Effects of radix astragali injection (黄芪注射液) on myocardial injury in septic shock rats

Objective: To investigate the effects and mechanism of radix astragali injection(黄芪注射液) on myocardial injury in rats with septic shock.Methods: Septic shock model was replicated by cecal ligation and puncture(CLP).SD rats were randomly divided into three equal groups: sham operation group(group C),septic shock group(group S) and radix astragali group(group R).Group R received radix astragali injection 10 g/kg(containing drug 2 g/ml).Group C and S received the same volume of normal saline only.Heart rate(HR) and mean average pressure(MAP) of three groups were detected continuously 20 hours after operation.Rats were sacrificed at 6 and 20 hours after operation,and the distribution of nuclear factor-κB(NF-κB) in myocardium and contents of malondialdehyde(MDA) were measured.The myocardial pathological changes of rat left ventricle were observed under an optical microscope and ultrastructural organization was detected under an electron microscope.Results: Compared with group C,the MAP gradually decreased and HR gradually increased at 6 hours after CLP(P0.01 and P0.05),and at 20 hours,both MAP and HR markedly decreased(both P0.01) in group S.However,MAP started decreasing at 12 hours(P0.05),and no obvious changes in HR in group R.There was almost no expression of NF-κB in myocardium of group C.The positive cell number and average optical density(OD) value of NF-κB protein was significantly higher in group S than those in group R and C at 6 hours(both P0.01).The positive cells were more in group R than those in group C(P0.05).The changes of NF-κB protein expression were not obvious at 20 hours in group R.The content of MDA was significantly higher in group S than those in group R and C at each time points(all P0.01).Those of group R were slightly higher than those of group C(both P0.05).There were less myocardial injuries in group R than those in group S under optical microscope and electron microscope at the same stages.Conclusion: Administration of radix astragali injection is likely to protect myocardium of rats with septic shock through inhibiting the activity of NF-κB and the release of MDA,preventing excessive inflammatory reaction and immune suppression.