LAUSR

BACKGROUND The therapeutic properties of Hippophae rhamnoides L. were already known in ancient Greece as well as in Tibetan and Mongolian medicine, which was commonly used for treatment of heart ailments, rheumatism, and brain disorders. Modern studies have indicated that Hippophae rhamnoides L. polysaccharide (HRP) can improve the cognitive impairment in mice with Alzheimer's disease (AD), but the specific mechanisms of the protective effect of HRP were not fully elucidated. RESULTS Our results showed that HRPI improved the pathological behaviors related to memory and cognition, and reduced Aβ peptide deposition and neuronal cell necrosis. In addition, pretreatment with HRPI decreased the level of TLR4 and MyD88, and reduced the release of inflammatory factors TNF-α and IL-6 in the brain of AD mice. Furthermore, the treatment with HRPI suppressed the expression level of Keap1, and increased the levels of Nrf2, antioxidant enzymes SOD and GSH-Px in the brain of AD mice. CONCLUSIONS On the whole, these findings revealed that HRPI could improve the learning and memory ability and attenuate the pathologic impairment in AD mice, and the underlying mechanisms may involve in mediating the oxidative stress and inflammatory, possibly through the regulation of Keap1/Nrf2 and TLR4/MyD88 signaling pathways. This article is protected by copyright. All rights reserved.