Catechin prevents endothelial dysfunction in the prediabetic stage of OLETF rats by reducing vascular NADPH oxidase activity and expression.

Objectives: In the prediabetic stage, hyperinsulinemia or insulin resistance is thought to be closely associated with oxidative stress, which is also the main contributor of endothelial dysfunction. Clinical studies have indicated that regular intake of green tea reduces the risk of cardiovascular diseases. This study examined whether catechin prevents endothelial dysfunction and hyperglycemia in the prediabetic stage of a type 2 diabetic (T2D) rat, the Otsuka Long-Evans Tokushima Fatty (OLETF) model.