Posted by Quintal on August 9, 2007, at 23:11:38
In reply to Re: Chrysin as an anxiolytic » Quintal, posted by Sigismund on August 9, 2007, at 22:54:18
Of course I've heard of that have Siggy. It's actually the other way around, chrysin inhibits aromatase, which converts testosterone into estrogen, hence its popularity with weight lifters (to minimize steroid-induced gynecomastia). All of the studies on chrysin aromatase inhibition found that oral administration was ineffective for this purpose, so I thought they were irrelevant to this topic. It seems that chrysin must be administered via the IV route to achieve full efficacy, either that, or be taken as the sulphate salt.
__________________________________________________1: J Med Food. 2003 Winter;6(4):387-90.Click here to read Links
Effects of chrysin on urinary testosterone levels in human males.
Gambelunghe C, Rossi R, Sommavilla M, Ferranti C, Rossi R, Ciculi C, Gizzi S, Micheletti A, Rufini S.Department of Clinical and Experimental Medicine, Division of Sports Medicine-Laboratorio delle Attivitą Motorie e Sportive, University of Perugia, Perugia, Italy. labsport@unipg.it
The equilibrium of sexual hormones in both sexes is controlled in vertebrates by the enzyme aromatase, a member of the cytochrome P450 superfamily, which catalyzes the conversion of androstenedione and testosterone into estrone and estradiol, respectively. Flavonoids are diphenolic compounds present in whole grains, legumes, fruits, and vegetables that are strongly implicated as protective in coronary heart disease, stroke, and cancer. One flavonoid, chrysin, found in high concentrations in honey and propolis, has been shown to be an inhibitor of aromatase enzyme activity. These foods are often used as supplements, particulary by sportsmen for their energetic and antioxidant properties. The aim of this study was to verify if daily treatment for 21 days with propolis and honey, containing chrysin, would modify urinary concentrations of testosterone in volunteer male subjects. In fact, aromatase inhibition by chrysin could block the conversion of androgens into estrogens with a consequent increase of testosterone, eventually measurable in urine samples. The obtained data did not show alterations of the levels of testosterone in the volunteers after 7, 14, and 21 days of treatment in comparison with baseline values and compared with measurements on the control subjects at the same time. In conclusion, the use of these foods for 21 days at the doses usually taken as oral supplementation does not have effects on the equilibrium of testosterone in human males.
PMID: 14977449 [PubMed - indexed for MEDLINE]
--------------------------------------------------Int J Sport Nutr Exerc Metab. 2000 Sep;10(3):340-59.Links
Effects of anabolic precursors on serum testosterone concentrations and adaptations to resistance training in young men.
Brown GA, Vukovich MD, Reifenrath TA, Uhl NL, Parsons KA, Sharp RL, King DS.Exercise Biochemistry Laboratory, Department of Health and Human Performance, Iowa State University, Ames, IA 50011, USA.
The effects of androgen precursors, combined with herbal extracts designed to enhance testosterone formation and reduce conversion of androgens to estrogens was studied in young men. Subjects performed 3 days of resistance training per week for 8 weeks. Each day during Weeks 1, 2, 4, 5, 7, and 8, subjects consumed either placebo (PL; n = 10) or a supplement (ANDRO-6; n = 10), which contained daily doses of 300 mg androstenedione, 150 mg DHEA, 750 mg Tribulus terrestris, 625 mg Chrysin, 300 mg Indole-3-carbinol, and 540 mg Saw palmetto. Serum androstenedione concentrations were higher in ANDRO-6 after 2, 5, and 8 weeks (p <.05), while serum concentrations of free and total testosterone were unchanged in both groups. Serum estradiol was elevated at Weeks 2, 5, and 8 in ANDRO-6 (p <.05), and serum estrone was elevated at Weeks 5 and 8 (p <.05). Muscle strength increased (p <.05) similarly from Weeks 0 to 4, and again from Weeks 4 to 8 in both treatment groups. The acute effect of one third of the daily dose of ANDRO-6 and PL was studied in 10 men (23 +/- 4 years). Serum androstenedione concentrations were elevated (p <.05) in ANDRO-6 from 150 to 360 min after ingestion, while serum free or total testosterone concentrations were unchanged. These data provide evidence that the addition of these herbal extracts to androstenedione does not result in increased serum testosterone concentrations, reduce the estrogenic effect of androstenedione, and does not augment the adaptations to resistance training.
PMID: 10997957 [PubMed - indexed for MEDLINE]
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