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Condensed tannins (CT), one of the most ubiquitous compounds in the plant kingdom, can modulate ruminal nutrient metabolism. Objectives were to study potential interactions of CT and polyunsaturated fatty acids (PUFA) on ruminal fermentation, biohydrogenation (BH), and methane production. Ruminal fluid obtained from lactating Holstein Friesian cows was used. All experiments were carried out as a completely randomized design with the same mixed diet: control (60:40 forage:concentrate) without supplement (CON), 2.5% soybean oil (SBO), and SBO + grape seed tannin extract (GSTE) at 0.2%, 0.4%, 0.6%, or 0.8% dietary DM (ST0.2, ST0.4, ST0.6, and ST0.8, respectively). Compared with CON (84.7 mM), total VFA concentration was not affected by SBO, but decreased (P < 0.001) with ST0.8 vs. ST0.6 (75.3 vs. 78.3 mM). Relative to CON, methane production was depressed (P < 0.001) by 17.7% and 28.0% in ST0.4 and ST0.8. The highest (P < 0.001) mean concentrations of c9,t11 CLA and C18:1 t11 were observed with ST0.4 compared with CON, but there was no difference between SBO and CT-containing diets. Disappearance of C18:2 c9,c12 was 49.1% vs. 50.3% in CON vs. SBO, whereas it ranged from 39.9% to 46.3% in CT-containing diets after 2 h incubation (P < 0.001). Concentrations of c9,t11 CLA with supplemental SBO and ST0.8 nearly peaked (P < 0.001) at 2 h incubation, but this fatty acid peaked (P > 0.05) at 6 h incubation and remained higher (P < 0.001; 15.9-17.0 µg/mL) at 24 h incubation with ST0.2, ST0.4, and ST0.6 compared with other diets (13.5-14.5 µg/mL). Compared with CON (50.6 µg/mL), concentration of C18:1 t11 with SBO and CT-containing diets reached a peak (P < 0.001; 241-265 µg/mL) at 12 h incubation. Concentration of C18:0 was 171%-231% higher (P < 0.001) with SBO and CT relative to CON at 24 h incubation. Overall, these results demonstrated that PUFA in SBO are more effective in modulating ruminal BH and CH4 production when combined with CT. However, high doses of added CT can reduce ruminal VFA concentration. Thus, a level of 0.4% GSTE added to diets containing 2.5% PUFA from plant origin might be suitable for optimizing ruminal fermentation and BH of C18:2 c9,c12 to fatty acid intermediates that could have beneficial effects to human health., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

This study was conducted to evaluate the effects of grape seed extract (GSE) on growth performance, immunity, antioxidant capacity, relative organ weight, jejunum morphology, ileal microflora, and meat quality in Pekin ducks. A total of 1,500 female 1-day-old Pekin ducklings (52.0 ± 0.2 g) were blocked based on body weight (BW) and randomly allocated into 3 treatments with 10 replicates of 50 birds each. The experiment lasted for 6 wk, and dietary treatments included corn-soybean meal-based diet supplemented with 0, 0.01, and 0.02% GSE. The supplementation of GSE increased (P < 0.05) body weight gain (BWG) and final BW linearly but decreased (P < 0.05) feed-to-gain ratio (F/G) linearly during day (D) 22 to 42 and the entire experiment. The inclusion of GSE increased (P < 0.05) serum superoxide dismutase, glutathione peroxidase, total antioxidative capacity, catalase, complement4, immunoglobin G, interleukin-2, and interferon-γ linearly but decreased (P < 0.05) serum malondialdehyde linearly. The relative weight of carcass, breast meat, and spleen in GSE treatments was increased (P < 0.05) linearly, whereas the relative weight of abdominal fat was decreased linearly (P < 0.05). Birds fed GSE1 and GSE2 diets had lower (P < 0.05) cook loss, 2-thiobarbituric acid reactive substances, and drip loss on day 3 and 5 linearly but higher (P < 0.05) pH 24h and water-holding capacity. The addition of GSE decreased (P < 0.05) jejunum crypt depth and ileal Escherichia coli counts linearly but increased (P < 0.05) jejunum villus height: crypt depth ratio and ileal Lactobacilli linearly. Taken together, the inclusion of GSE increased final BW and BWG, decreased F/G during day 22 to 42 and day 1 to 42, partially improved antioxidant activities, immunity, meat quality, and gut health in Pekin ducks., (Copyright © 2019. Published by Elsevier Inc.)

Grape seed extracts (GSE) contain several beneficial bioactive constituents; therefore, can be utilized as a potential feed additive in broiler chickens. An experiment was conducted to investigate the effect of supplementation of broiler chicken diets with GSE as a natural antioxidant at levels of 125, 250, 500, 1000 and 2000 ppm on the growth performance, serum lipid profile, liver glutathione-reduced, thigh muscle malondialdehyde and humoral immune response against Newcastle disease virus vaccines. This experiment was performed during the life-span of chickens from 0 to 42 days of age. The results of broilers fed on diet supplemented by GSE were compared with those fed on the basal diet (control) or the basal diet supplemented by butylated hydroxytoluene as a synthetic antioxidant (BHT, 125 ppm). No significant differences were observed in the growth performance, percent livability, total lipid, high and very low-density lipoprotein cholesterols when the use of GSE or BHT were compared with the control. Total cholesterol and low-density lipoprotein cholesterol were significantly decreased after intake of GSE compared with BHT in the feed diet. The glutathione-reduced level in liver tissues was significantly increased by inclusion of GSE, but not by BHT. Inclusion of GSE or BHT decreased significantly the malondialdehyde level found in meat tissue. The antibody titer against Newcastle disease virus vaccines was significantly elevated in 28 and 35-day-old broiler chickens fed with a diet supplemented with GSE or BHT, the former providing a higher response. It can be concluded that GSE can be used as an effective natural antioxidant and immunostimulant agent in broiler chicken diets, and that 125 to 250 ppm can be considered as the optimum dosage.

Silk fibroin (SF) from Bombyx mori has an excellent biocompatibility and thus be widely applied in the biomedical field. Recently, various SF-based composite nanofibers have been developed for more demanding applications. Additionally, grape seed extract (GSE) has been demonstrated to be powerful on antioxidation. In the present study, we dedicate to fabricate a GSE-loaded SF/polyethylene oxide (PEO) composite nanofiber by green electrospinning. Our results indicated the successful loading of GSE into the SF/PEO composite nanofibers. The introduction of GSE did not affect the morphology of the SF/PEO nanofibers and GSE can be released from the nanofibers with a sustained manner. Furthermore, comparing with the raw SF/PEO nanofibrous mats, the GSE-loaded SF/PEO nanofibrous mats significantly enhanced the proliferation of the skin fibroblasts and also protected them against the damage from tert-butyl hydroperoxide-induced oxidative stress. All these findings suggest a promising potential of this novel GSE-loaded SF/PEO composite nanofibrous mats applied in skin care, tissue regeneration and wound healing., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The role of dried distillers grains plus solubles (DDGS) and associative effects of different levels of grape seed meal (GSM) fortified in DDGS, used as both protein and energy sources in the diet, on ruminal fermentation and microbiota were investigated using rumen-simulation technique. All diets consisted of hay and concentrate mixture with a ratio of 48:52 [dry matter (DM) basis], but were different in the concentrate composition. The control diet contained soybean meal (13.5% of diet DM) and barley grain (37%), whereas DDGS treatments, unfortified DDGS (19.5% of diet DM), or DDGS fortified with GSM, either at 1, 5, 10, or 20% were used entirely in place of soybean meal and part of barley grain at a 19.5 to 25% inclusion level. All diets had similar DM, organic matter, and crude protein contents, but consisted of increasing neutral detergent fiber and decreasing nonfiber carbohydrates levels with DDGS-GSM inclusion. Compared with the soy-based control diet, the unfortified DDGS treatment elevated ammonia concentration (19.1%) of rumen fluid associated with greater crude protein degradation (~19.5%). Methane formation decreased with increasing GSM fortification levels (≥ 5%) in DDGS by which the methane concentration significantly decreased by 18.9 to 23.4 and 12.8 to 17.6% compared with control and unfortified DDGS, respectively. Compared with control, unfortified DDGS decreased butyrate proportion, and GSM fortification in the diet further decreased this variable. The proportions of genus Prevotella and Clostridium cluster XIVa were enhanced by the presence of DDGS without any associative effect of GSM fortification. The abundance of methanogenic archaea was similar, but their composition differed among treatments; whereas Methanosphaera spp. remained unchanged, proportion of Methanobrevibacter spp. decreased in DDGS-based diets, being the lowest with 20% GSM inclusion. The abundance of Ruminococcus flavefaciens, anaerobic fungi, and protozoa were decreased by the GSM inclusion. As revealed by principal component analysis, these variables were the microorganisms associated with the methane formation. Grape seed meal fortification level in the diet decreased DM and organic matter degradation, but this effect was more related to a depression of nonfiber carbohydrates degradation. It can be concluded that DDGS fortified with GSM can favorably modulate ruminal fermentation., (Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

The concentration profiles and the absorbed fraction (F) of the País grape seed extract in the human small intestine were obtained using a microscopic model simulation that accounts for the extracts' dissolution and absorption. To apply this model, the physical and chemical parameters of the grape seed extract solubility (C s), density (ρ), global mass transfer coefficient between the intestinal and blood content (k) (effective permeability), and diffusion coefficient (D) were experimentally evaluated. The diffusion coefficient (D = 3.45 × 10(-6) ± 5 × 10(-8) cm(2)/s) was approximately on the same order of magnitude as the coefficients of the relevant constituents. These results were chemically validated to discover that only the compounds with low molecular weights diffused across the membrane (mainly the (+)-catechin and (-)-epicatechin compounds). The model demonstrated that for the País grape seed extract, the dissolution process would proceed at a faster rate than the convective process. In addition, the absorbed fraction was elevated (F = 85.3%). The global mass transfer coefficient (k = 1.53 × 10(-4) ± 5 × 10(-6) cm/s) was a critical parameter in the absorption process, and minor changes drastically modified the prediction of the extract absorption. The simulation and experimental results show that the grape seed extract possesses the qualities of a potential phytodrug.

With the aim of investigating the potential of flavan-3-ols to influence the growth of intestinal bacterial groups, we have carried out the in vitro fermentation, with human faecal microbiota, of two purified fractions from grape seed extract (GSE): GSE-M (70% monomers and 28% procyanidins) and GSE-O (21% monomers and 78% procyanidins). Samples were collected at 0, 5, 10, 24, 30 and 48 h of fermentation for bacterial enumeration by fluorescent in situ hybridization and for analysis of phenolic metabolites. Both GSE-M and GSE-O fractions promoted growth of Lactobacillus/Enterococcus and decrease in the Clostridium histolyticum group during fermentation, although the effects were only statistically significant with GSE-M for Lactobacillus/Enterococcus (at 5 and 10 h of fermentation) and GSE-O for C. histolyticum (at 10 h of fermentation). Main changes in polyphenol catabolism also occurred during the first 10 h of fermentation; however, no significant correlation coefficients (P > 0.05) were found between changes in microbial populations and precursor flavan-3-ols or microbial metabolites. Together, these data suggest that the flavan-3-ol profile of a particular food source could affect the microbiota composition and its catabolic activity, inducing changes that could in turn affect the bioavailability and potential bioactivity of these compounds., (© 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.)

We previously reported that (-)-epigallocatechin-3-gallate (EGCG) and grape seed extract (GSE) at high concentration nearly blocked intestinal iron transport across the enterocyte. In this study, we aimed to determine whether small amounts of EGCG, GSE, and green tea extract (GT) are capable of inhibiting iron absorption, to examine if ascorbic acid counteracts the inhibitory action of polyphenols on iron absorption, and to explore the mechanisms of polyphenol-mediated apical iron uptake and basolateral iron release. An(55)Fe absorption study was conducted by adding various concentrations of EGCG, GSE, and GT using Caco-2 intestinal cells. Polyphenols were found to inhibit the transepithelial (55)Fe transport in a dose-dependent manner. The addition of ascorbic acid offset the inhibitory effects of polyphenols on iron transport. Ascorbic acid modulated the transepithelial iron transport without changing the apical iron uptake and the expression of ferroportin-1 protein in the presence of EGCG. The polyphenol-mediated apical iron uptake was inhibited by membrane impermeable Fe(2+) chelators (P < 0.001), but at a low temperature (4°C), the apical iron uptake was still higher than the control values at 37°C (P < 0.001). These results suggest that polyphenols enhance the apical iron uptake partially by reducing the conversion of ferric to ferrous ions and possibly by increasing the uptake of polyphenol-iron complexes via the energy-independent pathway. The present results indicate that the inhibitory effects of dietary polyphenols on iron absorption can be offset by ascorbic acid. Further studies are needed to confirm the current findings in vivo.

Purpose: Oxidative damage induced by H₂O₂ treatment can irreversibly damage the lens epithelium, resulting in cell death and cataract. Grape seed extract (GSE) is a widely consumed dietary supplement that has the capability to scavenge oxidants and free radicals. GSE contain 70%-95% standardized proanthocyanidins. The study described herein investigated the protective effect of Grape seed proanthocyanidin extract (GSPE) on H₂O₂-induced oxidative stress in human lens epithelial B-3 (HLEB-3) cells and the possible molecular mechanism involved., Methods: HLE-B3 cells exposed to different doses of H₂O₂ were cultured with various concentrations of GSPE and subsequently monitored for cell viability by the 4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT) assay. The apoptosis rate and ROS generation were detected by flow cytometric analysis. Expression of NF-кB/P65 and mitogen activated protein kinase (MAPK) proteins were measured by western blot., Results: GSPE clearly reduced H₂O₂ induced cell apoptosis and reactive oxygen species (ROS) generation and protected HLEB-3 cells from H₂O₂ induced oxidative damage. GSPE depressed H₂O₂-induced activation and translocation of NF-кB/p65. GSPE also depressed H₂O₂-induced phosphorylation of the p38 and c-Jun N-terminal kinase (JNK) proteins of the MAPK family at various time points studied., Conclusions: GSPE could be useful in attenuation of H₂O₂-induced oxidative stress and the activation of NF-кB and MAPK signaling in HLE-B3 cells, which suggests that GSPE has a potential protective effect against cataractogenesis.

Among procyanidins (PC), monomers, such as catechin and epicatechin, have been widely studied, whereas dimer and trimer oligomers have received much less attention, despite their abundance in our diet. Recent studies have showed that as dimers and trimers could be important in determining the biological effects of procyanidin-rich food, understanding their bioavailability and metabolism is fundamental. The purpose of the present work is to study the stability of PC under digestion conditions, the metabolism and the bioavailability by using a combination of in vitro and in vivo models. Simultaneously, the matrix effect of a carbohydrate-rich food on the digestibility and bioavailability of PC is investigated. The results show a high level of stability of PC under gastric and duodenal digestion conditions. However, the pharmacokinetic study revealed limited absorption. Free forms of dimers and trimers have been detected in rat plasma, reaching the maximum concentration 1 h after oral intake of a grape seed extract.