Grape Interactions

The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should consult with a qualified healthcare provider before starting a new therapy.

• Analgesics: A small case series suggested that grape seed extract (GSE) decreased abdominal pain associated with chronic pancreatitis (145).
• Antibacterials: Grape preparations or constituents, alone or in combination with other agents, inhibited bacteria growth, including Bacillus cereus ATCC 11778, B. subtilis ATCC 6633, Streptococcus faecalis TISTR 459, Pseudomonas aeruginosa ATCC 25517, Staphylococcus aureus ATCC 25093, Bacillus cereus, Listeria monocytogenes, most of the Lactobacillus strains (with the exception of L. helveticus H.), and others (4;200;201;62). In vitro, grape seed and skin extracts and grape pomace extract showed antibacterial activity against a variety of species (4;5). The combination of grape seed extract, green tea extract, and tartaric acid, has shown antibacterial activity against Listeria monocytogenes (200).
• Anticoagulants and antiplatelets: In humans and in vitro, Pycnogenol® or oligomeric proanthocyanidin (OPC) preparations may significantly and dose-dependently reduce platelet aggregation (71;73;72). Examples include Ginkgo biloba and garlic (Allium sativum). Grape seed may also increase blood levels of herbs processed by the liver, such as chasteberry (Vitex agnus-castus). In vitro, polyphenolic grape extract induced dose-dependent inhibition of thrombin receptor (PAR-1) activating peptide (TRAP)-induced and ADP-induced platelet aggregation (195). In vitro, blood containing red wine inhibited platelet adhesion to fibrinogen at high and low shear rates, while blood containing polyphenolic grape extract inhibited adhesion only at a low shear rate (202).
• Antidepressants: In vitro, (-)-trans-epsilon-viniferin, a resveratrol dimer, inhibited the uptake of 5-HT by human platelets and rat brain synaptosomes and the uptake of noradrenaline by rat brain synaptosomes (8). The resveratrol dimer also inhibited the activity of human recombinant monoamine oxidases A and B.
• Antidiarrheals: In weaning rats, grape seed procyanidins reduced the incidence of diarrhea (203).
• Antifungals: Grape extract inhibited the growth of Aspergillus niger (5).
• Antigout: In vitro, OPCs were strong and noncompetitive inhibitors of xanthine oxidase (74).
• Anti-inflammatory: Anti-inflammatory effects of grapes, grape products, and grape constituents have been shown in human, animal, and in vitro research (204;205;206;207;208;209;210;211;212;213;214;215).
• Antilipemics: In animals, OPCs decreased total cholesterol (216;217). In a clinical trial, the combination of chromium and grape seed extract significantly decreased LDL (136). In animals, there was conflicting evidence on whether grape seed increases, decreases, or maintains HDL concentration; however, a clinical trial found that grape seed did not significantly affect HDL (136;216;218). In animals, grape or its constituents restored blood triglycerides, VLDL cholesterol, and serum total lipoprotein levels, and increased HDL cholesterol (219). In vitro, reduced LDL oxidation was observed (220;69).
• Antineoplastics: Grape seed extract (GSE) has been studied extensively in animal and laboratory research to determine potential mechanisms of action for its potential chemotherapeutic effects, with most of the focus on the proanthocyanidins and gallic acid (221;222;223;224;225;226;227;228;229). In theory, grape seed may interact with other herbs or supplements with anticancer effects. In vitro and in animal studies, grape or its constituents exhibited antiproliferative and antimutagenic effects in normal and cancerous human and rodent cells (230;231;232;233).
• Antiobesity: In animals, resveratrol, purified from the stem of Vitis coignetiae Pulliat inhibited food intake (235).
• Antioxidants: In clinical trials and in vitro, OPCs had antioxidant properties (270;74;271;272;143). In human studies, grape or grape constituents demonstrated extensive antioxidant activity, including increased total antioxidant capacity, reduced levels of oxidation products, and increased erythrocyte glutathione reductase and plasma ascorbate (99). In animal studies, free radical production and markers of oxidative stress decreased (242;240;219). In vitro, increases were seen in free radical-scavenging activity and platelet nitric oxide release, while free radical release and lipid peroxidation were reduced (4;273;274;230;18;220;275;276;277;278).
• Antivenins: In human plasma ex vivo, the methanol extract of Vitis vinifera seed inhibited the procoagulation properties of Echis carinatus venom (7). In citrated plasma, edema, hemorrhage, myonecrosis, and coagulation were all reduced, as were the caseinolytic, hyaluronolytic, and fibrinogenolytic activities of the venom. Application of grape seed extract to the bite wound caused by a Russell's viper (Indian Daboia/Vipera russelli) or saw-scaled viper (Echis carinatus) ameliorated local effects of the venom; grape seed extract neutralized proteolytic and hyaluronidase activities and hemorrhage and edema-inducing activities, and also partially inhibited procoagulant activity and prevented the degradation of fibrinogen chains (6;7).
• Antivirals: According to review, resveratrol has antiviral properties (1). In vitro, grape and grape products or constituents inhibited the replication of the recombinant adenovirus vector Ad-5 and the secretion of HbsAg, HbeAg, and HBV DNA; and reduced the infectivity of the human enteric virus surrogates bacteriophage MS2, feline calicivirus (FCV-F9), hepatitis A virus strain HM175, and murine norovirus (MNV-1) (236;237;238).
• Cardiovascular Agents: In animals, grape or its constituents improved myocardial contractility index, coronary flow, and oxygen consumption; reduced myocardial ischemia reperfusion injury, myocardial infarction, and blood pressure; restored blood triglycerides, VLDL cholesterol, and serum total lipoprotein levels; and increased HDL cholesterol (239;18;240;219). In vitro, relaxation of intact precontracted aortic rings and reduced LDL oxidation were observed (220;69). In vitro and in animals, OPCs inhibited angiotensin I-converting enzyme activity by noncompetitive inhibition (199).
• COX inhibitors: In the highly metastatic human melanoma cell lines A375 and Hs294t, exposure to grape seed proanthocyanidins was associated with inhibition of cell migration and reduced levels of cyclooxygenase (COX)-2 and prostaglandin E2 (241).
• Dermatologic agents: Grape seed proanthocyanidins inhibited UV-radiation-induced oxidative stress in human epidermal keratinocytes (23;249). Grape has been used as a substrate for the synthesis of gamma-aminobutyric acid (GABA) by Lactobacillus plantarum for dermatological uses and compared to the use of pure GABA in a model of human skin (22). In vitro, in melanocytes, oligomeric proanthocyanidins from grape seeds inhibited ultraviolet-induced melanogenesis (250). The free radical-scavenging properties of oligomeric proanthocyanidins (OPCs) are hypothesized to protect skin from the harmful effects of UV radiation (23;251;252).
• Omega-3 fatty acids, fish oil, alpha-linolenic acid: Fractionated phenols from grape pomace extract inhibited the oxidation of lipids in fish oil and frozen muscle (280).
• Hepatoprotective agents: Animal studies suggest that oligomeric proanthocyanidins (OPCs) may have a hepatoprotective effect in the setting of hepatic injury (261). In vitro, resveratrol, a constituent of grape, had antiproliferative effects in human liver myofibroblasts (262).
• Hypotensives: According to a report of an adverse effect in a clinical study, Endotelon® may cause dizziness and hypertension (68). However, in vitro and clinical studies have shown that OPCs and grape seed extract may reduce hypertension (69;70;112;141).
• Immunomodulators: According to a review, animal studies show that grape products support the immune system (49). Secondary sources suggest that grape extract stimulates colony-forming efficiency and organogenic potential, and improves the maintenance of epidermal stem cells. In vitro, grape seed extract activated Th1 cells, potentially via induction of interferon-gamma (263).
• Neurologic Agent: According to review, resveratrol may have neuroprotective properties (1;20). Grape products have shown beneficial effects in animal models of Parkinson's disease and Alzheimer's disease (16;264;265;266;267). In a mouse model of Alzheimer's disease, grape seed extract has been shown to prevent deposition of beta-amyloid and attenuated brain inflammation (264).
• Nisin: In laboratory studies, grape seed extract and nisin, a mixture of antimicrobial polypeptides, had additive antibacterial effects on Listeria monocytogenes (201).
• Nitric oxide: Inhibition of nitric oxide synthesis reduced the stimulatory effect of grape extract on coronary flow in isolated guinea pig heart (239).
• Osteoporosis Agent: In vitro, syringetin, a constituent of grape, induced human osteoblast differentiation through the bone morphogenetic protein-2/extracellular signal-regulated kinase 1/2 pathway (258).
• Photosensitizers: In SKH-1 hairless mice, dietary grape seed proanthocyanidins inhibited UVB-induced oxidative stress and reduced UV-induced skin cancer in terms of incidence, multiplicity, and malignant transformation(252;268). Grape seed proanthocyanidins had photoprotective effects in UV-irradiated normal human melanocytes (250;249). Secondary sources suggest that grape extract affords UV protection.
• Phytoestrogens: In cultures of human breast cancer cells, resveratrol induced the expression of estrogen-responsive genes (259).
• Probiotics: In vitro, grape seed extract enriched in flavan-3-ols inhibited the growth of Lactobacillus acidophilus, Streptococcus thermophilus, and Lactobacillus fermentum, as well as some strains of bifidobacteria (286). In contrast, grape pomace polyphenolic extract significantly stimulated the growth of L. acidophilusin vitro (285). Probiotic bacteria showed better survival in model fruit juice supplemented with vitamin C, grape extract, and green tea extract than in model fruit juice alone (281).
• Resveratrol: In vitro, resveratrol potentiated the anticancer effects of grape seed extract (287).
• Vasodilator: In men with coronary heart disease, consumption of red grape polyphenol extract resulted in a significant increase in flow-mediated dilatation of the brachial artery (67). Blood pressure was reduced in rats with cardiovascular disease fed anthocyanin grape extract, procyanidin grape seed extract, and a vitaflavan polyphenolic grape seed extract(240). In vitro, grape caused endothelial-dependent vasorelaxation of isolated rat aortic rings (69).
• Vulnerary agents: In mice the topical application of a grape seed proanthocyanidin extract containing resveratrol increased wound healing (contraction and closure) (269).