Effects of the high-fat and high-cholesterol diet and metformin supplementation on (a) body weight, (b) serum total cholesterol (CHOL), (c) serum triglycerides (TG), (d) serum glucose (GLU), (e) serum insulin level and (f) homeostasis model assessment of insulin resistance (HOMA-IR) in the male mice: Data are expressed as means ± SD. ((a): n = 10–15; (b–f): n = 4–8 per group). * p < 0.05 as determined by one-way ANOVA followed by least significant difference test (LSD) post hoc test. NC, normal diet; HFC, high-fat and high-cholesterol diet; HFC + Met, HFC with metformin supplementation.