Effect of Nyctanthes arbor tristis leaf extract against scopolamine-induced cognitive impairment in rats
Nyctanthes arbor tristis (NATE) ethanol extract (150 mg/kg, orally) was evaluated for its protective effect against scopolamine-induced (1 mg/kg i.p.) cognitive impairments in rats using behavioral models like radial arm maze test, Morris water maze test and active avoidance test. NATE effect was evaluated and compared with the standard piracetam (200mg/kg i.p.). NATE (p<0.005) significantly reversed the impairment produced by the scopolamine in radial arm maze test. In addition, NATE also decreased the time period taken to find the hidden platform in Morris water maze test and increased number of avoidances in active avoidance paradigm. Acetylcholinesterase activity and thiobarbituric acid levels were significantly (p<0.005) decreased along with the rise in activities of superoxide dismutase and catalase. This might suggest that the NATE has protective effect against scopolamine-induced cognitive impairment in rats through acetylcholine muscarinic receptor pathway and also antioxidant activity. No significant changes were found in histopathological studies of brain.