Protective effect of Astragalus on insulitis and apoptosis of islet β cells in mice / 中华实用儿科临床杂志

ABSTRACT

Objective To investigate the protective effect of Astragalus on islet β cell apoptosis in vivo.Methods Fifty-six healthy male mice were divided into control group,diabetic mellitus (DM) group,and Astragalus pretreatment group.After pretreatment with different doses of Astragalus,each group of mice received intraperitoneal injection of Streptozotocin(STZ) in order to induce DM,and then the incidence of DM was observed.Serum nitric oxide (NO)was measured by the nitratase method,the activity of induced nitric oxide synthase(iNOS) was measured by chemical colorimetric method,and insulin level was detected by enzyme linked immunosorbent assay method.Insulitis score was evaluated according to pancreatic histology.Islet β cell apoptosis was measured by using a terminal dexynucleotidyl transferase(TdT)-mediated dUTP nick end labeling assay.Results 1.DM attack began 1 week after STZ injection in DM group.Pretreatment with 30 g/(kg · d) of Astragalus,DM appeared 2 weeks after STZ injection.Compared with DM group,the onset of DM was delayed,and the incidence of DM was significantly reduced(P ＜ 0.01).After pretreatment with 15 g/(kg · d) of Astragalus,the DM began 1 week after STZ injection,compared with DM group,the incidence of DM was reduced,but there was no statistical difference(P ＞ 0.05).2.Compared with DM group,after pretreatment with 30 g/(kg · d) of Astragalus,the activity of iNOS was significantly inhibited(all P ＜ 0.01),and then NO level significantly declined(all P ＜ 0.01),and the insulitis score and apoptosis of β cells were also significantly decreased (all P ＜ 0.01) ;after pretreatment with 15 g/(kg · d) of Astragalus,there was no statistical difference in all the indexes (all P ＞ 0.05).Conclusions Astragalus can protect islet β cells of mice in vivo,which is associated with its inhibition on the iNOS activity,reduction on NO generation,and can decrease β cells insulitis and apoptosis.Therefore,improving the body free radicals scavenger ability may prevent and delay the occurrence of DM.