Objective To investigate the effects of salidroside (SAL) on myocardial inflammatory cytokines and Hippo signaling pathway-related proteins in diabetes mellitus (DM) rats.Methods Four weeks old male SD rats were randomly divided into 3 groups:blank control group,DM model group (streptozotocin[STZ]group),and SAL intervention group (SAL group),with 5 rats in each group.Rat DM model was induced by intraperitoneal injection of STZ,and SAL was used to treat DM rats.Pathological changes of rat myocardium were observed by hematoxylin-eosin staining and Masson staining,and apoptosis of cardiomyocytes was analyzed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining.The expression of tumor necrosis factor α(TNF-α),interleukin (IL)-1β and IL-6 in myocardial tissues and peripheral blood was evaluated by enzyme-linked immunosorbent assay (ELISA).The expression of Hippo signaling pathway-related proteins was detected by Western blotting,and Yes-associated protein (Yap) mRNA was detected by real-time polymerase chain reaction.Results Compared with the blank control group,the arrangement of cardiomyocytes in the STZ group was disordered,myocardial fibrosis and apoptosis rate (P<0.01) were increased,the expression levels of TNF-α,IL-1β and IL-6 were significantly increased (all P<0.01),the expression of Hippo signaling pathway-related proteins mammalian sterile-20 like protein kinase 1/2(Mst1/2),large tumor suppressor 1/2(Lats1/2) and Yap was increased (P<0.05,P<0.01),the expression of phosphorylated (p)-Mst1/2,p-Lats1/2 and p-Yap was decreased (all P<0.01),Yap/p-Yap ratio was increased (P<0.01),and the expression level of Yap mRNA was also increased (P<0.01).After SAL intervention,myocardial fibrosis and the rate of apoptosis (P<0.01) were decreased,the expression levels of TNF-α and IL-6 were decreased (P<0.05,P<0.01),and the ratio of Yap/p-Yap and the expression of Yap mRNA were decreased (both P<0.01).Conclusion SAL can improve the cardiomyocyte function in DM rats,and the mechanism may be associated with inhibiting inflammatory reaction,reducing cardiomyocytes apoptosis and regulating Yap/p-Yap ratio.