INS and diabetes mellitus: Tea or tea extract was reported to increase the antioxidant capacity of serum in diabetes [27, 28], exert neuroprotective properties in DR [29], inhibit ocular neovascularization and vascular permeability [30], reduce systolic blood pressure and enhance both endothelial function and insulin sensitivity [31], and slow down age-related decreases in HDL-C concentrations [32].