The anti-depressant effect of Nelumbinis semen on rats under chronic mild stress induced depression-like symptoms.

Nelumbinis Semen is a well-known traditional herbal medicine frequently used in treatment of depression in many Asian countries. In this study, its anti-depression effects in rats were investigated by comparing the test results of those treated with Nelumbinis Semen to those treated with other herbal anti-depressants, including Rehmanniae Radix Preparat, Corni Fructus, Lycii Fructus, Pinelliae Rhizoma and Hypericum Perforatum. In order to induce depression-like symptoms, the animals were placed under chronic mild stress in the form of overnight illumination for 2 consecutive days. They were treated with the respective herbal extract and forced swimming tests were conducted afterwards. The anti-depression effects of each extract were then evaluated based on a measured index, which consisted of struggling time, first latency and first rest duration. These test results show that Nelumbinis Semen provides greater anti-depression effects than the other herbal extracts. Specifically, only the rats treated with Nelumbinis Semen showed significant increases in struggling time (43.9%, p < 0.005, p = 0.0037) and in first latency time (90.2%, p < 0.05, p = 0.0116). However, the first rest duration for Nelumbinis Semen treated rats was not significantly different from the other rats. It appears that Nelumbinis Semen provides even greater anti-depression effects than Hypericum Perforatum (commonly referred to as St. John's Wort, perhaps the most widely used natural antidepressant today). The anti-depression effects of Nelumbinis Semen might be due to the modulation of the amount of neurotransmitters involved in depression.