Present study evaluates the effect of Calotropis procera (Apocynaceae) dry latex on cognitive function in rats using scopolamine and electroconvulsive shock (ECS) induced amnesia model.
Materials and Methods:

Male Wistar rats were pretreated with 200, 400 and 800 mg/kg of C. procera dry latex in scopolamine-induced amnesia model. Dose showing maximum effect in cognitive performance was selected and further evaluated using scopolamine and ECS-induced amnesia model for its effect on neurochemical enzymes and cognitive performance. Acetylcholinesterase (AChE) activity, β amyloid1-42, and dopamine level were analyzed, while the cognitive performance was assessed by elevated plus maze, step-through passive avoidance test, and Morris water maze. Simultaneously, C. procera dry latex (25, 50, 100, 250, 500, and 1000 μg/mL) was screened for in vitro AChE inhibition assay.
Results:

Pretreatment with (200, 400 and 800 mg/kg) C. procera dry latex shows dose dependent increase in cognitive performance in scopolamine-induced amnesia. Further, pretreatment with the selected dose (800 mg/kg) showed significant improvement in transfer latency (P < 0.001, P < 0.01), escape latency (P < 0.05), time spent in target quadrant (P < 0.001) also significant decrease in AChE activity (P < 0.05), β amyloid1-42 level (P < 0.001), and increase in dopamine level (P < 0.01) in rat brain homogenate when compared with scopolamine and ECS disease control groups. IC50 for C. procera dry latex was found to be <1000 μg/mL.