Preventive and curative effect of Trigonella foenum-graecum L. seeds in C57BL/6J models of type 2 diabetes induced by high-fat diet

Trigonella foenum-graecum L. (TFG) is traditionally used to treat diabetes in North Africa. we therefore tested the effects of the hydro-alcoholic extract of TFG seeds in a C57/BL6J mouse model of diabetes induced by a standardised high-fat diet (HFD). Plant extracts (2 g/kg daily) were administered orally by gavage at the start of HFD, or after confirmation of established diabetes (17th week), for 20 or 18 weeks, respectively, to male C57BL/6J mice. Animals were weighed; food intake and plasma glucose, lipid profile, insulin and insulin resistance were measured. TFG extracts opposed the development of diabetes: compared with untreated HFD mice, TFG-treated HFD mice had lower mean (±SD) plasma glucose (129.3±39.4 vs. 183.1±19.1 mg/dL, p<0.05), plasma insulin (1.3±0.8 vs. 3.1±1.8 ng/mL, p<0.05) and triglycerides (18.9±12.9 vs. 48.9±12.1 mg/dL, p<0.05), and less insulin resistance as estimated by the homeostasis model assessment (HOMA: 9.7±11.1 vs. 38.3±26.6, p<0.05). In mice with established diabetes, TFG reduced fasting plasma glucose (170.4±24.1 vs. 229.0±20.8 mg/dL, p<0.05), plasma insulin (1.7± 1.3 vs. 3.3±14.3 ng/mL, p<0.05) and insulin resistance (HOMA: TFG: 19.2±15.7 vs. HFD control: 38.5±30.3, p<0.05). In addition, administration of TFG extract also caused significant reduction in triglycerides (17.9±9.7 vs. 62.8±18.3 mg/dL, p<0.05) and total cholesterol (1.30±0.20 vs. 1.80±1.10 g/L, p<0.05), and an increase in HDL-cholesterol (1.6±0.2 vs. 1.2±0.1 g/L). The plant extract had no effect on calorie intake or body weight. TFG extract opposed the development of experimental HFD diabetes in mice, and had an anti-diabetic effect in mice with established diabetes.