The objectives of this study were to determine and compare the anti-diabetic and anti-inflammatory effects of Antirrhinum majus L. extract (AME) in high fat diet-fed mice (HFD). C57BL/6 mice were assigned to five groups: ND (n=8; normal diet), HFD (n=8), and HFAME [HFD+100 mg/kg AME (n=10), HFD+300 mg/kg AME (n=8), and HFD+600 mg/kg AME (n=10) groups]. Mice were fed their assigned diets for 8 weeks. Mean body weight in the HFD group was 32% higher than in the ND group, but mean body weights in the HFAME groups were unchanged. Mean food efficiency ratio was higher in the HFD group than in ND controls, but significantly lower in HFD+600 mg/kg AME (n=10) groups than in the HFD group. Furthermore, liver, epididymal fat, and subcutaneous fat weights were lower in the HFAME groups than in the HFD group. In addition, mean plasma triglyceride and total cholesterol levels were significantly higher in the HFD group than in the ND gro12up, and lower in the HFAME groups than in the HFD group. Similarly, mean fasting blood glucose was significantly lower in the HFAME groups than in the HFD group. The serum insulin and glucose concentrations were remarkably lower in the HFAME groups than in the HFD group. Insulin sensitivity was measured by glucose tolerance testing (GTT) and insulin tolerance testing (ITT) after animals had been on their respective diets for 6 weeks, and GTT and ITT results in the HFAME groups were significantly lower than in the HFD group. Furthermore, levels of inflammatory cytokines, that is, of monocyte chemoattractant protein-1, interleukin-6, and interleukin-1β, were lower in the HFAME than in the HFD group. In addition, AME prevented HFD-induced increases in the expressions of pro-inflammatory genes in liver, epididymal adipose tissue, subcutaneous fat. AME improved insulin resistance and exhibited anti-diabetic effects in HFD mice. Our findings suggest AME has potential utility for the prevention of nonalcoholic fatty liver disease.

Keywords: Antirrhinum majus L., diabetes, insulin resistance, inflammatory cytokine, high fat diet