A randomized, double-blind, placebo-controlled, pilot study to evaluate the effect of whole grape extract on antioxidant status and lipid profile

Effect of grape-derived products on the serum levels of enzymes mainly produced by the liver: A systematic review and meta-analysis of parallel randomized controlled trials

In recent years, an increase in the incidence of liver diseases has been reported all over the world. This study aims to comprehensively summarize and quantitatively analyze the existing evidence concerning the effectiveness of grape-derived products on liver enzymes through a systematic review and meta-analytic approach. PubMed, Scopus, Cochrane Library, and ISI Web of Science were comprehensively searched until January 2024. Articles that reported the effect of grape-derived products on serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) levels were included. Weighted mean differences (WMDs) were pooled using a random-effects model. Nine studies were included in the meta-analysis. The results revealed that grape-derived products did not significantly change the concentrations of ALT (WMD: -2.70 IU/L, 95% CI: -6.14 to 0.75, p = 0.12), and AST (WMD: -1.42 IU/L, 95% CI: -3.54 to 0.70, p = 0.18). However, a significant reduction was observed in serum ALP levels (WMD: -5.49 IU/L, 95% CI: -9.57 to -1.4, p = 0.008). The present findings suggest that grape-derived products positively influence serum ALP levels among adults. However, a more comprehensive decision necessitates additional studies.

Photoperiod-Dependent Effects on Blood Biochemical Markers of Phenolic-Enriched Fruit Extracts

Fruits are rich in bioactive compounds, such as (poly)phenols, and their intake is associated with health benefits, although recent animal studies have suggested that the photoperiod of consumption influences their properties. Fruit loss and waste are critical issues that can be reduced by obtaining functional fruit extracts. Therefore, the aim of this study was to obtain phenolic-enriched extracts from eight seasonal fruits that can modulate blood biochemical parameters and to investigate whether their effects depend on the photoperiod of consumption. Eight ethanol-based extracts were obtained and characterized, and their effects were studied in F344 rats exposed to short (6 h light, L6) and long (18 h light) photoperiods. Cherry and apricot extracts decreased blood triacylglyceride levels only when consumed under the L6 photoperiod. Pomegranate, grape, and orange extracts reduced cholesterol and fasting glucose levels during the L6 photoperiod; however, plum extract reduced fasting glucose levels only during the L18 photoperiod. The results showed the importance of photoperiod consumption in the effectiveness of phenolic-enriched fruit extracts and promising evidence regarding the use of some of the developed fruit extracts as potential functional ingredients for the management of several blood biomarkers.

Grape seed extract supplementation in non-alcoholic fatty liver disease

Background: Despite rising non-alcoholic fatty liver disease (NAFLD) prevalence and its impact on liver health, there's a lack of studies on grape seed extract's (GSE) effect on oxidative stress and quality of life (QoL) in NAFLD patients. This study aims to fill this gap by the potential benefits of GSE in reducing oxidative stress and improving QoL. Methods: In this randomized clinical trial study, fifty patients with NAFLD were randomly assigned to receive either 2 tablets of GSE containing 250 mg of proanthocyanidins or placebo (25 participants in each group) for two months. QoL was evaluated using the SF-36 questionnaire, and oxidative stress variables (TAC, MDA, SOD, GPx, CAT, and IL-6) were measured at the beginning and end of the study. Results: Compared with the control group, the group supplemented with GSE experienced greater reductions in IL-6 and MDA (3.14±1.43 pg/ml vs. 2.80±0.31 pg/ml; 4.16±2.09 μM vs. 4.59±1.19 μM, p for all <0.05), as well as greater increases in TAC, SOD, and GPx levels (0.18±0.08 mM vs. -0.03±0.09 mM; 10.5±6.69 U/ml vs. 8.93±1.63 U/ml; 14.7±13.4 U/ml vs. 8.24±3.03 U/ml, p for all <0.05). Furthermore, the QoL questionnaire showed that physical limitations, general health, and total physical health were significantly improved in the GSE group compared with the placebo (17.0±42.0 vs. -12.0±37.5; 3.80±14.8 vs. -3.92±9.55; 5.08 5.26 vs. -7.01±13.7, p for all <0.05). Conclusions: GSE can be effective in improving oxidative stress and QoL in patients with NAFLD. More studies are needed to confirm the results of this study.

The Lipid-Lowering Efficacy of a Nutraceutical Combination Including Leucoselect Phytosome, Red Yeast Rice, Policosanol and Folic Acid in Dyslipidaemia Patients: Real-World Insights

BACKGROUND

Cardiovascular disease is a global health concern and reducing plasma LDL-C levels is a major goal in cardiovascular prevention. Our study aimed to evaluate the effectiveness of a nutraceutical formulation including leucoselect® phytosome®, red yeast rice, policosanol and folic acid on LDL-c levels in patients at low cardiovascular risk with dyslipidemia.

MATERIALS AND METHODS

We prospectively enrolled all consecutive patients with dyslipidemia at low cardiovascular risk who were unresponsive to diet and physical activity. Clinical assessments and laboratory analyses, encompassing lipid profile, hepatic function, and CPK levels, were performed at baseline prior to initiating treatment and repeated at the 12-week mark following administration of the study nutraceutical.

RESULTS

Sixty (60) consecutive patients (mean age 48.02 ± 10.1 years; 60% male) were included. At the 12-week follow-up, a statistically significant reduction in Total Cholesterol (13.1%) and LDL-c serum level (20.4%) was observed. Hepatic and muscular function remain stable over the time. The adherence to therapy was 99% and the persistence was maximum.

CONCLUSIONS

The nutraceutical formulation including leucoselect® phytosome® red yeast rice, policosanol and folic acid significantly reduced the LDL-c plasma levels, consistent with previous research showing that the bioactive component in red yeast rice-lovastatin-is effective in addressing problems with lipid metabolism. Importantly, it was safe and well-tolerated among patients with dyslipidemia in a real-world setting.

Low Dose Monacolin K Combined with Coenzyme Q10, Grape Seed, and Olive Leaf Extracts Lowers LDL Cholesterol in Patients with Mild Dyslipidemia: A Multicenter, Randomized Controlled Trial

Certain nutraceuticals, mainly containing red yeast rice, might be considered as an alternative therapy to statins in patients with dyslipidemia, although there is still insufficient evidence available with respect to long-term safety and effectiveness on cardiovascular disease prevention and treatment. The aim of this study was to assess the lipid-lowering activity and safety of a dietary supplement containing a low dose of monacolin K combined with coenzyme Q10, grape seed and olive tree leaf extracts in patients with mild hypercholesterolemia. In total, 105 subjects with mild hypercholesterolemia (low-density lipoprotein cholesterol LDL-C levels 140-180 mg/dL) and low CV risk were randomly assigned into three treatment groups: lifestyle modification (LM), LM plus a low dosage of monacolin K (3 mg), and LM plus a high dosage of monacolin K (10 mg) and treated for 8 weeks. The primary endpoint was the reduction of LDL-C and total cholesterol (TC). LDL-C decreased by 26.46% on average (p < 0.001) during treatment with 10 mg of monacolin and by 16.77% on average during treatment with 3 mg of monacolin (p < 0.001). We observed a slight but significant reduction of the triglyceride levels only in the high-dose-treated group (mean -4.25%; 95% CI of mean -11.11 to 2.61). No severe adverse events occurred during the study. Our results confirm the LDL-C-lowering properties of monacolin are clinically meaningful even in lower doses of 3 mg/day.

The effect of grape products on liver enzymes: A systematic review and meta-analysis of randomized controlled trials

The favorable influence of grape consumption on metabolic diseases has previously been shown in studies. We sought to assess the effects of grape intake on liver enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), in adults. We performed literature search in online databases, to find eligible randomized controlled trials (RCTs). we considered RCTs that met the following criteria: RCTs consisted of use of grape products on ALT, AST, and ALP in adults (≥18 years) with at least 2 weeks intervention duration. Pooling data from 11 trials showed that grape products intake significantly reduced ALP (p = .010), without any significant changes in ALT (p = .234) and AST (p = .300). In subgroup analysis, we found a significant reduction in ALP, ALT, and AST when the duration of intervention was ≥12 weeks, and when grape seed extract (GSE) was administered. The variable duration and dosage of intervention was one of the sources of bias in our meta-analysis. Additionally, participants involved in included studies had different physiological status and various age groups. Grape products administration may significantly improve ALT, AST, and ALP in adults in long-term interventions and/or when GSE is administered. It should be noted that the favorable effects of grape consumption were small and may not reach clinical importance.

Polyphenols and atherosclerosis: A critical review of clinical effects on LDL oxidation

Atherosclerosis is a major etiology of cardiovascular disease that causes considerable mortality. Oxidized low-density lipoprotein (oxLDL) is a fundamental attributor to atherosclerosis. Therefore, there seems to be an essential place for antioxidant therapy besides the current treatment protocols for coronary heart disease. Polyphenols are a class of compounds with substantial antioxidant properties that have shown the ability to reduce LDL oxidation in preclinical studies. However, clinical evidence has not been as conclusive although offering many promising signs. This review aims to examine the trials that have evaluated how dietary intake of polyphenols in different forms might influence the oxidation of LDL. Lowering the circulating cholesterol, incorporation into LDL particles, and enhancing systemic antioxidant activity are among the main mechanisms of action for polyphenols for lowering oxLDL. On the other hand, the population under study significantly affects the impact on oxLDL, as the type of the supplement and phenolic content. To conclude, although the polyphenols might decrease inflammation and enhance endothelial function via lowering oxLDL, there are still many gaps in our knowledge that need to be filled with further high-quality studies.

Protective Effects of Grape Juice on Vascular Damage Induced by Chlorine Free Radical in Rats

Grapes and their derivatives have antioxidant and cardioprotective properties. Therefore, we hypothesized that grape juice (GJ) could improve vascular oxidative damage caused by chlorine radicals (OCl⁻), which are excessively produced in vascular tissue during cardiovascular diseases (mainly diabetes and hypertension). The antioxidant capacity of GJ was analyzed by an electrochemical method, followed by administration in rats (100 or 300 mg/kg/d, via the oral) for seven days. Then, rats were sacrificed, and their aortas were isolated and subjected to isometric recordings or immuno-histochemical analyses with or without exposure to OCl⁻ (5, 20, or 100 μM, 60 min). Concentration-effect curves for acetylcholine (ACh) and sodium nitroprusside (SNP) were derived to analyze endothelium-dependent or independent vasore-laxation. The GJ presented with high antioxidant capacity, and treatment with GJ did not alter vascular relaxation induced by ACh or SNP. After exposure to OCl⁻, endothelium-denuded arteries showed preserved relaxation with SNP, whereas endothelium-intact arteries showed reduced relaxation with ACh. OCl⁻ at various concentrations induced significantly decreased relaxation of arteries (80.6±4.2%, 55.4±4.7%, and 28.1±5.9%, respectively) vs. control arteries (96.8±2.4%). However, treatment with GJ prevented loss in relaxation caused by 5 and 20 μM OCl⁻ and improved relaxation after exposure to 100 μM OCl⁻. Exposure to OCl⁻ induced increased nitrotyrosine immunostaining of endothelial cell layers, which was improved by GJ treatment. Altogether, vascular damage caused by OCl⁻ was prevented by treatment with GJ, and GJ prevented nitrosative stress in these vessels.

Statistics on the bioactive anthocyanin/proanthocyanin products in China online sales

Due to their potential beneficial effects, anthocyanins and proanthocyanins have attracted great concern worldwide. Recently, anthocyanin/proanthocyanin-related health products have occupied a certain proportion of the market. However, there has not been a systematical assessment on collecting and analyzing the relevant information. In this study, information of anthocyanin/proanthocyanin-related health products on sale on the four major online shopping platforms in China has been collected from November 2020 to February 2021. A total of 144 valid samples from 91 brands were collected, among which blueberries and grape seeds are the main sources of anthocyanins and proanthocyanins, respectively. Besides, the average anthocyanins/proanthocyanins content in these products is 22.71%. Improving eyesight, anti-asthenopia and anti-oxidation are widely mentioned among the anthocyanin-related products, while more proanthocyanin-related products declare for anti-oxidation, whitening & spot lighting, and delay of skin aging & repairing skin damage effects. Among the products, 77.78% are capsules and tablets, and the average unit price of anthocyanins/proanthocyanins is $ 5.26/g. Data analysis shows that searching for high-quality raw materials, researching on the varieties and content of anthocyanins/proanthocyanins, focusing on the intake of specific population, and exploring better storage forms of anthocyanins/proanthocyanins may be important field in the future to promote the development of the anthocyanin/proanthocyanin-related health products.

Protocatechuic acid attenuates lipopolysaccharide-induced septic lung injury in mice: The possible role through suppressing oxidative stress, inflammation and apoptosis

Here, we investigated the protective efficacy of protocatechuic acid (PCA) against lipopolysaccharide (LPS)-induced septic lung injury. Eighty-two male Balb/c mice were divided into six groups: control, PCA30 (30 mg/kg), LPS (10 mg/kg), PCA10-LPS, PCA20-LPS, and PCA30-LPS treated with 10, 20 and 30 mg/kg PCA, respectively, for seven days before intraperitoneal LPS injection. PCA pre-treatment, especially at higher dose, significantly reduced LPS-induced lung tissue injury as indicated by increased heat shock protein 70 and antioxidant molecules (reduced glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) accompanied by lower oxidative stress indices (malondialdehyde and nitric oxide). PCA administration decreased inflammatory mediators including myeloperoxidase, nuclear factor kappa B (NF-κB p65), and pro-inflammatory cytokines, and prevented the development of apoptotic events in the lung tissue. At the molecular level, PCA downregulated mRNA expression of nitric oxide synthase 2, C/EBP homologous protein, and high mobility group box1 in the lungs of all PCA-LPS treated mice. Thus, PCA-pre-treatment effectively counteracted sepsis-induced acute lung injury in vivo by promoting and antioxidant status, while inhibiting inflammation and apoptosis. PRACTICAL IMPLICATIONS: Sepsis-mediated organ dysfunction and high mortality is aggravated by acute lung injury (ALI). Therefore, new therapeutic approaches are needed to encounter sepsis-mediated ALI. Protocatechuic acid (PCA) is a naturally occurring phenolic acid with various biological and pharmacological activities. PCA is abundant in edible plants including Allium cepa L., Oryza sativa L., Hibiscus sabdariffa, Prunus domestica L., and Eucommia ulmoides. In this investigation we studied the potential protective role of pure PCA (10, 20 and 30 mg/kg) on LPS-mediated septic lung injury in mice through examining oxidative challenge, inflammatory response, apoptotic events and histopathological changes in addition to evaluating the levels and mRNA expression of heat shock protein 70, C/EBP homologous protein and high mobility group box1 in the lung tissue. The recorded results showed that PCA pre-administration was able to significantly abrogate the damages in the lung tissue associated septic response. This protective effect comes from its strong antioxidant, anti-inflammatory, and anti-apoptotic activities, suggesting that PCA may be applied to alleviate ALI associated with the development of sepsis.

The anti-obesogenic effects of dietary berry fruits: A review

The prevalence of obesity in the world is fearsomely climbing, which has brought about heavy threats on human health and economic development. For coping with this problem, researchers have looked at the profound potentials of natural products for resolving obesity because of their high efficiencies and few undesirable outcomes in the recent years. Berry fruits are huge reservoirs of bioactive components, and their anti-obesity potentials are arousing much interests. In this review, the current main strategies to manage obesity were summarized, including inhibiting appetite and lowering the food intake, improving energy expenditure and thermogenesis, suppressing absorption and digestion, reducing lipid synthesis and storage as well as modulating composition of gut microbiota. In addition, this review discussed the potentials of dietary berry fruits (blueberries, cranberries, raspberries, strawberries, mulberries, lingonberries, blackberries, black chokeberries, elderberries, bilberries, grape, blackcurrants, jaboticabas, red bayberries, sea-buckthorns, goldenberries and goji berries) to counteract obesity or obesity-associated complications based on recent animal experiments and human studies. Then, the bioaccessibility of phenolic compounds present in berry fruits was discussed. On the other hand, several challenges including securing effective dosage, further understanding their interaction with human tissues, improving bioavailability and protection of functional ingredients during delivery should be taken into account and conquered in the coming years.

Effects of grape products on inflammation and oxidative stress: A systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) were conducted to determine the effects of grapes and grape products on inflammation and oxidative stress among adults. PubMed, Scopus, ISI Web of Science, and Cochrane Library databases were searched up to July 2020 to identify RCTs investigating the effects of grape and grape products on inflammatory and oxidative stress markers. Weighted mean differences (WMD) were pooled using a random-effects model. Of the 8,962 identified studies, 24 RCTs (27 arms) were included in the statistical analysis. Grape products significantly reduced serum C-reactive protein (CRP) levels (WMD: -0.35 mg/L; 95% CI: -0.62, -0.09, p = .008), but they had no significant effect on serum tumor necrosis factor-alpha (TNF-α) (WMD = -1.08 pg/ml; 95% CI: -2.29, 0.11, p = .07), interleukin-6 (IL-6) (WMD = 0.13 pg/ml; 95% CI: -0.35, 0.60, p = .60), total antioxidant capacity (TAC) (WMD = 0.15; 95% CI: -0.35, 0.65, p = .54), or malondialdehyde (MDA) (WMD = 0.14; 95% CI: -0.64, 0.92, p = .72). The analysis indicated possible decreasing effects of grapes and grape products on CRP, but they might not be able to change IL-6, TNF-α, TAC, and MDA concentrations. Nonetheless, further studies are warranted before definitive conclusions may be reached.

The effect of grapes/grape products on glycemic response: A systematic review and meta-analysis of randomized controlled trials

The aim of this study was to perform a systematic review and meta-analysis of randomized clinical trials (RCTs) to examine the effect of grapes/grape products supplementation on glycemic indices in adults. Our systematic search to find relevant RCTs was performed up to February 2020 using PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar. Based on the heterogeneity between included studies, a random effects or a fixed model was applied in the meta-analysis, and results were expressed as weighted mean differences (WMD) with 95% confidence intervals (CI). Twenty-nine clinical trials (1,297 participants) fulfilled the eligibility criteria of the present meta-analysis. Overall, the grapes/grape products supplementation significantly reduced homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: -0.54, 95% CI: -0.91, -0.17, p = . 004) but did not affect fasting insulin levels (WMD: -0.90 μIU/ml, 95% CI: -1.04, 2.84, p = .362) and hemoglobin A1C (Hb1Ac) percentage (WMD: 0.00%, 95% CI: -0.10, 0.11, p = . 916) in the main analyses. In addition, changes to fasting blood glucose (FBG) levels were in favor of the control group (WMD: 1.19 mg/dl, 95% CI: 0.05, 2.34, p = .041). We found that giving grapes/grape products to adults might have beneficial effects on the HOMA-IR. Further, large-scale RCTs with longer duration are required to confirm these results.

The effect of grape products containing polyphenols on oxidative stress: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The literature showed that Grape Products Containing Polyphenols (GPCP) had anti-oxidant activity. However, the effects of GPCP on different biomarkers of oxidative stress are still controversial. In this regard, this systematic review and meta-analysis aimed to evaluate the effect of Grape Products Containing Polyphenols (GPCP) intake on oxidative stress markers.

METHODS

PubMed, Scopus, Web of Science, and Google Scholar data bases were searched up to August 20, 2020. A random-effects model, weighted mean difference (WMD), and 95% confidence interval (CI) were applied for data analysis. Meta-analysis was conducted over 17 eligible RCTs with a total of 633 participants. The study registration number is CRD42019116696.

RESULTS

A significant increase was observed in Total Antioxidant Capacity (TAC) (weighted mean difference (WMD) = 1.524 mmol/L, 95% confidence interval (CI): 0.83, 2.21). Intake of GPCP enhanced Superoxide Dismutase (SOD) (WMD = 0.450 mmol/L, 95% CI: 0.23, 0.66), TAC (WMD = 2.829 mmol/L, 95% CI: 0.13, 5.52), and Oxygen Radical Absorbance Capacity (ORAC) (WMD = 0.524 μmol/L, 95% CI: 0.42, 0.62) among healthy participants. Higher GPCP doses increased SOD (WMD = 0.539 U/mgHb, 95% CI: 0.24, 0.82) and ORAC (WMD = 0.377 μmol/L, 95% CI: 0.08, 0.67), whereas longer intervention periods enhanced ORAC (WMD = 0.543 μmol/L, 95% CI: 0.43, 0.64).

CONCLUSION

GPCP intake may partly improve status of oxidative stress, but further well-designed trials are required to confirm these results.

Effects of polyphenols on cardio-metabolic risk factors and risk of type 2 diabetes. A joint position statement of the Diabetes and Nutrition Study Group of the Italian Society of Diabetology (SID), the Italian Association of Dietetics and Clinical Nutrition (ADI) and the Italian Association of Medical Diabetologists (AMD)

AIM

A large body of evidence supports a role of polyphenols in the prevention of chronic diseases, i.e. type 2 diabetes (DMT2), cardiovascular diseases and some types of cancer. In the present manuscript, the effect of polyphenol/phenolic compounds on the main cardio-metabolic risk factors (body weight, blood pressure, blood glucose concentrations, plasma lipids, inflammation and oxidative stress) in humans will be discussed.

DATA SYNTHESIS

Epidemiological evidence supports the beneficial effects of polyphenol-rich diets in the prevention of T2D risk. However, the available evidence from randomized controlled clinical trials did not allow the identification of specific phenolic compounds or polyphenol-rich foods that effectively improve cardio-metabolic risk factors. The most promising results in terms of the management of cardio-metabolic risk factors derive from RCTs based on a long-term intake of polyphenol-rich foods and beverages. Therefore, future studies should focus on a diet containing different classes of polyphenols rather than a specific food or phenolic compound. The hypothesis is that a polyphenol-rich diet may have a pleiotropic effect on cardiometabolic risk factors thanks to the specific action of different polyphenol subclasses.

CONCLUSION

The lack of conclusive evidence on the effectiveness of polyphenols in the management of cardio-metabolic risk factors does not allow recommendation of their use as supplements to reduce T2D and CVD risk. However, the daily consumption of naturally polyphenol-rich foods and beverages might be advised according to the current nutritional dietary recommendation.

Impact of Grape Products on Lipid Profile: A Meta-Analysis of Randomized Controlled Studies

Background: Growing evidence shows that grape polyphenols can improve cardiovascular risk factors. Although there are clear data supporting a beneficial effect of grape supplementation on blood pressure and glucose metabolism, the effects of grape polyphenols on lipid metabolism are still controversial. Objective: We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of grape products on lipid profile. Design: A systematic search was performed in the PubMed, Web of Science, Scopus, and EMBASE databases without any language or publication year restriction. The reference lists of all retrieved articles were manually reviewed. RCTs evaluating the impact of grape products/juice/extracts on lipid profile were included. Difference in total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), oxidized low-density lipoprotein cholesterol (oxLDL-C), apolipoprotein (apo) A, apo B before and after administration of grape products or placebo were expressed as mean differences (MD) with pertinent 95% confidence intervals (95% CI). The impact of clinical and demographic features on effect size was assessed by meta-regression. Results: The administration of grape products is associated with a significant improvement of lipid profile, as evidenced by changes in TC (MD: −7.6 mg/dL (−0.2 mmol/L); 95% CI: −10.8, −4.4; p < 0.001), HDL-C (MD: 1.4 mg/dL (0.04 mmol/L); 95% CI: 0.8, 1.9; p < 0.001, I² = 74.7%, p < 0.001), LDL-C (−6.3 mg/dL (−0.16 mmol/L); 95% CI: −9.5, −3.0; p < 0.001), oxLDL-C (MD: −4.5 U/L; 95% CI: −7.5, −1.5; p = 0.003, I² = 90.6%, p < 0.001), apo B (MD: −2.4 mg/dL (−0.05 µmol/L); 95% CI: −4.5, −0.3; p = 0.026), and TG (MD: −14.5 mg/dL (−0.16 mmol/L); 95% CI: −17.7, −11.2; p < 0.001) levels in subjects receiving grape products compared to placebo. With regard to the extent of the lipid-lowering effect, compared to baseline values, the highest reduction was reported for LDL-C (MD: −5.6 mg/dL (−0.14 mmol/L); 95% CI: −9.5, −1.7; p = 0.005) and for oxLDL-C (MD: −5.0 U/L; 95% CI: −8.8, −1.2; p = 0.010, I² = 0%, p = 0.470). Conclusions: Grape polyphenols exert a favorable effect on lipid profile in humans by significantly reducing plasma levels of LDL-C and oxLDL-C.

Proanthocyanidins: Components, Pharmacokinetics and Biomedical Properties

Proanthocyanidins (PAs) are a group of polyphenols enriched in plant and human food. In recent decades, epidemiological studies have upheld the direct relationship between PA consumption and health benefits; therefore, studies on PAs have become a research hotspot. Although the oral bioavailability of PAs is quite low, pharmacokinetics data revealed that some small molecules and colonic microbial metabolites of PAs could be absorbed and exert their health beneficial effects. The pharmacological effects of PAs mainly include anti-oxidant, anticancer, anti-inflammation, antimicrobial, cardiovascular protection, neuroprotection, and metabolism-regulation behaviors. Moreover, current toxicological studies show that PAs have no observable toxicity to humans. This review summarizes the resources, extraction, structures, pharmacokinetics, pharmacology, and toxicology of PAs and discusses the limitations of current studies. Areas for further research are also proposed.

Effects of grape products on blood lipids: a systematic review and dose–response meta-analysis of randomized controlled trials

Grape products through several plausible mechanisms-of-action are reported to improve lipid profile. The present systematic review revealed that grape product supplementation might have a positive effect on achieving a lipid profile target.

Strategies to decrease oxidative stress biomarker levels in human medical conditions: A meta-analysis on 8-iso-prostaglandin F2α

The widespread detection of elevated oxidative stress levels in many medical conditions has led to numerous efforts to design interventions to reduce its effects. Efforts have been wide-ranging, from dietary changes to administration of antioxidants, supplements, e.g., omega-3-fatty acids, and many medications. However, there is still no systemic assessment of the efficacy of treatments for oxidative stress reduction across a variety of medical conditions. The goal of this meta-analysis is, by combining multiple studies, to quantitate the change in the levels of the popular oxidative stress biomarker 8-iso-prostaglandin F2α (8-iso-PGF2α) after a variety of treatment strategies in human populations. Nearly 350 unique publications with 180 distinct strategies were included in the analysis. For each strategy, the difference between pre- or placebo and post-treatment levels calculated using Hedges' g value of effect. In general, administration of antibiotics, antihyperlipidemic agents, or changes in lifestyle (g = - 0.63, - 0.54, and 0.56) had the largest effect. Administration of supplements, antioxidants, or changes in diet (g = - 0.09, - 0.28, - 0.12) had small quantitative effects. To fully interpret the effectiveness of these treatments, comparisons to the increase in g value for each medical condition is required. For example, antioxidants in populations with coronary artery disease (CAD) reduce the 8-iso-PGF2α levels by g = - 0.34 ± 0.1, which is quantitatively considered a small effect. However, CAD populations, in comparison to healthy populations, have an increase in 8-iso-PGF2α levels by g = 0.38 ± 0.04; therefore, the overall reduction of 8-iso-PGF2α levels is ≈ 90% by this treatment in this specific medical condition. In conclusion, 8-iso-PGF2α levels can be reduced not only by antioxidants but by many other strategies. Not all strategies are equally effective at reducing 8-iso-PGF2α levels. In addition, the effectiveness of any strategy can be assessed only in relation to the medical condition investigated.

Fruits for Prevention and Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVDs) are leading global health problems. Accumulating epidemiological studies have indicated that consuming fruits was inversely related to the risk of CVDs. Moreover, substantial experimental studies have supported the protective role of fruits against CVDs, and several fruits (grape, blueberry, pomegranate, apple, hawthorn, and avocado) have been widely studied and have shown potent cardiovascular protective action. Fruits can prevent CVDs or facilitate the restoration of morphology and functions of heart and vessels after injury. The involved mechanisms included protecting vascular endothelial function, regulating lipids metabolism, modulating blood pressure, inhibiting platelets function, alleviating ischemia/reperfusion injury, suppressing thrombosis, reducing oxidative stress, and attenuating inflammation. The present review summarizes recent discoveries about the effects of fruits on CVDs and discusses potential mechanisms of actions based on evidence from epidemiological, experimental, and clinical studies.

Assessment of the effect of grape seed cake inclusion in the diet of healthy fattening-finishing pigs

Modulatory capacity of bioactive compounds from different wastes has been scarcely investigated in pigs. This study aimed to evaluate the effects of dietary inclusion of grape seed cakes (GS diet) on performance and plasma biochemistry parameters as health indicators, as well as on several markers related to inflammation and antioxidant defence in the liver of fattening-finishing pigs. Twelve cross-bred pigs (TOPIG) were randomly assigned to one of two experimental diets: control and 5% grape seed cake diet during finishing period (24 days). No effect of GS diet on pig performance and blood biochemistry was observed. However, GS diet decreased significantly (-9.05%, p < .05) the cholesterol concentration (85.71 ± 0.94 mg/dl vs 94.24 ± 2.16 mg/dl) and increased IgA level (+49.90%, p < .05) in plasma (5.04 ± 0.5 mg/ml vs 3.36 ± 0.7 mg/ml). GS cakes decreased the inflammatory response in the liver of pigs fed with GS diet by lowering the Gene expression and protein concentration of pro-inflammatory cytokines (IL-1β, IL-8, TNF-α and IFN-γ) as well as the mRNA abundances of NF-κB signalling molecules. The antioxidant status was not increased by GS diet. The gene expression and activity of catalase decreased significantly. The gene expression of Nrf2, superoxide dismutase, glutathione peroxidase and heat-shock protein decreased, and no effect on their activity was observed with the exception of catalase activity which decreased. However, TBARS was reduced significantly. GS diet showed a modulatory effect on antioxidative status as well as anti-inflammatory and hypocholesterolic properties without effect on pig performance.

Grape Polyphenols' Effects in Human Cardiovascular Diseases and Diabetes

The consumption of fruits and vegetables, as well as foods enriched in bioactive compounds and nutraceuticals, has increased due to consumers' interest in the relevance of food composition for human health. Considerable recent interest has focused on bioactive phenolic compounds in grape, as they possess many biological activities, such as antioxidant, cardioprotective, anticancer, anti-inflammation, anti-ageing and antimicrobial properties. Observational studies indicate that the intake of polyphenol-rich foods improves vascular health, thereby significantly reducing the risk of hypertension, and cardiovascular disease (CVD). Other researchers have described the benefits of a grape polyphenol-rich diet for other types of maladies such as diabetes mellitus. This is a comprehensive review on the consumption of polyphenolic grape compounds, concerning their potential benefits for human health in the treatment of cardiovascular diseases and diabetes.

Impact of nutrients and food components on dyslipidemias: what is the evidence?

Dyslipidemias have been shown to bear a close association with an increased risk of cardiovascular diseases, atherosclerosis in particular. As efforts are being made to find alternative therapies and ways to prevent disease, there is a corresponding rise in public interest in food and/or active food components that contribute to an improved lipid profile and, thus, to better health. Besides supplying the basic nutrients necessary for well-being, some foods add further physiologic benefits. In fact, specific foods and bioactive components could be beneficial in controlling dyslipidemias. From a review of the literature on foods and bioactive compounds, their recommended quantities, and expected effects, we found that the following nutrients and food components could positively impact the lipid profile: monounsaturated and polyunsaturated fatty acids, soluble fiber, vegetable proteins, phytosterols, and polyphenols. Therefore, incorporating these components into the regular diets of individuals is justified, because they contribute additional positive effects. This suggests that they also be recommended in clinical practice.

Effect of grape and other berries on cardiovascular health

Cardiovascular disease is a leading cause of death globally. Many cardiovascular risk factors can be modified through lifestyle modification, including dietary patterns that emphasize daily consumption of a variety of fruits and vegetables. Recent observational and clinical studies suggest that flavonoids, especially those abundant in grapes and other berries, may be associated with health benefits, particularly cardiovascular benefits. Human clinical data support cardioprotective benefits of grapes through inhibition of platelet aggregation, decreased low-density lipoprotein (LDL) oxidation, reduction in oxidative stress and improvements in endothelial function. Emerging evidence suggests that grapes may also have a favorable effect on blood lipids, decrease inflammation and reduce blood pressure in certain populations. Studies to date have shown that berries can have a beneficial effect on reducing LDL oxidation. Limited data suggest that berries may have a favorable effect on endothelial health and blood pressure. This review summarizes the current literature on human clinical studies examining the cardioprotective benefits of grapes and berries. Collectively, these data support the recommendation to incorporate products made with grapes and other berries into a heart-healthy diet.

Low molecular weight phenolics of grape juice and winemaking byproducts: antioxidant activities and inhibition of oxidation of human low-density lipoprotein cholesterol and DNA strand breakage

Bioactive compounds belonging to phenolic acids, flavonoids, and proanthocyanidins of grape juice and winemaking byproducts were identified and quantified by HPLC-DAD-ESI-MS(n). The concentration of phenolic compounds in different grape cultivars was in the order Tempranillo > Cora > Syrah > Isabel. The insoluble-bound fraction was most prominent, contributing 63 and 79% to the total for Isabel and Tempranillo, respectively. Juice-processing byproducts had a higher content of free than esterified phenolics, but the opposite was noted for winemaking byproducts. Insoluble-bound phenolics were up to 15 and 10 times more effective as antioxidants than those of free and esterified fractions, respectively, as evaluated by the DPPH, ABTS, and H2O2 scavenging activities and reducing power determinations. In general, insoluble-bound phenolics (100 ppm) were more effective in inhibiting copper-induced human LDL-cholesterol oxidation than free and esterified phenolics, exhibiting equal or higher efficacy than catechin. Phenolic extracts from all fractions inhibited peroxyl radical-induced DNA strand breakage. These findings shed further light for future studies and industrial application of grape byproducts, which may focus not only on the soluble phenolics but also on the insoluble-bound fraction.