St. John's Wort =============== þ Can cause Serotonin Syndrome St. John's Wort is Hypericum perforatum - the active agent is hypericin which has an MAOI-like effect.[1] (While MAOI's are known to have bad food-drug interactions with organic amines, a Paperchase search doesn't show any reports of hypertensive crisis associated with hypericin.) Interestingly, there is a paper that shows the compound possesses anti-retroviral activity. [2] Because it is a food supplement, there is no guarantee that there is 0.3% hypericin in the pill even though that's what the label says. (I can't find a reference to a recent news story that showed some products had less than 20% of what was on the label). --Larry > [1] >Bladt S Wagner H >Inhibition of MAO by fractions and constituents of hypericum extract. J >Geriatr Psychiatry Neurol (1994 Oct) 7 Suppl 1:S57-9 > >The inhibition of monoamine oxidase (MAO) by six fractions from > hypericum extract and three characteristic constituents (as pure > substances) were analyzed in vitro and ex vivo to study the > antidepressive mechanism of action. Rat brain homogenates were used as > the in vitro model, while the ex vivo analysis was performed after > intraperitoneal application of the test substances to albino rats. > Massive inhibition of MAO-A could be shown with the total extract and > all fractions only at the concentration of 10(-3) mol/L. At 10(-4) > mol/L, one fraction rich in flavonoides showed an inhibition of 39%, > and all other fractions demonstrated less than 25% inhibition. Using > pure hypericin as well as in all ex vivo experiments, no relevant > inhibiting effects could be shown. From the results it can be concluded > that the clinically proven antidepressive effect of hypericum extract > cannot be explained in terms of MAO inhibition. > >Registry Numbers: 117-39-5 (Quercetin) > 198-55-0 (Perylene) > >Institutional address: > Institut fur Pharmazeutische Biologie der Universitat Munchen > Germany. >