ANTIDEPRESSANT ACTIVITY OF HYPERICUM-PERFORATUM AND HYPERFORIN - THE NEGLECTED POSSIBILITY

Efforts leading to the identification of hyperforin as an antidepressi ve component of therapeutically used alcoholic hypericum extracts are described and discussed. Initially, the effects of this unique and maj or constituent of the herb were detected in peripheral organs using in vitro models and an extract was obtained by supercritical extraction of the herb by carbon dioxide. These extracts are highly enriched in h yperforin (38.8%) and are devoid of hypericines and numerous other com ponents of alcoholic extracts. Studies with such an extract and with i solated hyperforin indicated that this acylphloroglucinol derivative c an inhibit serotonin-induced responses and uptake of this neurotransmi tter in peritoneal cells. Assuming that the effects of hyperforin were due to its actions on serotoninergic 5-HT3/5-HT4 receptors, further s tudies were conducted to investigate its effects on the CNS. These eff orts revealed its antidepressant activity in the behavioral despair te st and led to the working hypothesis that hyperforin and serotoninergi c mechanisms are involved in the antidepressant activities of alcoholi c hypericum extracts. The observations made during this study also ind icate that hyperforin is the major, but not the only antidepressive co mponent of alcoholic extracts.