Grape seed extract
Grape seed extracts are industrial derivatives from whole grape seeds that have a great concentration of vitamin E, flavonoids, linoleic acid and phenolic OPCs. The typical commercial opportunity of extracting grape seed constituents has been for chemicals known as polyphenols having antioxidant activity in vitro.
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[edit] Potential anti-disease effects
Human case reports and results from laboratory and animal studies provide preliminary evidence that grape seed extract may affect heart diseases such as high blood pressure and high cholesterol.[1] By limiting lipid oxidation, phenolics in grape seeds may reduce risk of heart disease, such as by inhibiting platelet aggregation and reducing inflammation.[2] 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 other potential chemopreventive effects.[3][4]
Preliminary research shows that grape seed extract may have other possible anti-disease properties, such as in laboratory models of
- wound healing —- OPCs induced vascular endothelial growth factor and accelerated healing of injured skin in mice[5]
- tooth decay -- seed phenolics may inhibit oral sugar metabolism and retard growth of certain bacteria that cause dental caries[6]
- osteoporosis -- grape seed extracts enhanced bone density and strength in experimental animals[7]
- skin cancer -- grape seed proanthocyanidins decreased tumor numbers and reduced the malignancy of papillomas[8]
- ultraviolet damage to skin -— dietary proanthocyanidins may protect against carcinogenesis and provide supplementation for sunscreen protection[9]
- anti-viral[10][11]
- hepatoprotection[12]
- venous insufficiency and edema[13]
There are 13 clinical trials (January, 2012) assessing potential effects of grape seed extracts on human diseases, such as breast cancer, blood estrogen levels in postmenopausal women, and coronary artery disease.[14]
[edit] Research
A recent randomized, double-blind, placebo-controlled crossover trial with 50 adults with coronary disease or ≥1 cardiac risk factors treated with muscadine grape seed supplementation conluded that: "Four weeks of muscadine grape seed supplementation in subjects with increased cardiovascular risk did not produce a statistically significant increase in brachial flow-mediated vasodilation or a significant change in other biomarkers of inflammation, lipid peroxidation, or antioxidant capacity. However, the muscadine grape seed supplement did result in a significant increase in resting brachial diameter. The clinical significance of the effect on resting diameter is not yet established. "[15]
However, a 2011 meta-analysis of randomized controlled trials, concluded that "grape seed extract appears to significantly lower systolic blood pressure and heart rate, with no effect on lipid or C-reactive protein levels."[16]
The US National Center for Complementary and Alternative Medicine (NCCAM) reported that oral administration of grape seed extract was well tolerated in people over 8 weeks of a clinical trial.[17] 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.[18]
A 2012 laboratory study showed that grape seed extract killed head and neck cancer cells while leaving healthy cells unharmed.[19]
[edit] Dosage, precautions and interactions
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.[20]
Oral grape seed extract is used in capsules or tablets usually containing 50 mg or 100 mg. Insufficient scientific information is known, however, about how long-term use of grape seed extract might affect health or any disease.
Side-effects and cautions, other NCCAM advisories.
- In general, grape seed extract is well tolerated when taken by mouth, although it is better tolerated when encapsulated, as its taste is bitter. It has been used safely for up to 8 weeks in clinical trials.
- 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 possible action of proanthocyanidins on limiting platelet adhesion,[21] grape seed extract may act as a blood-thinner, increasing clotting time.
[edit] Aromatase Inhibitor
Grape seed extract is also an aromatase inhibitor in vitro,[22] i.e. it may suppress the conversion of testosterone to estradiol.
[edit] References
- ^ Bagchi D, Sen CK, Ray SD, et al. (Feb-Mar 2003). "Molecular mechanisms of cardioprotection by a novel grape seed proanthocyanidin extract". Mutat Res. 523-524: 87–97. doi:10.1016/S0027-5107(02)00324-X. PMID 12628506. http://linkinghub.elsevier.com/retrieve/pii/S002751070200324X.
- ^ Vitseva O, Varghese S, Chakrabarti S, Folts JD, Freedman JE (October 2005). "Grape seed and skin extracts inhibit platelet function and release of reactive oxygen intermediates". J Cardiovasc Pharmacol. 46 (4): 445–51. doi:10.1097/01.fjc.0000176727.67066.1c. PMID 16160595. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=0160-2446&volume=46&issue=4&spage=445.
- ^ Kundu JK, Surh YJ (October 2008). "Cancer chemopreventive and therapeutic potential of resveratrol: mechanistic perspectives". Cancer Lett. 269 (2): 243–61. doi:10.1016/j.canlet.2008.03.057. PMID 18550275.
- ^ BBC news - December 2008 - Grape extract kills cancer cells
- ^ Khanna S, Venojarvi M, Roy S, et al. (October 2002). "Dermal wound healing properties of redox-active grape seed proanthocyanidins". Free Radic Biol Med. 33 (8): 1089–96. doi:10.1016/S0891-5849(02)00999-1. PMID 12374620. http://linkinghub.elsevier.com/retrieve/pii/S0891584902009991.
- ^ Smullen J, Koutsou GA, Foster HA, Zumbé A, Storey DM (2007). "The antibacterial activity of plant extracts containing polyphenols against Streptococcus mutans". Caries Res. 41 (5): 342–9. doi:10.1159/000104791. PMID 17713333.
- ^ Yahara N, Tofani I, Maki K, Kojima K, Kojima Y, Kimura M (June 2005). "Mechanical assessment of effects of grape seed proanthocyanidins extract on tibial bone diaphysis in rats". J Musculoskelet Neuronal Interact. 5 (2): 162–9. PMID 15951633. http://www.ismni.org/jmni/pdf/20/10YAHARA.pdf.
- ^ Katiyar SK (June 2008). "Grape seed proanthocyanidines and skin cancer prevention: Inhibition of oxidative stress and protection of immune system". Mol Nutr Food Res. 52 Suppl 1 (Suppl 1): S71–6. doi:10.1002/mnfr.200700198. PMC 2562900. PMID 18384090. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2562900.
- ^ Baliga MS, Katiyar SK (February 2006). "Chemoprevention of photocarcinogenesis by selected dietary botanicals". Photochem Photobiol Sci. 5 (2): 243–53. doi:10.1039/b505311k. PMID 16465310.
- ^ Su X, D'Souza DH.,"Grape seed extract for control of human enteric viruses." Appl Environ Microbiol. 2011 Jun;77(12):3982-7
- ^ Nair MP, Kandaswami C, Mahajan S, et al. (2002). "Grape seed extract proanthocyanidins downregulate HIV-1 entry coreceptors, CCR2b, CCR3 and CCR5 gene expression by normal peripheral blood mononuclear cells". Biol Res. 35 (3–4): 421–31. doi:10.4067/S0716-97602002000300016. PMID 12462994.
- ^ Pan X, Dai Y, Li X, Niu N, Li W, Liu F, Zhao Y, Yu Z.,"Inhibition of arsenic-induced rat liver injury by grape seed exact through suppression of NADPH oxidase and TGF-β/Smad activation." Toxicol Appl Pharmacol. 2011 Aug 1;254(3):323-31
- ^ University of Maryland Medical Center - Grape Seed
- ^ Search results for grape seed extracts, ClinicalTrials.gov, a service of the US National Institutes of Health
- ^ Mellen PB, Daniel KR, Brosnihan KB, Hansen KJ, Herrington DM"Effect of muscadine grape seed supplementation on vascular function in subjects with or at risk for cardiovascular disease: a randomized crossover trial." J Am Coll Nutr. 2010 Oct;29(5):469-75
- ^ Feringa HH, Laskey DA, Dickson JE, Coleman CI., "The effect of grape seed extract on cardiovascular risk markers: a meta-analysis of randomized controlled trials." J Am Diet Assoc. 2011 Aug;111(8):1173-81
- ^ Grape Seed Extract, Herbs at a Glance, US National Center for Complementary and Alternative Medicine
- ^ Brooker S, Martin S, Pearson A, et al. (April 2006). "Double-blind, placebo-controlled, randomised phase II trial of IH636 grape seed proanthocyanidin extract (GSPE) in patients with radiation-induced breast induration". Radiother Oncol. 79 (1): 45–51. doi:10.1016/j.radonc.2006.02.008. PMID 16546280.
- ^ http://medicalxpress.com/news/2012-01-grape-seed-neck-cancer-cells.html
- ^ Ray S, Bagchi D, Lim PM, et al. (2001). "Acute and long-term safety evaluation of a novel IH636 grape seed proanthocyanidin extract". Res Commun Mol Pathol Pharmacol. 109 (3–4): 165–97. PMID 11758648.
- ^ Shanmuganayagam D, Beahm MR, Osman HE, Krueger CG, Reed JD, Folts JD (1 December 2002). "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.n 132 (12): 3592–8. PMID 12468593. http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=12468593.
- ^ Ikuko Kijima, et al. (June 2006). "Grape Seed Extract Is an Aromatase Inhibitor and a Suppressor of Aromatase Expression". Cancer res. 66 (11): 5960–5967. doi:10.1158/0008-5472.CAN-06-0053. PMID 16740737. http://cancerres.aacrjournals.org/content/66/11/5960/F4.expansion.
[edit] External links
- Grape Seed Extract, from Herbs at a Glance (National Center for Complementary and Alternative Medicine, US National Institutes of Health)
