ABSTRACT
Recent studies have shown that diabetes induced cognitive dysfunction and impairs learning and memory. Palmatine is an isoquinoline alkaloid, and has multiple pharmacological effects, including anti-diabetic and antioxidant activity. This study was conducted, to evaluate the effect of Palmatine on learning and spatial memory impairment in STZ-induced diabetic rats. This experimental study was conducted on the male Wistar rats [n=32] with approximate weight of 240 +/- 40 grams. The rats were randomly allocated and were divided into 4 groups [n=8]: Control, Palmatine-treated non-diabetic, diabetic and Palmatine-treated diabetic groups. Diabetes was induced by STZ administration at the dose of 55 mg/kg through intraperitoneal route. Palmatine hydrochloride was administered subcutaneous at doses of 10 mg/kg/day 1 week after STZ injection for a period of 6 weeks. Blood samples were taken from the tail vein 1, 3, 5, 7 weeks after STZ injection to measure blood glucose levels. Behavioral tests including spatial recognition and objective recognition were performed at the end of study. Data were analyzed by using Prism-5, one way ANOVA and Tukey tests. In spatial recognition test, the number of entrance in new arm of the Ymaze, in the Palmatinetreated groups significantly increased in compare to diabetic group in both sixth and seventh weeks [P<0.05]. Number of rearing in new arm significantly increased in sixth and seventh weeks, compare to the diabetic group [P<0.05]. The number of recognition novel objects in the Palmatine-treated diabetic group significantly increased in compare to diabetic group [P<0.05]. Palmatine hydrochloride administration for 6 weeks improves cognitive dysfunction in streptozotocin-induced diabetic rats