The Effects Of Astragalus Polysaccharides On Anti Oxidative Ability And Neuroprotection On The Hippocampus In Immunosuppressed Mice

ObjectiveImmunosuppressed mice model was established by injecting cyclophosphamide(CTX)to detect the effect of Astragalus polysaccharides(Astragalus polysaccharide,APS)on histological changes of hippocampus and expression of Bax and Bcl-2 in hippocampus;by examining body weight and in the Total antioxidant capacity(TAOC),Superoxide Dismutase(SOD),Catalase(CAT)activity and Malonic Aldehyde(MDA)content in liver tissue of 4 groups to detect the damage and recovery mechanism in hippocampus that Bax and Bcl-2 involved by using different doses of APS in immunosuppressed mice,and then explore the effects of Astragalus Polysaccharides on anti-oxidative ability and neuroprotection on the hippocampus in immunosuppressed mice.Method1.Modelling immunosuppressed mice and grouping: 160 healthy male Kunming mice were randomly divided into 4 groups: Control group,Cyclophosphamide(CTX group),Cyclophosphamide + low dose APS group(CTX-L group)and Cyclophosphamide + high dose APS group(CTX-H group).2.Measuring weight once a week;after the last drug treatment,material of the liver tissue of each group was taken and then determined T-AOC,SOD and CAT activity and MDA content by colorimetric method.3.Histological observation: Using Nissl staining(toluidine blue's method)to observe the quantity and morphological change of CA1 and CA3 region in hippocampus in immunosuppressed mice after APS treatment.4.Location of positive immunoreactivity: Immunohistochemistry(IHC)was used to observe the location and amount changes of Bax and Bcl-2 positive immunoreactivity in hippocampal CA1 and CA3 region of each group.5.Quantification of protein expression: Western-blotting(WB)was used to detect the changes of Bax and Bcl-2 protein expression in hippocampus of each group,and Quantity one software was used to analysis Grey value to compare the Bcl-2/Bax ratio change.Result1.From the second week of establishing model,the weight of CTX group was lower than the control group obviously,and there was no difference between the APS group and the control group.2.Astragalus polysaccharide could significantly improve the T-AOC,SOD and CAT activity,decreased MDA content significantly in immunosuppressed mice.3.Nissl staining results showed that the immunosuppression induced by CTX could reduce the number of survival neurons in hippocampal CA1 and CA3 area,and the surviving neurons of CTX-L and CTX-H group was increased significantly.4.Result of IHC: There was a strong Bax expression in CA1 and CA3 in CTX group when compared with control group,and APS administration could decrease the Bax positive expression;the Bcl-2 positive expression of hippocampal CA1 and CA3 area in the CTX-L and CTX-H group were significantly higher than the control group.5.Result of WB: Bax protein expression in rat hippocampus of CTX group were increased than Control group,and Bax protein expression of CTX-L and CTX-H group significantly decreased than CTX group;the Bcl-2/Bax ratio in CTX group in mice hippocampus was significantly lower than the control group,and Bcl-2/Bax ratio in CTX-L and CTX-H group significantly higher than that of CTX group.Conclusion1.APS administration could improve the weight loss in low immune status that caused by CTX.2.APS administration could significantly improve T-AOC,SOD and CAT activity and decrease MDA content in the immunosuppressed mice,regulate the body's immune status by improving the body's redox state.3.APS administration could increase the surviving number of neurons in hippocampal CA1 and CA3 area,repair the damaged neurons;reduce positive expression of Bax of hippocampal CA1 and CA3 area in immunosuppressed mice significantly;the Bcl-2/Bax ratio of hippocampus in APS administration was significantly higher than the CTX group control group,showed that APS may be a potential neuroprotective agent against cell death through the Bax and Bcl-2 mediated pathways in the hippocampus.