Evaluation of antidepressant and in-vivo antioxidant effects of methanol leaf extract of Vernonia amygdalina

Abstract

Vernonia amygdalina remains a popular plant used in indigenous and folkoric medicine for the treatment of several diseases such as malaria, headaches, diabetes, hypertension, skin-related problems and many others. The aim of this study was to evaluate the antidepressant and antioxidant effects of the methanol leaf extract of Vernonia amygdalina in mice. The plant materials were extracted with methanol and the percentage yield was consistent. The antidepressant effect of the V. amygdalina methanol extract was evaluated at different doses (100, 200 and 400 mg/kg) in both sexes. The models employed was delayed restriction for 14 days, using the forced swimming test, tail suspension test and swim induced grooming. The methanol leaf extract of Vernonia amygdalina significantly decreased the immobility duration and significantly increased grooming time (P < 0.05), in the post swim behavioral observations. The extract of Vernonia amygdalina significantly increased the concentrations of reduced glutathione (GSH), (SOD) and reduced the level of malonidialdehyde (MDA) in the hippocampal homogenate across all doses (P < 0.05). Vernonia amygdalina acute toxicity data was calculated to be greater or equal to 5000 mg/kg. The results obtained in this study have indicated that the extract exerts antidepressant-like effects through the modulation of oxidative stress within specific regions of the brain, thus further research should be conducted to purify compounds responsible for the observed antidepressant effects.