ABSTRACT
Objective To test the hypothesis that astaxanthin may protect the plasma membrane from oxidative damage induced by hydrogen peroxide(H_2O_2).Methods Using H_2O_2- induced red blood cells damage as the model of oxidative damage of the plasma membrane,the protective effect of astaxanthin(1.0?10~(-7)、1.0?10~(-6)、1.0?10~(-5)mol?L~(-1)) on oxidated erythrocyte ghost was observed by the measurement of the haemolysis of the erythrocyte,the morphology of the erythrocyte,the content of malonidial aldehyde(MDA),the enzymatic activity of the superoxide dismutase(SOD),the membrane fluidity and the blocking degree.Results The rate of hematolysis and erythrocyte MDA content were increased significantly and SOD activity,membrane fluidity and blocking degree of the erythrocyte were decreased owing to the use of H_2O_2.When the astaxanthin was pretreated,the rate of hematolysis and MDA content of erythrocyte were decelerated obviously and the erythrocyte SOD activity,erythrocyte membrane fluidity and blocking degree were accelerated obviously.Conclusion Astaxanthin showed protective effect on the oxidative damage of plasma membrane induced by H_2O_2, and the possible mechanism was relevant with its antioxidation.
ABSTRACT
Objective To study the effects of D-glucosamine hydrochloride on the apoptosis of gastric carcinoma cell line SGC-7901 and its mechanism.Methods SRB assay was used to examine the effects of D-glucosamine hydrochloride on the growth inhibition of SGC-7901.The cell-cycle and expression of cytochrome-C were observed by flow cytometry,the concentrations of intracellular Ca2+ was determined by CLSM and the expressions of cyclinB1,calcinerin were investigated by Western-Blot.Results D-glucosamine hydrochloride could block SGC-7901 cell-cycle at S phase of cell division,increase the concentration of intracellular Ca2+ and decrease the expression of cyclinB1,the expressions of calcinerin and cytochrome-c were increased respectively.Conclusion Block of cell-cycle may be one of the mechanism of inducing cell apoptosis by D-glucosamine hydrochloride.
ABSTRACT
Objective To study the effect of GAH on lymphocytes proliferation and its mechanism. Methods MTT, fluorescence probe and immunofluorescent methods were used to investigate the effects of GAH on the lymphocytes proliferation, intracelluar Ca2+ concentration and expression of calcineurin(CaN). Results GHA induced lymphocyte proliferation, raised the intracelluar Ca2+ concentration and calcineurin expression. Conclusions GAH is a new kind of activator, which can induce lymphocyte proliferation through Ca2+ signal pathway.