Posted by SalArmy4me on July 10, 2001, at 13:26:16
In reply to Okay, what about 5-HTP?, posted by Pattisun on July 10, 2001, at 10:02:47
Psychosomatics
Volume 61(5) September/October 1999 p 712 Dietary Supplements and Natural Products as Psychotherapeutic Agents
Fugh-Berman, Adriane MD; Cott, Jerry M. PhD:5-HTP is the intermediate metabolite of the amino acid L-tryptophan in the serotonin pathway. Therapeutic use of 5-HTP bypasses the conversion of tryptophan into 5-HTP by the enzyme tryptophan hydroxylase, the rate-limiting step in serotonin synthesis. Tryptophan hydroxylase can be inhibited by numerous factors, including stress, insulin resistance, vitamin B6 deficiency, and insufficient magnesium (147). The same factors can decrease serotonin by another mechanism: By increasing the conversion of tryptophan to kynurenine via tryptophan oxygenase, less tryptophan is available for serotonin production. 5-HTP is commercially produced by extraction from the seeds of an African plant, Griffonia simplicifolia, and this extract is available in the United States. Antidepressant effects seem to be more consistent with 5-HTP than with tryptophan (139, 148).
Although the same potential may exist for 5-HTP to interact with MAO inhibitors and SRIs, in many studies, they have been successfully combined to enhance the therapeutic effect (156, 157). It is unclear whether L-5-HTP is subject to the same sort of contamination as tryptophan and whether it can cause EMS. Although several cases of EMS-like syndromes have been reported in people ingesting L-5-HTP, in only one of these was the substance analyzed. In 1994, a typical case of EMS was reported in a 28-year-old woman who did not ingest the substance orally but was exposed to 5-HTP by handling powder fed to her two children (who were being treated with 5-HTP for a defect in tetrahydrobiopterin synthesis) (158). The children’s father, who also prepared medication for the children, never manifested any signs or symptoms of exposure. Although both children were asymptomatic, they were found to have increased white blood cell counts and mild eosinophilia that resolved after they were switched to a different lot of 5-HTP. Subsequent high-performance liquid chromatography analysis of the case-associated lot found a minor peak (dubbed peak X) that may represent a contaminant (examination of multiple lots revealed the presence of peak X in one of nine other lots sampled).
In 1998, peak X was reported to be a [beta]-carboline derivative (6-hydroxy-1,2,3,4,4a,9a-hexa-hydro-[beta]-carboline-3-carboxylic acid), similar in chemical structure to two contaminants in EMS-associated tryptophan (159). An analysis of six over-the-counter 5-HTP products purchased from health food stores (two synthetic and four seed extracts) found that all six contained low levels of peak X. Although levels of peak X were only 3% to 15% of levels found in case-implicated 5-HTP, investigators point out that consumption of 300 to 900 mg/d could bring intake to case-implicated levels. An ataxia study in which 28 patients were treated with L-5-HTP and carbidopa was halted due to the development of eosinophilia in three patients. Two of these cases demonstrated only mild elevations in eosinophils; the third patient had marked eosinophilia (36%, or 5500 eosinophils/mm3) but had also been concurrently exposed to mace (1-chloroacetophenone).
In conclusion, contaminated L-tryptophan has been definitively associated with EMS. 5-HTP has been linked with several unusual cases of EMS-like symptoms and one convincing but unusual case of EMS in which the route of exposure was topical (and possibly respiratory) rather than oral. The recent identification of a [beta]-carboline component in all six brands tested is nevertheless worrisome; more research needs to be done to elucidate the potential risks of 5-HTP.
poster:SalArmy4me
thread:69588
URL: http://www.dr-bob.org/babble/20010708/msgs/69620.html