Abstract:

Objective To investigate the protective effects of Angelica Sinensis polysacchairides (ASP) on the testis of aging mice induced by D-galactose(D-Gal) and its mechanism. Methods Forty male C57BL/6 J mice were randomly divided into the normal,ASP normal,aging model and ASP aging model groups,with 10 mice in each group.The aging model group mice were subcutaneously injected with D-Gal(120 mg/kg，qd×42);the normal group mice were subcutaneously injected with saline of the same dose at the same time;the ASP normal group mice were subcutaneously injected with the same amount of saline,qd×15,and following intraperitoneally injected with ASP(140 mg/kg，qd×27);the ASP aging model group were the same as the aging model group, from the 16th day of establishment of the aging model group on, the mice were subcutaneously injected with the same dose and the same time of ASP.The 2nd day after model establishment,peripheral blood was collected from the inner canthus vein and the content of serum testosterone was measured;the testes were sampled and testicular index determined; paraffin sections and HE staining of the testes were prepared,the testis histopathology was observed;frozen sections of the testes were prepared,the aging of testicular cells was detected by senescence associated-β-galactosidase(SA-β-Gal) staining;the tissue homogenate of testes was prepared,the activity of superoxide dismutase(SOD) was evaluated by enzymatic method ,the total antioxidant capacity(T-AOC) was detected by 2,2’-amino-di(3-ethyl-benzothiazoline sulphonic acid-6) ammonium salt(ABTS),the content of malondialdehyde(MDA) was measured by thiobarbituric acid method ;the expression of aging-related proteins P53 and P21 was detected by Western blotting. Results There is no significant difference in the wet weight of testis and the index of testicular organs in the groups,but the testicular tissue structure of the aging model group was obviously damaged.The layers of the spermatogenic cells in seminiferous epithelium,the testicular interstitial cells and the serum testosterone level significantly decreased;the positive cells detected by SA-β-Gal stain markedly increased;the activity of superoxide dismutase(SOD) and the total antioxidant capacity(T-AOC) obviously decreased,while the content of malondialdehyde(MDA) increased significantly;and the expression of P53 and P21 was evidently up-regulated.Compared the ASP aging model group with the aging model group,the testicular tissue structure was not obviously damaged.The number of the spermatogenic cells,the testicular interstitial cells and the serum testosterone level decreased less evidently,the SA-β-Gal stain positive cells decreased significantly;the activity of superoxide dismutase(SOD) and the total anti oxidant capacity(T-AOC) increased significantly,while the content of malondialdehyde(MDA) decreased significantly;and the expression of P53 and P21 was remarkably down-regulated. Conclusion ASP can antagonize testis aging induced by D-galactose in mice.Inhibition of oxidative stress damage and the expression of senescence-associated genes may be the underlying mechanism.

Key words: Angelica Sinensis polysacchairides, D-galactose, Testicular protection, Oxidative stress damage, Western blotting, Aging mouse