Effects of a fermented buckwheat flower and leaf extract on the blood glucose and lipid profile of type 2 diabetic db/db mice.

Objective To determine the efficacy of a fermented buckwheat flower and leaf extract (EFBFL) for the reduction of blood glucose and lipid dysregulation in spontaneously obese type 2 diabetic db/db mice, and to explore the possible mechanisms involved. Methods Forty 9-week-old male db/db mice were randomly allocated to a high-dose EFBFL group (EFBFL-H), a low-dose EFBFL group (EFBFL-L), a metformin hydrochloride positive control group (MEG), and a db/db control group (MG), and there was also a db/m negative control group (NCG) (n = 10). Oral glucose tolerance tests (OGTT) were performed after 7 weeks of treatment. At the end of 8 weeks of treatment, random blood glucose (RBG), glycosylated hemoglobin (HbAlc), fasting plasma glucose (FPG), fasting serum insulin (FINS) , triglyceride (TG), serum total cholesterol (TC), free fatty acids (FFA), high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol (LDL-c) were measured, the homeostasis model assessment-insulin resistance (HOMA-IR) was calculated. Immunohistochemistry and western blotting measured the expression of glucose transporter4 (GLUT4) and peroxisome proliferator-activated receptor γ (PPAR-γ) by in skeletal muscle. Results The MG mice had a significantly increased in RBG, HbAlc, the HOMA-IR level, the serum of TG, TC, LDL-c, but a decreased in glucose tolerance and the protein expression of GLUT4 and PPAR-γ compared with the NCG. Compared with the MG, EFBFL groups significantly decreased RBG, HbAlc, and the HOMA-IR level, increased glucose tolerance. Meanwhile EFBFL groups reduced the serum TG, TC, and LDL-c in a dose-dependent manner. In addition, EFBFL increased the protein expression of GLUT4 and PPAR-γ in the skeletal muscle of db/db mice. There was significant difference between the MG group and EFBFL groups. Conclusion These findings suggest that EFBFL has anti-diabetic effects in db/db mice, ameliorating glucose intolerance, lipid dysregulation, and insulin resistance.