No abstract

Natural plants which are effective in Alzheimer's disease (AD) management are of pharmacological importance, though there is little or no scientific proof for most of their claims. This study sought to evaluate the effect of Hog plum (Spondias mombin) and Ogbo (Parquetina nigrescens) leaves extracts on antioxidant levels and activities of key enzymes linked to cognitive function in scopolamine-induced cognitive dysfunctioned rats. Rats were pretreated with S. mombin (SM) and P. nigrescens (PN) leaves extracts (50 and 100 mg/kg), donepezil (5 mg/kg) for 2 weeks via oral administration before induction of memory impairment via single i.p. administration of scopolamine (3 mg/kg body weight). Experimental rats were subjected to behavioral tests to check for cognitive performance before experiment termination. The activities of hippocampal key enzymes linked to cognitive function were determined. Results showed that pretreatment with SM and PN prevented the cognitive impairment induced by scopolamine. Furthermore, increased cholinesterases, adenosine deaminase (ADA), ATP hydrolysis, monoamine oxidase (MAO), and arginase activities induced by scopolamine were significantly reduced in rats treated with SM and PN leaves extract.Additionally, elevated malondialdehyde (MDA) and reactive oxygen species (ROS) levels observed in scopolamine-induced rats were reduced significantly in SM-and PN-pretreated rats. Decreased AMP hydrolysis, and nitric oxide and antioxidant level induced by scopolamine were prevented in pretreated rats. This study concluded that SM and PN leave extract effectiveness in cognitive management may be due to their high antioxidant activities and neuromodulatory effects on key enzymes linked to AD.