted using standardized Hypericum extracts, with a dose of total hypericin ranging from 0.5 to 2.7 mg, which confirmed such activity. Indeed, a meta-analysis of these studies revealed that Hypericum extract was significantly superior to placebo, and similarly effective as standard antidepressants [18]. Of importance, undesirable side effects were noted in only a small number of patients. Nowadays, it is therefore generally recognized that Hypericum extract is a safe and effective drug in the treatment of mild to moderately severe depressive disorders [25].
Numerous in vitro experiments and in vivo animal studies have been conducted to reveal the mechanism of action responsible for the antidepressant activity of Hypericum extract. First, it was suggested that Hypericum extracts inhibit monoamino oxidase (MAO) because of its hypericin content [27]. However, later studies showed that MAO was more effectively inhibited by flavonoid aglycones present in the plant [2, 26 and 29]. These results are in agreement with a computer-supported model analysis comparing the molecular structures of extract components with known MAO inhibitors [15]. Controversially, an ex vivo study showed no MAO inhibition in rats administered with Hypericum extract [2]. Another possible mechanism associated with the antidepressant activity of Hypericum extracts includes inhibition of catechol-O-methyltransferase (COMT) by flavonoid aglycones [29]. On the other hand, it was argued that the concentration of these substances is too low to be responsible for the therapeutic effect of Hypericum extract [29].
The effect of Hypericum extract and some constituents on several neurotransmitters and their receptors of the central nervous system were evaluated in vitro. It was shown that neither the extract nor hypericin or kaemferol, had any relevant effect on the tested receptors [19]. However, Hypericum extract significantly inhibited the presynaptic reuptake of serotonine [19], and demonstrated a postsynaptic inhibition of the serotonine uptake [19, 20 and 24]. Furthermore, studies on animals that were treated with Hypericum extract demonstrated adaptive changes, namely a downregulation of β-receptors, a significant upregulation of postsynaptic 5-HT2-receptors, and an increased density of 5-HT1A and 5-HT2A receptors [28]. Recently, Hypericum extract has been shown to have in vitro a high affinity for GABAA and GABAB receptors [8]. Moreover, the affinity of several Hypericum constituents [1] for the benzodiazepine binding sites that are part of the GABAA receptor was investigated in vitro. Amentoflavone showed a high affinity for this receptor binding site, while hypericin, quercitrin, luteolin, rutin, hyperoside, and I3,II8-biapigenin demonstrated a low affinity (>1 μM).
Furthermore, several animal studies have been conducted in view of identifying the active component(s). Both Hypericum extract and pure hypericin increased the activity of mice in a water wheel [23]. It was demonstrated that the total Hypericum extract as well as the two fractions rich in flavonoids and hypericins induced a significant decrease of the immobility time in the Porsolt forced swimming test [4]. The data obtained by Butterweck [5], administering hypericin and pseudohypericin in combination with a fraction containing procyanidins, confirm that naphthodianthrones are antidepressant constituents of Hypericum and suggest that the dopaminergic system is involved in their action . Recently, it has been hypothesized that hyperforin, the major lipophilic constituent of Hypericum, could be the active principle responsible for the antidepressant activity of the extract [7].
In the present study, the effect of Hypericum extracts and some pure constituents on the behavior of rats was investigated to provide better insights on the pharmacological activity of the plant extract. First, the total Hypericum extract, the pure naphthodianthrone derivatives (hypericin/pseudohypericin and protohypericin) were used in the open-field test to evaluate the exploratory behavior of rats.
Because the request of compounds able to treat depressive disorders combined with anxiety has increased remarkably over the past few years [17], the same substances were tested in the light–dark model of anxiety in rats. Furthermore, the specificity of the anxiolytic effect of the total extract on the GABA–benzodiazepine receptor system was challenged by using the benzodiazepine antagonist Flumazenil.
The demonstration that the total extract indeed exerts an anxiolytic effect in rats prompted us to explore further the potential mechanism of action studying its effect on the GABA–benzodiazepine receptor system and on the glutamatergic system. Thus, we have used the patch-clamp technique in the whole-cell configuration to test the modulation of GABA and NMDA currents by crude extract and by hypericin and pseudohypericin.
Methods
Preparation of Total Extract of Hypericum perforatumA dry extract of Hypericum perforatum was purchased from Indena (Milano, Italy). The amount of hypericin and pseudohypericin present in the extract was quantified using HPLC and fluorescence detection, as described [30], and was determined to be 0.11 and 0.43%, respectively, corresponding to 0.54% total hypericins (hypericin/pseudohypericin 1/4). Besides, the percentage of protoforms (protohypericin and protopseudohypericin) present in the plant extract was determined by calculating the peak difference before and after light irradiation of the extract. In the total extract, 17.4% of the total hypericins (hypericin and pseudohypericin) was present as their protoforms, which is in agreement with previously reported results [10]. This means that the total extract contains 0.09% of protoforms (protohypericin and protopseudohypericin).
Preparation of Hypericin, Protohypericin, and PseudohypericinHypericin and protohypericin were prepared as described previously [11]. Briefly, emodin (2.5 mg), isolated from cortex Frangulae, was dissolved in 125 ml acetic acid, and 30 g SnCl2·2H2O, dissolved in 75 ml HClconc, was added. After refluxing for 3 h at 120°C and cooling to room temperature, the formed emodin anthrone was filtered off and dried. Protohypericin was synthesized via oxidative dimerization by heating emodin anthrone (2 g) in a mixture of 45 ml pyridine/piperidine (10/1) in the presence of 4 g pyridine-1-oxide and 100 mg FeSO4 at 100°C under nitrogen for 1 h in strict dark conditions. After synthesis, the crude protohypericin was purified by silica column chromatography (elution: ethylacetate/water 100/2.5, followed by elution of the compound with ethylacetate/acetone/water 80/20/2.5) under dark conditions to prevent photoconversion into hypericin. In a second purification step, protohypericin was chromatographed on a Sephadex LH20 column (dichloromethane/methanol/acetone 55/30/15) under the same conditions. In the case of the hypericin synthesis, protohypericin was light irradiated before the second purification step to convert protohypericin into hypericin by a photocyclization reaction [3]. Hypericin was then further purified by Sephadex LH20 column chromatography. The synthesis yield for protohypericin was 20% (purity >98%, content of hypericin: 1.01%, as determined by HPLC), and in the case of hypericin 28% (purity >99%).
Pseudohypericin was prepared starting from ground herb (500 g) of Hypericum perforatum (Denolin, Brussels, Belgium). First, the herb was percolated with dichloromethane, ethylacetate, and finally acetone. After evaporation of the acetone extract (1200 ml) under reduced pressure, the residue (7.8 g) was dissolved in ethylacetate and purified with silica column chromatography [silica gel 60 (63–200 μm), Merck, Darmstadt, Germany] using ethylacetate, ethylacetate/water (100/2.5) and finally ethylacetate/water/acetone (100/2.5/30) as eluent. Fractions of the latter, containing high contents of pseudohypericin and hypericin as demonstrated by TLC [Alugram Sil G/UV254 plates (Macherey-Nagel, Düren, Germany), solvent: toluene/ethylacetate/formic acid (50/40/10)], were pooled and evaporated under reduced pressure. The residue (534 mg) was dissolved in methanol/acetone/dichloromethane (30/15/55) and further purified with column chromatography on Sephadex LH20 (Pharmacia, Uppsala, Sweden) using methanol/acetone/dichloromethane (30/15/55) as eluent. Fractions containing pseudohypericin were pooled and dried under reduced pressure (yield: 0.03%). The compound was purified a second time with column chromatography on Sephadex LH20 under the same conditions to obtain pure pseudohypericin (purity: >99%, content of hypericin: 0.44%, as analyzed by HPLC).
All compounds were characterized with 1H-NMR (Gemini 200 MHz, Varian), LSI mass spectrometry (Kratos Concept IH) and UV/VIS spectrophotometry (Hewlett-Packard, CA). The data were comparable with literature data [6, 10 and 11].
AnimalsMale Sprague–Dawley rats (Harlan–Nossan, Udine, Italy) weighing 200–220 g, were housed with free access to food and water, and manteined on a 12 L:12 D cycle, at a constant temperature of 24°C.
The experimental procedures are in compliance with the National Institutes of Health Guide for care and use of laboratory animals and with the European Communities Council Directive of 24 november 1986 (86/609/EEC).
Administration of Test SubstancesFood, but not water, was withdrawn 1.5 h prior to drug administration. Test substances were freshly prepared in propyleneglycol/water (50/50) and administered orally by gavage in a final volume of 10 ml/kg body weight. The vehicle did not induce any change vs nontreated rats in both animal tests. The doses of total extract administered were 926, 1852, and 2778 mg/kg, corresponding to 5, 10, and 15 mg/kg total hypericins (hypericin/pseudohypericin 1/4) respectively. Because 17.4% of the total hypericins in the total extract was present as protoforms, a dose of 2 mg/kg protohypericin was chosen, which approximately corresponds to 10–15 mg/kg total hypericins. Tests were performed in rats, 1 h after oral administration of tested compounds (between 0900 and and 1300 h).
Locomotor BehaviorLocomotor activity was studied in rats by open-field test. Each animal was placed in the centre of a square arena (100 × 100 × 50 cm h) with a black floor. Rats were continuously filmed with a telecamera connected to a computerized system (Motion Analyzer BM800, Biomedica Mangoni, Pisa, Italy). The following parameters were recorded during the 10-min test: 1) the total pathway length during ambulatory activity, 2) number of crossings of 20 × 20 cm. squares, and 3) number of rearings. Furthermore, the system provides the route pattern for each rat.
Light–Dark Model of AnxietyThe light–dark model was used according to Crawley and Goodwin [9]. A two-compartment chamber (40 × 60 × 20 cm h) was used in which a brightly illuminated area (40 × 40 cm) and a dark section (40 × 20 cm) are separated by a wall with a round hole (diameter 13 cm). At the start of the test the rats were placed in the illuminated part of the cage. The following parameters were recorded during 5 min: 1) latency time for the first crossing to the dark compartment, 2) the number of crossings between the light and the dark area, and 3) the total time spent in the illuminated part of the cage.
Diazepam, used as reference drug, was injected IP at the dose of 1.5 mg/kg, 20 min before the test. In the same test Flumazenil, used as BZD central receptors antagonist, was injected IP, at a dose of 3 mg/kg, 15 min after the administration of the total extract.
Statistical AnalysisEach value represents the mean ± SEM calculated from a test group of 8–22 rats. Significance of differences vs. the control group was statistically evaluated by one-way ANOVA, with the Dunnett Multiple Comparisons posttest.
Primary Cultures of Cerebellar Granule CellsPrimary culture of cerebellar granule neurons were prepared from 7–8-day-old Sprague–Dawley rats as previously described [12]. Briefly, cells from cerebella were dispersed with trypsin (0.24 mg/ml) (Sigma, St. Louis, MO) and plated at a density of 106 cells/ml on 35-mm Falcon dishes coated with poly-Image-lysine (10 μg/ml, Sigma). Cells were grown in basal Eagle's Medium (Irvine Scientific, Santa Ana, CA), supplemented with 10% fetal bovine serum (Hyclone Lab, UT), 2 mM glutamine, and 100 μg/ml gentamycin (Sigma), and manteined at 37°C in 5% CO2. Cytosine arabinofuranoside (10 μM; Sigma) was added to the cultures 24 h after plating to prevent astroglia proliferation.
Electrophysiological RecordingsWe have used the patch-clamp technique [14] in the whole-cell configuration on single neuron after 7 days in culture. Electrodes were pulled from borosilicate glass (Hidelgberg, Germany) on a vertical puller (PB-7, Narishige), and had a resistence of 5–7 MOhm when filled with KCl internal solution. Currents were amplified with an Axopatch 1D amplifier (Axon Instruments, Foster City, CA), filtered at 5 kHz and digitized at 10 kHz by using pClamp software (Axon Instruments).
Solutions and drugsIntracellular solution contains (mM): KCl 140, MgCl2 3, EGTA 5, HEPES 5, ATP-Na 2; pH 7.3 with KOH. Cells were continuosly perfused with the external solution (mM): NaCl 145, KCl 5, CaCl2 1, HEPES 5, Glucose 5, Sucrose 20, pH 7.4 with NaOH. GABA, NMDA, and Glycine were purchased from Sigma.
Drug applicationHypericin, pseudohypericin, and the crude extract were dissolved in DMSO and diluted at the final concentration in extracellular medium (DMSO f.c. less than 0.1%). NMDA and GABA were dissolved in the extracellular solution. All drugs were applied directly by gravity through a Y-tube perfusion system [21]. Drug application had a fast onset, and achieved a complete local perfusion of the recorded cell.
Data AnalysisElectrophysiological data were analysed using the software Clampex (Axon Instrument).
Results
Locomotor BehaviorThe data reported in Fig. 1 demonstrate that Hypericum extract increases the total length of pathway, the number of crossings and rearings measured during the open-field test. The effect of the total extract, when compared with that of vehicle, was statistically significant at a dose of 2778 mg/kg, containing 15 mg/kg total hypericins. Interestingly, the total extract significantly increased the number of rearings, even at the lowest dose tested. Figure 1 also shows the results obtained administering a fraction containing hypericin/pseudohypericin (1/4) and the pure protohypericin at a dose corresponding to 2778 mg/kg of the total extract (15 and 2 mg/kg, respectively). No significant difference in the different evaluated parameters was determined in comparison to vehicle-treated rats.
Enlarge Image (15K)Fig. 1. Locomotor behavior of rats during the open-field test, performed 1 h after oral administration of tested compounds. Total extract was administered at different doses: 926, 1852, and 2778 mg/kg, equivalent to 5, 10, and 15 mg/kg total hypericins, respectively. The activity of total extract is compared to that of hypericin/pseudohypericin 1/4 and of protohypericin corresponding to 2778 mg/kg total extract. Values represent the mean ± SEM (n = 8–12); *p < 0.05, **p < 0.01 vs. vehicle-treated rats
Examples of pattern routes, as registered by the telecamera, are reported in Fig. 2.
Enlarge Image (18K)Fig. 2. Examples of pattern routes of rats treated with the higher dose of total extract (2778 mg/kg) in comparison with vehicle-treated rats
Anxiolytic Effect
The Hypericum extract increased significantly the latency time in the light–dark model of anxiety, at a dose of 1852 mg/kg, whereas the effects seen at 926 and 2778 mg/kg were not significantly different from the control group, treated with vehicle (Fig. 3). These data point out to an inverted U-shaped activity of the total extract. In Fig. 3 any change in latency time vs. vehicle-treated rats was observed for the other test substances administered at a dose corresponding to 1852 mg/kg total extract. The anxiolytic activity elicited by total extract of Hypericum is quite similar to that obtained with the injection of 1.5 mg/kg of diazepam. The results reported in Table 1 demonstrate that the anxiolytic effect of the total extract is blocked by the administration of BZD receptors antagonist, Flumazenil (3 mg/kg, IP).
Enlarge Image (5K)Fig. 3. Latency time (expressed in seconds) to the first crossing from the light to dark compartment evaluated in the light–dark test, 1 h after oral administration of tested compounds. Rats were treated with different doses (926, 1852, and 2778 mg/kg body weight) of total extract; the doses of hypericin/pseudohypericin 1/4 or protohypericin corresponding to 1852 mg/kg total extract were 10 and 2 mg/kg, respectively. Diazepam was used as reference drug: the test was performed 20 min after the IP injection of a dose of 1.5 mg/kg. Values represent the mean ± SEM (n = 8–22); **p < 0.01 vs. vehicle-treated rats
Table 1. Inhibitory effect of flumazenilon anxiolytic activity elicited by hypericum perforatum total extract
Full Size TableBecause in all cases only one crossing from the illuminated area to the dark part was registered, the total time spent in the illuminated area was equal to the latency time.
Electrophysiological StudiesApplication of the crude extract (at a concentration that is comparable to hypericin 10 μM) alone or together with GABA or NMDA produces at the first trial an inward current followed by a complete desensitization of the cells that hampered any further analysis (data not shown). GABA-activated chloride current was decreased by the coapplication with hypericin 10 μM; the effect was reversible (Fig. 4A).
Enlarge Image (6K)Fig. 4. Modulation of GABA-evoked current by hypericin and pseudohypericin. (A) Representative trace of Cl− current evoked by GABA 10 μM and by GABA 10 μM Hypericin 10 μM (straight bar = duration of the application). Holding potential (Hp) = −60 mV. (B) Histogram showing the dose response of the modulation of the GABA-elicited current by increasing doses of the two substances. Each bar is the mean ± SE of at least six cells
Hypericin 10 μM reduced (−43 ± 8%, n = 13), while the same concentration of pseudohypericin potentiated (57 ± 15%, n = 9), GABA-evoked Cl currents. The modulatory effects of hypericin and pseudohypericin are dose dependent (Fig. 4B).
Application of NMDA 100 μM, in the presence of Glycine 10 μM, elicits a slowly desensitizing current that is reduced by 10 μM hypericin (Fig. 5A).
Enlarge Image (8K)Fig. 5. Modulation of NMDA-evoked current by hypericin and pseudohypericin. (A) Recording of the current evoked by the application of 100 μM NMDA and 100 μM NMDA Hypericine 10 μM in the presence of Glycine 10 μM (straight bar = duration of the application), Hp = −60 mV. (B) Histogram showing the % reduction of NMDA-evoked current after coapplication of increasing concentrations of hypericin or pseudohypericin. Each bar is the mean ± SE of at least six cells
NMDA-activated currents are negatively modulated either by hypericin 10 μM (−30 ± 10, n = 7) or by pseudohypericin 10 μM (−20 ± 8, n = 5) (Fig. 5B).
DiscussionIt is generally recognized that Hypericum perforatum extract is useful in the treatment of depressive disorders. There is good evidence that Hypericum is better than placebo in treating some depressive disorders. Moreover, Hypericum seems to have fewer side effects than some other antidepressants.
Hypericum extract contains at least 10 groups of components that may contribute to its pharmacological effect. These include naphthodianthrones, flavonoids, xanthones, phloroglucinols, and bioflavonoids [22]. Despite the amount of experimental and clinical studies, the mechanism of the antidepressant effect is still under debate.
In the present study we demonstrate that the total extract of the plant affects locomotor behavior only when administered at doses much higher than those eliciting antidepressant effects, as described by Butterweck [4]. The fractions containing only hypericin/pseudohypericin or protohypericin failed to alter the different parameters evaluated during the open-field test, suggesting that other components must be involved in the pharmacological activity of the plant.
Also, by the light/dark model of anxiety we demonstrated the ability of the total extract but not the single fractions to counteract anxiety in rats, submitted to an aversive stimolous (light).
The fact that the anxiolytic effect was blocked by the injection of a BZD antagonist, Flumazenil, suggests the implication of the BZD receptor system in the anxiolytic effect of Hypericum total extract.
Electrophysiological studies evidenced that hypericin negatively affects GABA-evoked chloride currents, but also that pseudohypericin potentiates them. The same constituents induce a reduction of NMDA mediated currents.
In light of these data, we suggest that the anxiolytic effect could be partly linked to the facilitatory activity of pseudohypericin on GABA evoked currents and to the inhibitory influence on glutamatergic transmission mediated by NMDA receptors, because it has been previously reported that an antagonism of NMDA receptor function produces an anxiolytic effect [16].
As a whole it seems likely to conclude, beside the difficulties in reconciling the role played by the single constituents, that the present demonstration of the anxiolytic effect of Hypericum extracts, could open up the clinical use of Hypericum in the treatment of depression complicated by anxiogenic components, a clinical condition where pure antidepressant or anxiolytic drugs are only modestly effective.
References
1. K.H. Baureithel, K. Berger Büter, A. Engesser, W. Burkard and W. Schaffner, Inhibition of benzodiazepine binding in vitro by amentoflavone, a constituent of various species of Hypericum.. Pharm. Acta Helv. 72 (1997), pp. 153–157. Abstract-MEDLINE | Abstract-EMBASE | Order Document
2. S. Bladt and H. Wagner, Inhibition of MAO by fractions and constituents of Hypericum extract. J. Geriatr. Psychiatry Neurol. 7 Suppl. 1 (1994), pp. S57–S59. Abstract-MEDLINE | Abstract-EMBASE | Order Document
3. H. Brockmann and R. Mühlmann, Über die photochemische Cyclisierung des Helianthrons und Dianthrons zum meso-Naphthodianthron. Chem. Ber. 82 (1949), pp. 348–357.
4. V. Butterweck, A. Wall, U. Liefländer-Wulf, H. Winterhoff and A. Nahrstedt, Effects of the total extract and fractions of Hypericum perforatum in animal assays for antidepressant activity. Pharmacopsychology 30S (1997), pp. 117–124. Abstract-MEDLINE | Abstract-EMBASE | Order Document
5. V. Butterweck, F. Petereit, H. Winterhoff and A. Nahrstedt, Solubilized hypericin and pseudohypericin from Hypericum perforatum exert antidepressant activity in the forced swimming test. Planta Med. 64 (1998), pp. 291–294. Abstract-MEDLINE | Abstract-Elsevier BIOBASE | Abstract-EMBASE | Order Document
6. D.W. Cameron and W.D. Raverty, Pseudohypericin and other phenanthroperylenequinones. Aust. J. Chem. 29 (1976), pp. 1523–1533.
7. S.S. Chatterjee, S.K. Bhattacharya, M. Wonnemann, A. Singer and W.E. Müller, Hyperforin as a possible antidepressant component of Hypericum extracts. Life Sci. 63 (1998), pp. 499–510. SummaryPlus | Full Text Links | PDF (942 K)
8. J.M. Cott, In vitro receptor binding and enzyme inhibition by Hypericum perforatum extract. Pharmacopsychology 30S (1997), pp. 108–112. Abstract-MEDLINE | Abstract-EMBASE | Order Document
9. J. Crawley and F.K. Goodwin, Preliminary report of a simple animal behavior model for the anxiolytic effects of benzodiazepines. Pharmacol. Biochem. Behav. 13 (1980), pp. 167–170. Abstract | Abstract References | PDF (297 K)
10. H. Falk and W. Schmitzberger, On the nature of "soluble" hypericin in Hypericum species. Monatshefte Chem. 123 (1992), pp. 731–739. Full Text via CrossRef
11. H. Falk, J. Meyer and M. Oberreiter, A convenient semisynthetic route to hypericin. Monatshefte Chem. 124 (1993), pp. 339–341. Full Text via CrossRef
12. V. Gallo, M.T. Ciotti, A. Coletti, F. Aloisi and G. Levi, Selective release of glutamate from cerebellar granule cells differentiating in culture. Proc. Natl. Acad. Sci.USA 79 (1982), pp. 7919–7923. Abstract-EMBASE | Abstract-MEDLINE | Order Document | Full Text via CrossRef
13. A.C. Giese, Hypericism. Photochem. Photobiol. Rev. 5 (1980), pp. 229–255.
14. O.P. Hamil, A. Marty, E. Neher, B. Sakmann and F.J. Sigworth, Improved patch clamp techniques for high resolution current recording from cells and free-membrane patches. Pflugers Arch. 391 (1981), pp. 85–100.
15. H.D. Höltje and A. Walper, Molecular Modeling zum antidepressiven Wirkmechanismus von Hypericum—Inhaltsstoffen. Nervenheilkunde 12 (1993), pp. 339–340. Abstract-EMBASE | Order Document
16. M. Karcz-Kubicha, M. Jessa, M. Nazar, A. Plaznik, S. Hartmann, G.C. Parsons and W. Danysz, Anxiolitic activity of glycine-B antagonist and partial agonists—No relation to intrinsic activity in the patch clamp. Neuropharmacology 36 (1997), pp. 1355–1367. SummaryPlus | Full Text Links | PDF (1549 K)
17. H.M. Kravitz, L. Fogg, J. Fawcett and J. Edwards, Antidepressant or antianxiety? A study of the efficacy of antidepressant medication. Psychiatr. Res. 32 (1990), pp. 141–149. Abstract | Abstract References | PDF (681 K)
18. K. Linde, G. Ramirez, C.D. Mulrow, A. Pauls, W. Weidenhammer and D. Melchart, St John's wort for depression—An overview and meta-analysis of randomised clinical trials. Br. Med. J. 313 (1996), pp. 253–258. Abstract-MEDLINE | Abstract-Elsevier BIOBASE | Order Document
19. W.E. Müller and C. Schäfer, Johanniskraut. DAZ 13 (1996), pp. 17–24. Abstract-EMBASE | Order Document
20. W.E. Müller, M. Rolli, C. Schäfer and U. Hafner, Effects of Hypericum extract (LI 160) in biochemical models of antidepressant activity. Pharmacopsychology 30S (1997), pp. 102–107. Abstract-MEDLINE | Abstract-EMBASE | Order Document
21. K. Murase, P.D. Ryu and M. Randic, Excitatory and inhibiting aminoacids and peptide-induced responses in acutely isolated rat spinal horn neurons. Neurosci. Lett. 103 (1989), pp. 56–63. Abstract | Abstract References | PDF (420 K)
22. A. Nahrstedt and V. Butterweck, Biologically active and other chemical constituents of the herb of Hypericum perforatum L. Pharmacopsychiatry 30 (1997), pp. 129–134. Abstract-MEDLINE | Abstract-EMBASE | Order Document
23. S.N. Okpanyi and M.L. Weischer, Tierexperimentelle Untersuchungen zur psychotropen Wirksamkeit eines Hypericum-Extractes. Arzneimittleforschung 37 (1987), pp. 10–13. Abstract-MEDLINE | Abstract-EMBASE | Order Document
24. S. Perovic and W.E.G. Müller, Pharmacological profile of Hypericum extract—Effect on serotonin uptake by postsynaptic receptors. Arzneimittleforschung 45 (1995), pp. 1145–1148. Abstract-EMBASE | Abstract-MEDLINE | Order Document
25. E. Schrader, B. Meier and A. Brattstrom, Hypericum treatment of mild-moderate depression in a placebo-controlled study. A prospective, double-blind, randomized, placebo-controlled, multicentre study. Hum. Psycopharmacol. 13 (1998), pp. 163–169. Abstract-Elsevier BIOBASE | Abstract-EMBASE | Order Document | Full Text via CrossRef
26. B. Sparenberg, L. Demisch and J. Hölzl, Untersuchungen über antidepressive Wirkstoffe von Johanniskraut. Pharm. Ztg. Wiss. 138 (1993), pp. 50–54. Abstract-EMBASE | Order Document
27. O. Suzuki, Y. Katsuma, M. Oya, S. Bladt and H. Wagner, Inhibition of monoamine oxidase by hypericin. Planta Med. 50 (1984), pp. 272–274. Abstract-EMBASE | Abstract-MEDLINE | Order Document
28. R. Teufel-Mayer and J. Gleitz, Effects of long-term administration of Hypericum extracts on the affinitiy and density of the central serotonergic 5-HT1A and 5-HT2A receptors. Pharmacopsychology 30S (1997), pp. 113–116. Abstract-MEDLINE | Abstract-EMBASE | Order Document
29. H.M. Thiede and A. Walper, Inhibition of MAO and COMT by Hypericum extracts and hypericin. J. Geriatr. Psychiatry Neurol. 7 Suppl. 1 (1994), pp. S54–S56. Abstract-MEDLINE | Abstract-EMBASE | Order Document
30. A.L. Vandenbogaerde, A. Kamuhabwa, E.M. Delaey, B.E. Himpens, W.J. Merlevede and P.A. de Witte, Photocytotoxic effect of pseudohypericin versus hypericin. J. Photochem. Photobiol. B 45 (1998), pp. 87–94. Abstract | PDF (892 K)
Corresponding Author Contact Information Requests for reprints should be addressed to Prof. M. Baraldi, Dipartimento di Scienze Farmaceutiche, Università degli studi di Modena e Reggio Emilia, Via Campi 183, I-41100 Modena, Italy
Posted by sdb on June 27, 2006, at 23:57:50
In reply to Re: hypericum - paroxetine panic maze study (long), posted by sdb on June 27, 2006, at 18:36:55
hpa axis an new approach for crh-1 antagonists?
Flavonoids of St. John’s Wort Reduce HPA Axis Function in the Rat
V. Butterweck1, M. Hegger2, H. Winterhoff2
1 Department of Pharmaceutics, University of Florida, Gainesville, FL, USA
2 Institute of Pharmacology and Toxicology, Münster, Germany
Abstract
Material and Methods
Acknowledgements
References
Seitenanfang
AbstractA common biological alteration in patients with major depression is the activation of the hypothalamic-pituitary-adrenal (HPA) axis, manifested as hypersecretion of adrenocorticotropic hormone (ACTH) and cortisol. The hyperactivity of the HPA axis in depressed patients can be corrected during clinically effective therapy with standard antidepressant drugs such as imipramine, indicating that the HPA axis may be an important target for antidepressant action. We previously showed that a methanolic extract of St. John’s wort (SJW) and hypericin, one of its active constituents, both have delayed effects on the expression of genes that are involved in the regulation of the hypothalamic-pituitary-adrenal (HPA) axis [1], whereas the phloroglucinol derivative hyperforin was inactive in the same model [2]. Since flavonoids of SJW are also discussed as active constituents it was of interest to determine whether these compounds can modulate HPA axis function. Imipramine (15 mg/kg), hypericin (0.2 mg/kg), hyperoside (0.6 mg/kg), isoquercitrin (0.6 mg/kg) and miquelianin (0.6 mg/kg) given daily by gavage for two weeks significantly down-regulated circulating plasma levels of ACTH and corticosterone by 40 - 70 %. However, none of the compounds tested had an effect on plasma ACTH and corticosterone levels after chronic treatment (daily gavage for 8 weeks). Our data suggest that besides hypericin, flavonoids of SJW play an important role in the modulation of HPA axis function. Furthermore, the results support the hypothesis that flavonoids are involved in the antidepressant effects of SJW.
Hypericum perforatum (Clusiaceae) commonly known as St. John’s wort (SJW), is used in many countries for the treatment of mild to moderate forms of depression. Several clinical studies provide evidence that SJW is as effective as conventional synthetic antidepressants [3], [4]. A series of bioactive compounds has been detected in the crude material (for review see [5]). The pharmacological activity of SJW extracts has been reviewed previously [6]. Recent reports have shown that the antidepressant activity of Hypericum extracts can be attributed to the phloroglucinol derivative hyperforin [7], to the naphthodianthrones hypericin and pseudohypericin [8], and to several flavonoids [9], [10]. The role and the mechanisms of these different compounds is still a matter of debate. But, taking these previous findings together, it is likely that several constituents are responsible for the clinically observed antidepressant efficacy of SJW.
In patients with depression, a considerable number of endocrine findings is reported, most prominent are the changes in the hypothalamic-pituitary-adrenal (HPA) axis. Hypersecretion of ACTH and plasma cortisol have been reported in 40 - 50 % of patients suffering from depression [11], [12]. Normalization of the hyperactive HPA system occurs during successful antidepressant pharmacotherapy of depressive illness [13].
Previous work in rats established that long-term treatment with imipramine, fluoxetine, idazoxan, and phenelzine reduces HPA axis activity with delayed onset (after 2 weeks) [14], [15]. Based on the results of Brady et al. [14], [15] we recently studied the effects of short-term (2 weeks) and long-term (8 weeks) administration of imipramine, a methanolic SJW extract, and hypericin on the expression of genes that may be involved in the regulation of the HPA axis [1]. Our data showed that imipramine, SJW extract, and hypericin given daily for 8 weeks but not for 2 weeks significantly decreased levels of CRH mRNA in the PVN. Comparable to imipramine the SJW extract as well as hypericin reduced plasma ACTH and corticosterone levels after 2 weeks of daily treatment, but not after 8 weeks [1].
Because some authors emphasized hyperforin as the major active principle of SJW extract we recently determined whether daily administration of a lipophilic CO2 extract enriched with hyperforin, and a hyperforin derivative (hyperforin trimethoxybenzoate; TMB) had effects on the levels of the above-mentioned mRNAs in a manner similar to the methanolic SJW extract and hypericin in the short-term/long-term administration paradigm [2]. However, a lipophilic CO2 extract as well as hyperforin-TMB failed to affect gene transcription involved in HPA axis control and did not alter plasma levels of ACTH and corticosterone [2].
Since hyperoside, isoquercitrin and miquelianin have been shown to exhibit antidepressant activity in animal models of depression [9], it was of interest in the present study to examine whether these compounds might also act on the HPA axis after short- and long-term treatment.
The major novel finding of the present study is that the flavonoids hyperoside (quercetin 3-O-galactoside), isoquercitrin (quercetin 3-O-glucoside) as well miquelianin (quercetin 3-O-glucuronide) significantly down-regulated plasma ACTH and corticosterone levels in the short-term treatment paradigm similar to the changes elicited by the prototypic synthetic antidepressant imipramine and the naphthodianthrone hypericin (∼40 % and ∼60 %, respectively) - a finding which has not been reported yet for this class of compounds.
Daily treatment over 2 weeks with the tricyclic antidepressant imipramine caused a significant decrease (p < 0.05) in both ACTH (40 % reduction from baseline) and corticosterone (46 % reduction from baseline) compared to vehicle-treated animals (Fig. [1] a, b). A similar decrease in ACTH and corticosterone levels after two weeks of daily treatment was observed for the naphthodianthrone hypericin (74 % and 43 % reduction from baseline, respectively, p < 0.01) and the flavonoids hyperoside, isoquecitrin and miquelianin (∼40 to ∼60 % reduction from baseline, respectively). The replication of the imipramine and hypericin effect [1] and the addition of significant data based on administration of flavonoids further validate the short-term/long-term treatment paradigm for the assessment of efficacy of candidate antidepressant drugs.
None of the substances caused any significant alteration in plasma ACTH and corticosterone after 8 weeks of daily treatment (Fig. [2] a,b). The functional consequences of these findings are not clear. Probably the relatively high baseline levels of ACTH and corticosterone might be a reason for these dissociative effects after two and eight weeks. It can be speculated that different adrenal responsiveness after both time points might play an important role in mediating the ACTH effects, but this needs to be explored by further experimentation. The fact, that we did not observe significant alterations in plasma ACTH and corticosterone levels after the 8 weeks treatment period with any of the substances confirms our previous findings [1]. However, the imipramine-mediated effects on ACTH and corticosterone after 8 weeks are ambivalent, since some studies have reported decreased levels of ACTH and corticosterone plasma levels after long-term imipramine treatment of rats [14], [16]. One reason for these discrepancies might be the large variability in daily imipramine doses used in the different studies. Some studies using imipramine in rats have used doses of 10 - 30 mg/kg/day [17], [18], others have used lower doses of 5 mg/kg/day [14], [16]. In these studies the substance was given interaperitoneally, whereas in the present study 15 mg/kg of imipramine were given orally by gavage. Interestingly, it has been shown in pharmacokinetic studies that the route of administration has an influence on imipramine levels [19]. During intramuscular or intraperitoneal administration, the parent drug impramine predominated in the plasma, and, conversely, the demethylated metabolite desipramine predominated during oral administration [19]. Thus, it can be speculated that the effects observed in the present study are due to desipramine. However, the imipramine dosage used in the present study was selected from the doses shown in animal models to correlate with antidepressant activity [1].
The potency of the Hypericum extract on HPA axis effects [1] could also be demonstrated with pure hypericin, hyperoside, isoquercitrin and miquelianin. It appears, therefore, that besides hypericin the flavonoids represent a possible major active principle which may contribute to the beneficial effect of Hypericum extract after oral dosing. In a recent in vitro study it could be shown that miquelianin - besides crossing walls from the small intestine - was able to cross the blood-brain barrier as well as the blood-cerebrospinal fluid barrier [20]. This finding gives further evidence for our assumption that flavonoids are able to reach the CNS after oral administration. Since only low doses of flavonoids were necessary to reduce plasma ACTH and corticosterone levels (0.6 mg/kg compared to 20 mg/kg of imipramine) these compounds might be used as a template for the development of new antidepressants in the future. In conclusion, in how far there might be synergistic or additive effects of single flavonoids needs to be established in future investigations.
Abbildung in neuem Fenster zeigenFig. 1 A,B: Adrenocorticotropin (ACTH) and corticosterone levels in plasma in the short-term (2 weeks) treatment paradigm; a = control; b = imipramine; c = hypericin; d = hyperoside; e = isoquercitrin; f = miquelianin. * p < 0.05; ** p < 0.01. Bars indicate ± SEM.
Abbildung in neuem Fenster zeigenFig. 2 A,B:Adrenocorticotropin (ACTH) and corticosterone levels in plasma in the long-term (8 weeks) treatment paradigm; a = control; b = imipramine; c = hypericin; d = hyperoside; e = isoquercitrin. Bars indicate ± SEM.
Seitenanfang
Material and MethodsAnimals: Male CD rats (150 - 180 g, Charles River WIGA, Sulzfeld, Germany) were single housed in a 12 h light/dark cycle, with lights off at 19.00 h, at a constant temperature of 25 ± 1 °C and free access to food (Altromin 1324, Altromin Lage, Germany) and tap water. Rats were randomly assigned to the various experimental groups (n = 10/group) and weighed daily. The experimental procedures used in this work were officially approved by the Regierungspräsident, Münster (A 92/99). Animals were decapitated between 9.00 and 11.00 h; the last drug administration was the day before between 16.00 and 17.00 h. Trunk blood was collected on ice-chilled EDTA-coated (10 mL) tubes containing 500 KIU aprotinin/mL, centrifuged, and plasma was frozen at -70 °C until use.
Chronic antidepressant treatment: Imipramine-HCl was purchased from Sigma (Deisenhofen, Germany), hypericin, hyperoside and isoquercitrin from Roth (Karlsruhe, Germany; purity > 95 %). Miquelianin was a gift of Prof. Dr. A. Nahrstedt, Institut für Pharmazeutische Biologie und Phytochemie, WWU Münster.
All substances were administered orally using the gavage technique; imipramine (15 mg/kg), hyperoside (0.6 mg/kg), isoquercitrin (0.6 mg/kg) and miquelianin (0.6 mg/kg) were dissolved in deionized water. All substances contained ethanol in a concentration of 160 μL/10 mL. As hypericin is sparely soluble in water, an ethanolic stock solution was prepared: 5 mg hypericin were dissolved in 2.5 mL ethanol (stock solution). 0.5 mL stock solution was diluted with water to a final concentration of 0.1 mg/kg hypericin. Control animals received deionized water with an ethanol content of 160 μL/10 mL. The final application volume of each solution was 10 mL/kg b. w. Treatment was performed between 16.00 and 17.00 h every day. The hypericin dosage of 0.2 mg/kg was chosen corresponding to [8], the hyperoside, isoquercitrin and miquelianin dosage was chosen because of their demonstrated efficacy in the forced swimming test [9]. Because the amount of miquelianin was limited, this compound was only tested in the 2 weeks treatment paradigm.
Measurement of corticosterone and adrenocorticotropic hormone (ACTH): A radioimmunoassay (RIA) of corticosterone was performed using [125I]corticosterone, antiserum, and the standard solution in a kit from ICN Biomedical (Costa Mesa, CA, USA). The assay was adapted to rat serum conditions. Precipitation was done using a second antibody solid phase. ACTH was measured using a DSL kit (Webster, Texas, USA). Both assays were performed according to manufacturer’s instructions. The inter- and intraassay coefficients of variance for ACTH were 10.6 % and 6.9 %, respectively, with a detection limit of 10 pg/mL. For corticosterone, the inter- and intraassay coefficients of variance were 7.2 % and 4.4 %, with a detection limit of 25 ng/mL.
Statistics: Statistical procedures were performed by use of the STATVIEW statistical software package, version 5.0 (SAS®, USA). All data were expressed as the mean ± SEM. Group mean differences were ascertained with analysis of variance (ANOVA). Multiple comparisons among treatment means were checked with the Student-Newman-Keuls post-hoc test. The results were considered significant if the probability of error was < 5 %.
Seitenanfang
AcknowledgementsWe thank Prof. Dr. A. Nahrstedt (Institut für Pharmazeutische Biologie und Phytochemie, WWU Muenster, Germany) for the generous supply of miquelianin. We acknowledge the Steigerwald Arzneimittel GmbH (Darmstadt, Germany) for financial support of this study.
Seitenanfang
References1 Butterweck V, Winterhoff H, Herkenham M. St. John's wort, hypericin, and imipramine: a comparative analysis of mRNA levels in brain areas involved in HPA axis control following short-term and long-term administration in normal and stressed rats. Mol Psychiatry 2001; 6: 547-64
2 Butterweck V, Winterhoff H, Herkenham M. Hyperforin-containing extracts of St. John's wort fail to alter gene transcription in brain areas involved in HPA axis control in a long-term treatment regimen in rats. Neuropsychopharmacol 2003; 28: 2160-8
3 Schrader E. Equivalence of St John's wort extract (Ze 117) and fluoxetine: a randomized, controlled study in mild-moderate depression. Int Clin Psychopharmacol 2000; 5: 61-8
4 Woelk H. Comparison of St John's wort and imipramine for treating depression: randomised controlled trial. Brit Med J 2000; 321: 536-9
5 Nahrstedt A, Butterweck V. Biologically active and other chemical constituents of the herb of Hypericum perforatum L. Pharmacopsychiatry 1997; 30: 129-34
6 Butterweck V. Mechanism of action of St. John's wort in depression: What is known? CNS Drugs 2003; 17: 539-62
7 Müller WE, Singer A, Wonnemann M, Hafner U, Rolli M, Schäfer C. Hyperforin represents the neurotransmitter reuptake inhibiting constituent of Hypericum extract. Pharmacopsychiatry 1998; 31: 16-21
8 Butterweck V, Petereit F, Winterhoff H, Nahrstedt A. Solubilized hypericin and pseudohypericin from Hypericum perforatum exert antidepressant activity in the forced swimming test. Planta Med 1998; 64: 291-4
9 Butterweck V, Jürgenliemk G, Nahrstedt A, Winterhoff H. Flavonoids from Hypericum perforatum show antidepressant activity in the forced swimming test. Planta Med 2000; 66: 3-6
10 Noeldner M, Schotz K. Rutin is essential for the antidepressant activity of Hypericum perforatum extracts in the forced swimming test. Planta Med 2002; 68: 577-80
11 Gold PW, Licinio J, Wong ML, Chrousos GP. Corticotropin releasing hormone in the pathophysiology of melancholic and atypical depression and in the mechanism of action of antidepressant drugs. Ann NY Acad Sci 1995; 771: 716-29
12 Holsboer F, Barden N. Antidepressants and hypothalamic-pituitary-adrenocortical regulation. Endocr Rev 1996; 17: 187-205
13 Barden N, Reul JM, Holsboer F. Do antidepressants stabilize mood through actions on the hypothalamic-pituitary-adrenocortical system?. Trends Neurosci 1995; 18: 6-11
14 Brady LS, Whitfield HJr, Fox RJ, Gold PW, Herkenham M. Long-term antidepressant administration alters corticotropin-releasing hormone, tyrosine hydroxylase, and mineralocorticoid receptor gene expression in rat brain. Therapeutic implications. J Clin Invest 1991; 87: 831-7
15 Brady LS, Gold PW, Herkenham M, Lynn AB, Whitfield HJ. The antidepressant fluoxetine, idazoxan and phenelzine alter corticotropin-releasing hormone and tyrosine hydroxylase mRNA levels in rat brain: therapeutic implications. Brain Res 1992; 572: 117-25
16 Frost P, Bornstein S, Ehrhart-Bornstein M, O’Kirwan F, Hutson C, Heber D, Go V, Licinio J, Wong ML. The prototypic antidepressant drug, imipramine, but not Hypericum perforatum (St. John's Wort), reduces HPA-axis function in the rat. Horm Metab Res 2003; 35: 602-6
17 Armario A, Garcia-Marquez C. Tricyclic antidepressants activate the pituitary-adrenal axis in the rat. Tolerance to repeated drug administration. Eur J Pharmacol 1987; 140: 239-44
18 Kitamura Y, Araki H, Gomita Y. Influence of ACTH on the effects of imipramine, desipramine and lithium on duration of immobility of rats in the forced swim test. Pharmacol Biochem Behav 2002; 71: 63-9
19 Rigal J, Albin H, Fanca X, Demotes-Mainard F, Vincon G. The influence of the route of administration of imipramine on imipramine and desipramine blood levels. J Clin Psychopharmacol 1989; 9: 364-7
Juergenliemk G, Boje K, Huewel S, Lohmann C, Galla HJ, Nahrstedt A. In vitro studies indicate that miquelianin (quercetin 3-O-beta-glucuronopyranoside) is able to reach the CNS from the small intestine. Planta Med 2003; 69: 1013-7
Posted by sdb on June 28, 2006, at 16:29:03
In reply to Re: hypericum - paroxetine panic maze study (long), posted by sdb on June 27, 2006, at 18:44:55
Thanks Bob for cleaning the hypericum to alternative to keep order and quality (what I think is important and a priority as a moderator)
substitute act not self-interview. Only read this if you are interested. No trigger content.
The neuropharmacology studies definately prove that sjw does many things in the brains. From
these studies I shortly frequented, were many differences of the substances of an sjw abstract itself. Maybe there could be a problem of inconsistency, dosages and non compliance (to wait 6 weeks for an effect!). After all that some of these sjw abstracts can work is assured. And for some of the pbabble it works or worked. Feel free to articulate what your are thinking about.sdb, OOAB
(owner of a brain)Here's a meta-analysis from the
British Medical Journal:
http://bmj.bmjjournals.com/cgi/content/full/313/7052/253Review article, Klaus Linde, MD:
http://bjp.rcpsych.org/cgi/content/full/186/2/99Negative Jama abstract:
JAMA. 2002 Apr 10;287(14):1807-14. Related Articles, Links
Click here to read
Comment in:* Evid Based Ment Health. 2002 Nov;5(4):111.
* JAMA. 2002 Apr 10;287(14):1853-4.
* JAMA. 2002 Jul 24-31;288(4):446-7; author reply 448-9.
* JAMA. 2002 Jul 24-31;288(4):446; author reply 448-9.
* JAMA. 2002 Jul 24-31;288(4):446; author reply 448-9.
* JAMA. 2002 Jul 24-31;288(4):447-8; author reply 448-9.
* JAMA. 2002 Jul 24-31;288(4):447; author reply 448-9.
* JAMA. 2002 Jul 24-31;288(4):448; author reply 448-9.Some positive abstracts:
Effect of Hypericum perforatum (St John's wort) in major depressive disorder: a randomized controlled trial.
Hypericum Depression Trial Study Group.
CONTEXT: Extracts of Hypericum perforatum (St John's wort) are widely used for the treatment of depression of varying severity. Their efficacy in major depressive disorder, however, has not been conclusively demonstrated. OBJECTIVE: To test the efficacy and safety of a well-characterized H perforatum extract (LI-160) in major depressive disorder. DESIGN AND SETTING: Double-blind, randomized, placebo-controlled trial conducted in 12 academic and community psychiatric research clinics in the United States. PARTICIPANTS: Adult outpatients (n = 340) recruited between December 1998 and June 2000 with major depression and a baseline total score on the Hamilton Depression Scale (HAM-D) of at least 20. INTERVENTIONS: Patients were randomly assigned to receive H perforatum, placebo, or sertraline (as an active comparator) for 8 weeks. Based on clinical response, the daily dose of H perforatum could range from 900 to 1500 mg and that of sertraline from 50 to 100 mg. Responders at week 8 could continue blinded treatment for another 18 weeks. MAIN OUTCOME MEASURES: Change in the HAM-D total score from baseline to 8 weeks; rates of full response, determined by the HAM-D and Clinical Global Impressions (CGI) scores. RESULTS: On the 2 primary outcome measures, neither sertraline nor H perforatum was significantly different from placebo. The random regression parameter estimate for mean (SE) change in HAM-D total score from baseline to week 8 (with a greater decline indicating more improvement) was -9.20 (0.67) (95% confidence interval [CI], -10.51 to -7.89) for placebo vs -8.68 (0.68) (95% CI, -10.01 to -7.35) for H perforatum (P =.59) and -10.53 (0.72) (95% CI, -11.94 to -9.12) for sertraline (P =.18). Full response occurred in 31.9% of the placebo-treated patients vs 23.9% of the H perforatum-treated patients (P =.21) and 24.8% of sertraline-treated patients (P =.26). Sertraline was better than placebo on the CGI improvement scale (P =.02), which was a secondary measure in this study. Adverse-effect profiles for H perforatum and sertraline differed relative to placebo. CONCLUSION: This study fails to support the efficacy of H perforatum in moderately severe major depression. The result may be due to low assay sensitivity of the trial, but the complete absence of trends suggestive of efficacy for H perforatum is noteworthy.
[Hypericum perforatum extract in treatment of mild to moderate depression. Clinical and pharmacological aspects]
[Article in German]
Laakmann G, Jahn G, Schule C.
Psychiatrische Klinik der Universitat Munchen, Nussbaumstrasse 7, 80336 Munchen. Prof.Laakmann@psy.med.uni-muenchen.de
For many years, hypericum extracts have been used in the treatment of depressive disorders. The therapeutical use of these extracts has been predominantly justified for a long time by the clinical evidence of efficacy and only partly by results of scientific studies. The aim of the present investigation is to perform a meta-analysis of the placebo- and verum-controlled studies carried out till now, to examine the relevance of hyperforin and hypericin for the clinical efficacy of St. John's Wort, to discuss biochemical and pharmacoendocrinological studies investigating the mechanism of action, and to describe side effects and interactions of hypericum extracts. In particular during recent years, methodologically quite sophisticated studies have been performed. The comprehensive evaluation of all studies available suggests a significant superiority of hypericum extracts over placebo, despite the negative results of two recently published American trials, and a therapeutic efficacy comparable to that of synthetic antidepressants in mildly to moderately depressed patients. Furthermore, it has been suggested in preclinical and clinical studies that the content of hyperforin but not of hypericin decisively contributes to the antidepressant efficacy of hypericum extracts. Hyperforin has been demonstrated in biochemical investigations--like synthetic antidepressants--to inhibit the reuptake of the neurotransmitters norepinephrine, serotonin, and dopamine. Hypericum extracts can be regarded as well tolerated, and they extend the variety of pharmacotherapeutical options in the treatment of depression, especially in outpatients. However, interactions in combination treatments are possible by interference with the cytochrom P450 system, thereby changing plasma levels of other medications.
Efficacy of St. John's wort extract WS 5570 in major depression: a double-blind, placebo-controlled trial.
Lecrubier Y, Clerc G, Didi R, Kieser M.
Unite Institut National de la Sante et de la Recherche Medicale 302, Hopital Pitie Salpetriere, Paris, France. lecru@ext.jussieu.fr
OBJECTIVE: In a double-blind, randomized, placebo-controlled trial with 375 patients the authors investigated the antidepressant efficacy and safety of 300 mg t.i.d. of hydroalcoholic Hypericum perforatum extract WS 5570. METHOD: The study participants were male and female adult outpatients with mild to moderate major depression (single or recurrent episode, DSM-IV criteria). After a single-blind placebo run-in phase, the patients were randomly assigned, 186 to WS 5570 and 189 to placebo, after which they received double-blind treatment for 6 weeks. Follow-up visits were held after 1, 2, 4, and 6 weeks. The primary outcome measure was the change from baseline in the total score on the 17-item Hamilton Depression Rating Scale. In addition, analyses of responders (patients with at least a 50% reduction in Hamilton total score) and patients with remissions (patients with a total score of 6 or less on the Hamilton scale at treatment end) were carried out, and subscale/subgroup analyses were conducted. The design included an adaptive interim analysis performed after random assignment of 169 patients with options for group size adjustment or early termination. RESULTS: Compared to placebo, WS 5570 produced a significantly greater reduction in total score on the Hamilton depression scale and significantly more patients with treatment response or remission. It was more effective in patients with higher baseline Hamilton scores and led to global reduction of depression-related core symptoms, assessed with the melancholia subscale of the Hamilton scale. The placebo and WS 5570 groups had comparable adverse events. CONCLUSIONS: H. perforatum extract WS 5570 was found to be safe and more effective than placebo for the treatment of mild to moderate depression.
St John's wort for depression.
: Cochrane Database Syst Rev. 2005 Apr 18;(2):CD000448.Linde K, Mulrow CD, Berner M, Egger M.
Centre for Complementary Medicine Research, Department of Internal Medicine II, Technische Universitat Munchen, Kaiserstr. 9, Munich, Germany, 80801. Klaus.Linde@lrz.tu-muenchen.de
BACKGROUND: Extracts of the plant Hypericum perforatum L. (popularly called St. John's wort) have been used in folk medicine for a long time for a range of indications including depressive disorders. OBJECTIVES: To investigate whether extracts of hypericum are more effective than placebo and as effective as standard antidepressants in the treatment of depressive disorders in adults; and whether they have have less adverse effects than standard antidepressant drugs. SEARCH STRATEGY: Trials were searched in computerized databases (Cochrane Collaboration Depression, Anxiety & Neurosis Group Clinical Trials Registers; PubMed); by checking bibliographies of pertinent articles; and by contacting manufacturers and researchers. SELECTION CRITERIA: Trials were included if they: (1) were randomized and double-blind; (2) included patients with depressive disorders; (3) compared extracts of St. John's wort with placebo or standard antidepressants; and (4) included clinical outcomes such as scales assessing depressive symptoms. DATA COLLECTION AND ANALYSIS: Information on patients, interventions, outcomes and results was extracted by at least two independent reviewers using a standard form. The main outcome measure for comparing the effectiveness of hypericum with placebo and standard antidepressants was the responder rate ratio (responder rate in treatment group/responder rate in control group). The main outcome measure for adverse effects was the number of patients dropping out for adverse effects. MAIN RESULTS: A total of 37 trials, including 26 comparisons with placebo and 14 comparisons with synthetic standard antidepressants, met the inclusion criteria. Results of placebo-controlled trials showed marked heterogeneity. In trials restricted to patients with major depression, the combined response rate ratio (RR) for hypericum extracts compared with placebo from six larger trials was 1.15 (95% confidence interval (CI), 1.02-1.29) and from six smaller trials was 2.06 (95% CI, 1.65 to 2.59). In trials not restricted to patients with major depression, the RR from six larger trials was 1.71 (95% CI, 1.40-2.09) and from five smaller trials was 6.13 (95% CI, 3.63 to 10.38). Trials comparing hypericum extracts and standard antidepressants were statistically homogeneous. Compared with selective serotonin reuptake inhibitors (SSRIs) and tri- or tetracyclic antidepressants, respectively, RRs were 0.98 (95% CI, 0.85-1.12; six trials) and 1.03 (95% CI, 0.93-1.14; seven trials). Patients given hypericum extracts dropped out of trials due to adverse effects less frequently than those given older antidepressants (Odds ratio (OR) 0.25; 95% CI, 0.14-0.45); such comparisons were in the same direction, but not statistically significantly different, between hypericum extracts and SSRIs (OR 0.60, 95% CI, 0.31-1.15). AUTHORS' CONCLUSIONS: Current evidence regarding hypericum extracts is inconsistent and confusing. In patients who meet criteria for major depression, several recent placebo-controlled trials suggest that the tested hypericum extracts have minimal beneficial effects while other trials suggest that hypericum and standard antidepressants have similar beneficial effects. As the preparations available on the market might vary considerably in their pharmaceutical quality, the results of this review apply only to the products tested in the included studies.
Posted by sdb on June 28, 2006, at 18:37:42
In reply to Re: hypericum - some more studies (average long), posted by sdb on June 28, 2006, at 16:29:03
Sorry about starting thread of sdb answered by sdb. I am just interested in the pharmacology, the clinical studies compared and the experiences here. Maybe this can help some people.
In Europe there are clear standartized extracts like e.g. Ze117, Li160. What means standardisation? -It means a lot. Why? -Because it is from a plant with many substances playing together a role.
Standartisation means more than give a concentration of "standardized to 0.3% hypericin and 3% hyperforin" (look to pharmacology studies and differences between whole abstracts and isolated molecules). There are much more substances involved. Thus it depends what you're taking from the plant, where the plant is growing, what are the contents of the ground, how was the weather, from which plant are the substances -> there are up to 400 hypericums. I am asking the question if there are such standardisations e.g. in the US similar as in Europe. Does somebody know more?sdb
post skriptum: always sorry about not responding immediately, but I am always here maybe in a week again.
The woelk H. study with Ze117 (standart)
========================================Comparison of St John's wort and imipramine for treating depression: randomised controlled trial.
Woelk H.
Klinik fur Psychiatrie und Psychotherapie, Akademisches Lehrkrankenhaus der Universitat Giessen, Licher Strasse 106, D-35394 Giessen, Germany.
OBJECTIVES: To compare the efficacy and tolerability of Hypericum perforatum (St John's wort extract) with imipramine in patients with mild to moderate depression. DESIGN: Randomised, multicentre, double blind, parallel group trial. SETTING: 40 outpatient clinics in Germany. Participants: 324 outpatients with mild to moderate depression. INTERVENTION: 75 mg imipramine twice daily or 250 mg hypericum extract ZE 117 twice daily for 6 weeks. MAIN OUTCOME MEASURES: Hamilton depression rating scale, clinical global impression scale, and patient's global impression scale. RESULTS: Among the 157 participants taking hypericum mean scores on the Hamilton depression scale decreased from 22.4 at baseline to 12.00 at end point; among the 167 participants taking imipramine they fell from 22.1 to 12.75. Mean clinical global impression scores at end point were 2.22 out of 7 for the hypericum group and 2.42 for the imipramine group. On the 7 point self assessments of global improvement completed by participants (score of 1 indicating "very much improved" and 7 indicating "very much deteriorated") mean scores were 2.44 in the hypericum group and 2.60 in the imipramine group. None of the differences between treatment groups were significant. However, the mean score on the anxiety-somatisation subscale of the Hamilton scale (3.79 in the hypericum group and 4.26 in the imipramine group) indicated a significant advantage for hypericum relative to imipramine. Mean scores on the 5 point scale used by participants to assess tolerability (score of 1 indicating excellent tolerability and 5 indicating very poor tolerability) were better for hypericum (1.67) than imipramine (2.35). Adverse events occurred in 62/157 (39%) participants taking hypericum and in 105/167 (63%) taking imipramine. 4 (3%) participants taking hypericum withdrew because of adverse events compared with 26 (16%) taking imipramine. CONCLUSIONS: This Hypericum perforatum extract is therapeutically equivalent to imipramine in treating mild to moderate depression, but patients tolerate hypericum better.
Posted by linkadge on June 28, 2006, at 21:25:29
In reply to Re: hypericum - some more studies (maybe too long), posted by sdb on June 28, 2006, at 18:37:42
I think the biggest reason for the "controversy" is that it is available over the counter.
There are many things at stake when considering SJW effective. It would cause problems for both psychiatrists and drug companies.
You may have dozens of studies that say it works, but only one "SJW no better than placebo" will make it on the news.
Linkadge
Posted by sdb on June 28, 2006, at 22:17:08
In reply to Re: hypericum - some more studies (maybe too long), posted by linkadge on June 28, 2006, at 21:25:29
Thanks linkadge for your response (see babblemail).
Somebody else; studies, personal experience, thoughts?
sdb
This is the end of the thread.
Psycho-Babble Alternative | Extras | FAQ
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.org
Script revised: February 4, 2008
URL: http://www.dr-bob.org/cgi-bin/pb/mget.pl
Copyright 2006-17 Robert Hsiung.
Owned and operated by Dr. Bob LLC and not the University of Chicago.