Abstract:The mechanism of Guiqi polysaccharides(GQP) in delaying the aging of rat brain tissue was investigated. 60 SD rats were randomly divided into the control group(Control), model group (Model), GQP low-dose group(LP), GQP medium-dose group(MP), GQP high-dose group(HP), and positive drug resveratrol group(Res).The aging model of rats was established by subcutaneous injection of D-galactose(D-gal). The experimental group and the positive drug group were orally administered GQP and resveratrol, respectively. The activities of total superoxide dismutase(T-SOD) and glutathione(GSH) were determined and the level of malondialdehyde(MDA) and ATP of ratbrain tissues were measured. The pathological changes of brain tissue were observed by hematoxylin-eosin (HE) staining.The change of mitochondrial membrane potential and the degree of swelling of mitochondrial membrane were detected. In addition,the expression levels of Bax and Bcl-2 were tested by immunohistochemical method. The results showed that D-gal significantly reduced the levels ofT-SOD, GSH and ATP in brain tissues of rats, and significantly increased the content of MDA(P<0.05). However, GQP and Res reversed the above indicators(P<0.05). There were insignificant pathological changes of brain tissue in normal rats, but the nuclei in model group were significantly enlarged and deep-stained, and GQP significantly alleviated the above-mentioned lesions. Compared with the control group, the mitochondrial membrane potential, ATP content and Bcl-2 expression were significantly decreased(P<0.01), while the mitochondrial membrane was significantly swollen and the expression of Bax was increased in model group(P<0.01). Meanwhile, GQP and Res increased the mitochondrial membrane potential, ATP content and Bcl-2 expression (P<0.05), but decreased the swelling of mitochondrial membrane and the expression of Bax(P<0.05).Consequently, it was suggested that GQP might play a role in delaying aging by reducing the oxidative damage and changing the mitochondrial function.
