Antidepressant effect of methanol stem bark extract of adansonia digitata l. (malvaceae) in mice

Abstract

Adansonia digitata (Malvaceae) is a plant native to Africa with all its parts used extensively since ancient times in traditional medicine for different purposes including psychiatric disorders. The plant has been used ethnomedicinally as a remedy for depression. The aim of the study was to investigate the antidepressant activity of the methanol stem bark extract of A. digitata. Phytochemical screening and acute oral toxicity (LD50) study were done using standard procedures. Antidepressant activity of the extract (250-1000 mg/kg) was evaluated using tail suspension test (TST) and forced swim test (FST) in mice. Tests for motor co-ordination deficit and stimulant activity were evaluated using beam walking assay (BWA) and open field test (OFT), respectively. The effect of the methanol stem bark extract of A. digitata was tested using the novel object recognition task (NORT). The phytochemical screening of the extract showed the presence of steroids, tannins, flavonoids, alkaloids and saponins. The LD50 was found to be greater than 5000 mg/kg orally. The extract significantly (P < 0.01) and dose-dependently decreased the duration of immobility in the TST and FST. There was no significant change in the number of lines crossed and on the number of foot slips in the OFT and BWA, respectively. The extract showed no significant effect on cognition in the NORT. In conclusion, the methanol stem bark extract of A. digitata possesses antidepressant activity.