In the context of type 2 diabetes and metabolic syndrome, catechins regulate blood glucose by improving insulin sensitivity and suppressing the expression of key gluconeogenic enzymes in the liver, as shown in Figure 3B,C; their antioxidant and anti-inflammatory actions alleviate adipose tissue inflammation, reduce hepatic steatosis and inflammation, improve insulin resistance, and promote fatty acid oxidation and energy metabolism via AMPK pathway activation. Here, INS is linked to type 2 diabetes mellitus.