Effect of Cyperus rotundus tubers ethanolic extract on learning and memory in animal model of Alzheimer

Alzheimer's disease (AD) is a degenerative disorder that leads to progressive cognitive decline. The memory dysfunction of AD has been associated with a cortical cholinergic deficiency and loss of cholinergic neurons of the nucleus basalis of Meynert (NBM). This study investigated the effect of Cyperus rotundus tubers ethanolic extract on learning and memory in the rat model of Alzheimer's and intact rats. In this experimental study, 49 male Wistar rats were divided randomly into seven groups. Wistar rats received bilateral electric lesions of the NBM. The NBM-lesioned rats received Cyperus rotundus tubers ethanolic extract (100 and 200 mg/kg; ip) for 15 days while the control and sham groups received distilled water. Intact rats received extract without any surgery. Passive avoidance learning and memory performance was assessed using passive avoidance paradigm, and Morris water maze test used for spatial learning and memory evaluation. In shuttle box test, the initial latency significantly decreased in Alzh+ CRT (NBM-lesioned rats that received extract) groups. Step through latency significantly increased in Alzh+ CRT groups. In Morris water maze task, in the probe trial, Alzh+ CRT groups demonstrated a significant preference for the quadrant in which the platform was located on the preceding day. The decrease in the escape latency improved significantly in Alzh+ CRT groups when compared with Alzh (NBM-lesioned rats) group. The results suggest that Cyperus rotundus tubers ethanolic extract has some repairing effects on the memory and behavioral disorders produced by lesioning of the NBM in rats.