Objective To investigate the mechanism of astragaloside Ⅰ,the active constituent of milkvetch root,in inhibiting podocyte injury and improving diabetic kidney disease.Methods According to the body weight,60 male db/db mice were randomly divided into the model group,astragaloside Ⅰ low-dose group(10 mg/kg),astragaloside Ⅰ medium-dose group(20 mg/kg),astragaloside Ⅰ high-dose group(40 mg/kg),and valsartan group(10mg/kg),with 12 mice per group.Twelve db/db littermate control db/m mice were used as the control group.The drug was administered by gavage for 8 weeks.Transmission electron microscope was used to observe the ultrastructure of the kidney;immunohistochemistry and Western blotting were used to detect the expression of nephrotic protein(nephrin),a marker of renal podocytes;enzyme-linked immunosorbent assay was used to detect the contents of interleukin-1β(IL-1β)and interleukin-18(IL-18)in the serum of mice;Western blotting was used to detect the protein expressions of NOD-like receptor thermoprotein domain-related protein 3(NLRP3),cysteinyl aspartate specific proteinase 1(Caspase-1),and Gasdermin D(GSDMD)in kidney tissue.Results Compared with the control group,the glomeruli of the model group showed obvious podocyte loss and foot process fusion;the protein expression of nephrin was decreased(P＜0.05);the contents of IL-1 β and IL-18 in serum were increased(P＜0.05);the protein expressions of NLRP3,Cleaved-Caspase-1,and GSDMD-N were increased(P＜0.05).Compared with the model group,the renal pathological damage in the astragaloside Ⅰ administration groups were alleviated;the protein expression of nephrin was increased(P＜0.05);the contents of IL-1β and IL-18 in serum were decreased(P＜0.05);the protein expressions of NLRP3,Cleaved-Caspase-1,and GSDMD-N were decreased(P＜0.05).Conclusion Astragaloside Ⅰ may play a role in intervening diabetic kidney disease by inhibiting pyroptosis and improving podocyte injury.