INS and diabetes mellitus: Compared with the control group, rats from the diabetes mellitus + vehicle group showed high fasting blood glucose (4.7 ± 0.9 mmol/L vs 13.1 ± 1.7 mmol/L, P < 0.05), high non‐fasting blood glucose (8.3 ± 2.3 mmol/L vs 22.3 ± 2.5 mmol/L, P < 0.05), high glycated hemoglobin levels (4.36 ± 0.29% vs 7.65 ± 0.75%, P < 0.05) and decreased insulin levels (2.50 ± 0.38 ng/mL vs 0.56 ± 0.14 ng/mL, P < 0.05) after 3 months.