The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 6 No.
3 • June 2003
Rutin May Be Essential for the Antidepressant Activity of St. John’s Wort
Scientists studying a series of ethanolic and methanolic extracts of Hypericum perforatum (St. John’s Wort) in an animal model for antidepressant activity (the forced swimming test) found that only one methanolic research extract had no effect in the in vivo pharmacological experiments. They found by analytical characterization that the inactive extract had a reduced level of the diglycoside flavonoid rutin. Addition of rutin to the inactive extract to produce a rutin concentration in the normal range resulted in a pharmacological effect similar to that of the other extracts. According to their results, the amount of rutin needed was not dose-dependent, indicating the need for a threshold amount.
The authors suggest that, since flavonoids can modulate the bioavailability of drugs via transport through biological membranes, via interactions with P-glycoprotein multiple drug transporters or by modulating the cytochrome P450 drug-metabolizing enzyme system, rutin may enhance the bioavailability of Hypericum constituents necessary for its antidepressant actions.
- Noldner and Schotz. Rutin is essential for the antidepressant activity of Hypericum perforatum extracts in the forced swimming test. Planta Med 68:577-80 (2002).