Clitorea ternatea, a herb from Indian folklore, improves streptozotocin-induced diabetes and diabetes-induced cognitive decline in rats.

Objective: To study the antidiabetic, neurochemical-antioxidant and cognition protective effects of Clitorea ternatea leaves on a rat model of diabetic cognitive decline.

Methods: Antidiabetic activity was evaluated by serum glucose and body weight estimation in ethanol extract of Clitorea ternatea (EECT)-treated diabetic rats. Effects of EECT on spatial working memory (SWM) and spatial reference memory (SRM) were evaluated by Y-maze and Morris water maze tests respectively. Neurochemical-antioxidant effects of EECT were studied by acetylcholinesterase assay, and measurements of thiobarbituric acid reactive substances (TBARSs), superoxide dismutase (SOD) and catalase (CAT) levels in diabetic rats.

Results: The 200 and 400 mg/kg of EECT showed a significant antidiabetic activity by decreasing serum glucose level (P<0.05, P<0.01), and there was a significant increase in the body weight in 400 mg/kg of EECT-treated diabetic rats (P<0.01). EECT was found to cause significant increases in SWM and SRM in retention trials on Y-maze and Morris water maze respectively (P<0.05, P<0.01). Significant decreases in acetylcholinesterase activity and TBARS level, and significant increase in CAT level were observed in rats treated with 200 and 400 mg/kg of EECT compared with rats in the diabetic control group (P<0.05 or P<0.01). Significant increase was also found in SOD in rats treated with 400 mg/kg of EECT.

Conclusion: Clitorea ternatea exhibits antidiabetic and antioxidant activities, offers the protection against diabetes-induced cognitive decline, and warrants the need for further studies to elucidate its mode of action.