Neuroprotective effects of methanol extract of Terminalia macroptera leaf in mice

Abstract

The plant Terminalia macroptera has been reported to possess many pharmacological activities. The aim of the present study was to screen the effect of the methanol extract of T. macroptera against ketamine-induced mice model of psychosis and the apomorphine climbing test. The behavioural studies entailed an evaluation of locomotor activity, stereotypic behaviours in the open field and stereotypic climbing behaviour, immobility duration in the forced swim test, memory retention using the Y- maze and descent latency effects on catalepsy in the woodblock of methanol extract of T. macroptera (100-400 mg/kg) administered orally. The acute toxicity study as well as the phytochemical study was also carried out. Animals treated with the methanol extract of T. macroptera demonstrated significant reduction in locomotor activity, stereotypic behaviours, immobility duration, and increase in memory retention and decreased descent latency. The LD50 was found to be greater than 5000 mg/kg indicating that the extract is safe for consumption and phytochemical studies revealed the presence of flavonoids, tannins, saponins, cardiac glycosides and alkaloids which might be responsible for its pharmacological activity. This study concluded that methanol extract of T. macroptera could ameliorate ketamine-induced behavioural abnormalities in mice indicating its promising effect as a neuroprotective agent in the management of psychotic symptoms. Key words: Behaviours, ketamine, neuroprotection, psychosis, stereotype, Terminalia macroptera.