Common Name Grape Seed

Latin Binomial Vitis vinifera L.
Family: Vitaceae

Part Used Seed

Active Constituents Grape seed extract is a source of proanthocyanidins.
Proanthocyanidins are polyphenol oligomers derived from flavan-3-ols and flavan-3,4-diols.
Stilbenes
Resveratrol
Polydatin
Pterostilbene
Anthraquinones
Emodin

Side Effects None known. Long-term studies are needed.

Dosage Grape seed extract can be taken as tablets or capsules. These supplements should contain about 95% proanthocyanidins. While no daily dose is set, trials have used 100-300mg per day.

Herbal Use/Indication Grape seed extract is used as an antioxidant, to prevent coronary heart disease (CHD), stroke, and to strengthen capillaries and improve circulation to the extremities. (42)
Grape seed extract is often used to treat conditions associated with vascular function such as diabetes mellitus, varicose veins, impotence, and tingling in the arms and legs. (42)

Pharmacological Action Proanthocyanidins are believed to have the following effects:

Antioxidant: neutralizing free radicals, blocking lipid peroxidation and stabilizing cell membranes.
Inhibit the destruction of collagen by stabilizing the activity of 1-antitrypsin. 1-antitrypsin inhibits the actions of destructive enzymes.
Inhibit the release of histamine and prostaglandins.
Inhibit platelet aggregation.

Contra-Indications Proanthocyanidins inhibit platelet aggregation, and thus patients with bleeding disorders should use grape seed extract with caution. Additionally, patients should not use grape see extract for more than 14 days before surgery.
Pregnancy and lactation
Since there have been an insufficient number of studies on grape seed extract, caution should be used when pregnant or lactating.
Drug-Interactions
Caution should be used in patients who are taking anticoagulants, aspirin, and anti-platelet drugs.

Summary Preliminary evidence suggests that grape seed extract may reduce serum cholesterol levels, improve vascular function, and act as an anti-oxidant. However, more studies are needed.

Mason P. Dietary Supplements. Third edition. Grayslake, Il. Pharmaceutical Press; 2007. 387p.