Introduction: We recently demonstrated that Salacia Chinensis Extract (SCE) inhibits alpha-glucosidase, pancreatic lipase and HMG CoA reductase.
Hypothesis: We hypothesized that SCE may regulate glucose metabolism and down regulate NF-κB. In this study, we observed changes in liver protein expression levels of GLUT-2, PPAR-gamma, p-IRS-1, Nrf2 in rats fed with SCE and a high-fat diet and HFD/STZ.
Methods: Eight week old male Wistar rats (six groups) were treated as follows: Group I control group (non-diabetic rats) fed a regular diet; Group II rats fed regular diet and administrated with SCE (100 mg/kg BW per day); Group III rats fed a high fat diet (HFD; 42% of calories from fat); Group IV rats fed a HFD and administrated with SCE (100 mg/kg BW); Group V rats fed a HFD and then injected streptozotocin (STZ, 40 mg/kg, i.p.) and Group VI rats treated as the previous group (HFD+STZ) and then were administered SCE (100 mg/kg BW per day). All animal procedures were approved by the Animal Experimentation Ethics Committee of Firat University. Blood analysis for glucose, insulin, triglycerides (TG), cholesterol (CHOL), free fatty acids, Serum MDA and liver MDA a marker of oxidative stress, and serum total antioxidant capacity (TAC) were estimated. Glucose transporter 2 (GLUT-2), Peroxisome proliferator-activated receptor gamma (PPAR-γ), p-insulin receptor substrate 1 (p-IRS-1), and nuclear factor (erythroid-derived 2)-like 2 (Nrf2), nuclear factor kappa B (NF-κB) proteins in liver and kidney tissues were evaluated by Western blotting.
Results: As shown in Table, HFD and STZ treatment significantly decreased body weight compared with other treatments. A significant decrease in glucose, insulin, lipid profile, MDA and increase in TAC were observed in SCE treatment groups. Additionally, an increase in protein levels of GLUT2, PPARγ, p-IRS, Nrf2 in liver and kidney of rats (P< 0·05) and a decrease in liver and kidney NF-kB levels (P< 0·05) were observed by administration SCE in the treatment groups.
Conclusion: These results suggest SCE may modulate glucose and lipid metabolism by regulation of glucose transporters and NF-kB and Nrf2 pathway.