The effects of soyferment-tempeh on lipid profile, retinol-binding protein 4 (RBP4), and phosphoenolpyruvate carboxykinase (PEPCK) gene expression in type 2 diabetic mice

Abstract

Type 2 diabetes can cause oxidative stress leading to the accumulation of reactive oxygen species. Soyferment-Tempeh, a fermented soybean product with aerobic and anaerobic R. oligosporus incubation has a high content of isoflavones, which are antioxidants that can regulate oxidative stress in diabetes. In this study, we evaluated the effects of Soyferment-Tempeh on lipid profile and the expression of Retinol binding protein 4 (RBP4) and Phosphoenolpyruvate Carboxykinase (PEPCK) genes in type 2 diabetic mice model. A total of 30 eight-week-old mice were divided into the following six groups: Nondiabetic, diabetic mice, diabetic mice with metformin, and diabetic mice with Soyferment-Tempeh doses of 10, 20, or 40 mg/100 g BW/day, respectively. Treatments were administered orally by gavages. Before and after 3 weeks of treatment, blood was drawn to measure blood glucose levels and lipid profiles. After sacrificing the mice, livers were used for the assessment of RBP4 and PEPCK gene expression. In streptozotocin-induced diabetic mice, supplementation with three separate doses of Soyferment-Tempeh for 21 days decreased blood glucose, total cholesterol, triglycerides, low-density lipoprotein (LDL) level, atherogenic index, and increased high-density lipoprotein (HDL) level significantly (p<0.001). RBP4 gene expression was significantly lower in the Soyferment-Tempeh of dose 10mg/100g BW treatment groups (p<0.05), but PEPCK gene expression was not significantly different (p>0.05). These results demonstrated that supplementation with Soyferment-Tempeh decreases blood glucose level, atherogenic index, improves lipid profile, and decreases RBP4.