Concentrations Of Grape Seed Extract Research Articles

Heated and unheated lupin protein‐grape seed extract conjugates stabilizing and structuring high internal phase oil‐in‐water emulsions

AbstractPlant‐based high internal phase oil‐in‐water emulsions (HIPEs) are promising fat replacers. However, producing stable HIPES with improved viscoelastic properties is a challenge for the food industry. Conjugation of plant proteins, such as lupin protein isolate, with phenolic compounds, such as proanthocyanidins from grape seed extract, associated (or not) with moderate heat treatment arise as potential methods to tune the surface properties of proteins and, consequently, the droplet‐droplet interactions that drive the viscoelastic properties of HIPEs. In this way, unheated (UHC) and heated (85°C, 15 min) (HC) lupin protein (LPI)‐grape seed extract (GSE) conjugates were produced and used to stabilize HIPEs. Evaluation of stability by Turbiscan and oil loss by centrifugation over 56 days of storage did not reflect the kinetic stability of HIPEs against process conditions. Under shearing, UHC‐stabilized emulsions at high GSE concentrations showed oil release, whereas all HC‐stabilized HIPEs released oil. However, the increase in GSE concentration and heat treatment improved the viscosity and storage modulus (G′) of HIPEs, possibly due to the droplet‐droplet interaction originating from hydrophilic and hydrophobic interactions in UHC and HC‐stabilized HIPEs, respectively. This pivotal study confirmed that conjugation of a plant protein with GSE and heat treatment could improve the viscoelastic properties of HIPEs and produce HIPEs with superior texture (higher G′).

In Vitro Culture of Ovine Spermatogonial Stem Cells: Effects of Grape Seed Extracts and Vitamin C

Background: Spermatogonial stem cells (SSCs) transmit genetic information to the next generation. For the successful transplantation of these cells, the culture medium of these cells must be optimized. Objectives: This study investigated the natural antioxidant of grape seed extract (GSE) in comparison to vitamin C in the culture medium of SSCs. Methods: A Soxhlet extractor was used to prepare ethanolic and acetonic extracts, and the Clevenger apparatus was used to prepare aqueous extracts of grape seeds. Then, their antioxidant capacities were determined using the DPPH method. The SSCs were extracted from lamb testicular tissue by a two-step digestion method, and different concentrations of GSE and vitamin C were investigated for survival, colony formation, and expression of apoptotic-related genes. Results: The results showed that the acetonic extract in the concentration of 400 µg/mL showed about 90% antioxidant properties based on the DPPH test; nevertheless, the aqueous and ethanolic extracts had only 50% of their antioxidant properties at this concentration. The acetonic extracts significantly decreased the viability of SSCs without any colony formation when used in a culture medium. The highest survival rate was obtained from the ethanolic extracts of grape seeds at the concentration of 50 µg/mL, and a significant difference was obtained with ethanolic extracts (100 to 1000 µg/mL) (P < 0.05). The viability of SSCs treated with vitamin C (50 µg/mL) was significantly higher (P < 0.05) than the control and 5 - 25 µg/mL of vitamin C groups. Conclusions: Aqueous, ethanolic, and acetonic extracts of grape seeds should not be used in the culture of SSCs. However, the use of 25 - 50 µg/mL of vitamin C is recommended in the culture of SSCs.

Low concentrations of grape seed extract maintain osteoblast morphology, cell adhesion, and mineralization.

The increase in life expectancy has led to a higher incidence of osteoporosis, characterized by an imbalance in bone remodeling. Several drugs are used for its treatment, but most promote undesirable side effects. The present investigation evaluated the effects of two low concentrations of grape seed extract (GSE) rich in proanthocyanidins on MC3T3-E1 osteoblastic cells. The cells were cultured in an osteogenic medium and divided into control (C), 0.1 µg/mL GSE (GSE0.1), and 1.0 µg/mL GSE (GSE1.0) groups to evaluate cell morphology, adhesion, and proliferation, in situ alkaline phosphatase (ALP) detection, mineralization and immunolocalization of osteopontin (OPN). The data obtained were analyzed by statistical tests for a significance of 5%. Cell morphology was maintained with both GSE concentrations, whereas cell adhesion significantly increased within three days in all groups. Cell proliferation increased significantly at seven days of culture, followed by a significant decrease in all experimental periods, with no statistical difference among them. In situ detection of ALP and mineralization increased with time, but within each period, no statistical differences among groups were observed. The expression of osteopontin was distributed regularly with more intensity after 24 hours in the GSE0.1 group. After three days, OPN expression was more intense in the control group, followed by GSE0.1 and GSE1.0 groups. Data obtained suggest that low concentrations of GSE do not affect the morphology and may stimulate the functional activity of osteoblastic cells.

A Systematic Quantitative Determination of the Antimicrobial Efficacy of Grape Seed Extract against Foodborne Bacterial Pathogens

Concerns regarding the role of antimicrobial resistance (AMR) in disease outbreaks are growing due to the excessive use of antibiotics. Moreover, consumers are demanding food products that are minimally processed and produced in a sustainable way, without the use of chemical preservatives or antibiotics. Grape seed extract (GSE) is isolated from wine industry waste and is an interesting source of natural antimicrobials, especially when aiming to increase sustainable processing. The aim of this study was to obtain a systematic understanding of the microbial inactivation efficacy/potential of GSE against Listeria monocytogenes (Gram-positive), Escherichia coli and Salmonella Typhimurium (Gram-negative) in an in vitro model system. More specifically, for L. monocytogenes, the effects of the initial inoculum concentration, bacterial growth phase and absence of the environmental stress response regulon (SigB) on the GSE microbial inactivation potential were investigated. In general, GSE was found to be highly effective at inactivating L. monocytogenes, with higher inactivation achieved for higher GSE concentrations and lower initial inoculum levels. Generally, stationary phase cells were more resistant/tolerant to GSE as compared to exponential phase cells (for the same inoculum level). Additionally, SigB appears to play an important role in the resistance of L. monocytogenes to GSE. The Gram-negative bacteria under study (E. coli and S. Typhimurium) were less susceptible to GSE as compared to L. monocytogenes. Our findings provide a quantitative and mechanistic understanding of the impact of GSE on the microbial dynamics of foodborne pathogens, assisting in the more systematic design of natural antimicrobial-based strategies for sustainable food safety.

Nano and micro lupin protein-grape seed extract conjugates stabilizing oil-in-water emulsions

Conjugation of plant proteins with phenolic compounds has been an efficient strategy to improve the limited capacity of this kind of protein to stabilize emulsions. In this sense, the stabilizing capacity of lupin protein-grape seed extract conjugates in the form of nano (NC) or micro (MC) particles was evaluated in oil-in-water emulsions. Covalent binding between lupin protein isolate (LPI) and grape seed extract (GSE) was confirmed by quantification of total free sulfhydryl groups and fluorescence assays in both NC and MC for all GSE concentrations tested (0.04–1.2 wt%). The main differences between MC and NC were the larger size and surface hydrophobicity of the former, reflecting different stabilizing capacities. The droplet size and microstructure of all emulsions after 28 days of storage suggest that NC- and MC-stabilized emulsions were highly stable to coalescence. However, NC produced emulsions with a higher tendency to flocculation. Increasing the GSE concentration in the conjugates attenuated the droplet flocculation, resulting in emulsions with improved kinetic stability. Results indicate that the dominant stabilizing mechanism of the conjugates is Pickering-type, although others may occur simultaneously. Indeed, MC produced emulsions with better stability with no visible creaming and more complex rheological properties. A gel-like behavior (G’>G’’) was observed from oscillatory rheology, which was considered an additional stabilizing mechanism. In contrast, NC produced emulsions with predominantly liquid-like behavior (G’’>G’). Shear resistance was evaluated after homogenization of the emulsions, showing that the 3D network formed in the emulsions was rapidly recovered, including the highly structured MC-stabilized emulsions. Different properties of emulsions stabilized by NC or MC indicate potential varied applications in the food industry. The conjugation of GSE with LPI showed improvements in the overall stability of the emulsions, demonstrating the great potential for usage of these conjugates in the formulation of highly stable emulsion-based systems, even using a protein of limited stabilizing capacity.

Biodegradable Active Packaging Material Containing Grape Seed Ethanol Extract and Corn Starch/κ-Carrageenan Composite Film.

An active film composed of corn starch/κ-carrageenan and ethanolic grape seed extract (0, 1, 3, and 5 wt% of GSE on corn starch basis) were successfully prepared using the solvent casting technique. The effects of the different concentrations of ethanolic grape seed extract (GSE) on the physicochemical properties, antioxidant properties, and antibacterial properties of CS/κC films were analyzed. The results showed that the addition of GSE inhibited the recrystallization of starch in the composite film. The glass transition temperature of composite film is 121.65 °C. With the addition of GSE, the surface roughness of the composite film increased, and the cross-section displayed a stratification phenomenon. Meanwhile, when GSE was added to the composite film, the tensile strength of the composite film decreased (3.50 ± 0.27 MPa), the elongation at break increased (36.87 ± 2.08%), and the WVP increased (1.58 ± 0.03 g mm/m2·d· kPa). With the increase of the concentration of GSE in the composite film, the a* value and b* value of the composite film increase, the L* value decreases, and the opacity increases. The lipid oxidation test proved that the composite films containing 1% GSE has a significant inhibitory effect on the oxidation of lard (p < 0.05). The above results indicate that the GSE can be used as a food-grade packaging material and has a good application prospect in the food industry.

Air frying combined with grape seed extract inhibits Nε-carboxymethyllysine and Nε-carboxyethyllysine by controlling oxidation and glycosylation

Advanced glycation end products (AGE), compounds formed in meat at the advanced stage of Maillard reaction, are easily exposed to thermal processing. Improving cooking condition and adding antioxidants are 2 common ways for AGE reduction. The present work compared the inhibition of grape seed extract (GSE) on levels of free and protein-bound Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL) in chicken breast under deep-frying and air-frying conditions. Efficiency of 5 concentrations of GSE (0.0, 0.2, 0.5, 0.8, and 1.0 g/kg) in retarding oxidation, glyoxal (GO), methylglyoxal (MGO), lysine (Lys), Maillard reaction degree (A294, A420), and Shiff's base were tested. Results showed that 0.5 g/kg GSE before heating significantly (P < 0.05) reduced AGE in fried breast chicken, whereas excessive supplementation of GSE (0.8 and 1 g/kg) was reverse. Air frying was found significantly (P < 0.05) better than deep frying to reduce the precursor substances (GO, MGO, and Lys) of AGE. In conclusion, GSE-derived polyphenols exhibited different inhibitory effects on oxidation and glycosylation at different concentrations. We found that 0.5 g/kg of GSE combined with air frying was the best recommendation for inhibiting CML and CEL.

Could a higher crosslink concentration affect the bond strength of fiberglass post using different modes of universal adhesive?

Grape seed extract (GSE) is a proanthocyanidin-rich plant-derived agents and have been shown to increase dentin biomechanical properties and resistance of dentin collagen to degradation. High GSE concentrations had never been studied for bond strength (μTBS) maily in root canal dentin. This study investigated the effect of high concentrations of GSE in a shorter clinical time on the bond strength of fiberglass posts through the application of Universal adhesive in two modes (etch-and-rinse and self-etching).Seventy-two single-rooted bovine teeth were prepared and divided randomly into six groups (n = 12) according to surface treatment and application mode of Universal adhesive. Two groups were etched with 37% phosphoric acid to expose collagen fibrils and a biomodification agent was applied next at two different higher concentrations (30% and 50% GSE), for 1 min. For the other two groups, GSE was previously applied and after Single Bond adhesive was used in self-etching system mode. The other sample were divided in two groups without GSE application, in the total-etch and self-conditioning of universal adhesive. Then, the fiber posts were enveloped with composite resin and cemented with RelyX Ultimate. The samples were sectioned in discs with thickness of 1 mm and submitted to the push-out test at 0.5 mm/min. Two teeth from each group were prepared for confocal electron microscopy to understand the adhesive behavior on dentin biomodified by GSE. The data presented homogeneity and were statistically analyzed using two-way ANOVA and Bonferroni's complementary analysis (α = 0.01). The 50% GSE used with the self-etching system maintained the μTBS values when compared to its control group (p > 0.0172). The values of etch-and-rinse groups reduced after using 30% and 50% GSE (p < 0.0001), but were similar among each other (p = 1.00). Based on the confocal images and μTBS values we can suggest that higher GSE concentration promotes buffering of collagen fibrils when the dentin was previously demineralized with phosphoric acid. However, when GSE was used as self-etching mode, it could lead the GSE particles along with adhesive, keeping μTBS values similar to the control group.

Preliminary Studies on the Application of Grape Seed Extract in the Dyeing and Functional Modification of Cotton Fabric

Cotton has the shortcomings of having no antibacterial, antioxidant and ultraviolet (UV) protection properties, which are of great importance for health protection purposes. In the present study, grape seed extract (GSE) mainly composed of proanthocyanins (tannins) was employed to simultaneously import pale colors and the three aforementioned functions to cotton fabric. The tests on the application conditions of GSE showed that pH and GSE concentration had great impact on the color depth of cotton fabric, and the color hue of dyed fabric could be controlled in the absence of pH regulators due to the weakly acidic nature of GSE solution. The fabric dyed with 10%owf (on the weight of fabric) GSE exhibited an excellent inhibition effect towards Escherichia coli, whereas the one dyed with 20%owf GSE had high antioxidant activity of 97%. The fabric dyed with 5%owf GSE offered excellent UV protection. This study reveals that GSE can be used as a functional finishing agent for health protection in cotton textiles in addition to coloration capability.

Estrogen Receptor Beta (ERβ) May Act as Mediator in Apoptotic Induction of Grape Seed Extract (GSE)

Background:Grape seed extract is a complex mixture of polyphenols. Its anti-tumor effects have been reported by several studies. Estrogen receptors (ERs) are commonly considered as important markers for breast cancer. The present study aimed to evaluate the apoptotic effects of GSE on MCF7 breast cancer cells and assessed the expression of ERβ during treatment of cells with GSE. Material and Methods:The half maximal inhibitory concentration (IC50) of GSE in MCF7 breast cancer cells were calculated by treating cells with serial dilution of GSE for 48 hours and cell viability evaluated using MTT assay. Then cells assigned to three groups: control (no treatment), DMSO (cells treated with 0.05% of DMSO) and GSE group (cells treated with of GSE for 48 hours). The apoptosis assay was performed by detecting Annexin V protein by flow cytometry. The gene expression of ERβ and caspase-3 was evaluated by Real-Time PCR. Results:Cells in GSE group treated with GSE IC50 concentration for 48 hours. Annexin V staining assay, represented early apoptosis detected by flow cytometry analysis showed significantly higher expression (p<0.01) than control and DMSO groups. Moreover, results of Real-Time PCR showed a significant expression in ERβ and caspase-3 genes in GSE group compared to control and DMSO groups (Fold change = 2.3 and 3.5, respectively). Conclusion:GSE may induce apoptosis in MCF7 human breast cancer cells by activation of ERβ gene.

Effects of Grape Seed Extract and Proanthocyanidin B2 on In Vitro Proliferation, Viability, Steroidogenesis, Oxidative Stress, and Cell Signaling in Human Granulosa Cells.

Reactive oxygen species (ROS) which lead to oxidative stress affect ovarian function. Grape seed extract (GSE) could be proposed as an effective antioxidant, particularly due to its proanthocyanidin content. In this study, we investigated a dose effect (0, 0.01, 0.1, 1, 10, 50, and 100 μg/mL) of GSE and proanthocyanidin B2 (GSPB2) on the ROS content, cell proliferation, cell viability, and steroidogenesis in both primary luteinized granulosa cells (hGC) and the tumor granulosa cell line (KGN). The levels of ROS were measured using ROS-Glo assay. Cell proliferation and viability were evaluated by [3H]-thymidine incorporation and Cell Counting Kit-8 (CCK8) assay, respectively. Steroid secretion was evaluated by radioimmunoassay. We also analyzed the cell cycle component protein level and signaling pathways by immunoblot and the NOX4 mRNA expression by RTqPCR. From 0.1 to 1 μg/mL, GSE and GSBP2 reduced the ROS cell content and the NOX4 mRNA levels, whereas, GSE and GSBP2 increased the ROS cell content from 50 to 100 μM in both hGC and KGN. GSE and GSPB2 treatments at 50 and 100 μg/mL induced a delay in G1 to S phase cell cycle progression as determined by fluorescence-activated cell sorting. Consequently, they reduced cell growth, cyclin D2 amount, and Akt phosphorylation, and they increased protein levels of p21 and p27 cyclin-dependent kinase inhibitors. These data were also associated with an increase in cell death that could be due to a reduction in Bcl-2-associated death promoter (BAD) phosphorylation and an increase in the cleaved-caspase-3 level. All these negative effects were not observed at lower concentrations of GSE and GSPB2 (0.01 to 10 μg/mL). Interestingly, we found that GSE and GSPB2 treatments (0.1 to 100 μg/mL) improved progesterone and estradiol secretion and this was associated with a higher level of the cholesterol carriers, StAR (steroidogenic acute regulatory protein), CREB (Cyclic adenosine monophosphate Response Element-binding protein), and MAPK ERK1/2 (Mitogen-Activated Protein Kinases Extracellular signal-Regulated Kinases 1/2) phosphorylation in both hGC and KGN cells. Taken together, GSE and GSPB2 (0.1–10 μg/mL) in vitro treatments decrease oxidative stress and increase steroidogenesis without affecting cell proliferation and viability in human granulosa cells.

Effect of grape seed extract on heat resistance of Clostridium perfringens vegetative cells in sous vide processed ground beef

The heat resistance (57.5–65 °C) of a three-strain cocktail of Clostridium perfringens vegetative cells in sous vide processed ground beef supplemented with 0–3% grape seed extract (GSE) was quantified. The surviving cell population was enumerated on tryptose–sulfite–cycloserine agar. The decimal reduction (D)-values in beef that included no GSE were 67.11, 17.15, 4.02, and 1.62 min at 57.5, 60, 62.5, and 65 °C, respectively. Addition of 1.0% GSE resulted in concomitant decrease in heat resistance as evidenced by reduced bacterial D-values. The D-values in beef with added 1.0% GSE were 62.89, 13.70, 3.47 and 1.46 min at 57.5, 60, 62.5, and 65 °C, respectively. The heat resistance was further decreased when the GSE concentration in beef was increased to 2 or 3%. The z-values in beef with or without GSE were similar, ranging from 4.41 to 4.56 °C. The results of this study would be beneficial to the retail and institutional food service establishments in estimating re-heating time and temperature for sous vide processed ground beef to ensure safety against C. perfringens.

Dual Anticoagulant/Antiplatelet Activity of Polyphenolic Grape Seeds Extract.

Because of the side-effects of commonly used anti-platelet and anticoagulant drugs, investigations into plant substances with similar activities are very common. Based on our own studies in recent years, we estimate that it is possible to use natural compounds to both inhibit coagulation pathway enzymes and to reduce blood platelets’ activation. As such, in our current study we wanted to verify the anti-platelet and anticoagulant properties of grape seed extract (GSE) using in vitro models. During our analysis, the following parameters were analyzed: Coagulation times, thromboelastometry assays (coagulation time, clot formation time and maximum clot firmness), aggregation of platelets and phosphorylation of vasodilator-stimulated phosphoprotein (VASP). Adenosine diphosphate (ADP)-induced aggregation was lower in GSE 7.5 µg/mL as well as in GSE 15.0 µg/mL. A similar dependence was observed in VASP assays for GSE 7.5 µg/mL and GSE 15 µg/mL. The effect on plasma coagulation tests was distinct only with GSE 15 µg/mL. All of the thromboelastometry variables were statistically significant with 15.0 µg/mL GSE concentration. Our results show, for the first time, the multi-potential effect of grape seed extract on coagulation systems, and clearly suggest that grape seed extract could be considered a promising nutraceutical in the prevention of cardiovascular thrombotic events caused by different mechanisms.

Direct and transdentinal biostimulatory effects of grape seed extract rich in proanthocyanidin on pulp cells.

To evaluate the potential biostimulatory effects of grape seed extract (GSE) on a primary culture of human pulp cells. Human molars were used to obtain the primary pulp cell culture and 0.5-mm dentine discs. For GSE direct exposure, dose-response (0.0065-6.5%) and time response (1-60min of contact) were examined. For transdentinal exposure, 0.65% of GSE was tested for 24h. Cellular metabolism, nitric oxide and collagen production, and cell morphology alterations were assessed at periods of 24 and 72h. After cell differentiation and direct exposure to GSE, the total protein production (TP), alkaline phosphatase activity (ALP) and formation of mineralization nodules (MN) were assessed. The results were analysed by parametric tests or non-parametric tests (α=0.05). The lower concentration of GSE tested (0.0065%) was associated with an increase in cellular metabolism, a reduction in the production of nitric oxide and an increase in extracellular matrix synthesis (collagen). Distinct behaviours were observed for the different concentrations, without a reduction of cellular metabolism >10% compared with the control, either when applied directly or transdentinally. SEM revealed no significant change in cell morphology, except for the positive control (H2 O2 ). There was no difference in TP, ALP or MN between the control group and the group exposed to GSE. Treatment with grape seed extract, even at the highest concentration and longest period, caused neither direct nor transdentinal cytotoxic effects on human pulp cells. Grape seed extract components may play a biostimulatory role and protect dental pulp cells when in direct contact.

Bisphenol A vascular toxicity: Protective effect of Vitis vinifera (grape) seed extract and resveratrol.

The underlying mechanism of Bisphenol A (BPA)-induced vascular toxicity and the protective role of grape seed extract (GSE) and resveratrol were investigated in vitro and in vivo. Human umbilical vein endothelial cells (HUVECs) were exposed to different concentrations of GSE and resveratrol. Then, BPA was added to the cells and cell viability and effects on the protein level of cell adhesion molecules were measured through MTT and western blotting. Animals were randomly divided into control, GSE (3 and 12mg·kg-1 ·day-1 ip), resveratrol (100mg·kg-1 ·day-1 ip), BPA (35mg·kg-1 ·day-1 , gavage), BPA plus GSE (3, 6, and 12mg·kg-1 ·day-1 ip), BPA plus resveratrol (25, 50, and 100mg·kg-1 ·day-1 ip), and BPA plus vitamin E (200IU/kg per every other day ip). After 2months, contractile and relaxant responses were evaluated on the isolated aorta. BPA increased the level of aorta malondialdehyde (p<0.001) and decreased vascular responses to KCl (p<0.01), phenylephrine (p<0.001), and acetylcholine (p<0.01). In HUVECs, BPA (IC50 : 220μM) increased protein level of vascular cell adhesion molecule (p<0.05) and cleaved capase3 (p<0.001). GSE, resveratrol, and vitamin E cotreatment restored toxic effects of BPA in some levels. BPA vascular toxicity was attributed to lipid peroxidation and endothelial dysfunction. The protective role of GSE and resveratrol against BPA-endothelial dysfunction could be attributed to their potent antioxidant properties.

The effects of Chitosan and grape seed extract-based edible films on the quality of vacuum packaged chicken breast fillets

The effect of grape seed extract (GSE) (at 5, 10 and 15%) incorporated into chitosan (CH) film was evaluated by considering its physico-mechanical properties, antioxidant and antimicrobial activities in order to show improved shelf life for vacuum-packed food under refrigerated conditions. GSE-incorporated films showed higher water vapor permeability, elastic modulus, opacity, and a* and b* values (p < 0.05). Increasing the GSE concentration lowered the transmittance and L* values. The addition of GSE provided antioxidant activity to the CH films and the addition of 15% GSE into CH films inhibited the oxidation of chicken breast fillets during refrigerated storage (p < 0.05). GSE-incorporated CH films inhibited Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Pseudomonas aeruginosa more efficiently than CH films alone. CH films incorporating 15% GSE inhibited total mesophilic aerobic bacteria (TMAB) and coliforms in chicken breast fillets (p < 0.05) and provided a 1.50–2.33 log reduction in TMAB and coliforms, respectively, during storage. These results reveal that the inclusion of GSE into CH films has the potential to help develop antioxidant/antimicrobial packaging for food products.

Effects of grape seed extract, quercetin and vitamin C on ovine oocyte maturation and subsequent embryonic development

The present study aimedtoevaluate the effects of grape seed extract (GSE) versus quercetin and vitamin C on in vitro oocytematurationand embryodevelopmentin sheep. The free radical scavenging activity of different concentrations of each product was measured by 1, 1- diphenyl-2-picryl hydrazyl (DPPH). Oocytes were collected from ovaries of slaughtered ewes and matured in TCM-199 medium containing fetal calf serum, follicle stimulating hormone (FSH), estradiol-17 β, sodium pyruvate, and gentamicin sulfate. The in vitro fertilization and culture were performed using Bracket and Oliphant's (BO) medium and modified Charles Rosenkrans medium with amino acids (mCR2aa), respectively. The results showed that the hydroalcoholic extract of grape seed had free radical scavenging activity. IC50 value for GSE, vitamin C, and quercetin was found to be 585 µg/mL, 53 µg/mL, and 43 µg/mL, respectively. The concentrations, which showed beneficial effects on oocyte maturation and early development based on the mean number of cleavage, morula and blastocyst rates, were 25-200 µg/mL, 5 or 15 µg/mL, and 800 µg/mL, respectively, for vitamin C, quercetin and GSE. However, there were no significant differences between different concentrations of GSE and control. Findings also highlight the great effect on blastocyst rate while adding GSE at 800 µg/mL. However, the best rate of blastocyst production was obtained in presence of quercetin. Findings suggested the need for further studies on special molecules derived from GSE.

Assessment of antimicrobial activity of sodium hypochlorite, calcium hypochlorite and grape seed extract against Enterococcus faecalis

OBJECTIVE: This study aimed to assess the antimicrobial action of calcium hypochlorite [Ca(OCl)2] at concentrations of 2.5% and 6%, and of grape seed extract (GSE) at concentrations of 10%, 30%, and 50%, against Enterococcus faecalis, comparing it to the action of 6% sodium hypochlorite (NaOCl).METHODS: Saline solution was used as negative control. The inhibition halos of microbial growth were verified by the agar disk diffusion method. Twelve Petri plates were used for seeding with culture medium of approximately 5 mm in thickness. In each plate, 5 disks of pure and sterile antibiogram, soaked in the substances to be tested, were used and taken to the plate containing the seededbacterial strain. The plates remained in aerobic bacteriological incubator for 24 h at 37°C temperature. After 24 h, the inhibition halos were measured with a digital caliper. Analysis of Variance (ANOVA) was used for statistical analysis followed by Tukey's complementary test, at 5% significance.RESULTS: The 6% Ca(ClO)2 presented inhibition halo statistically higher than the other solutions (p&lt;0.05), followed by 2.5% Ca(ClO)2, which was statistically similar to 6% NaOCl (p&gt;0.05). The GSE concentrations resulted in lower inhibition halos of active substances and the different concentrations were similar to each other. Lastly, saline solution presented the same inhibition halos in all groups (p&lt;0.05).CONCLUSION: It may be concluded that 6% Ca(OCl)2 presented higher antimicrobial activity than 6% NaOCl. On the other hand, all GSE concentrations were lower than NaOCl and Ca(OCl)2.

Use of grape seed extract for improving the shear bond strength of total-etching adhesive to bleached enamel.

This study was to ascertain if grape seed extract (GSE) can restore the shear bond strength (SBS) of total-etching adhesive to enamel immediately after bleaching. Immediately after bleaching with Beyond gel, different concentrations of GSE were applied to the surface of bovine enamel for 1 min before bonding of resin composite with Adper single bond 2 or All-Bond 3 adhesive. SBS values and debonding modes were recorded. Structure of the bonding interface and elements on enamel surface were analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy (XPS). SBS was found to be compromised significantly in 0 and 2.5% GSE groups. GSE (≥5%) could restore the SBS to the level of control. Failure in the adhesive joint was always the major debonding mode. No significant difference was found by XPS. Thus, GSE can restore the SBS compromised after bleaching in 1 min if the concentration is ≥5%.

Optimization of supplementation with maltodextrin and grape seed extract for improving quality of shredded Korean cabbage (Brassica rapa L. ssp. Pekinensis) during salting process

The aim of this study was to develop a new salting condition that included added maltodextrin (MD) and grape seed extract (GSE) to ensure the microbiological safety and quality of salted shredded Korean cabbage. Response surface methodology (RSM) was used to analyze the effects of four independent variables (NaCl concentration, salting duration, MD concentration, and GSE concentration). The following response variables were evaluated: reduction in total aerobic bacteria, yeast, and mold counts; weight loss and salt content; and taste, texture, and overall acceptability of salted shredded Korean cabbage. The optimal salting conditions include a combination of 10.09~10.32% NaCl, 9.45~10.00% MD, and 234~300 ppm GSE in a ternary salting solution and a salting duration of 5.68~5.94 hr. This optimal combination reduced total aerobic bacterial and yeast/molds counts by 3.33 and 1.45 log CFU/g, respectively, while maintaining high sensory scores for taste, texture, and overall acceptability of the salted shredded Korean cabbage. In addition, the optimal conditions yielded more acceptable weight loss and salt content characteristics. The results suggest that use of the optimized combination of salting conditions can improve the microbiological safety and quality of salted shredded Korean cabbage used for commercial kimchi production.