Grape seed extract

Grape seed extracts are industrial derivatives from whole grape seeds. Typically, the commercial opportunity of extracting grape seed constituents has been for chemicals known as polyphenols, including oligomeric proanthocyanidins recognized as antioxidants.

Potential anti-disease effects

Human case reports and results from laboratory and animal studies show that grape seed extract may be useful to treat heart diseases such as high blood pressure and high cholesterol. [ [http://www.ncbi.nlm.nih.gov/pubmed/12628506 Bagchi D, Sen CK, Ray SD, Das DK, Bagchi M, Preuss HG, Vinson JA. Molecular mechanisms of cardioprotection by a novel grape seed proanthocyanidin extract. Mutat Res. 2003 Feb-Mar;523-524:87-97.] ] By limiting lipid oxidation, phenolics in grape seeds may reduce risk of heart disease, such as by inhibiting platelet aggregation and reducing inflammation. [ [http://www.ncbi.nlm.nih.gov/pubmed/16160595 Vitseva O, Varghese S, Chakrabarti S, Folts JD, Freedman JE. Grape seed and skin extracts inhibit platelet function and release of reactive oxygen intermediates. J Cardiovasc Pharmacol. 2005 Oct;46(4):445-51] ] While such studies are promising, more research including long-term studies in humans is needed to confirm initial findings.

A polyphenol contained in grape seeds is resveratrol which may interfere with cancer cell growth and proliferation, as well as induce apoptosis, among a variety of potential chemopreventive effects. [ [http://www.ncbi.nlm.nih.gov/pubmed/18550275 Kundu JK, Surh YJ. Cancer chemopreventive and therapeutic potential of resveratrol: Mechanistic perspectives. Cancer Lett. 2008 Jun 10. [Epub ahead of print] ]

Grape seed components may also be active against HIV by inhibiting virus expression and replication. [ [http://www.ncbi.nlm.nih.gov/pubmed/12462994 Nair MP, Kandaswami C, Mahajan S, Nair HN, Chawda R, Shanahan T, Schwartz SA. Grape seed extract proanthocyanidins downregulate HIV-1 entry coreceptors, CCR2b, CCR3 and CCR5 gene expression by normal peripheral blood mononuclear cells. Biol Res. 2002;35(3-4):421-31] ]

Preliminary research shows that grape seed extract may have other possible anti-disease properties, such as in laboratory models of

* wound healing -- grape seed proanthocyanidins induced vascular endothelial growth factor and accelerated healing of injured skin in mice. [ [http://www.ncbi.nlm.nih.gov/pubmed/12374620 Khanna S, Venojarvi M, Roy S, Sharma N, Trikha P, Bagchi D, Bagchi M, Sen CK. Dermal wound healing properties of redox-active grape seed proanthocyanidins. Free Radic Biol Med. 2002 Oct 15;33(8):1089-96.] ]
* tooth decay -- seed phenolics may inhibit oral sugar metabolism and retard growth of certain bacteria causing dental caries. [ [http://www.ncbi.nlm.nih.gov/pubmed/17713333 Smullen J, Koutsou GA, Foster HA, Zumbé A, Storey DM. The antibacterial activity of plant extracts containing polyphenols against Streptococcus mutans. Caries Res. 2007;41(5):342-9.] ]
* osteoporosis -- grape seed extracts enhanced bone density and strength in experimental animals. [ [http://www.ncbi.nlm.nih.gov/pubmed/15951633 Yahara N, Tofani I, Maki K, Kojima K, Kojima Y, Kimura M. Mechanical assessment of effects of grape seed proanthocyanidins extract on tibial bone diaphysis in rats. J Musculoskelet Neuronal Interact. 2005 Jun;5(2):162-9.] ]
* skin cancer -- grape seed proanthocyanidins decreased tumor numbers and reduced the malignancy of papillomas. [ [http://www.ncbi.nlm.nih.gov/pubmed/18384090 Katiyar SK. Grape seed proanthocyanidines and skin cancer prevention: Inhibition of oxidative stress and protection of immune system. Mol Nutr Food Res. 2008 Apr 2;52(S1):71-76] ]
* ultraviolet damage to skin -- dietary proanthocyanidins may protect against carcinogenesis and provide supplementation for sunscreen protection. [ [http://www.ncbi.nlm.nih.gov/pubmed/16465310 Baliga MS, Katiyar SK. Chemoprevention of photocarcinogenesis by selected dietary botanicals. Photochem Photobiol Sci. 2006 Feb;5(2):243-53] ]

Currently, there are four clinical trials underway to assess the effect of grape seed extracts on human breast cancer, blood estrogen levels in postmenopausal women, and coronary artery disease. [ [http://clinicaltrials.gov/ct2/results?term=grape+seed Search results for grape seed extracts, ClinicalTrials.gov, a service of the US National Institutes of Health] ]

Dosage, precautions and interactions

Oral grape seed extract is typically used as capsules or tablets usually containing 50 mg or 100 mg, or as a liquid to add drops to water and/or other drinks. Insufficient scientific information is known, however, about how long-term use of grape seed extract might affect health or any disease.

In a 12-month study, the safety of dietary intake of grape seed proanthocyanidins in a dose of 100 mg per kg per day was demonstrated in rodents. [ [http://www.ncbi.nlm.nih.gov/pubmed/11758648 Ray S, Bagchi D, Lim PM, Bagchi M, Gross SM, Kothari SC, Preuss HG, Stohs SJ. Acute and long-term safety evaluation of a novel IH636 grape seed proanthocyanidin extract. Res Commun Mol Pathol Pharmacol. 2001 Mar-Apr;109(3-4):165-97] ]

The US National Center for Complementary and Alternative Medicine (NCCAM) reports that oral administration of grape seed extract was well tolerated in people over 8 weeks of a clinical trial. [ [http://nccam.nih.gov/health/grapeseed/ Grape Seed Extract, Herbs at a Glance, US National Center for Complementary and Alternative Medicine] ] In one completed clinical trial, grape seed extract did not alleviate the hardening of breast tissue in female patients undergoing radiation therapy to treat breast cancer. [ [http://www.ncbi.nlm.nih.gov/pubmed/16546280 Brooker S, Martin S, Pearson A, Bagchi D, Earl J, Gothard L, Hall E, Porter L, Yarnold J. Double-blind, placebo-controlled, randomised phase II trial of IH636 grape seed proanthocyanidin extract (GSPE) in patients with radiation-induced breast induration. Radiother Oncol. 2006 Apr;79(1):45-51.] ]

Other NCCAM advisories

* side effects most often include headache, a dry, itchy scalp, dizziness or nausea
* interactions between grape seed extract and medicines or other supplements have not been carefully studied

Due to the action of proanthocyanidins on limiting platelet adhesion, [ [http://www.ncbi.nlm.nih.gov/pubmed/12468593 Shanmuganayagam D, Beahm MR, Osman HE, Krueger CG, Reed JD, Folts JD. Grape seed and grape skin extracts elicit a greater antiplatelet effect when used in combination than when used individually in dogs and humans. J Nutr. 2002 Dec;132(12):3592-8.] ] grape seed extract may increase the clotting time of blood.

The following statements are deduced, as the interactions implied have not been systematically examined in scientific studies. When grape seed extract is taken with anticoagulant drugs (including clopidogrel, Ticlid, heparin, warfarin, and aspirin), the effect of the drug may be increased, resulting in uncontrolled bleeding. Herbal products that might interact with grape seed extracts and inhibit blood clotting are Danshen, Devil's Claw, Eleuthero, Garlic, Ginger (in high amounts), Ginkgo, Horse Chestnut, Panax Ginseng, Papain, Red Clover, and Saw Palmetto.Fact|date=June 2008

References

External links

* [http://nccam.nih.gov/health/grapeseed/ Grape seed extract, from Herbs at a Glance, National Center for Complementary and Alternative Medicine, US National Institutes of Health, March 2007]