The effect of chlorogenic acid on learning and memory and acetylchoinesterase activity in rats with cognitive deficit induced by intracerebroventricular streptozotocin

Chlorogenic acid (CGA) is a major polyphenolic component of coffee. Reduction in the risk of a variety of diseases following CGA consumption has been mentioned in recent studies. The effect of CGA on learning and memory in rats with cognitive deficit induced by intracerebroventricular streptozotocin (STZ) and acetylchoinesterase (AChE) activity was evaluated in this study. For this purpose, 32 male Wistar rats (250-290 g) were divided into four different groups as: control, control plus CGA, STZ treated group, and CGA-treated STZ group. STZ was injected (bilaterally, 3 mg/kg body weight, on days 1 and 3). CGA was administered through intraperitoneal route at a dose of 50 mg/kg for 14 days started one week after STZ injection. To evaluate the spatial learning and memory, Y maze (alternation behavior) and passive avoidance tests were used. Finally, AChE activity was measured via specific kits in hippocampal homogenate. CGA-treated STZ group did not show significant improvement in spontaneous alternation behavior as compared to STZ group. In passive avoidance test, there was significant difference between STZ and CGA-treated STZ groups. In the latter group, learning and memory was improved. In STZ group, AChE activity as compared to control group significantly increased and treatment with CGA significantly decreased the levels of AChE. Administration of CGA can improve learning and memory in passive avoidance test with apparently no improvement of spatial memory. Also, CGA can modulate the AChE activity in the hippocampus. Therefore, these results demonstrate the effectiveness of CGA in preventing part of cognitive deficits caused by ICV STZ in rats and also show its potential in the treatment of neurodegenerative diseases such as Alzheimer’s disease.