With the development of social economy, the improvement of people's living standards, the change of lifestyle and the aging of social population, the prevalence of diabetes mellitus is on the rise all over the world. It has become another global public health problem seriously endangering human health after cardiovascular and cerebrovascular diseases and tumors. Diabetes is not only characterized by persistent hyperglycemia, but also the damage of vascular complications caused by hyperglycemia. Vascular endothelial cells (VEC) are the first barrier of human blood vessels, which regulate the structure and function of blood vessels. VEC is the first site affected by hyperglycemia. Hyperglycemia can inhibit the migration, proliferation and vascular changes of endothelial cells; A large number of studies have confirmed that endothelial dysfunction, including the imbalance between vasodilator and vasoconstrictor, anticoagulant and procoagulant, or growth inhibitory and growth promoting factors, plays a key role in the occurrence and development of VR. Therefore, the elucidation of the mechanism of early vascular injury is helpful to prevent or delay the occurrence and development of diabetic vascular remodeling, and VEC as an intervention point of vascular remodeling has a good prospect. It is of great significance to open up a new way to treat diabetic vascular complications.

    Grape seed proanthocyanidins is a natural polyphenol compound extracted from grape seeds. It is one of the most powerful free radical scavengers found so far. It has strong antioxidant and anti nonenzymatic glycosylation activities, and has strong cardiovascular protection; As a natural plant component, it has no obvious toxic reaction and is widely used at home and abroad. Among them, dimer is the most widely distributed among all kinds of proanthocyanidins and has the strongest antioxidant activity. Grape seed proanthocyanidin B2 is the main component of GSPE, and the activity of proanthocyanidin B2 in 8 isomers is the strongest.Procyanidin B2 China has applied for a patent in the preparation of drugs for the prevention and treatment of diabetes and vascular complications. Many studies have shown that procyanidins have much stronger anti-oxidation and free radical scavenging abilities than ve and VC. They can prevent and treat a variety of diseases caused by free radicals, including heart disease, arthritis, etc. they also have the function of improving human microcirculation.

    Procyanidins, as natural antioxidants, are becoming more and more popular in drugs, health products and cosmetics because of their strong free radical scavenging ability and cardiovascular system activity. It has become one of the top ten botanical drugs. At present, foreign countries have developed various products and obtained patent protection. Procyanidins are used in Germany and Romania to treat microcirculation diseases; France has invented a preparation for the treatment of periodontal disease with proanthocyanidins oligomers or monomers as active substances and obtained patent protection. In France, grape seed proanthocyanidins are also used to make vascular protectors and anti-inflammatory agents; Germany has developed and patented procyanidins for the treatment of alcoholism. In addition, the anti wrinkle, whitening, moisturizing and anti radiation effects of procyanidins have opened up broad prospects in the field of cosmetics.!