Grape Skin Extract

 

Grape is used for preventing cardiovascular disease, varicose veins, haemorrhoids, atherosclerosis, hypertension, peripheral vascular disease, oedema associated with injury or surgery, and myocardial or cerebral infarction.

Grape seed is used for diabetes complications such as neuropathy or retinopathy, improving wound healing, preventing dental caries, cancer prevention, age-related macular degeneration (ARMD), poor night vision, liver cirrhosis, allergic rhinitis, and prevention of collagen breakdown.

Grape products contain phenolic compounds including oligomeric proanthocyanidins (OPCs), proanthocyanidins, flavonols, and polyflavan-3-ols. Proanthocyanidins are responsible for producing the red colour of grapes. Red grape varieties provide more antioxidant protection than white or blush grape varieties. Red wine also contains approximately 10 times the amount flavonoids of white wine. Grape flavonoids have a wide variety of effects including antioxidant, vasodilating, anti-lipoperoxidant activity, and antiplatelet properties that might prevent heart disease.

Specific flavonoids in grape products include quercetin, catechin, myricetin, and kaemferol, for antioxidant effects, inhibition of low-density lipoprotein (LDL) oxidation, and vasodilating activity. The flavonoids appear to decrease superoxide production, increase nitric oxide release from platelets, modestly increase the levels of antioxidants such as alpha-tocopherol, and decrease platelet protein-kinase C (PKC) activity.

Studies

Phenolic compounds in grape skins inhibit protein tyrosine kinases, a group of enzymes that play a key role in cell regulation. Compounds that inhibit these enzymes also suppress the production of a protein that causes blood vessels to constrict, thus reducing the flow of oxygen to the heart. This protein, called endothelin-1, is thought to be a key contributing agent in the development of heart disease.

Some evidence suggests that proanthocyanidins from grape seeds can decrease reperfusion injury after cardiac ischemia by removing free radicals. This might also decrease the incidence of cardiac arrhythmias that sometimes occurs in cardiac reperfusion injury.

Preliminary evidence also suggests grape seed proanthocyanidins may provide greater protection against reactive oxygen species, free radical-induced lipid peroxidation, and DNA damage than the combination of vitamin E, vitamin C, and beta-carotene or a combination of vitamin E and vitamin C.