Cholinergic Enhancing and Antioxidant Effect of Vigna subterranea (L.) Verdc. (Fabaceae) Landrace Aqueous Extract on Scopolamine-Induced Amnesia in Male Swiss Mice

Abstract

The present study was conducted to investigate protective effects of the aqueous extract of V. subterranea seeds landrace on amnesia induced by scopolamine in mice. V. subterranea aqueous extract (100, 200 and 400 mg/kg BW) was administered by gavage for nine consecutive days and memory impairment was induced by repeated intraperitoneal injection of scopolamine (1.5 mg/kg). The Y-maze (YM), Morris water maze (MWM), novel object recognition paradigm (NOR) and the T maze (TM) were used to assess learning, memory and retention. Superoxide dismutase (SOD), Catalase (CAT), Malondialdehyde (MDA) levels and Acetylcholine esterase activity was also evaluated in the mice hippocampi homogenates. V. subterranea aqueous extract (400 mg/kg) significantly increased the percentage of spontaneous alternation in the YM task and decreased escape latency in the MWM. Moreover, this dose brought about a significantly improvement in the time spent in the preferred TM arm and discrimination index in the NOR tasks despite repeated scopolamine injection. Additionally, low acetylcholine esterase levels, reduced lipid peroxidation (malondialdehyde) but increased antioxidant enzymes (catalase and superoxide dismutase) activity was observed in hippocampi homogenate of mice pre-treated with the extract. A protective action against hippocampal cell damage was also evident. This finding suggests that the aqueous extract of V. subterranea seed landrace may improve learning and memory.