St. John's wort (Hypericum perforatum): a review of the current pharmacological, toxicological, and clinical literature

Rationale: St. John's wort (Hypericum per foratum) has recently gained popu larity as an alternative treatment for mild to moderate depression. Given t he current widespread use of this herbal remedy, it is important for medica l professionals to understand the potential pharmacological pathways throug h which Hypericum may exert an antidepressant effect. Objectives: (I) To re view the current pharmacological, toxicological, and clinical literature av ailable on Hypericum, and (2) to provide a synthesis of this information in to a form that may be easily used by health care providers. Method: A compr ehensive review of the recent scientific literature (January 1990-March 200 0) was performed using the following electronic databases and reference pub lications: MEDLINE, The Cochrane Library, HealthSTAR, Current Contents (all editions), European Scientific Cooperative on Phytotherapy monographs, Ger man Commission E monographs, and the Physicians' Desk Reference for Herbal Medicines, Ist edition. Results: One hundred and seven (107) publications i n the English language and three publications in German were included in th e review. Collectively, the data suggest that therapeutic preparations of H ypericum extract appear to exert potentially significant pharmacological ac tivity within several neurochemical systems believed to be implicated in th e pathophysiology of depression. However, little information exists regardi ng the safety of Hypericum, including potential herb-drug interactions. Con clusions: Additional research on the pharmacological and biochemical activi ty of Hypericum and its several bioactive constituents is necessary to furt her elucidate the models) of antidepressant action. Given what is currently known and unknown about the biological properties of Hypericum, those who choose to use this herb should be closely monitored by a physician.