Polysaccharides from Pleurotus ostreatus alleviate cognitive impairment in a rat model of Alzheimer’s disease

This study was conducted to evaluate the effects of polysaccharides extracted from Pleurotus ostreatus (POP) on d-galactose and AlCl3-induced cognitive impairments. A behavioral test suggested that POP significantly decreased escape latency and increased crossing parameters of platform quadrant in a Morris water maze test. Furthermore, POP decreased error numbers and increased passive avoidance latency in a step-down test. Biochemical examinations revealed that POP significantly elevated superoxide dismutase, glutathione peroxidase, and catalase activities; and reduced malondialdehyde levels and acetylcholinesterase activity. Moreover, POP could decrease amyloid β peptide formation and tau phosphorylation by elevating the expression of protein phosphatase 2A as well as by reducing the expression of amyloid precursor protein (APP), β-site APP clearing enzyme1, and glycogen synthase kinase 3beta. These findings provide scientific evidence to support the exploitation of POP as a safe and effective drug to prevent and treat Alzheimer's disease.