Pyrola incarnata demonstrates neuroprotective effects against β-amyloid-induced memory impairment in mice

Abstract

This study aims to investigate the neuroprotective effects of Pyrola incarnata against β-amyloid-induced memory impairment in mice. Ethanol extract of Pyrola incarnata (EPI) was obtained and led to eleven phytochemicals successfully by isolation and purification, which were elucidated by spectroscopic analysis (1H NMR, 13C NMR and HR-ESI-MS). Thereinto, ursolic acid was gained as most abundant monomer. C57BL/6 mice were intracerebroventricular injected with aggregated Aβ25–35. Open-field test, Barnes maze test and Morris water maze were conducted for evaluating cognition processes of EPI and ursolic acid. EPI significantly improved learning and memory deficits, attenuated the Aβ25–35 level of deposition immunohistochemically. Further studies revealed that ursolic acid as bioactive phytochemical of P. incarnata improved spatial memory performance and ameliorated Aβ25–35 accumulation by activating microglia cells and up-regulating Iba1 level in the hippocampus. These findings suggest P. incarnata could improve the cognition of mice and be a promising natural source for the treatment of neurodegenerative disease.