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.

ObjectiveTo investigate the mechanism of salvianolic acid F （Sal F） in repairing the high glucose-induced injury in human kidney-2 （HK-2） cells via the B-cell lymphoma-2 （Bcl-2）-associated X protein （Bax）/cysteinyl aspartate-specific proteinase 3 （Caspase-3）/gasdermin-E （GSDME） pathway. MethodThe cell counting kit-8 （CCK-8） was used to measure the relative viability of HK-2 cells exposed to high glucose and different concentrations （2.5， 5， 10， 20 μmol·L^-1） of Sal F and the relative viability of HK-2 cells treated with Sal F for different time periods. The levels of lactate dehydrogenase （LDH） and interleukin-1β （IL-1β） in the supernatant of the cell culture were measured by the LDH assay kit and enzyme-linked immunosorbent assay （ELISA） kit， respectively. Flow cytometry combined with Annexin V-FITC/propidium iodide （PI） and Hoechst 33342/PI staining was employed to reveal the proportion of PI-positive HK-2 cells exposed to high glucose. Western blotting was employed to determine the protein levels of Bax， Bcl-2， cytochrome C， cysteinyl aspartate-specific proteinase （Caspase）-9， Caspase-3， and GSDME in the HK-2 cells exposed to high glucose and treated with Sal F. The 2，7-dichlorodihydrofluorescein diacetate fluorescence probe （DCFH-DA） and mitochondrial membrane potential assay kit （JC-1） were used to determine the production of reactive oxygen species （ROS） and the mitochondrial membrane potential in the HK-2 cells exposed to high glucose and treated with Sal F. ResultCompared with the blank group， the model group showed decreased cell viability （P<0.01）， elevated levels LDH and IL-1β， increased proportion of PI-positive cells （P<0.01）， up-regulated protein levels of Bax， cytochrome C， Caspase-9， Caspase-3， and GSDME （P<0.01）， down-regulated protein level of Bcl-2 （P<0.01）， decreased mitochondrial membrane potential， and excessive ROS accumulation. Compared with the model group， Sal F repaired the high glucose-induced injury in HK-2 cells （P<0.05）， lowered the levels of LDH and IL-1β （P<0.05， P<0.01）， and decreased the proportion of PI-positive cells （P<0.01）. In addition， Sal F down-regulated the protein levels of Bax， cytochrome C， Caspase-9， Caspase-3， and GSDME and up-regulated the protein level of Bcl-2 （P<0.05， P<0.01）， increased the mitochondrial membrane potential， and decreased the accumulation of ROS in HK-2 cells. ConclusionSal F can reduce the production of ROS， restore the balance of mitochondrial membrane potential， and inhibit pyroptosis via the Bax/Caspase-3/GSDME signaling pathway to repair the high glucose-induced injury in HK-2 cells.