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 n-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 beta 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), beta-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. (C) 2016 Elsevier B.V. All rights reserved.