The Indian spice tumeric (Curcuma longa) is a well-known traditional herbal medicine. These scientists evaluated it role in treating a mouse model for depression. In these models the animals become immobilized (still) by the despair caused by an inescapable external physical stress. Antidepressants reduce the duration of immobility. They extracted tumeric into water. They gave mice from 140 to 560 milligrams per kilogram body weight of the extract by mouth for 14 days. They found that greater doses of tumeric produced less immobility of the stressed mice. They used the tail suspension test and the forced swimming test. The effect of 560 milligrams per kilogram of the extract was greater than the comparison antidepressant fluoxetine (Prozac). The extracts, at the dose of 140 mg/kg or greater for 14 days, significantly inhibited the enzyme monoamine oxidase A (MAO) activity in mouse whole brain. In contrast only the highest dose of the extract, 560 mg/kg inhibited MAO B activity in mouse brains. MAO inhibitors are an important class of currently used antidepressants. Fluoxetine (Prozac) showed only a tendency to inhibit MAO A and B activity in animal brain in the study. Fluoxetine is in the class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). Neither the extract nor fluoxetine, at the doses tested, reduced locomotor activity. These scientists concluded that that C. longa had antidepressant effects in this mouse model. They suggest that this effect of tumeric may be due to its inhibition of MAO A.
Antidepressant activity of aqueous extracts of Cur…[J Ethnopharmacol. 2002]