The Effects Of Astragalus Polysaccharide On Isoproterenol-conducted Apoptosis Of Hypertrophy Cardiomyocytes

ObjectiveTo explore the effects of astragalus polysaccharide on isoproterenol-conducted apoptosis of hypertrophy cardiomyocytes and demonstrate the possible mechanism.MethodsAnimal experiment: 45 SD rats were randomly assigned to control group,ISO group,ISO+APS 800mg/kg/d group,ISO+APS 400mg/kg/d group and ISO+APS 200mg/kg/d group.ISO model group and administration groups received ISO(10mg/kg/d)by intraperitoneal injection for 2 weeks.After modeling,control group and ISO group were treated with purified water by intragastric administration for 6 weeks,and administration groups were treated with APS of corresponding concentrations respectively by intragastric administration for 6 weeks.At the end of the eighth week,HMI、LVMI parameters were observed.Pathological sections were made by HE staining and TDM parameters were observed.TUNEL experiment was performed to detect the myocardial apoptosis percentage.Western blot was used to quantify protein expressions of bcl-2、bax and caspase-3.Cell experiment: H9C2 cardiomyocytes were randomly divided into control group,ISO(10umol/L)model group,APS(10ug/ml)group,APS(1ug/ml)group and APS(0.1ug/ml)group.ISO group was treated with ISO 48 h to establish hypertrophy model.APS groups with different dose were administrated with APS for 48 h after treated with ISO for 48 h.Coomassie brilliant blue staining was used to measure total protein content of H9C2.Methyl thiazolyl tetrazolium method was used to determine cell viability of H9C2 cardiomyocyte.Flow cytometry was used to measure cell apoptotis rate.Western blot was used to detect protein expression of bcl-2,bax and caspase-3ResultsAnimal experiment: Compared with control group,the ISO model group markedly elevated the level of HMI,LVMI,TDM,the apoptosis percentage and the protein expressions of bax and caspase-3,meanwhile the protein expression of bcl-2 was markedly decreased.Compared with the ISO model group,APS administration groups decreased the level of HMI,LVMI,TDM,the apoptosis percentage and the protein expression of caspase-3.Cell experiment:Compared with control group,the ISO model group markedly increased total protein content.The flow cytometry results showed that the apoptosis percentage was increased in ISO group.Meanwhile,cell viability was decreased and the protein expressions of bax and caspase-3 were up-regulated while the protein expression of bcl-2 was markedly down-regulated in ISO group.Compared with the ISO model group,APS administration groups decreased total protein content,reduced apoptosis percentage,increased cell viability.In addition,APS(10ug/ml)group and APS(1ug/ml)group down-regulated the protein expression of bax and up-regulated the expression of bcl-2.APS APS(10ug/ml,1ug/ml,0.1ug/ml)could reduced the protein expression of caspase-3.ConclusionAPS could inhibited isoproterenol-conducted apoptosis of hypertrophy cardiomyocytes,which may be related with influencing the protein expressions of bcl-2,bax and caspase-3.