Safety evaluation of proanthocyanidin-rich extract from grape seeds

Grape seed-derived procyanidins decreases neuropathic pain and nerve regeneration by suppression of toll-like receptor 4-myeloid differentiation factor-88 signaling

Background: Recent studies have shown that peripheral nerve regeneration process is closely related to neuropathic pain. Toll-like receptor 4 (TLR4) signaling was involved in different types of pain and nerve regeneration. TLR4 induced the recruitment of myeloid differentiation factor-88 adaptor protein (MyD88) and NF-κB-depended transcriptional process in sensory neurons and glial cells, which produced multiple cytokines and promoted the induction and persistence of pain. Our study aimed to investigate procyanidins's effect on pain and nerve regeneration via TLR4-Myd88 signaling. Methods: Spinal nerve ligation (SNL) model was established to measure the analgesic effect of procyanidins. Anatomical measurement of peripheral nerve regeneration was measured by microscopy and growth associated protein 43 (GAP43) staining. Western blotting and/or immunofluorescent staining were utilized to detect TLR4, myeloid differentiation factor-88 adaptor protein (MyD88), ionized calcium-binding adapter molecule 1 (IBA1) and nuclear factor kappa-B-p65 (NF-κB-p65) expression, as well as the activation of astrocyte and microglia. The antagonist of TLR4 (LPS-RS-Ultra, LRU) were intrathecally administrated to assess the behavioral effects of blocking TLR4 signaling on pain and nerve regeneration. Result: Procyanidins reduced mechanical allodynia, thermal hyperalgesia and significantly suppressed the number of nerve fibers regenerated and the degree of myelination in SNL model. Compared with sham group, TLR4, MyD88, IBA1 and phosphorylation of NF-κB-p65 were upregulated in SNL rats which were reversed by procyanidins administration. Additionally, procyanidins also suppressed activation of spinal astrocytes and glial cells. Conclusion: Suppression of TLR4-MyD88 signaling contributes to the alleviation of neuropathic pain and reduction of nerve regeneration by procyanidins.

Dietary grape seed proanthocyanidin extract supplementation improves antioxidant capacity and lipid metabolism in finishing pigs

Grape seed proanthocyanidin extract (GSPE) plays a significant role in body health, including improving antioxidant capacity and maintaining lipid metabolism stability. However, whether dietary GSPE supplementation can improve lipid metabolism in finishing pigs remains unclear. Here 18 castrated male Duroc × Landrace × Yorkshire finishing pigs were randomly divided into three groups with six replicates and one pig per replicate. Pigs were fed a basal diet (control), a basal diet supplemented with 100 mg/kg GSPE, or a basal diet supplemented with 200 mg/kg GSPE for 30 days. Antioxidant analysis showed that dietary 200 mg/kg GSPE supplementation increased glutathione, total antioxidant capacity and glutathione peroxidase levels, and reduced malondialdehyde levels in serum, muscle and liver. Dietary 200 mg/kg GSPE supplementation also upregulated the mRNA and protein levels of nuclear-related factor 2 (Nrf2). Lipid metabolism analysis showed that dietary GSPE supplementation increased serum high-density lipoprotein cholesterol levels and reduced serum triglyceride and total cholesterol levels. Besides, GPSE upregulated the mRNA expression of lipolysis- and fatty acid oxidation-related genes downregulated the mRNA expression of lipogenesis-related genes, and activated the AMPK signal in finishing pigs. Together, we provided evidence that dietary GSPE supplementation improved the antioxidant capacity and lipid metabolism in finishing pigs.

Dual-functional etchants that simultaneously demineralize and stabilize dentin render collagen resistant to degradation for resin bonding

OBJECTIVES

To develop dual-functional etchants that could demineralize and stabilize dentin collagen simultaneously, and to assess the effects of these etchants on collagen crosslinking, biostability and resin bonding properties under clinically relevant conditions.

METHODS

Dual-functional etchants were prepared by mixing 56% glycolic acid and 17% phosphoric acid and adding 1% of theaflavins (TF) or proanthocyanidins from grape seed extract (GSE). The etchant without crosslinker was used as control. The prepared human dentin specimens were treated with the 3 etchants for 30 s and analyzed for chemical interaction using Fourier transform infrared spectroscopy and resistance of the demineralized layer to collagenase degradation using electron microscopy (EM). Resin-dentin interfacial bonding properties were evaluated after 24 h and after 10,000 thermocycling through microtensile bond strength (μTBS), nanoleakage and matrix metalloproteinases (MMPs) activity via in situ zymography. Statistical analysis was done using ANOVA and post- hoc Tuckey's test.

RESULTS

Compared to control, TF and GSE dual-functional etchants were able to demineralize dentin, induce collagen crosslinking and protect the demineralized layer from collagenase degradation within 30 s. High resolution EM images showed better protection with TF etchant compared to GSE. There was a significant reduction in μTBS and an increase in nanoleakage and MMPs activity in control after thermocycling (p < 0.05) while these changes weren't seen in dual-functional etchants.

SIGNIFICANCE

Dual-functional etchants, especially TF containing, provide collagen protection against degradation and result in stable μTBS and less nanoleakage and MMPs activity under clinically relevant conditions.

Microbiological and Clinical Effects of a Proanthocyanidin-enriched Extract from Rumex acetosa in Periodontally Healthy Carriers of Porphyromonas gingivalis: a Randomized Controlled Pilot Study

Rumex acetosa significantly inhibits the adhesion of Porphyromonas gingivalis (P. g.) to eukaryotic host cells in vitro. The objective of this randomized placebo-controlled pilot-trial was to analyze effects of a mouth rinse containing 0.8% (w/w) of a quantified proanthocyanidin-enriched extract from Rumex acetosa (RA1) on microbiological, clinical, and cytological parameters in systemically healthy individuals without history of periodontitis, harboring P. g. intraorally. 35 subjects received a supragingival debridement (SD) followed by mouth rinsing (3 times daily) with either RA1 mouth rinse solution (test) or placebo (control) for 7 days as adjunct to routine oral hygiene. Supragingival biofilm samples were taken at screening visit, baseline (BL), 2, 4, 7 and 14 days after SD. P. g. and 11 other oral microorganisms were detected and quantified by rtPCR. Changes in the oral microbiota composition of one test and one control subject were assessed via high throughput 16S rRNS gene amplicon sequencing. Approximal Plaque Index (API) and the modified Sulcular Bleeding Index (SBI) were assessed at BL, 7- and 14-days following SD. Brush biopsies were taken at BL and 14 d following SD. Intergroup comparisons revealed no significant microbiological, cytological, and clinical differences at any timepoint. However, a significant reduction in SBI at day 14 (p = 0.003) and API at day 7 (p = 0.02) and day 14 (p = 0.009) was found in the test group by intragroup comparison. No severe adverse events were observed. The results indicate that RA1 mouth rinse is safe but does not seem to inhibit colonization of P. g. or improve periodontal health following SD.

The natural tannins oligomeric proanthocyanidins and punicalagin are potent inhibitors of infection by SARS-CoV-2

The Coronavirus Disease 2019 (COVID-19) pandemic continues to infect people worldwide. While the vaccinated population has been increasing, the rising breakthrough infection persists in the vaccinated population. For living with the virus, the dietary guidelines to prevent virus infection are worthy of and timely to develop further. Tannic acid has been demonstrated to be an effective inhibitor of coronavirus and is under clinical trial. Here we found that two other members of the tannins family, oligomeric proanthocyanidins (OPCs) and punicalagin, are also potent inhibitors against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with different mechanisms. OPCs and punicalagin showed inhibitory activity against omicron variants of SARS-CoV-2 infection. The water extractant of the grape seed was rich in OPCs and also exhibited the strongest inhibitory activities for viral entry of wild-type and other variants in vitro. Moreover, we evaluated the inhibitory activity of grape seed extractants (GSE) supplementation against SARS-CoV-2 viral entry in vivo and observed that serum samples from the healthy human subjects had suppressive activity against different variants of SARS-CoV-2 Vpp infection after taking GSE capsules. Our results suggest that natural tannins acted as potent inhibitors against SARS-CoV-2 infection, and GSE supplementation could serve as healthy food for infection prevention.

The Protective Role of Dietary Polyphenols in Urolithiasis: Insights into Antioxidant Effects and Mechanisms of Action

Urolithiasis is a common urological disease with increasing prevalence and high recurrence rates around the world. Numerous studies have indicated reactive oxygen species (ROS) and oxidative stress (OS) were crucial pathogenic factors in stone formation. Dietary polyphenols are a large group of natural antioxidant compounds widely distributed in plant-based foods and beverages. Their diverse health benefits have attracted growing scientific attention in recent decades. Many literatures have reported the effectiveness of dietary polyphenols against stone formation. The antiurolithiatic mechanisms of polyphenols have been explained by their antioxidant potential to scavenge free radicals and ROS, modulate the expression and the activity of endogenous antioxidant and prooxidant enzymes, regulate signaling pathways associated with OS, and maintain cell morphology and function. In this review, we first describe OS and its pathogenic effects in urolithiasis and summarize the classification and sources of dietary polyphenols. Then, we focus on the current evidence defining their antioxidant potential against stone formation and put forward challenges and future perspectives of dietary polyphenols. To conclude, dietary polyphenols offer potential applications in the treatment and prevention of urolithiasis.

Grape Seed Components as Protectors of Inflammation, DNA Damage, and Cancer

PURPOSE OF REVIEW

Oxidative stress is related to the pathogenesis of several chronic diseases, including inflammatory processes. Free radicals excess increase not only oxidative stress but also genomic instability. Polyphenols are non-enzymatic antioxidants that act as a defense barrier against free radicals and non-radical oxidants. The purpose of this article was to review published articles relating dietary polyphenols contained in grape seed proanthocyanidin extracts with its potential for reversing DNA damage.

RECENT FINDINGS

Proanthocyanidin components exert pleiotropic actions having several biological, biochemical, and significant pharmacological effects and showed the ability to reduce cytotoxicity and genotoxicity. Grape seed proanthocyanidin extracts showed the ability to reduce cytotoxicity and genotoxicity through the comet assay and the micronucleus technique.

Insights on Dietary Polyphenols as Agents against Metabolic Disorders: Obesity as a Target Disease

Obesity is a condition that leads to increased health problems associated with metabolic disorders. Synthetic drugs are available for obesity treatment, but some of these compounds have demonstrated considerable side effects that limit their use. Polyphenols are vital phytonutrients of plant origin that can be incorporated as functional food ingredients. This review presents recent developments in dietary polyphenols as anti-obesity agents. Evidence supporting the potential application of food-derived polyphenols as agents against obesity has been summarized. Literature evidence supports the effectiveness of plant polyphenols against obesity. The anti-obesity mechanisms of polyphenols have been explained by their potential to inhibit obesity-related digestive enzymes, modulate neurohormones/peptides involved in food intake, and their ability to improve the growth of beneficial gut microbes while inhibiting the proliferation of pathogenic ones. Metabolism of polyphenols by gut microbes produces different metabolites with enhanced biological properties. Thus, research demonstrates that dietary polyphenols can offer a novel path to developing functional foods for treating obesity. Upcoming investigations need to explore novel techniques, such as nanocarriers, to improve the content of polyphenols in foods and their delivery and bioavailability at the target sites in the body.

Redox Biomarkers Assessment after Oral Administration of Wine Extract and Grape Stem Extract in Rats and Mice

Wine and by-products of the winemaking process, such as grape stems, are rich in bioactive polyphenolic compounds that might be beneficial for animal and human health. In recent years, the administration of dietary polyphenols with strong antioxidant and cytoprotective properties has constituted an emerging line of research interest toward disease prevention. However, in scientific literature, only a limited number of studies have investigated the safety and the toxicological risks of polyphenolic compounds in vivo. Based on the above, the purpose of the present study was two-fold: first, to examine the effects of oral administration of a grape stem extract, derived from the Greek red wine Mavrodaphne, on mice redox biomarkers; and second, to investigate the biological effects of oral administration of a wine extract, derived from the emblematic Greek red wine Xinomavro, on rats. Toward this purpose, body weight, growth rate, hematological, biochemical, and histopathological parameters, as well as a panel of redox biomarkers, were examined. According to our results, the administration of Mavrodaphne grape stem extract in mice induced alterations in redox homeostasis, preventing mice from the adverse effects of lipid peroxidation. Contrariwise, the administration of Xinomavro wine extract induced both beneficial and harmful outcomes on rat redox status determined by the examined tissue. Collectively, our study reports that the Mavrodaphne grape stem extract, a serious pollutant when disposed in environmental matrices, is an important source of bioactive polyphenolic compounds that could protect from oxidative damage and improve animal and human health. Finally, the Xinomavro wine extract exerts tissue-specific changes in redox balance, which are indicative of the complexity that characterizes the biological systems.

Co-treatment with grape seed extract and mesenchymal stem cells in vivo regenerated beta cells of islets of Langerhans in pancreas of type I-induced diabetic rats

BACKGROUND

Nowadays, diabetes mellitus is known as a silent killer because individual is not aware that he has the disease till the development of its complications. Many researchers have studied the use of stem cells in treatment of both types of diabetes. Mesenchymal stem cells (MSCs) hold a lot of potential for regenerative therapy. MSCs migrate and home at the damaged site, where they can aid in the repair of damaged tissues and restoring their function. Oxidative stress and inflammation represent a huge obstacle during MSCs transplantation. Therefore, the present study aimed to evaluate the role of grape seed extract (GSE) administration during MSCs transplantation in streptozotocin (STZ)-induced type I diabetes. Furthermore, testing some of GSE components [procyanidins(P)-B1 and P-C1] in conjunction with MSCs, in vivo, was performed to determine if one of them was more effective in relieving the measured attributes of diabetes more than the whole GSE.

METHODS

Firstly, GSE was prepared from the seeds of Muscat of Alexandria grapes and characterized to identify its phytochemical components. Experimental design was composed of control group I, untreated diabetic group II, GSE (300 mg/kg)-treated diabetic group III, MSCs (2 × 10⁶ cells/rat)-treated diabetic group IV and GSE (300 mg/kg)/MSCs (2 × 10⁶ cells/rat)-treated diabetic group V. Type I diabetes was induced in rats by intravenous injection with 65 mg/kg of STZ. Treatment started when fasting blood glucose (FBG) level was more than 200 mg/dl; GSE oral administration started in the same day after MSCs intravenous injection and continued daily for 30 consecutive days.

RESULTS

The results showed that GSE/MSCs therapy in type I-induced diabetic rats has dramatically managed homeostasis of glucose and insulin secretion; together with, improvement in levels of inflammatory markers and oxidative stress.

CONCLUSION

Co-treatment with GSE and MSCs in vivo regenerates beta cells in type I-induced diabetic rats.

Consumption of Grapes Modulates Gene Expression, Reduces Non-Alcoholic Fatty Liver Disease, and Extends Longevity in Female C57BL/6J Mice Provided with a High-Fat Western-Pattern Diet

A key objective of this study was to explore the potential of dietary grape consumption to modulate adverse effects caused by a high-fat (western-pattern) diet. Female C57BL/6J mice were purchased at six-weeks-of-age and placed on a standard (semi-synthetic) diet (STD). At 11 weeks-of-age, the mice were continued on the STD or placed on the STD supplemented with 5% standardized grape powder (STD5GP), a high-fat diet (HFD), or an HFD supplemented with 5% standardized grape powder (HFD5GP). After being provided with the respective diets for 13 additional weeks, the mice were euthanized, and liver was collected for biomarker analysis, determination of genetic expression (RNA-Seq), and histopathological examination. All four dietary groups demonstrated unique genetic expression patterns. Using pathway analysis tools (GO, KEGG and Reactome), relative to the STD group, differentially expressed genes of the STD5GP group were significantly enriched in RNA, mitochondria, and protein translation related pathways, as well as drug metabolism, glutathione, detoxification, and oxidative stress associated pathways. The expression of Gstp1 was confirmed to be upregulated by about five-fold (RT-qPCR), and, based on RNA-Seq data, the expression of additional genes associated with the reduction of oxidative stress and detoxification (Gpx4 and 8, Gss, Gpx7, Sod1) were enhanced by dietary grape supplementation. Cluster analysis of genetic expression patterns revealed the greatest divergence between the HFD5GP and HFD groups. In the HFD5GP group, relative to the HFD group, 14 genes responsible for the metabolism, transportation, hydrolysis, and sequestration of fatty acids were upregulated. Conversely, genes responsible for lipid content and cholesterol synthesis (Plin4, Acaa1b, Slc27a1) were downregulated. The two top classifications emerging as enriched in the HFD5GP group vs. the HFD group (KEGG pathway analysis) were Alzheimer's disease and nonalcoholic fatty liver disease (NAFLD), both of which have been reported in the literature to bear a causal relationship. In the current study, nonalcoholic steatohepatitis was indicated by histological observations that revealed archetype markers of fatty liver induced by the HFD. The adverse response was diminished by grape intervention. In addition to these studies, life-long survival was assessed with C57BL/6J mice. C57BL/6J mice were received at four-weeks-of-age and placed on the STD. At 14-weeks-of-age, the mice were divided into two groups (100 per group) and provided with the HFD or the HFD5GP. Relative to the HFD group, the survival time of the HFD5GP group was enhanced (log-rank test, p = 0.036). The respective hazard ratios were 0.715 (HFD5GP) and 1.397 (HFD). Greater body weight positively correlated with longevity; the highest body weight of the HFD5GP group was attained later in life than the HFD group (p = 0.141). These results suggest the potential of dietary grapes to modulate hepatic gene expression, prevent oxidative damage, induce fatty acid metabolism, ameliorate NAFLD, and increase longevity when co-administered with a high-fat diet.

Association of Dietary Intake of Polyphenols with an Adequate Nutritional Profile in Postpartum Women from Argentina

HJ-Biplot analysis is a multivariate graphic representation that collects data covariation structure between variables and individuals to represent them in a low-dimensional space with the highest quality in the same reference system. Consequently, it is a promising technique for evaluating dietary exposure to polyphenols and accurately characterizing female nutrition. Herein, we hypothesized that polyphenol intake defines specific clusters with dietary impacts, which can be assessed using HJ-Biplot, based on a cross-sectional study in Argentina. The study included 275 healthy postpartum women who provided information about their food frequency intake and other conditions, which were then used to evaluate polyphenolic intake using the Phenol-Explorer database. Outcomes were established using HJ-Biplot for clustering and ANOVA to compare their impact on diet quality indicators. Two HJ-Biplot models were run (for intakes >20 mg/d and 5∼20 mg/d, respectively) to identify three clusters per model with excellent statistical fitness to explain the data. Thus, specific polyphenolic clusters with potentially bioactive and safe compounds were defined despite significant interindividual variability. In fact, women with the lowest polyphenolic intake exhibited worse dietary quality, body fat, and physical activity. As a result, HJ-Biplot proved to be an effective technique for clustering women based on their dietary intake of these compounds. Furthermore, cluster membership improved the intake of antioxidants, water, fiber, and healthy fats. Additionally, women with formal jobs and a higher educational level showed a better diet. Dietary polyphenols are critical during postpartum because they exert beneficial effects on women and breastfed infants.

Chemical Diversity of Flavan-3-Ols in Grape Seeds: Modulating Factors and Quality Requirements

Grape seeds are a rich source of flavan-3-ol monomers, oligomers, and polymers. The diverse profile of compounds includes mainly B-type procyanidins (especially C4→C8 linked molecules) and the key monomers, catechin, and epicatechin that are positively implicated in the 'French Paradox'. Today grape seed nutraceuticals have become a multi-million-dollar industry. This has created incentives to elucidate the variations in chemistry across cultivars, to identify signs of adulteration, and to understand the intrinsic and extrinsic factors controlling the expression of metabolites in the seeds' metabolome. This review provides a critical overview of the existing literature on grape seed chemistry. Although the biosynthetic pathways for polymeric procyanidins in seeds have not yet been explained, abiotic factors have been shown to modulate associated genes. Research of extrinsic factors has demonstrated that the control of procyanidin expression is strongly influenced, in order of importance, by genotype (species first, then variety) and environment, as claimed anecdotally. Unfortunately, research outcomes on the effects of abiotic factors have low certainty, because effects can be specific to genotype or variety, and there is limited control over physical metrics in the field. Thus, to gain a fuller understanding of the effects of abiotic factors and biosynthetic pathways, and realise potential for optimisation, a more fundamental research approach is needed. Nevertheless, the current synthesis offers insight into the selection of species or varieties according to the profile of polyphenols, as well as for optimisation of horticultural practices, with a view to produce products that contain the compounds that support health claims.

Grape Seed Proanthocyanidin Alleviates Intestinal Inflammation Through Gut Microbiota-Bile Acid Crosstalk in Mice

Regulation of gut microbiota and modulation of bile acid (BA) composition are potential strategies for the treatment of intestinal inflammation. This study aimed to investigate the effect of grape seed proanthocyanidin (GSP) on intestinal inflammation and to understand its mechanism. C57BL/6J male mice (7–8 weeks old) were used in experiments. Antibiotics were applied to deplete gut microbiota to evaluate the contribution of gut microbiota to the effect of dietary GSP. Intestinal-specific farnesoid X receptor (FXR) inhibitor was used to analyze the role of FXR signaling. In this study, GSP alleviated intestinal inflammation induced by LPS and altered the gut microbiota accompanied by increased abundance of hydroxysteroid dehydrogenase (HSD) producing microbes. GSP activated the intestinal FXR signaling pathway and increased gene expression of enzymes of the alternative BA synthetic pathway, which associated with elevated levels of chenodeoxycholic acid (CDCA) and lithocholic acid (LCA) in liver and feces. However, gut microbiota depletion by antibiotics removed those effects of GSP on mice injected with LPS. In addition, the protective effect of GSP on mice challenged with LPS was weakened by the inhibition of intestinal FXR signaling. Further, the mixture of CDCA and LCA mirrored the effects of GSP in mice injected with LPS, which might verify the efficiency of CDCA and LCA on intestinal inflammation. Taken together, our results indicated that GSP exerted an intestinal protection role in the inflammation induced by LPS, and these effects were mediated by regulating gut microbiota-BA crosstalk.

(Poly)phenol toxicity in vivo following oral administration: A targeted narrative review of (poly)phenols from green tea, grape, and anthocyanin-rich extracts

Fruit- and vegetable-derived (poly)phenols are secondary plant metabolites that may have beneficial effects on human health when consumed regularly. Recent years have seen rapid growth in both consumer demand for and research interest in (poly)phenol-rich dietary supplements, natural colorants, and functional foods. As these products continue to enter the marketplace and (poly)phenol intake patterns change from traditional food products to these sources, attention must be paid to the potential for toxicity from consuming elevated doses of (poly)phenols. To date, much remains unknown regarding the safety of high doses of (poly)phenols, especially in vivo. In this targeted narrative review, we summarize evidence from in vivo investigations of (poly)phenol toxicity after oral administration of green tea extracts, grape-derived phenolics, and anthocyanin-rich extracts. There is limited evidence of overt toxicity from oral ingestion of these (poly)phenol-rich sources, though more research on the safety of high doses-as well as defining what constitutes a "high" dose of both individual and complex mixtures of (poly)phenols-is needed before these observations can be used to create dietary guidance for consumers.

Theaflavins as a novel cross-linker quickly stabilize demineralized dentin collagen against degradation

To investigate the ability of theaflavins (TF) from black tea to protect dentin collagen against enzymatic degradation via cross-linking effect under clinically relevant conditions. 10-µm-thick dentin films were microtomed from dentin slabs of human molars. Following demineralization, films or slabs were treated with TF at two concentrations (0.4% and 2%) for 30 s. A well-known collagen cross-linker grape seed proanthocyanidins (PA) was used as control. Collagen cross-linking interactions and stabilization against enzymatic degradation were investigated by Fourier transform infrared spectroscopy, weight loss, hydroxyproline release, and scanning/transmission electron microscopy. Data were analyzed by ANOVA, Tukey’s and Student’s T test (α = 0.05%). The results showed collagen cross-linking and stabilization efficacy was dependent on TF/PA concentrations. At 2.0%, TF and PA offered nearly full protection to collagen; at 0.4%, TF exhibited a significantly better collagen stabilization effect than PA (P < 0.05), while untreated collagen was completely digested. It’s concluded that TF cross-links dentin collagen within a clinically relevant time (30 s) and offers excellent collagen protection against enzymatic degradation, with efficacy comparable to or better than PA. The study supports the potential use of TF as a novel, promising collagen cross-linker for degradation resistant, long-lasting dentin bonding in composite restorations.

Relative effect of Malayer Shahani and Asgari grapes seed extract on inducing apoptosis in human leukemia cells

Background

Previous studies have suggested that consuming fruit and vegetable can lower the risk of several cancers, including breast, colorectal, and lung cancers.

Aims

The present study aims to investigate the in vitro anticancer effects of Shahani and Asgari grape seed extract (GSE) grown in Malayer City of Iran on HL-60 cancer. However, to the best of the author's knowledge, it is the first time in this study that the antiproliferative effect of Shahani and Asgari GSE is compared.

Materials and Methods

Shahani and Asgari GSE Was extraction white method of Liquid/liquid extraction with ethyl acetate. Then assessing cytotoxic activities of Shahani and Asgari GSE on the HL-60 cells was tested using MTT assay.

Results

The results show that compared with the control group, seed extract of both Shahani and Asgari at the various concentrations (25, 50, 100, and 200 μg/ml) had a significantly inhibitory effect on HL-60 cell proliferation that was dose dependent. However, Shahani GSE at different concentrations (50, 100, and 200 μg/ml) indicated a significantly higher inhibitory effect compared to Asgari GSE. In addition, GSE can induce cell cycle arrest at G0/G1 cells. Furthermore, GSE of Asgari and Shahani remarkably increased the induction of HL-60 cell apoptosis depending on its dose. However, at the concentration of 200 μg/ml, GSE induced cell necrosis rather than apoptosis.

Conclusion

Seed extract of both Shahani and Asgari at the various concentrations had a significantly inhibitory effect on HL-60 cell proliferation that was dose dependent.

Proanthocyanidin-functionalized hydroxyapatite nanoparticles as dentin biomodifier

OBJECTIVE

This study evaluated the potential combined effects of nanohydroxyapatite and proanthocyanidin on the remineralization and collagen stabilization of demineralized dentin.

METHODS

Seventy-five coronal dentin beams (6 × 1 × 1 mm³) were randomly allocated into five experimental groups (n = 15): Sound (no treatment), Control (pH-cycling), nHAp (nanohydroxyapatite), nHAp_PA (Proanthocyanidin-functionalized nanohydroxyapatite), and PA (proanthocyanidin) treatments. The sound group (negative control) were immersed in distilled water over the experimental period. The remaining groups were submitted to a pH-cycling process for 14 days. Following the de-re mineralization process, specimens corresponding to the control group (positive control) were immersed in distilled water whereas the test groups were immersed in 1 mL of respective solution treatment (nHAp, nHAp_PA, or PA) for 1 min. The dentin samples were analyzed to determine their chemical composition (ATR-FTIR and Thermogravimetric) and mineralogical (XRD) characteristics as well as their mechanical response, obtained by three-point bending test.

RESULTS

Higher phosphate content (v₄ PO₄: ATR-FTIR) and amount of mineral (XRD) was observed in the nHAp_PA group. Furthermore, a larger induction of collagen cross-links (ATR-FTIR) and %Organic Matter (TGA) would indicate the PA incorporation and the achievement of dentin matrix stability. These effects on dentin properties were related to increasing flexural strength (MPa), demonstrating that 15% w/v nHAp_PA treatment improved the mechanical properties of the samples.

SIGNIFICANCE

nHAp_PA shows significant potential for promoting remineralization while improving collagen stability into demineralized dentin in a clinically feasible period of 1 min.

An overview on the role of plant-derived tannins for the treatment of lung cancer

Lung cancer is the leading cause of cancer-related death globally. Despite many advanced approaches to treat cancer, they are often ineffective due to resistance to classical anti-cancer drugs and distant metastases. Currently, alternative medicinal agents derived from plants are the major interest due to high bioavailability and fewer adverse effects. Tannins are polyphenolic compounds existing as specialized products in a wide variety of vegetables, fruits, and nuts. Many tannins have been found to possess protective properties, such as anti-inflammatory, anti-fibrotic, anti-microbial, anti-diabetic, and so on. This review aims to summarize the current knowledge addressing the anti-cancer effects of dietary tannins and their underlying molecular mechanisms. In vivo and in vitro studies provide evidences that anti-cancer effects of various tannins are predominantly mediated through negative regulation of transcription factors, growth factors, receptor kinases, and many oncogenic molecules. In addition, we also discussed the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of tannins, clinical trial results as well as our perspective on future research with tannins.

Dihydromyricetin Imbues Antiadipogenic Effects on 3T3-L1 Cells via Direct Interactions with 78-kDa Glucose-Regulated Protein

BACKGROUND

Obesity is among the most serious public health problems worldwide, with few safe pharmaceutical interventions. Natural products have become an important source of potential anti-obesity therapeutics. Dihydromyricetin (DHM) exerts antidiabetic effects. The biochemical target of DHM, however, has been unknown. It is crucial to identify the biochemical target of DHM for elucidating its physiological function and therapeutic value.

OBJECTIVES

The objective of this study was to identify the biochemical target of DHM.

METHODS

An abundant antiadipogenic flavanonol was extracted from the herbal plant Ampelopsis grossedentata through bioassay-guided fractionation and characterized with high-resolution LC-MS and 1H and 13C nuclear magnetic resonance. Antiadipogenic experiments were done with mouse 3T3-L1 preadipocytes. A biochemical target of the chemical of interest was identified with drug affinity responsive target stability assay. Direct interactions between the chemical of interest and the protein target in vitro were predicted with molecular docking and subsequently confirmed with surface plasmon resonance. Expression levels of peroxisome proliferator-activated receptor γ (PPARγ), which is associated with 78-kDa glucose-regulated protein (GRP78), were measured with real-time qPCR.

RESULTS

DHM was isolated, purified, and structurally characterized. Cellular studies showed that DHM notably reduced intracellular oil droplet formation in 3T3-L1 cells with a median effective concentration of 294 μM (i.e., 94 μg/mL). DHM targeted the ATP binding site of GRP78, which is associated with adipogenesis. An equilibrium dissociation constant between DHM and GRP78 was 21.8 μM. In 3T3-L1 cells upon treatment with DHM at 50 μM (i.e., 16 μg/mL), the expression level of PPARγ was downregulated to 53.9% of the solvent vehicle control's level.

CONCLUSIONS

DHM targets GRP78 in vitro. DHM is able to reduce lipid droplet formation in 3T3-L1 cells through a mode of action that is plausibly associated with direct interactions between GRP78 and DHM, which is a step forward in determining potential applications of DHM as an anti-obesity agent.

Impact of grape pomace flour (GPF) on immunity and immune-antioxidant-anti-inflammatory genes expression in Labeo rohita against Flavobacterium columnaris

This study evaluates the effects of dietary inclusion of grape pomace flour (GPF) on growth, antioxidant, anti-inflammatory, innate-adaptive immunity, and immune genes expression in Labeo rohita against Flavobacterium columnaris. In both normal and challenged fish the growth rate, hematology and biochemical parameters significantly increased when fed with 200 and 300 mg GPF enriched diets; similarly the activities of antioxidants and innate-adaptive immune parameters, such as malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), phagocytic (PC), respiratory burst (RB), alternative pathway complement (ACP), lysozyme (Lyz), and total immunoglobulin M (IgM) significantly increased in both groups. Similarly, the immune, antioxidant, and anti-inflammatory-related gene mRNA expression was significantly up-regulated in head kidney (HK) tissues. The challenged fish fed without GPF always exhibited lower values of all the studied parameters. The results indicate that both normal and challenged fish treated with 200 mg GPF inclusion diet had significantly enhanced growth rate, antioxidant status, and immune defense mechanisms than with 300 mg GPF diet in L. rohita against F. columnaris.

Proanthocyanidins Should Be a Candidate in the Treatment of Cancer, Cardiovascular Diseases and Lipid Metabolic Disorder

The conventional view of using medicines as routine treatment of an intractable disease is being challenged in the face of extensive and growing evidence that flavonoids in foods, especially proanthocyanidins (PAs), can participate in tackling fatal diseases like cancer, cardiovascular and lipid metabolic diseases, both as a precautionary measure or as a dietary treatment. Although medical treatment with medicines will remain necessary in some cases, at least in the short term, PAs’ function as antioxidant, anti-inflammatory drugs, signal pathway regulators remain critical in many diseases. This review article demonstrates the physical and biological properties of PAs, summarizes the health benefits of PAs found by researchers previously, and shows the possibility and importance of being a dietary treatment substance.

Grape Seed Proanthocyanidins Induce Apoptosis and Cell Cycle Arrest of HepG2 Cells Accompanied by Induction of the MAPK Pathway and NAG-1

Hepatocellular carcinoma (HCC) is one of the common malignancies leading to death. Although radiotherapy and chemotherapy have certain effects, their side effects limit their therapeutic effect. Phytochemicals have recently been given more attention as promising resources for cancer chemoprevention or chemotherapy due to their safety. In this study, the effects of grape seed proanthocyanidins (GSPs) on the apoptosis, cell cycle, and mitogen-activated protein kinase (MAPK) pathway-related proteins and non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) expression of HepG2 cells were investigated. The results showed that GSPs inhibited the viability of HepG2 cells in a time- and dose-dependent manner, induced apoptosis and G2/M phase cell cycle arrest, and regulated cell cycle-related proteins, cyclin B1, cyclin-dependent kinase 1, and p21. GSPs also increased reactive oxygen species production and caspase-3 activity. In addition, GSPs also increased the expression of p-ERK, p-JNK, p-p38 MAPK and NAG-1, and GSPs-induced NAG-1 expression was related to the MAPK pathway-related proteins. These data suggest that GSPs may be promising phytochemicals for HCC chemoprevention or chemotherapy.

Anti-neoplastic Potential of Flavonoids and Polysaccharide Phytochemicals in Glioblastoma

Clinically, gliomas are classified into four grades, with grade IV glioblastoma multiforme being the most malignant and deadly, which accounts for 50% of all gliomas. Characteristically, glioblastoma involves the aggressive proliferation of cells and invasion of normal brain tissue, outcomes as poor patient prognosis. With the current standard therapy of glioblastoma; surgical resection and radiotherapy followed by adjuvant chemotherapy with temozolomide, it remains fatal, because of the development of drug resistance, tumor recurrence, and metastasis. Therefore, the need for the effective therapeutic option for glioblastoma remains elusive. Previous studies have demonstrated the chemopreventive role of naturally occurring pharmacological agents through preventing or reversing the initiation phase of carcinogenesis or arresting the cancer progression phase. In this review, we discuss the role of natural phytochemicals in the amelioration of glioblastoma, with the aim to improve therapeutic outcomes, and minimize the adverse side effects to improve patient's prognosis and enhancing their quality of life.

Genotoxicity Assessment of Three Nutraceuticals Containing Natural Antioxidants Extracted from Agri-Food Waste Biomasses

Grapes and apples are the most cultivated fruits in the Mediterranean basin and their agricultural processing is responsible for the production of a large amount of bio-waste. The reuse of this food biomass would increase the volume of recyclable/renewable biomaterial and lower the environmental impact due to the increasing demand for these biological products. To this purpose, agri-food waste from grape and apple processing have become an important source of phytochemicals, and many pharmaceutical industries are using it as starting material to produce dietary supplements, functional foods, and food additives for human consumption. In virtue of the chemical diversity and complexity of agri-food biowaste, developers and producers of nutraceuticals are advised to assess the safety of their final nutraceutical products, in compliance with European Food Safety Authority regulation. Here, we use the Ames test to assess the mutagenicity of three nutraceuticals obtained from agri-food waste biomasses: Taurisolo® from grape pomace of Vitis vinifera L. cv 'Aglianico', AnnurComplex® from Malus pumila M. cv 'Annurca' and Limoncella Apple Extract from Malus domestica B. cv 'Limoncella'. The results showed that all three nutraceuticals were non-mutagenic.

Preventative and Therapeutic Potential of Flavonoids in Peptic Ulcers

Peptic ulcer disease is a common gastrointestinal tract disorder that affects up to 20% of the population of the world. Treatment of peptic ulcer remains challenging due to the limited effectiveness and severe side effects of the currently available drugs. Hence, natural compounds, owing to their medicinal, ecological, and other safe properties, are becoming popular potential candidates in preventing and treating peptic ulcers. Flavonoids, the most abundant polyphenols in plants, exhibit gastroprotective effects against peptic ulcer both in vivo and in vitro. In this review, we summarized the anti-ulcer functions and mechanisms, and also the bioavailability, efficacy, and safety, of flavonoid monomers in the gastrointestinal tract. Flavonoids exerted cytoprotective and rehabilitative effects by not only strengthening defense factors, such as mucus and prostaglandins, but also protecting against potentially harmful factors via their antioxidative, anti-inflammatory, and antibacterial activities. Although controlled clinical studies are limited at present, flavonoids have shown a promising preventable and therapeutic potential in peptic ulcers.

Computational and In Vitro Investigation of (-)-Epicatechin and Proanthocyanidin B2 as Inhibitors of Human Matrix Metalloproteinase 1

Matrix metalloproteinases 1 (MMP-1) energetically triggers the enzymatic proteolysis of extracellular matrix collagenase (ECM), resulting in progressive skin aging. Natural flavonoids are well known for their antioxidant properties and have been evaluated for inhibition of matrix metalloproteins in human. Recently, (-)-epicatechin and proanthocyanidin B2 were reported as essential flavanols from various natural reservoirs as potential anti-inflammatory and free radical scavengers. However, their molecular interactions and inhibitory potential against MMP-1 are not yet well studied. In this study, sequential absorption, distribution, metabolism, and excretion (ADME) profiling, quantum mechanics calculations, and molecular docking simulations by extra precision Glide protocol predicted the drug-likeness of (-)-epicatechin (−7.862 kcal/mol) and proanthocyanidin B2 (−8.145 kcal/mol) with the least reactivity and substantial binding affinity in the catalytic pocket of human MMP-1 by comparison to reference bioactive compound epigallocatechin gallate (−6.488 kcal/mol). These flavanols in docked complexes with MMP-1 were further studied by 500 ns molecular dynamics simulations that revealed substantial stability and intermolecular interactions, viz. hydrogen and ionic interactions, with essential residues, i.e., His218, Glu219, His222, and His228, in the active pocket of MMP-1. In addition, binding free energy calculations using the Molecular Mechanics Generalized Born Surface Area (MM/GBSA) method suggested the significant role of Coulomb interactions and van der Waals forces in the stability of respective docked MMP-1-flavonol complexes by comparison to MMP-1-epigallocatechin gallate; these observations were further supported by MMP-1 inhibition assay using zymography. Altogether with computational and MMP-1–zymography results, our findings support (-)-epicatechin as a comparatively strong inhibitor of human MMP-1 with considerable drug-likeness against proanthocyanidin B2 in reference to epigallocatechin gallate.

Procyanidin B1, a novel and specific inhibitor of Kv10.1 channel, suppresses the evolution of hepatoma

Recently, we and other groups revealed that aberrant expression of Kv10.1 channel, a voltage-gated potassium ion channel, contributes to a variety of tumorigenesis process.Potent and selective inhibitor of Kv10.1 is urgently needed, both as pharmacological tools for studying the physiological functions of this enigmatic channel and as potential leads for development of anti-tumor drugs. In this study, Procyanidin B1, a natural compound extracted from the grape seed, was identified as a potent, specific inhibitor, which can inhibit the Kv10.1 channel in a concentration-dependent manner (IC₅₀ = 10.38 ± 0.87 μM), but has negligible effects on other potassium channels, including Kir2.1, HERG or KCNQ1. It was demonstrated that Procyanidin B1 directly binds to Kv10.1 channel and inhibits its currents, without increasing intracellular Ca²⁺. Further, three amino acids, I550, T552, and Q557 in the C-linker domain of Kv10.1 were found critical for forming the binding pocket of Procyanidin B1 with Kv10.1 channel.In addition, Procyanidin B1 inhibits migration and proliferation of liver cancer cells (HuH-7 cells, HepG2 cells) through inhibiting Kv10.1, but not in Kv10.1 negatively expressed cell lines. Next, we assayed the tumor suppressing effect of Procyanidin B1 on cell line-derived xenograft mouse model. Our data showed that 15 mg/kg Procyanidin B1 can significantly suppress the growth of the tumor (HepG2) with an inhibition rate of about 60.25%. Compared with cisplatin, Procyanidin B1 has no side effect on the normal metabolismof the mice. The present work indicated that Procyanidin B1 is a proming liver cancer anti-tumor drug, and also confirmed that Kv10.1 can serve as a potential, tumor-specific drug target.

Dietary grape seed procyanidins suppressed weaning stress by improving antioxidant enzyme activity and mRNA expression in weanling piglets

This study was conducted to investigate the effect of grape seed procyanidins (GSP) on growth performance, digestive enzyme activity, antioxidant enzyme activity and mRNA expression in weanling piglets. A total of 96 piglets (Pietrain × Large White) with an average initial body weight (BW) of 8.4 ± 1.7 kg were weaned at 28 days, and randomly divided into 4 groups. Four groups of animals were fed with a basic diet supplemented with various doses of GSP (0, 40, 70 and 100 mg/kg respectively) during the 28-day treatment period. The results showed that the group receiving 40 mg/kg GSP significantly increased the average daily gain (ADG, p < .05) and decrease the feed/gain ratio (F/G, p < .05). Interestingly, the incidence of diarrhoea was significantly reduced in the groups of 40 and 70 mg/kg GSP, but it was increased in the group of 100 mg/kg GSP. Subsequent biochemical studies indicated that dietary GSP significantly increased the activities of digestive enzymes and antioxidant enzymes, including amylase (Amy), lipase(LPS, p < .05), glutathione peroxidase activity (GSH-Px, p < .05), superoxide dismutase activity (SOD, p < .05) and total antioxidant capacity (T-AOC, p < .05) in serum, liver and muscle, increased the expression of GSH-Px, SOD and CAT genes (p < .05) in the liver, and decreased the level of malondialdehyde (MDA, p < .05) in serum, liver and muscle. Taken together, these studies revealed that low GSP supplement in diets can improve growth performance of weaned piglets, which is associated with increased digestive and antioxidant enzyme activities and enhanced resistance to weanling stress.

Health-Promoting Properties of Proanthocyanidins for Intestinal Dysfunction

The intestinal barrier is constantly exposed to potentially harmful environmental factors, including food components and bacterial endotoxins. When intestinal barrier function and immune homeostasis are compromised (intestinal dysfunction), inflammatory conditions may develop and impact overall health. Evidence from experimental animal and cell culture studies suggests that exposure of intestinal mucosa to proanthocyanidin (PAC)-rich plant products, such as grape seeds, may contribute to maintaining the barrier function and to ameliorating the pathological inflammation present in diet-induced obesity and inflammatory bowel disease. In this review, we aim to update the current knowledge on the bioactivity of PACs in experimental models of intestinal dysfunction and in humans, and to provide insights into the underlying biochemical and molecular mechanisms.

B procyanidins of Annona crassiflora fruit peel inhibited glycation, lipid peroxidation and protein-bound carbonyls, with protective effects on glycated catalase

Advanced glycation end-products (AGEs) have been reported as results of increased oxidative stress. Consequently, the search for new antioxidant and anti-glycating agents is under intense investigation. Plant-derived procyanidins have previously demonstrated anti-glycation properties. Thus, this study aimed to isolate procyanidins from Annona crassiflora fruit peel, a species from the Brazilian Savanna, and investigate their antioxidant and anti-glycation effects. Free radical scavenging and quenching properties, formation of reactive oxygen species (ROS), AGEs, protein carbonyl and thiol groups, lipid peroxidation, crosslinked AGEs, as well as glycated catalase activity, were analyzed. In addition, in silico assessment of absorption, distribution, metabolism, excretion and toxicity was carried out. The procyanidins-enriched fraction, named here as F7, showed high antioxidant and anti-glycation capacities, with inhibitory activities against lipid peroxidation, and AGEs and ROS formation. In addition, there were reductions in AGEs-induced crosslinks and protein carbonyls and protective effects against oxidation of thiol groups and glycated-catalase. ADMET predictions of F7 showed favorable absorption and distribution, with no hepatotoxicity or mutagenicity. Together, our results support the anti-glycation activities of the procyanidins-enriched fraction from A. crassiflora, and suggest that these effects are triggered, at least in part, by scavenging free radical and dicarbonyls intermediates.

Grape Seed Proanthocyanidins Induce Autophagy and Modulate Survivin in HepG2 Cells and Inhibit Xenograft Tumor Growth in Vivo

Liver cancer is one of the leading causes of death worldwide. Although radiotherapy and chemotherapy are effective in general, they present various side effects, significantly limiting the curative effect. Increasing evidence has shown that the dietary intake of phytochemicals plays an essential role in the chemoprevention or chemotherapy of tumors. In this work, HepG2 cells and nude mice with HepG2-derived xenografts were treated with grape seed proanthocyanidins (GSPs). The results showed that GSPs induced autophagy, and inhibition of autophagy increased apoptosis in HepG2 cells. In addition, GSPs also reduced the expression of survivin. Moreover, survivin was involved in GSPs-induced apoptosis. GSPs at 100 mg/kg and 200 mg/kg significantly inhibited the growth of HepG2 cells in nude mice without causing observable toxicity and autophagy, while inducing the phosphorylation of mitogen-activated protein kinase (MAPK) pathway-associated proteins, p-JNK, p-ERK and p-p38 MAPK and reducing the expression of survivin. These results suggested that GSPs might be promising phytochemicals against liver cancer.

Effect of grape seed extract-containing phosphoric acid formulations on bonding to enamel and dentin

The aim was to evaluate the effect of 2% grape seed extract (GSE) containing phosphoric acid (PhA) on the bond strength to enamel and dentin. The control group was 37% PhA. The following three PhA formulations with 2% GSE and 20% ethanol were obtained: GSE5 = 5% PhA; GSE10 = 10% PhA; and GSE20 = 20% PhA. The enamel and dentin surfaces of molars were etched with the acid solutions, followed by Scotchbond Multi-Purpose adhesive and composite resin application. The tensile bond strength (TBS) test evaluated the bond to enamel after 24 h, and the microtensile bond strength (μTBS) test evaluated the bond to dentin after 24 h and 12-month water storage. Etched enamel and dentin were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The TBS data were submitted to one-way ANOVA, while µTBS data were submitted to two-way ANOVA and Tukey's test (α = 0.05). The TBS (MPa) to enamel did not significantly differ among the control (48.1 ± 15.7), GSE5 (46.1 ± 9.6), GSE10 (49.8 ± 13.6) and GSE20 (44.1 ± 11.9) groups (p = 0.537). The µTBS (MPa) to dentin of the control (28.4 ± 14.4) and GSE20 (24.1 ± 8.1) groups were significantly higher than those of the GSE5 (16.8 ± 7.4) and GSE10 (17.5 ± 6.6) groups at 24 h (p < 0.006). After 12-month storage, only GSE5 (21.0 ± 7.8) and GSE10 (17.6 ± 8.0) did not show significantly decreased μTBS (p > 0.145). SEM micrographs showed a shallower enamel etching pattern for GSE5. AFM images showed the formation of collagenous globular structures for GSE5 and GSE10. The different acid solutions did not influence the TBS to enamel, and the µTBS to dentin was stable over time when dentin was etched with GSE5 and GSE10.

Effect of feeding grape seed Proanthocyanidin extract on production performance, metabolic and anti-oxidative status of dairy cattle

ABSTRACT Aims to investigate the effects of grape seed proanthocyanidin extract (GSPE) on production performance, metabolism, and anti-oxidative status of Holstein dairy cattle in early lactation. Forty-eight multiparous Holstein dairy cattle were assigned to four groups (CON, G20, G40 and G80) and supplied with 0, 20, 40, and 80mg GSPE/kg of body weight/day. G20 significantly increased milk yield compared with other groups. Milk protein and non-fat-solids were increased in G20, G40 and G80 groups compared with the control group only at the 7th day during the experiment. No significant difference was observed in milk fat and somatic cell count, nor on parameters of energy metabolism in blood, liver function and kidney function between the four groups. There was no significant difference in glutathione peroxidase, superoxide dismutase, total antioxidant capacity, and hydrogen peroxide between the groups; but the malondialdehyde content of G20 significantly increased at day 14 in comparison with CON, and tended to increase at the 28th day. In conclusion, feeding 20mg GSPE/kg of body weight/day was associated with a significant increase in milk yield without detrimental effects on liver or kidney function and with substantial energy metabolism and antioxidant parameters improvement in early lactation dairy cattle.

Hepatic and gastroprotective activity of Serjania marginata leaf aqueous extract in Nile tilapia (Oreochromis niloticus)

The aim of this study was to assess the leaf aqueous extract composition of Serjania marginata and the effects of its inclusion on the diet of Nile tilapia (Oreochromis niloticus), with respect to the activity of digestive enzymes and enzymes associated with the metabolism of the liver and intestine and liver histopathology. Fish (initial mean weight, 54.36 ± 17.04 g) were divided into groups: fasting (without feeding), control (commercial feed), and treatment (commercial feed with leaf aqueous extract of Serjania marginata), and in each aquarium, there were five individuals and the fish fed ad libitum for 15 days. Treatment fish had ingested on average 224.3 mg of extract/kg of fish/day. In the extract analysis by mass spectrometry, quercitrin, isoquercitrin, A-type proanthocyanidin trimer, and quinic acid were identified. In the enzymatic activity, fish from the treatment group showed higher level of alkaline phosphatase, while the hepatotoxic markers (AST and ALT) and levels of lipase, amylase, and nonspecific protease did not differ (p > 0.05). In liver histopathological analysis, it was observed that fish from the treatment showed normal structure, while abnormalities were associated with control (fibrosis, loss of cordonal architecture, vacuolated hepatocytes with nucleus displaced to the periphery) and fasting (reduction in hepatocyte size and sinusoidal space). The intestine histopathology evidenced that the extract favored the development of goblet cells and intestinal fold height. The results indicated that the leaf aqueous extract of S. marginata assists in the structural maintenance of the liver and intestine and stimulates intestinal alkaline phosphatase production in Nile tilapia, suggesting that the identified compounds act on the liver and intestine, showing hepatoprotective effects and stimulating intestinal digestion.

Pretreatment of Grape Seed Proanthocyanidin Extract Exerts Neuroprotective Effect in Murine Model of Neonatal Hypoxic-ischemic Brain Injury by Its Antiapoptotic Property

Grape seed proanthocyanidin extract (GSPE), an active component extracted from the grape, has been reported to demonstrate antioxidant, anti-inflammatory, anticancer, and antiapoptosis effects. However, little is known about the role of GSPE on neonatal hypoxic-ischemic (HI) brain injury. The aim of this study was to evaluate the neuroprotective effect of GSPE pretreatment on neonatal HI brain injury in mice. A modified Rice-Vannucci method was performed to induce neonatal HI brain injury in the 7-day-old mouse pups pretreated with GSPE or vehicle. The infarct volumes were determined by TTC staining. TUNEL staining was used to detect cells apoptosis, and the expressions of apoptosis-related proteins: bax, bcl2, and cleaved caspase-3 were assayed by Western blot. Behavioral tests were also conducted to assess the functional recovery after injury. We showed that the brain damage and neurobehavioral outcomes improvement was observed in GSPE pretreated group. GSPE was proved to suppress apoptosis through inhibition of bax and cleaved caspase-3 expression. It demonstrates that GSPE could alleviate brain damage maybe through its antiapoptotic activity in a neonatal HI brain injury model, and GSPE has the potential to be a new drug for effective prevention of this disorder.

Tannins and vascular complications of Diabetes: An update

BACKGROUND

Diabetes mellitus is a chronic metabolic disorder associated with persistent increased level of glucose in the blood. According to a report by World Health Organisation (WHO), prevalence of diabetes among adults over 18 years of age had reached to 8.5% in year 2014 which was 4.7% in 1980s. The Prolong increased level of glucose in blood leads to development of microvascular (blindness, nephropathy and neuropathy) and macrovascular (cardiovascular and stroke) degenerative complications because of uncontrolled level of glucose in blood. This also leads to the progression of oxidative stress and affecting metabolic, genetic and haemodynamic system by activation of polyol pathway, protein kinase C pathway, hexosamine pathway and increases advanced glycation end products (AGEs) formation. Diabetes mellitus and its associated complications are one of the major leading causes of mortality worldwide. Various natural products like alkaloids, glycosides, flavonoids, terpenoids and polyphenols are reported for their activity in management of diabetes and its associated diabetic complications. Tannins are systematically studied by many researchers in past few decades for their effect in diabetes and its complications.

AIM

The present review was designed to compile the data of tannins and their beneficial effects in the management of diabetic complications.

METHOD

Literature search was performed using various dataset like pubmed, EBSCO, proQuest Scopus and selected websites including the National Institutes of Health (NIH) and the World Health Organization (WHO).

RESULTS

Globally, more than 400 natural products have been investigated in diabetes and its complications. Tannins are the polyphenolic compounds present in many medicinal plants and various dietary sources like fruits, nuts, grains, spices and beverages. Various reports have shown that compounds like gallic acid, ellagic acid, catechin, epicatechin and procynidins from medicinal plants play major role in controlling progression of diabetes and its related complications by acting on molecular pathways and key targets involved in progression. Many chemists used above mentioned phyto-constituents as a pharmacophore for the developing new chemical entities having higher therapeutic benefits in management of diabetic complications.

CONCLUSION

This review focuses on the role of various tannins in prevention and management of diabetic complications like diabetic nephropathy, diabetic neuropathy, diabetic retinopathy and diabetic cardiomyopathy. It will help researchers to find some leads for the development of new cost effective therapy using dietary source for the management of diabetic complications.

Bioactive Compounds from Theobroma cacao: Effect of Isolation and Safety Evaluation

Plants, including most food and feed plants, produce a broad range of bioactive chemical compounds. Among these compounds, polyphenols are reported to provide beneficial effects as anti-carcinogenic, anti-atherogenic, anti-inflammatory, immune modulating, anti-microbial, vasodilatory and analgesic. Cocoa (Theobroma cacao), a major, economically important, international crop, has been related to several nutritional benefits, which have been associated with the phenolic fraction. The main subclass of flavonoids found in cocoa is flavanols, particularly (epi)catechins monomers, and their oligomers, also known as procyanidins. In this study, these compounds were isolated by different methodologies as solid phase extraction (SPE), semi-preparative high-performance liquid chromatography (HPLC) and membrane technologies to obtain different polyphenolic profiles by HPLC coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and to test their cytotoxicity. Finally, different polyphenolic profiles were collected, where the combination of both semi-preparative HPLC and SPE technologies provided the most purified fractions. Filtration with membranes and SPE provide extracts with different composition depending on the pore size of membranes and on the solvent, respectively. In addition, the results of toxicity assay indicated low levels in all fractions.

Flavonoids for preserving pancreatic beta cell survival and function: A mechanistic review

Although the currently available antidiabetic medications are effective in managing hyperglycemia, vascular complications are common in diabetic patients. Cohort studies have shown preserved beta cell function has a protective role against the development of diabetic complications. Accordingly, beta cell mass and function are important pharmacological targets in the field of diabetes. Growing number of evidence supports the efficacy of flavonoids (e.g., quercetin, kaempferol, luteolin, and epicatechin) for prevention and attenuation of diabetes consequences. The focus of this paper is to give an overview regarding the effects of flavonoids on pancreatic beta cells. Experiments on insulin-releasing cell lines, isolated pancreatic islets, and diabetic animal models have shown that flavonoids strengthen the survival processes and insulin secretory capacity of beta cells. The proposed mechanisms by which flavonoids preserve beta cells survival (against cytokines, glucotoxicity, and lipotoxicity) include inhibition of NF-κB signaling, activation of PI3K/Akt pathway, inhibition of nitric oxide generation, and decrease of reactive oxygen species levels. Improving mitochondrial bioenergetic function and stimulating pathways of insulin secretion (e.g., PLC/PKC and/or cAMP/PKA signaling) are mechanisms by which flavonoids improve the secretory capacity of beta cells. These beneficial effects of flavonoids are of great importance because may protect beta cells of diabetic patients before dramatic dysfunction and degeneration.