INS and type 2 diabetes mellitus: In this experiment, a high-fat diet combined with intraperitoneal injection of streptozotocin (STZ) was used to induce T2DM in male SD rats28–30(high-fat diet leads to increased adiposity and insulin resistance, and the combination of STZ destroys the pancreatic β-cells and reduces insulin secretion, which together exacerbate the accumulation of lipid and metabolic disorders).