Study 1: In this clinical trial, 30 middle-aged Japanese adults with prehypertension were orally administered a daily dose of either 200 mg (low dose) or 400 mg (high dose) of grape seed proanthocyanidin extract (GSPE) for 12 weeks. Compared to placebo, the group administered with 400 mg GSPE showed a significant improvement in mean systolic blood pressure and vascular elasticity.

Study 2: In this clinical trial, 61 healthy subjects whose LDL cholesterol levels were between 100 and 180 mg/dL were administered daily dose of either 200 mg (low dose) or 400 mg (high dose) grape seed proanthocyanidin extracts (GSPE) rich in OPCs for 12 consecutive weeks. Results showed that MDA-LDL (a marker of LDL oxidation) was significantly lower than baseline 12 weeks after GSPE administration. Meanwhile, the group administered with a daily dose of 400 mg of GSPE showed a significant decrease in MDA-LDL levels as early as 6 weeks after GSPE administration. These findings suggest the beneficial effects of GSPE on cardiovascular health in those with high levels of LDL cholesterol, to support healthy arteries.

Study 1: In this clinical trial, prehypertensive men (aged 35 to 51 years) with screening blood pressure >140/90 mm Hg without anti-hypertensive or lipid-lowering medication were orally administered with 640 mg anthocyanins or placebo daily for 4 weeks. Compared to placebo, high-density lipoprotein (HDL)-cholesterol and blood glucose were significantly higher in anthocyanin group. Additionally, several plasma polyphenols were significantly increased 1 to 3 hours following anthocyanin intake. These findings suggest the beneficial effects of anthocyanins on individuals with elevated blood pressure and normal lipid levels.

Study 2: In this meta-analysis, the effects of grape seed extract (GSE) on glycemic control, serum lipoproteins, inflammation and body weight were analysed. Fifty trials were included in this meta-analysis and pooling effect size from the studies showed that GSE administration resulted in a significant improvement in fasting blood glucose, total cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides and C-reactive protein (CRP) concentrations, which CRP is an inflammation marker. These findings suggest the beneficial effects of GSE on metabolic health (Phytother Res. 34(2): 239-253 (2020)).

Study 1: In this study, stressed mice were orally administered with grape juice enriched with red grape polyphenols for 5 days. This resulted in two-fold decrease in the expression of genes involved in inflammation and oxidation mechanisms (IL-6, TNF-a, NOX-2, HMOX1), but three-fold increase in the expression of genes related to protection against oxidative stress (Nrf2). Additionally, the grape juice increased antioxidant enzyme activity (catalase, SOD activity, TBARS) and reduced lipid peroxidation in the brain. These findings suggest the potential benefits of grape extract in supporting brain health.
Res. 34(2): 239-253 (2020)).

Study 2: In this study, mice were administered with grape seed extract for 5 days and the results showed a decrease in the level of reactive oxygen species in the brains, which may help support lower inflammation, moderate oxidative processes, and limit lipid peroxidation. Collectively, these findings suggest the neuroprotective effects of grape seed extract (Antioxidants (Basel). 10(1): 46 (2021)).

Study 3: In this clinical trial, healthy, middle-aged, overweight adults were orally administered with 90 mg anthocyanin-rich chokeberry (Aronia melanocarpa) extract (AME), 150 mg AME or placebo for 24 weeks and their cognitive function, mood and vascular functions were evaluated. Compared to placebo, AME improved psychomotor speed, which is the time taken to process new information and respond physically. Besides, 150 mg AME supports healthy brachial diastolic blood pressure. These findings suggest the potential benefits of AME on cognitive performance and vascular function in middle-aged individuals.

Study 1: In this in vitro study, the effect of chokeberry (Aronia melanocarpa) extract on human skin condition was determined, focusing on synthesis of type I collagen, which is the major protein in the skin. Chokeberry extract showed increased proliferation of human skin fibroblasts. Additionally, treatment with chokeberry extract increased the transcription of COL1A1 mRNA, which encodes the major component of type I collagen, in a dose-dependent manner. Besides, the chokeberry extract inhibited the expression of MMP1 and MMP3, which are enzymes that degrade collagen. As a result, an increase in type I collagen was observed along with the decrease in MMP1 protein. The findings suggest the beneficial effects of chokeberry extract in the treatment of damaged or aged skin.

Study 2: In an animal test, rats treated with methylprednisolone, which is a type of steroid used to treat different inflammatory conditions, showed retarded growth and inhibited collagen synthesis. Nonetheless, administration of citrus bioflavonoids to the rats were able to partially or completely counteract the inhibitory effects of the steroid on collagen formation. This study suggests the beneficial effects of citrus bioflavonoids on collagen formation (Am J Physiol. 206: 179-182 (1964)).

Study 3: In this in vitro study, skin fibroblasts were irradiated with ultraviolet UVA and the protective effects of grape seed extract on the fibroblasts were assessed. High doses of UVA caused damage to fibroblast structure and inhibited their growth. However, adding grape seed extract increased cell viability and effectively protected the cells from UVA damage. This study suggests the efficacy of grape seed extract to protect against UV-induced skin damage and premature skin aging (J Cosmet Dermatol. 20(4): 1271-1282 (2021).

In this study, mice were administered grape seed proanthocyanidin extract (GSPE) and their effects on bones and joints were studied. Administration of grape seed extract ameliorated the arthritic symptoms of collagen-induced arthritis, which are collagen and bone destruction. Besides, GSPE suppressed osteoclast (a type of bone cell that breaks down bone tissue) differentiation and promoted osteoblast (cell that forms bone tissue) differentiation simultaneously, improving arthritic manifestations of arthritis mice. These findings suggest the beneficial effects of GSPE in supporting inflammation-related bone loss.

Ulcerative colitis (UC) is a chronic inflammatory disease of colorectum with an underlying excessive immune response affecting the quality of life of the patients. In this study, dextran sodium sulfate (DSS)-induced UC mice were administered grape seed proanthocyanidin extract (GSPE) and GSPE remarkably prevented DSS-induced weight loss and colon length shortening in UC mice. Additionally, GSPE significantly attenuated the expression of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and elevated the expression of anti-inflammatory cytokine IL-10 in the colon tissues and serum of DSS-induced colitis mice. These findings suggest the potential of GSPE in supporting healthy inflammatory response in subjects with digestive inflammation.

Study 1: In this clinical trial, 51 subjects (aged 18 to 65 years) with body mass index (BMI) 22 – 30 kg/m2 ate an ad libitum (freely as one wishes) lunch and dinner twice for 3 days, and grape seed extract were taken 30 to 60 minutes prior to each meal. For subjects with an energy requirement equal or greater than 7.5 MJ/day, 24-hour energy intake was reduced by 4% In grape seed extract group, compared to placebo group, without further effects on satiety, mood or tolerance. These findings suggest that grape seed extract could aid in weight management by reducing energy intake in normal to overweight dietary unrestrained subjects.

Study 2: In this study, mice were divided into 3 groups, which were normal diet control group (ND), high-fat diet control group (HD) and high-fat diet plus grape seed extract supplemented group (HD+GSE) and the experiment was conducted for 12 weeks. Compared to HD group, GSE supplementation reduced the weight gain, epididymal and back fat weights in mice fed high-fat diets. Additionally, blood lipid concentrations were lower in the HD+GSE group than in the HD group. Serum HDL-cholesterol (good cholesterol) concentrations were higher in the HD+GSE group compared with the other groups. Besides, GSE supplementation increased mRNA levels of lipolytic (fat breakdown) genes such as carnitine palmitoyltransferase-1 (CPT-1), and decreased mRNA levels of lipogenic (fat production) genes such as acetyl CoA carboxylase (ACC). These findings suggest the beneficial effects of GSE in weight management.