The effects of lignan-riched extract of Shisandra chinensis on amyloid-beta-induced cognitive impairment and neurotoxicity in the cortex and hippocampus of mouse

Abstract

Ethnopharmacological relevance: The fruits of Schisandra chinensis (Trucz.) Baill. (Schisandraceae) which have been used as a tonic especially for kidney yin deficiency in Chinese traditional medicine are recently receiving attention for its preventive activity on age-related neurodegenerative diseases. A variety of studies demonstrated the cognitive-enhancing effects of Schisandra chinensis through animal tests and also in clinical trials. Aim of study: In this study, we attempted to investigate the effects of the lignan-riched extract of Schisandra chinensis fruits (ESP-806) on neurotoxicity and memory impairment induced by A beta(1-42) injection in mice. Materials and methods: The fruits of Schisandra chinensis were extracted with the mixture of n-hexane:ethanol (9:1), which is riched with bioactive dibenzocyclooctadiene lignans, schizandrin, gomisin N, wuweigisu C. After oral treatment of ESP-806 (100 mg/kg body weight) followed by injection of A beta(1-42) (2 mu g/mouse, i.c.v.), novel object recognition and passive avoidance tests were evaluated. To verify the cognition enhancing effects of ESP-806, we examined the effects of ESP-806 on the activities of beta-secretase and acetylcholinesterase, and the contents of A beta and the reduced glutathione within the cortex and hippocampus of A beta-injected mice. Results: Oral treatment of ESP-806 (100 mg/kg body weight) significantly attenuated A beta(1-42)-induced memory impairment evaluated by behavioral tests. Furthermore, the treatment of ESP-806 attenuated the elevation of beta-secretase activity accompanying the reduced level of A beta(1-42) in the cortex and hippocampus of the brain. ESP-806 also significantly inhibited the acetylcholinesterase activity in the hippocampus and increased the content of the reduced glutathione in the cortex and hippocampus of mouse brain. Conclusions: These data suggested that the extract of Schisandra chinensis fruits riched with dibenzocyclooctadiene lignans may be useful in the prevention and treatment of Alzheimer's disease. (C) 2013 Elsevier Ireland Ltd. All rights reserved.