DKS-26

Glucagon‐like peptide‐1 (GLP‐1) is an important target for diabetes therapy based on its key role in maintaining glucose and lipid homeostasis. This study was designed to investigate antidiabetic and hepatoprotective effects of a novel oleanolic acid derivative DKS26 in diabetic mice and elucidate its underlying GLP‐1 related antidiabetic mechanisms in vitro and in vivo.

The therapeutic effects of DKS26 were investigated in streptozotocin (STZ)‐induced and db/db diabetic mouse models. Levels of plasma glucose, glycosylated serum protein (GSP), lipid profiles, insulin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), oral glucose tolerance (OGT), pancreatic islets and hepatic histopathological morphology, liver lipid levels and expression of pro‐inflammatory cytokines were assessed. Intestinal NCI‐H716 cells and diabetic models were used to further validate its potential GLP‐1‐related antidiabetic mechanisms.

DKS26 treatment (100 mg·kg−1·day−1 ) decreased plasma levels of glucose, GSP, ALT and AST; ameliorated OGT and plasma lipid profiles; augmented plasma insulin levels; alleviated islets and hepatic pathological morphology; and reduced liver lipid accumulation, inflammation and necrosis in vivo. Furthermore, DKS26 enhanced GLP‐1 release and expression, accompanied by elevated levels of cAMP and phosphorylated PKA in vitro and in vivo.

DKS26 exerted hypoglycaemic, hypolipidaemic and islets protective effects, which were associated with an enhanced release and expression of GLP‐1 mediated by the activation of the cAMP/PKA signalling pathway, and alleviated hepatic damage by reducing liver lipid levels and inflammation. These findings firmly identified DKS26 as a new viable therapeutic option for diabetes control.

Acute kidney injury (AKI) is a common critical clinical disease with high morbidity and mortality rates. Ischemia-reperfusion (IR) is the main cause of AKI, and there is no effective treatment or prevention. Therefore, it is critical to screen for effective therapeutic agents and to find therapeutic targets. DKS26 is a derivative of oleanolic acid (OA) optimized for bioavailability while retaining the anti-inflammatory, antioxidant, and anti-apoptotic properties of OA. This study aimed to investigate the therapeutic effects of DKS26 on AKI and its underlying molecular mechanisms. We established an AKI model in vivo and in vitro and observed that DKS26 had an ameliorative effect on IR or H/R-induced renal tubular epithelial cell injury and reduced oxidative stress, inflammation, and apoptosis. Meanwhile, Swiss TargetPrediction and AutoDock Vina analysis revealed that DKS26 may interact with vitamin D receptors (VDR) through hydrogen bonding, suggesting that DKS26 may exert effects through VDR. In this study, we found that DKS26 treatment enhanced the stability of the VDR protein, promoted the binding of VDR to p-NF-κB P65Ser311, reduced the entry of p-NF-κB P65Ser311 into the nucleus, and inhibited the transcription of downstream inflammatory genes as well as their own expression, thus exerting its protective effect. In summary, these findings suggest that DKS26 may be a promising preventive strategy and provide a theoretical and experimental basis for AKI treatment.