Chronic metabolic effects of novel gut-oriented small-molecule GPR119 agonists in diet-induced obese mice.

Abstract

The pharmacological activation of G-protein coupled receptor-119 (GPR119) modulates glucose, energy, and hepatic lipid homeostasis in type-2 diabetes (T2D). We developed synthetic small-molecule GPR119 agonists targeting gastrointestinal receptors. This study investigates the chronic metabolic effects of lead candidates, ps297 and ps318, individually and in combination with sitagliptin, a dipeptidyl peptidase-IV (DPP-IV) inhibitor, in high-fat diet (HFD)-induced obese (DIO) mice. In a 10-week dose-escalation protocol, DIO mice were orally treated with the investigational agents alone (10-90 mg/kg/day) and in combination with sitagliptin (20 mg/kg/day). Weekly body weight, food intake, and random blood glucose levels were monitored during the treatment phase. Post-treatment, an intraperitoneal glucose tolerance test (ipGTT), estimation of plasma biomarkers and haematological assessment were conducted. The treatment's effect on hepatic steatosis was studied by estimating liver biomarkers and histological examinations. Ten-week sitagliptin combination therapy with the investigational entities restored incretins, insulin, and other metabolic hormonal secretions, accompanied by improved glucose homeostasis and retarded weight gain. Interestingly, monotherapy with investigational agents improved liver health by reducing liver weight, liver enzymes, and inflammation. Hepatic effects were further enhanced by co-administration of sitagliptin, evident by amelioration in hepatic steatosis endpoints such as liver weight, plasma liver enzyme concentrations, hepatic triglycerides (TG), total cholesterol (CHO), hydroxyproline content, and cytokine levels. Histopathological investigations confirmed regression in hepatic steatosis in the combination groups. These findings demonstrate the therapeutic potential of novel gut-oriented GPR119 agonists in combination with a DPP-IV inhibitor to ameliorate metabolic dysfunction-associated steatohepatitis (MASH), warranting further mechanistic investigations.