Bioaccessibility and Antioxidant Capacity of Grape Seed and Grape Skin Phenolic Compounds After Simulated In Vitro Gastrointestinal Digestion

Grapes present recognized beneficial effects on human health due to their polyphenolic composition. The grape overproduction together with the wine sales down and the world socioeconomic situation makes the wine grape valorization a promising strategy to give an added-value to this natural product. The objective of the present work was to study the influence of in vitro gastrointestinal digestion on antioxidant capacity and polyphenolic profile of skin and seed extracts of different grape varieties (Tempranillo, Graciano, Maturana tinta and Hondarrabi zuri). After in vitro gastrointestinal digestion, total phenolic content (TPC) of seed polyphenolic extracts decreased significantly for all the varieties. The highest decrease was for Tempranillo going from 108 ± 9 to 50 ± 3 mg / g dry matter (dm). This variety also showed the highest decrease of 90% in antioxidant capacity. However, for all the skin polyphenolic extracts there was an increase in TPC. The highest variation was also for Tempranillo. It varied from 10.1 ± 0.8 to 55.1 ± 0.9 mg / g dm. Among red varieties Tempranillo skin polyphenolic extract showed the lowest undigested anthocyanin content but the highest bioaccessibility index (BI) of 77%. For flavanols, flavonols and procyanidins the seed polyphenolic extracts showed a BI at the intestinal phase between 11% for (+)-epicatechin gallate to 130% procyanidin A2. The results of this study suggest that grape skin extracts and grape seed extracts are a reliable source of bioaccessible antioxidant polyphenols, to be used for the development of antioxidant supplements with specific functionalities depending on the grape variety.

The Effects of Grape Seed Oligomeric Proanthocyanidin and Nisin on Dental Pulp Stem Cells

Objective

This study aimed to evaluate the biological effects of "proanthocyanidin" (PA), and "nisin" (Ni), on dental pulp stem cells (DPSCs) and LPS-induced DPSCs as well as their antimicrobial effects against S. aureus and E. coli.

Materials and methods

After characterization of DPSCs, cytotoxicity of PA and Ni on DPSCs were evaluated using a water-soluble tetrazolium salt (WST-1). The cytokines and chemokines released by DPSCs and the expression levels of IL-6, IL-8, and TNF alpha were detected with human Cytokine Array C5 and enzyme-linked immunosorbent assay (ELİSA), respectively. The antibacterial activities of PA and Ni were tested using the drop plate method.

Results

PA at 75 μg/ml increased cell viability, decreased TNF-α expression of DPSCs, did not show any cytotoxic effects on LPS-induced DPSCs, and also showed a tendency to decrease TNF-α expression. PA at 75 μg/ml exhibited higher expressions of TIMP-2, OPG, IL-7, and IL-8 in LPS-induced DPSCs compared to DPSCs. Ni at 100 μg/ml decreased TNF-α expression in DPSCs with no cytotoxic effects. It provided increased cell viability and a downregulation trend of TNF-α expression in LPS-induced DPSCs. Both Ni and PA provided strong antibacterial effects against S. aureus. Ni at 200μg/ml had strong antibacterial effects against E. coli without affecting negatively the viability of both DPSCs and LPS-induced DPSCs and showed anti-inflammatory activity by decreasing TNF-α expression. PA provided strong antibacterial effects against E. coli at 200 μg/ml but affected DPSCs viability negatively.

Conclusion

PA and Ni at specific concentrations exhibited immunomodulatory activity on DPSCs and LPS-induced DPSCs without any cytotoxic effects and strong antibacterial effects on S. aureus.

Novel grape seed extract nanoparticles attenuate amikacin-induced nephrotoxicity in rats

Amikacin (AMK), an antibiotic, is prescribed for treating various bacterial diseases like urinary tract infections, encephalitis, asthma and joint infections. The most significant side effects, which affect 1 to 10% of consumers, are kidney injury and ototoxicity. Several studies discussed the role of grape seed extract (GSE) in renoprotection against AMK. The current study aimed to extract Muscat of Alexandria grape seeds followed by its characterization to determine its bioactive components and elements. GSE nanoparticles was prepared and tested, in vitro, to determine its safety for the in vivo experiment. Experimental groups were control group I, AMK group II, GSE (50 mg/kg)-AMK group III, GSE (100 mg/kg)-AMK group IV, GSE NPs (25 mg/kg)-AMK group V and GSE NPs (50 mg/kg)-AMK group VI. Groups 2-6 received 100 mg/kg/day of AMK by intramuscular injection for two weeks for the induction of experimental nephrotoxicity. Groups 3-6 received daily doses of GSE or GSE NPs by oral gavage, concurrently, with AMK for two weeks. GSE was rich in polyphenol compounds like proanthocyanidins, phenolic acids like gallic and egallic acids, catechine and epicatechine. GSE NPs have a smooth surface and a size that ranged from 40 to 70 nm; and have an anti-oxidant, anti-inflammatory, anti-cytotoxic and anti-microbial in vitro effects. It reduced oxidative stress and inflammation that followed AMK administration; and attenuated the AMK-induced nephrotoxicity. GSE NPs were safe to be used in vivo as a renoprotective agent against AMK; where, it reduced the oxidative stress and inflammation.

Winery by-products as a feed source with functional properties: dose-response effect of grape pomace, grape seed meal, and grape seed extract on rumen microbial community and their fermentation activity in RUSITEC

BACKGROUND

Grape and winery by-products have nutritional values for cattle and also contain functional compounds like phenols, which not only bind to protein but can also directly affect microbiota and their function in the rumen. We characterized the nutritional and functional effects of grape seed meal and grape pomace as well as an effective dosage of grape phenols on ruminal microbiota and fermentation characteristics using a rumen simulation technique.

RESULTS

Six diets (each n = 8) were compared including a control diet (CON, no by-product), a positive control diet (EXT, CON + 3.7% grape seed extract on a dry matter (DM) basis), two diets with grape seed meal at 5% (GS-low) and 10% (GS-high), and two diets with grape pomace: at 10% (GP-low) and 20% (GP-high), on a DM basis. The inclusion of the by-product supplied total phenols at 3.4%, 0.7%, 1.4%, 1.3%, and 2.7% of diet DM for EXT, GS-low, GS-high, GP-low, and GP-high, respectively. Diets were tested in four experimental runs. All treatments decreased ammonia concentrations and the disappearances of DM and OM (P < 0.05) compared to CON. EXT and GP-high lowered butyrate and odd- and branch-chain short-chain fatty acids while increased acetate compared to CON (P < 0.05). Treatments did not affect methane formation. EXT decreased the abundance of many bacterial genera including those belonging to the core microbiota. GP-high and EXT consistently decreased Olsenella and Anaerotipes while increased Ruminobacter abundances.

CONCLUSION

The data suggest that the inclusion of winery by-products or grape seed extract could be an option for reducing excessive ammonia production. Exposure to grape phenols at a high dosage in an extract form can alter the rumen microbial community. This, however, does not necessarily alter the effect of grape phenols on the microbial community function compared to feeding high levels of winery by-products. This suggests the dominant role of dosage over the form or source of the grape phenols in affecting ruminal microbial activity. In conclusion, supplementing grape phenols at about 3% of diet DM is an effective dosage tolerable to ruminal microbiota.

The benefits of grape seed extract in neurological disorders and brain aging

Common neurological disorders, including neurodegenerative diseases, stroke, epilepsy, autism and psychiatric disorders, affect many people worldwide and threaten their lives and health by inducing movement disorders, behavioral disorders, or a combination of both. Oxidative stress and neuroinflammation play a central role in neuronal damage and neurological diseases induction and progression. In addition, protein homeostasis (proteostasis) impairment occurs in many neurodegenerative diseases, which plays a critical role in the progression of the pathology. Grape seed contains several flavonoids and non-flavonoids and exerts potent antioxidant and anti-inflammatory effects. In addition, polyphenols and flavanols can maintain cellular proteostasis. Since impaired proteostasis is closely involved in all amyloid diseases, particularly neurodegenerative diseases, grape seeds extract can be a valuable therapeutic agent. Therefore, this review discusses the protective and therapeutic mechanisms of grape seed against neurological disorders and, in the end, links GSE to microRNAs as future therapeutic developments.

UHPLC-Q-Orbitrap /MS2 identification of (+)-Catechin oxidation reaction dimeric products in red wines and grape seed extracts

B-type procyanidin dimers and (+)-catechin dimeric oxidation products were analyzed in grape seed extracts and red wines (UHPLC-Q-Orbitrap MS). The different dimers had different fragmentation patterns according to their interflavan linkage position. Oxidation dimeric compounds had a specific fragment ion at m/z 393, missing for B-Type dimers fragmentations. A fragment ion at m/z 291 occurred and was specific for oxidation dimeric compounds with a COC linkage. Higher level oxidation products had abundant specific fragments: m/z 425, 397 and 245. These fragmentations were useful to identify them in complex samples such as grape seed extracts and wines. Three grape varieties and three ripening stages were selected and the corresponding seed extracts were obtained. The analyses revealed an increasing trend for the oxidation markers during grape ripening. The analysis of Syrah wines (2018, 2014, 2010) showed a decreasing trend of these molecules during wine ageing which might be due to further oxidation.

Grape seed powder increases gastrointestinal motility

Grape seed is an important natural bioactive product with various health benefits. Interstitial cells of Cajal (ICCs) are pacemaker cells in the gastrointestinal (GI) tract. The present study investigated the effects of grape seed powder (GSP) on ICC properties and GI motility. GSP depolarized the pacemaker potentials of ICCs in a dose‑dependent manner. Y25130 or SB269970 slightly inhibited GSP‑induced effects. However, Y25130 and SB269970 together completely blocked GSP-induced effects. In the presence of inhibitors of protein kinase C, protein kinase A, or mitogen-activated protein kinase, GSP‑induced ICC depolarization was inhibited. GSP increased the intestinal transit rate in normal mice and in mice with acetic acid-induced GI motility disorder. In addition, the levels of motilin and substance P were elevated after GSP dosing. These results demonstrate that GSP can regulate GI motility, and therefore, it is a potential therapeutic agent for treating GI motility disorders.

Antioxidant and polyphenol content of different Vitis vinifera seed cultivars and two facilities of production of a functional bakery product

This study aimed to examine the differences between the antioxidant capacity, and the total polyphenol content of the seed of eight different grape varieties. We also attempt to create a functional loaf enriched with grape seed meal. To achieve this goal, 3, 6, and 9% of the grape seed meal were added to the loaves made of bread flour and gluten-free flour mixture, and then the changes in their antioxidant and polyphenol content were examined. Based on the results, there were significant differences between the polyphenol and antioxidant content of grape seed varieties. The antioxidant content of the grape seeds varied between 228.50 mg AAE/g (94.80 mg TE/g) and 438.33 mg AAE/g (181.86 mg TE/g) in case of fatty samples, and between 176.29 mg AAE/g (41.24 mg TE/g) and 424.91 mg AAE/g (99.40 mg TE/g) in case of defatted samples. The total polyphenol content of the fatty samples changed between 91.16 and 221.81 mg GAE/g; in case of defatted samples, it ranged from 46.01 to 207.68 mg GAE/g. Rhine Riesling contained the greatest amount of these compounds. The functionality of loafs was confirmed by spectrophotometric analysis. Total polyphenol content ranged from 0.91 to 3.16 mg GAE/g in case of wheat loafs, and from 1.39 to 5.92 mg GAE/g in case of gluten-free loafs, while the total antioxidant content changed between 0.70 and 6.44 mg AAE/g in case of wheat loafs, and ranged from 2.55 to 9.75 in case of gluten-free loafs.

GRAPHIC ABSTRACT

Evaluating the radioprotective effect of single dose and daily oral consumption of green tea, grape seed, and coffee bean extracts against gamma irradiation

INTRODUCTION

The aim of this study was to investigate and compare the radio-protective effect of green tea, grape seed, and coffee bean extracts in different oral consumption methods in mice.

MATERIALS AND METHODS

In this experimental-quantitative study 150 mice in 15 equally sized groups were used. For each extract, two groups received 200 mg/kg of herbal extracts' combination for 7 and 30 consecutive days before irradiation, and one group received 800 mg/kg of the extract 2 h before irradiation (3 Gy gamma-rays of Co-60). The similar groups were classified to receive a combination of the plant extracts (green tea, grape seed, and coffee bean). Irradiation without consuming plant extract (irradiated group), and a control group were also devised. Alkaline comet and micronucleus assays were used to investigate the radioprotective effect on mice blood and bone marrow cells, respectively.

RESULTS

Consumption of all plant extracts significantly decreased the radiation damage to blood and bone marrow cells, compared to the irradiated group (p < 0.01), with grape seed extract showing higher protective effect. Continuous daily oral consumption (one week/month) showed a significant higher radioprotective effect compared to single consumption (p < 0.05). Continuous consumption of the combination of the extracts showed a higher radio-protection in comparison to each of the plant extracts (p < 0.03).

CONCLUSIONS

The radioprotective effect of continuous consumption (for one week/month) of the plant extracts was greater than single dose. In continuous consumption protocols, we found the synergetic property and higher radioprotective effect of the plant extract combination compared to each one.

Changes in rainbow trout (Oncorhynchus mykiss) growth and mucosal immune parameters after dietary administration of grape (Vitis vinifera) seed extract

The effect of dietary grape (Vitis vinifera) seed extract (GSE) on growth performance and mucosal immune parameters in rainbow trout (Oncorhynchus mykiss) fry was studied. Fish (1.3 g mean weight) were randomly distributed in nine tanks (15 fish per tank) and fed diets containing GSE at 0 (control), 100, and 200 mg kg^-1for 60 days. The results showed that growth parameters were enhanced in both treatment groups compared to the control group. Histological examination of fish skin showed higher epidermis thickness, goblet cell density, and volume density in the GSE groups compared to the values of the control group. Furthermore, the villus height, goblet cell density, and intraepithelial lymphocytes were increased in the fish intestine in those fish fed GSE, with respect to control fish. Feeding fish with low dose of GSE (100 mg kg^-1) up-regulated the expression of some immune-relevant genes, including complement component 3 (C3), lysozyme (Lys), omDB-3, interferon gamma (IFN-γ), and tumor necrosis factor-α (TNF-α) in different mucosal tissues. However, feeding fish the high dose of GSE (200 mg kg^-1) mostly enhanced expression of these genes in the skin. Besides, skin mucus of fish fed GSE showed bactericidal activity against Yersinia ruckeri. It was concluded that GSE, especially at 100 mg kg^-1, modulates the growth performance and mucosal immunity of rainbow trout.

Elucidation of the 3D structure of grape seed 7S globulin and its interaction with malvidin 3-glucoside: A molecular modeling approach

Plant proteins are biopolymers with interesting technological applications for the food industry due to their ability to interact with phenolic compounds such as anthocyanins. The 3D structure of the 7S globulin from grape seed was elucidated for the first time using a homology model. The constructed 3D model showed that grape seed 7S globulin is rich in α-helices and β-sheets stabilized by six disulfide bridges. The interaction with the major grape anthocyanin malvidin-3-glucoside was also assessed by Docking and Molecular Dynamic simulation. Theoretical results demonstrated that 7S globulin interacts with Mv3glc through hydrogen, alkyl and π-alkyl bonds and the flavylium cation is oriented towards a hydrophobic region of the protein, being protected from hydration. Results provide valuable insights for understanding the mechanisms involved in the molecular interaction of grape anthocyanins with grape seed proteins that could be relevant to use them as potential color protecting agents in food industry applications.

root tip cells

Excessive doses of toxic metals such as cobalt may cause detrimental hazards to exposed organisms. Six groups of onion bulbs were formed to investigate the therapeutic effects of grape seed extract (GSE) against cobalt(II) nitrate (Co(NO₃)₂) exposure in Allium cepa L. root tips. Control group was irrigated with tap water, while the latter groups were exposed to 150 mg/L GSE, 300 mg/L GSE, 5.5 ppm Co(NO₃)₂, 5.5 ppm Co(NO₃)₂ + 150 mg/L GSE and 5.5 ppm Co(NO₃)₂ + 300 mg/L GSE, respectively. Co(NO₃)₂ treatment seriously inhibited the root growth, germination and weight gain of the bulbs. Mitotic index was significantly decreased, whereas the chromosomal aberrations and micronuclei incidence exhibited a remarkable increase. In addition, Co(NO₃)₂ induced a variety of anatomical disorders in onion roots. Lipid peroxidation levels of the cellular membranes were assessed measuring the malondialdehyde content (MDA). MDA amount in Co(NO₃)₂-treated group reached the highest level among all groups. Co(NO₃)₂ treatment enhanced the activity of superoxide dismutase and catalase. The addition of GSE to Co(NO₃)₂ solution substantially suppressed the negative effects of Co(NO₃)₂ in a dose-dependent manner by strengthening the antioxidant defence system and reducing the cytotoxicity. Moreover, there was a significant recovery in growth parameters following the grape seed addition to Co(NO₃)₂. GSE had a remarkable reduction in genotoxicity when treated as a mixture with Co(NO₃)₂. Overall data obtained from this investigation proved that GSE, as a promising functional by-product, had a protective effect on Allium cepa L. against the toxic effects of Co(NO₃)₂.

The effect of grape seed and green tea extracts on the pharmacokinetics of imatinib and its main metabolite, N-desmethyl imatinib, in rats

BACKGROUND

Imatinib is mainly metabolized by CYP3A4 and to a lesser extent by other isoenzymes, with N-desmethyl imatinib being its major equipotent metabolite. Being a CYP3A4 substrate, imatinib co-administration with CYP3A4 modulators would change its pharmacokinetic profile. The cancer chemoprevention potential and anticancer efficacy of many herbal products such as grape seed (GS) and green tea (GT) extracts had led to an increase in their concomitant use with anticancer agents. GS and GT extracts were demonstrated to be potent inhibitors of CYP3A4. The aim of this study is to investigate the effect of standardized GS and/or GT extracts at two different doses on the pharmacokinetics of imatinib and its metabolite, N-desmethyl imatinib, in SD-rats.

METHODS

Standardized GS and/or GT extracts were administered orally once daily for 21 days, at low (l) and high (h) doses, 50 and 100 mg/kg, respectively, before the administration of a single intragastric dose of imatinib. Plasma samples were collected and analyzed for imatinib and N-desmethyl imatinib concentrations using LC-MS/MS method, then their non-compartmental pharmacokinetic parameters were determined.

RESULTS

h-GS dose significantly decreased imatinib's Cmax and the [Formula: see text] by 61.1 and 72.2%, respectively. Similar effects on N-desmethyl imatinib's exposure were observed as well, in addition to a significant increase in its clearance by 3.7-fold. l-GT caused a significant decrease in imatinib's Cmax and [Formula: see text] by 53.6 and 63.5%, respectively, with more significant effects on N-desmethyl imatinib's exposure, which exhibited a significant decrease by 79.2 and 81.1%, respectively. h-GT showed similar effects as those of l-GT on the kinetics of imatinib and its metabolite. However, when these extracts were co-administered at low doses, no significant effects were shown on the pharmacokinetics of imatinib and its metabolite. Nevertheless, increasing the dose caused a significant decrease in Cmax of N-desmethyl imatinib by 71.5%.

CONCLUSIONS

These results demonstrated that the pharmacokinetics of imatinib and N-desmethyl imatinib had been significantly affected by GS and/or GT extracts, which could be partially explained by the inhibition of CYP3A-mediated metabolism. However, the involvement of other kinetic pathways such as other isoenzymes, efflux and uptake transporters could be involved and should be characterized.

Emulsion gels as delivery systems for phenolic compounds: Nutritional, technological and structural properties

Polyphenols have interesting antioxidant properties and could help prevent certain diseases. Emulsion gels (EGs) have characteristics that make them a promising alternative system for supplying several bioactive compounds simultaneously, among them polyphenols. We produced four EGs containing olive oil, soy protein and a cold gelling agent based on alginate. One basic formulation (ES) contained only these ingredients and was used as a reference, while the other three also contained different solid polyphenol extracts from grape seed (G), grape seed and olive (O) or grape total (T), called ESG, ESO and EST, respectively. The corresponding EGs were prepared by mixing soy protein, alginate, water and one of these types of polyphenol extract (G, O or T), using a homogenizer. Then, the olive oil was gradually added to the mixture and finally, each mixture was placed in a metal container under pressure and chilled for 24 h until they formed an EG. The composition (including concentrations of phenolic metabolites), and technological and structural properties of these EGs were evaluated. Hydroxytyrosol was identified in all the EGs, but ESO showed the highest (P < 0.05) content. The EGs with added polyphenols showed contents of gallic acid, flavanol monomers and derivatives, with ESG showing the highest (P < 0.05) content. All the EGs showed optimal thermal stability, while colour and texture parameters were significantly influenced by the type of polyphenol extract added. No significant differences in the frequency or half-bandwidth of the 2923 and 2853 cm^-1 infrared bands were observed.

The possible neuroprotective role of grape seed extract on the histopathological changes of the cerebellar cortex of rats prenatally exposed to Valproic Acid: animal model of autism

Autism Spectrum Disorder (ASD) is a heterogeneous neurodevelopmental disease characterized by defect in verbal and nonverbal communications. As, the cerebellum has the greatest number of neurons and synapses in the central nervous system so, the cerebellum has emerged as one of the target brain areas affected in autism. The aim of this work was to study the biochemical, immunohistochemical and ultrastructural characteristics of autism and the possible neuroprotective role of grape seed extract. In this study 28 male pups were divided into Control groups; Group I (saline), Group II (GSE 400 mg/kg), Group III (VPA 500 mg/kg) and Group IV (VPA and GSE). Cerebellar hemispheres were dissected out and prepared to determine the oxidative stress markers, histological, immunohistochemical and morphometric study were done. A significant elevation in oxidative stress markers in off spring of VPA treated rats in comparison to control group was detected. A significant decrease in the Purkinje cell count and nuclear size were observed. Numerous shrunken cells with hyperchromatic nuclei and ultrastructural degeneration of cytoplasmic organelles were detected. A significant rise in the area percentage of GFAP-positive immune stained cells in comparison to that of the control groups was seen. Strikingly, GSE revealed significant improvement in the oxidative stress markers and then the histological and morphometric picture of the cerebellum. GSE has neuroprotective effect on the cerebellum of VPA treated rats through its potent antioxidant effect.

Grape seed extract supplement increases bone callus formation and mechanical strength: an animal study

Background

The positive effects of grape seed proanthocyanidin extract (GSPE) on bone health, which is a potent antioxidant, are known but its effects on fracture healing are not sufficiently covered in the literature. This study aims to investigate the effects of GSPE on fracture healing and biomechanics of healing bone.

Materials and methods

Sixty-four adult Wistar-Albino male rats were divided into 8 groups of 8 animals in each group. Osteotomy was performed to the right femurs of all groups except the negative control (G1) and positive control (G2) groups, and intramedullary Kirchner wire was used for fixation. GSPE was given to half of the rats (G2-G4-G6-G8) 100 mg/kg/day by oral gavage. The rats were sacrificed on the tenth (G3–G4), twentieth (G5–G6), and thirtieth (G1–G2–G7–G8) days, respectively, and histopathological, radiological, and biomechanical examinations were performed.

Results

Histopathological examination of the specimens from the callus tissues revealed that bone healing was more prominent in the groups supplemented with GSPE (G4, G6, G8). There was a statistically significant improvement in radiological recovery scores and callus volumes in groups with GSPE. When biomechanical strengths were evaluated, it was found that GSPE increased bone strength not only in fracture groups but also in the positive control group (G2).

Conclusions

As a result, this study showed that GSPE, a potent anti-oxidant, had a positive effect on bone healing and improved mechanical strength of the healing bone.

The impact of distillation process on the chemical composition and potential prebiotic activity of different oligosaccharidic fractions extracted from grape seeds

The study was designed to evaluate how the distillation process is able to affect the composition and bioactivity of oligosaccharides contained in the grape seeds. Different oligosaccharidic fractions have been extracted both before and after grape pomace distillation in order to valorize this by-product. A multistep solid-phase extraction approach (C-18 and carbograph cartridges) has been applied to purify and fractionate the oligosaccharidic compounds. Chemical characterization of the fractions was performed using a UPLC-ESI-MSⁿ method. Complex oligosaccharides consist principally of neutral oligosaccharides rich in arabinose and glucose. Then, the oligosaccharides contained in the different fractions as potential functional ingredients with prebiotic activity toward well-known probiotic bacteria, such as Lactobacillus acidophilus and Lactobacillus plantarum, were evaluated. Data showed how, in some combination, oligosaccharidic fractions obtained may be considered a novel "functional ingredient" with potential prebiotic activity mainly towards L. acidophilus.

Growth of Clostridium perfringens in sous vide cooked ground beef with added grape seed extract

The growth of Clostridium perfringens from spore inocula was studied in sous vide cooked ground beef with added 0 to 3% grape seed extract (GSE). C. perfringens did not grow at 4 °C with or without GSE present. Lag time (LT) was 95 h in control samples at 15 °C, whereas 1-3% GSE addition significantly (p < .05) extended LT to 244 h or longer. Generation time (GT) in 3% GSE added beef was similar to that of control (19 h, 3% GSE versus 18 h, control) at 15 °C. At 20 °C, GT was 1.5 h in samples without GSE; however, 1-3% GSE addition extended GT about 2-3 folds (p < .05). Lag time at 20 °C was 23 h in control samples, while LT was 40-59 h in samples containing GSE. Interestingly, GSE did not affect LT at 25 °C; however, significantly (p < .05) longer GT was observed in 3% GSE added samples than the other sample groups. Additionally, GSE from 1 to 3% in beef extended the period needed to reach 6 log cfu/g at 15 or 20 °C, while 3% GSE was required at 25 °C. The findings suggest that GSE exhibits concentration and temperature dependent inhibitory effect on growth of C. perfringens in sous vide cooked ground beef. Grape seed extract can be used to extend the shelf-life and ensure the microbiological safety of sous vide cooked meat products.

Investigation of antioxidant ability of grape seeds extract to prevent oxidatively induced DNA damage by gas chromatography-tandem mass spectrometry

Phenolic compounds have been studied elaborately for their efficacy to improve health and to protect against a wide variety of diseases. Herein this study, different analysis methods were implemented to evaluate the antioxidant properties of catechin and cyanidin using their standard substances and as they found in the grape seeds extracts. Total phenol contents were 107.39±8.94mg GAE/g dw of grape seeds for grape seed extract (GSE) and 218.32±10.66mg GAE/g dw of grape seeds for acid-hydrolyzed grape seed extract (AcGSE). The extracts were analyzed by HPLC-DAD system and the results showed the presence of catechin, gallic acid, chlorogenic acid and ellagic acid in the processed methanolic extract and cyanidin, gallic acid and ellagic acid in the processed acidified methanolic extract. The protective abilities of catechin and cyanidin were tested against the oxidation of DNA. The results showed that cyanidin has better protection of DNA against oxidation than catechin. GSE and AcGSE were revealed to inhibit the oxidatively induced DNA damage. GSE decreased about 57% of damage caused by the Fenton control sample. This study could show new aspects of the antioxidant profiles of cyanidin and catechin.

Effect of plant extracts on lipid and protein oxidation of mackerel (Scomber scombrus) mince during frozen storage

The effects of different plant extracts [green tea extract (GTE), grape seed extract (GSE), and pomegranate rind extract (PRE)] at a level of 100 ppm equivalent phenolics and butylated hydroxytoluene (BHT) on the changes in quality of fish (Scomber scombrus) mince during 6 months frozen storage at -18 ± 1 °C were investigated. During storage, significant oxidative reactions in both the lipids and proteins were observed with the increase in thiobarbituric acid reactive substances (TBARS) and carbonyls and decrease in sulphydryl groups and protein solubility. BHT and PRE effectively inhibited lipid oxidation as lower peroxide and TBARS values were observed. Moreover, antioxidants added to minced fish significantly reduced protein oxidation compared to control without any antioxidant. The minced fish containing PRE had lower carbonyl and higher sulphydryl contents, but no significant differences for carbonyl and sulphydry contents were observed among antioxidant sources. Protein solubility decreased with increase in storage period. The loss of protein solubility was higher in control samples than in antioxidant treated ones. Among antioxidant sources, PRE was an excellent antioxidant toward both lipid and protein oxidations. Therefore, it could be a potential source of natural antioxidants in minced fish during frozen storage.

Masquelier's grape seed extract: from basic flavonoid research to a well-characterized food supplement with health benefits

Careful characterization and standardization of the composition of plant-derived food supplements is essential to establish a cause-effect relationship between the intake of that product and its health effect. In this review we follow a specific grape seed extract containing monomeric and oligomeric flavan-3-ols from its creation by Jack Masquelier in 1947 towards a botanical remedy and nutraceutical with proven health benefits. The preparation's research history parallels the advancing insights in the fields of molecular biology, medicine, plant and nutritional sciences during the last 70 years. Analysis of the extract's flavanol composition emerged from unspecific colorimetric assays to precise high performance liquid chromatography - mass spectrometry and proton nuclear magnetic resonance fingerprinting techniques. The early recognition of the preparation's auspicious effects on the permeability of vascular capillaries directed research to unravel the underlying cellular and molecular mechanisms. Recent clinical data revealed a multitude of favorable alterations in the vasculature upon an 8 weeks supplementation which summed up in a health benefit of the extract in healthy humans. Changes in gene expression of inflammatory pathways in the volunteers' leukocytes were suggested to be involved in this benefit. The historically grown scientific evidence for the preparation's health effects paves the way to further elucidate its metabolic fate and molecular action in humans.

Age related differences in the plasma kinetics of flavanols in rats

Dietary flavanols produce beneficial health effects; once absorbed, they are recognized as xenobiotics and undergo Phase-II enzymatic detoxification. However, flavanols with a degree of polymerization greater than 2 reach the colon, where they are subjected to microbial metabolism and can be further absorbed and undergo Phase-II reactions. In this sense, flavanols' health-promoting properties are mainly attributed to their metabolic products. Several age-related physiological changes have been evidenced, and it is known that flavanols' bioavailability is affected by internal factors. Therefore, this study aimed to elucidate whether animals of different ages, specifically young and adult rats, exhibit differences in their flavanol metabolism and plasma bioavailability. To accomplish this, an acute dose of a grape seed polyphenol extract was administered to male rats; after 2, 4, 7, 24 and 48 h, flavanols and their Phase-II and microbial metabolites were quantified by HPLC-ESI-MS/MS in plasma. The results indicated important age-related quantitative differences in plasma flavanol metabolites. Interestingly, adult rats presented a remarkable reduction in flavanol absorption and Phase-II flavanol metabolism. Consequently, microbial-derived flavanol metabolism is triggered by higher flavanol affluence in the colonic tract. Furthermore, young rats presented a faster metabolic profile than adult rats. Hence, our results indicate that the physiological bioactivities of flavanols may depend on age.

Preparative HSCCC isolation of phloroglucinolysis products from grape seed polymeric proanthocyanidins as new powerful antioxidants

Polymeric proanthocyanidins isolated from a grape seed phenolic extract were hydrolysed in the presence of phloroglucinol into monomer catechins and their nucleophile derivatives. Each of the phloroglucinolysis products was successfully separated and isolated in large amount by semi-preparative HSCCC technique under the optimized conditions based on a selection of suitable solvent system. The optimized solvent system consisted of n-hexane-ethyl acetate-water (1:80:80, v/v/v) with a combination of head-tail and tail-head elution modes. By only one-step HSCCC separation, the purity of each obtained phloroglucinolysis product, including monomer catechins and their nucleophile derivatives was above 76%, verified by UPLC. The structures of these products were tentatively identified by UPLC based on their retention time and further confirmed by MS and (1)H NMR analysis. Furthermore, by DPPH, ABTS and FRAP assays, it was verified that all these phloroglucinolysis products possessed strong antioxidant activities, being catechin-nucleophile derivatives more powerful than free catechins.

Effect of grape seed powder on oxidative stability of precooked chicken nuggets during frozen storage

The inhibitory effect of grape seed powder (GSP) on lipid oxidation in chicken nuggets during frozen storage for 5 months was investigated. Chicken nuggets were prepared by dipping into batter containing GSP and pre-fried at 180 °C and then stored at -18 °C. Prefried chicken nugget crusts showed antioxidant properties. Primary oxidation products, determined by the peroxide value (POV) and conjugated diene (CD) concentration, gradually increased until month 2 and then declined, which is an indication of secondary lipid oxidation. Thiobarbituric acid reactive substance (TBARS) values slowly increased during the first 2 months of storage and then slightly decreased. However, at the end of the storage period, the levels were increased to 0.4 mg MDA/kg meat and were lowest in 10 % GSP (0.104 mg MDA/kg meat). The para-anisidine values (pAV) increased in all samples during storage. Generally, samples treated with GSP had lower POV, pAV, TBARS, and CD values compared to the control. These findings indicated that GSP significantly (p < 0.05) retarded lipid oxidation in precooked chicken nuggets.

The effects of grape seed and colchicine on carbon tetrachloride induced hepatic damage in rats

This study aims to determine the effects of grape seed and colchicine on carbon tetrachloride (CCl4) induced hepatic damage and on some serum biochemical parameters. Sixty male Wistar albino rats (200-250 g) were randomly divided into six groups (ten rats/group) and included the control group the group were given isotonic sodium chloride (1 mL/kg b.w) intraperitonealy (i.p.), group 2 the group treated i.p. injection of CCl4 (1.0 mL/kg b.w) in corn oil twice in the first week, Groups 3 and 4 injected with CCl4 as described for group 2 and the rats were orally given (100 mg/kg b.w) GSE and i.p. injected (10 μg/rat) with colchicine for four weeks, respectively and groups 5 and 6 were the grape seed and colchicine control groups in which rats were orally given grape seed (100 mg/kg b.w) and i.p. injected with colchicine (10 μg/rat), respectively. Anorexia, weight loss, motionlessness and hepatic colour variation at necropsy were observed in groups 2, 3, and 4. Hyperemia, focal bleeding, fat degeneration, changes ranging from degenerative to necrotic, increase in connective tissue elements, pronounced in portal sites in particular, and infiltration of lymphoid series cell observed in the livers of the rats in group 2, treated with CCl4. Histological hepatic changes in the rats in group 3 and 4 were similar to those in group 2. The levels of serum total protein, albumin and globulin decreased in groups 2, 3, and 4, compared with groups 1, 5 and 6; aspartate transaminase (ALT) activities increased. The lowest alkaline phosphatase (ALP) activities were in groups 4 and 5. We concluded that GSE and colchicine have not sufficient ameliorative effects to CCl4 induced acute hepatic damage.

Suppression of oxidative stress by grape seed supplementation in rats

Polyphenol-rich grape seeds have a beneficial effect on human health. The present study was performed to investigate the effects of grape seeds on antioxidant activities in rats. Male Sprague-Dawley rats were randomly divided into a control diet group (C), a high-fat diet group (HF), a 5% grape seed-supplemented control diet group (G), and a 5% grape seed-supplemented high-fat diet group (HG). Dietary supplementation with grape seeds reduced serum concentrations of lipid peroxides compared with those in the C and HF groups. The hepatic level of lipid peroxides decreased significantly in the grape seed groups compared with that in the C and HF groups. Superoxide dismutase activity in the G group increased significantly compared with that in the C group. Catalase activity tended to be higher by feeding grape seeds. The grape seed diet increased glutathione peroxidase activity in the C group. Glutathione-S-transferase activity increased significantly in the G group compared with that in the C group. Hepatic content of total glutathione increased significantly in the HG group but decreased significantly in the HF group. The ratio of reduced glutathione and oxidized glutathione increased by feeding the grape seed diet. Total vitamin A concentration was significantly higher in HG group than in other groups. Liver tocopherol content of the G and HG groups was significantly higher than that of the control groups. These results suggest that dietary supplementation with grape seeds is beneficial for suppressing lipid peroxidation in high fat-fed rats.

Fatty acid composition, oxidative stability, antioxidant and antiproliferative properties of selected cold-pressed grape seed oils and flours

Cold-pressed chardonnay, muscadine, ruby red, and concord grape seed oils and their defatted flours were studied for their fatty acid composition, oxidative stability and antioxidant and antiproliferative activities. The phenolic profiles of the seed flours were also measured. The most abundant fatty acid in the oils was linoleic acid, ranging from 66.0g/100g of total fatty acids in ruby red seed oil to 75.3g/100g of total fatty acids in concord seed oil. The oils were also high in oleic acid and low in saturated fat. Ruby red grape seed oil recorded the highest oxidative stability index of 40h under the accelerated conditions. Total phenolic content (TPC) was up to 100 times lower in the oils than in the flours. Lutein, zeaxanthin, cryptoxanthin, β-carotene, and α-tocopherol levels were also measured. DPPH radical-scavenging capacity ranged from 0.07 to 2.22mmol trolox equivalents (TE)/g of oil and 11.8 to 15.0mmol TE/g of flour. Oxidative stability of menhaden fish oil containing extracts of the seed flours was extended by up to 137%. HPLC analysis was conducted to determine the levels of free soluble, soluble conjugated and insoluble bound phenolics in the seed flours. The phenolic compounds analyzed included catechin, epicatechin, epicatechin gallate, quercetin, gallic acid, and procyanidins B1 and B2. Antiproliferative activity was tested against HT-29 colon cancer cells. All of the seed flours and muscadine seed oil registered significant (P<0.05) inhibition of cancer cell growth. The results from this study demonstrate the potential of developing value-added uses for these seed oils and flours as dietary sources of natural antioxidants and antiproliferative agents for optimal health.