Enhancing effect of Tiliacora triandra leaves extract on spatial learning, memory and learning flexibility as well as hippocampal choline acetyltransferase activity in mice

OBJECTIVE: The present study investigates the effect of Tiliacora triandra leaf extract on spatial learning, memory, and learning flexibility as well as hippocampal choline acetyltransferase (ChAT) activity in mice. MATERIALS AND METHODS: Thirty male ICR mice were randomly divided into three groups including 10% Tween 80, T. triandra 300 mg/kg and T. triandra 600 mg/kg. All administrations were done orally for 18 consecutive days. Spatial learning, memory and learning flexibility were assessed using the Morris water maze. ChAT activity and hippocampal neuronal cell number were assessed by immunohistochemistry and histological methods, respectively. RESULTS: The results demonstrated that T. triandra leaf extract (300 and 600 mg/kg) significantly enhances spatial learning and learning flexibility. Only 300 mg/kg of T. triandra significantly improved the spatial memory. The hippocampal ChAT activity and total hippocampal cell number were significantly increased in T. triandra-treated groups. CONCLUSION: The present study indicated that T. triandra leaf extract improves the spatial learning, memory and learning flexibility, exerts neuroprotective effects on hippocampal neurons and maintains ChAT activity in this brain area.