Pterocarpus marsupium heartwood extract restores learning, memory and cognitive flexibility in a STZ-NA induced diabetes animal model

Objective: Study was designed to assess the P.marsupium heartwood aqueous extract effect on diabetes induced cognitive impairment. Methods: Diabetes mellitus was induced by Streptozotocin (STZ) & Nicotinamide (NA) intraperitoneal route injection. Animals were divided into 7 groups for comparing the activity of P.marsupium at two doses 250 mg/kg & 500 mg/kg b. w against standard (Glibenclamide) & controls groups. Rats having blood glucose above 250 mg/dL were considered as diabetic. Learning & memory was tested using Morris water maze. Time taken to reach the platform (escape latencies) by animals was noted from day 1 to 8 and probe trial was conducted on day 9 to record the time spent in the different quadrants. Results: Blood glucose levels were significantly (p<0.001) reduced in plant treated and glibenclamide groups when compared to diabetic controls. Also both the treated groups had decreased escape latencies in learning phase. During probe trial, test and standard treated groups spent significantly more time in target quadrant with less entries into other quadrants compared to untreated diabetic controls. Conclusion: The results of this investigation revealed that extract of P. marsupium provides beneficial effects on learning and memory in diabetes rats by providing the potential antihyperglycemic action.