Antihyperglycemic effect of extra virgin sacha inchi oil in type 2 diabetic rats: Mechanisms involved in pancreatic β-cell function and apoptosis

The purpose of the study was to investigate the anti-hyperglycemic effect of extra virgin sacha inchi oil (EVSIO) and its possible mechanisms and actions against pancreatic β-cell death and dysfunction in type 2 diabetic (T2D) rats. T2D rats were induced with a high-fat diet and low-dose of streptozotocin. The rats were then treated for 5 weeks with EVSIO (0.5, 1, and 2 ml/kg), or pioglitazone. Biochemical and histopathological studies, oxidative and inflammatory markers, and expression of apoptotic-related proteins were then evaluated. EVSIO treatment exhibited a dose-dependent reduction of fasting blood glucose, area under the curve of glucose, total cholesterol, and triglyceride levels in the diabetic rats, while improved pancreatic β-function was demonstrated by increasing pancreatic and serum insulin levels. EVSIO treatment effectively lowered atrophic pancreatic islets and reduced the level of serum and pancreatic MDA in the diabetic rats. In addition to serum and pancreatic GPx activities in the diabetic rats, EVSIO also augmented serum SOD. Increased levels of NF-κB, TNF-α and IL-6 present in the diabetic rats were greatly reduced by EVSIO treatment. Furthermore, EVSIO revealed an anti-apoptotic effect on the diabetic rat pancreas by upregulating Bcl-2, and downregulating Bax and cleaved caspase-3 protein expression. The overall study results demonstrated the potential anti-hyperglycemic effect of EVSIO in the diabetic rats. The beneficial effects of EVSIO may be attributed to its ability to improve pancreatic β-cell function and ameliorate β-cell apoptosis by inhibiting oxidative stress and inflammatory cytokines.