Posted by KaraS on January 6, 2005, at 0:37:14
In reply to St. John's Wort Dopamine, posted by Iansf on January 5, 2005, at 13:31:05
> St. John's Wort Might Act Via Dopamine Pathway
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> NEW YORK (Reuters Health) Dec 27 - The herbal depression remedy St. John's wort (Hypericum perforatum) appears to increase plasma concentration of dihydroxyphenylacetic acid (DOPAC), the main metabolite of dopamine, indicating a novel mode of action, according to German and US researchers.
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> In the November issue of Clinical Pharmacology and Therapeutics, Dr. Christoph Schroeder of Medical University Charite, Berlin, and colleagues note that in vitro studies have suggested that the agent's effect may be in part due to inhibition of monoamine transporters and monoamine oxidase.
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> To investigate, the researchers randomized 16 healthy subjects to a crossover study of St. John's wort 300 mg three times daily or placebo for 7 days. In addition, seven subjects were randomly assigned to a third study arm in which they were also given the tricyclic antidepressant imipramine for 7 days.
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> Compared to placebo, imipramine increased resting blood pressure and heart rate as well as causing a marked orthostatic tachycardia. No such effects were seen with St. John's wort.
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> Moreover, St. John's wort had no effect on plasma concentrations of norepinephrine or its main metabolite. However, plasma DOPAC concentrations increased in every subject given the remedy.
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> Thus, the researchers conclude that the findings do not support the concept that the agent "elicits a major change in norepinephrine uptake or monoamine oxidase activity."
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> The DOPAC effect, they add, may indicate "a heretofore unknown mode of action and should be followed up."
That's fascinating. Thanks for posting this. I had always assumed that SJW was more serotonergic than anything else. I wonder if it could be taken with a noradrenergic to augment it.
poster:KaraS
thread:438130
URL: http://www.dr-bob.org/babble/alter/20050101/msgs/438386.html