Recent advances and uses of grape flavonoids as nutraceuticals

Kaempferol Synergistically Enhances Cisplatin-induced Apoptosis and Cell Cycle Arrest in Colon Cancer Cells

Colon cancer remains a significant global health concern, necessitating the continuous exploration of novel therapeutic strategies. Cisplatin is a first-line chemotherapy medication that is frequently used to treat patients for a variety of malignancies, including colon cancer. However, a major obstacle to its clinical usefulness is acquired resistance. This research investigates the synergistic effects of kaempferol, a natural flavonoid with known anti-cancer properties, in combination with cisplatin, in colon cancer cells. Our study employed colon cancer cell lines to evaluate the individual and combined cytotoxic effects of kaempferol and cisplatin. The results demonstrated a notable enhancement in the cytotoxicity of colon cancer cells when treated with a combination of kaempferol and cisplatin compared to individual treatments. This synergistic effect was further characterized by an increase in apoptosis, as evidenced by morphological changes and biochemical markers of apoptosis and cell cycle. The investigations revealed that the combined treatment led to the modulation of key apoptotic pathways, including the upregulation of pro-apoptotic factors and downregulation of anti-apoptotic factors. Additionally, the synergistic effect was associated with the inhibition of cell proliferation and induction of cell cycle arrest. The findings of this study suggest that the combination of kaempferol and cisplatin holds promise as a potent therapeutic strategy for colon cancer treatment, potentially enhancing the efficacy of conventional chemotherapy while minimizing adverse effects. Further in-depth investigations, including in vivo studies, are warranted to validate these findings and explore the translational potential of this synergistic approach in clinical settings.

Flavonoid compounds and their synergistic effects: Promising approaches for the prevention and treatment of psoriasis with emphasis on keratinocytes - A systematic and mechanistic review

Psoriasis, a chronic autoimmune skin disorder, causes rapid and excessive skin cell growth due to immune system dysfunction. Numerous studies have shown that flavonoids have anti-psoriatic effects by modulating various molecular mechanisms involved in inflammation, cytokine production, keratinocyte proliferation, and more. This study reviewed experimental data reported in scientific literature and used network analysis to identify the potential biological roles of flavonoids' targets in treating psoriasis. 947 records from Web of Sciences, ScienceDirect database, Scopus, PubMed, and Cochrane library were reviewed without limitations until June 26, 2023. 66 articles were included in the systematic review. The ten genes with the highest scores, including interleukin (IL)-10, IL-12A, IL-1β, IL-6, Tumor necrosis factor-α (TNF-α), Janus kinase 2 (JAK 2), Jun N-terminal kinase (JUN), Proto-oncogene tyrosine-protein kinase Src (SRC), Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and Signal transducer and activator of transcription 3 (STAT3), were identified as the hub genes. KEGG pathway analysis identified connections related to inflammation and autoimmune responses, which are key characteristics of psoriasis. IL-6, STAT3, and JUN's presence in both hub and enrichment genes suggests their important role in flavonoid's effect on psoriasis. This comprehensive study highlights how flavonoids can target biological processes in psoriasis, especially when combined for enhanced effectiveness.

Enhancing wine shelf-life: Insights into factors influencing oxidation and preservation

Background

Understanding the shelf life of wine is complex and involves factors such as aroma preservation, flavour development and market acceptance. Ageing potential, crucial for flavour complexity, exposes wine to oxidation, influenced by oxygen, temperature and light, with an impact on quality. This type of oxidation is non-enzymatic, is catalyzed by metal ions and alters colour and flavour.

Scope and approach

This review examines the dynamics of wine preservation, focusing on oxidation and the impact of closure. Corks allow controlled oxygen transfer, while screw caps offer a nearly hermetic closure. Oxygen transfer rates vary, with natural corks having fluctuating rates and synthetic corks causing over-exposure. Additives such as sulphur dioxide and alternative substitute such as lysozyme and ascorbic acid are examined for their role in preventing oxidation and ensuring microbiological stability.

Key findings and conclusions

Closure choice significantly affects wine preservation. Balancing oxygen exposure, temperature, and light is vital. Effective management, including the strategic use of preservatives and additives, is crucial for maintaining quality and extending shelf life. This review underscores the delicate equilibrium necessary for preserving wine quality from production to consumption.

Investigation of the Functional Components in Health Beverages Made from Polygonatum cyrtonema Rhizomes Provides Primary Evidence to Support Their Claimed Health Benefits

This study aims to understand the functional component compositions of traditional herbal health beverages made from Polygonatum cyrtonema rhizomes and to reveal the pharmacodynamic chemical basis for their claimed health benefits. Two traditional methods, rhizome decoction and rhizome infusion, were used to make health herbal beverages, including "Huangjin" tea and "Huangjin" wine, respectively. The secondary metabolites of "Huangjin" beverages were investigated and compared by widely targeted metabolomics. The results clearly showed that the major functional components in "Huangjin" beverages were phenolic acids, flavonoids, and alkaloids. The "Huangjin" wine has a greater variety of flavonoids and alkaloids than "Huangjin" tea, and the functional components in "Huangjin" wine were more abundant than those in "Huangjin" tea. Homoisoflavones and amide alkaloids were the dominating flavonoids and alkaloids in "Huangjin" wine, respectively. Continuous rhizome infusion could not increase the content of functional components in "Huangjin" wine. In conclusion, this study not only provides primary evidence to support the claimed health benefits of "Huangjin" beverages but also suggests that making traditional herbal beverages by rhizome infusion has superior health benefits than making them by rhizome decoction, which is attributed to the higher yields of functional components extracted by Chinese liquor than hot water. Therefore, Chinese liquor shows advantages in its use as a superior binary ethanol-water solvent in making herbal health beverages to enhance the solubility of poorly water-soluble functional components.

Cosmetic Products with Potential Photoprotective Effects Based on Natural Compounds Extracted from Waste of the Winemaking Industry

Grape marc is a by-product resulting from the winemaking industry that still contains beneficial compounds that can be valorized. Thus, we report here the possibility of using polyphenolic extracts of grape marc origin to obtain sun protection creams. The extractions were performed in ethanol and acetone solutions using pomace from different grape varieties (Merlot, Bläufrankisch, Fetească Neagră, Isabella) as a raw material. The obtained extracts were analyzed in order to determine the total phenolic content, the antioxidant activity, and the sun protection factor (SPF) via Mansur spectrophotometric assay. The best results were achieved using 70% ethanol in water as a solvent. The extracts with the highest potential photoprotective effects are from the Merlot variety (SPFspectrophotometric = 7.83 ± 0.76). The sunscreens were prepared using the 70% ethanolic extract of the Merlot variety evaporated to dryness, redissolved in either distilled water or ethanol. The SPF estimated in vitro via the COLIPA method showed values of 14.07 ± 1.50 and 11.46 ± 1.32 for the aqueous and ethanolic extracts, respectively, when working with a cream to polyphenolic extract a ratio of 1/1 (w/w). At the same time, the use of aqueous polyphenolic extracts ensures the better stability of creams compared with the ethanolic ones.

Microencapsulation of Grape Pomace Extracts with Alginate-Based Coatings by Freeze-Drying: Release Kinetics and In Vitro Bioaccessibility Assessment of Phenolic Compounds

The phenols from grape pomace have remarkable beneficial effects on health prevention due to their biological activity, but these are often limited by their bioaccessibility in the gastrointestinal tract. Encapsulation could protect the phenolics during digestion and influence the controlled release in such an intestine where their potential absorption occurs. The influence of freeze-drying encapsulation with sodium alginate (SA) and its combination with gum Arabic (SA-GA) and gelatin (SA-GEL) on the encapsulation efficiency (EE) of phenol-rich grape pomace extract and the bioaccessibility index (BI) of phenolics during simulated digestion in vitro was investigated. The addition of a second coating to SA improved the EE, and the highest EE was obtained with SA-GEL (97.02-98.30%). The release of phenolics followed Fick's law of diffusion and the Korsmeyer-Peppas model best fitted the experimental data. The highest BI was found for the total phenolics (66.2-123.2%) and individual phenolics (epicatechin gallate 958.9%, gallocatechin gallate 987.3%) using the SA-GEL coating were used. This study shows that freeze-dried encapsulated extracts have the potential to be used for the preparation of various formulations containing natural phenolic compounds with the aim of increasing their bioaccessibility compared to formulations containing non-encapsulated extracts.

Improving Soluble Phenolic Profile and Antioxidant Activity of Grape Pomace Seeds through Fungal Solid-State Fermentation

Grape pomace seeds contain abundant phenolic compounds, which are also present in both soluble and insoluble forms, similar to many other plant matrices. To further increase the extractable soluble phenolics and their antioxidant activities, grape pomace seeds were fermented with different fungi. Results showed that solid-state fermentation (SSF) with Aspergillus niger, Monascus anka, and Eurotium cristatum at 28 °C and 65% humidity had a significantly positive impact on the release of soluble phenolics in grape pomace seeds. Specifically, SSF with M. anka increased the soluble phenolic contents by 6.42 times (calculated as total phenolic content) and 6.68 times (calculated as total flavonoid content), leading to an overall improvement of antioxidant activities, including DPPH (increased by 2.14 times) and ABTS (increased by 3.64 times) radical scavenging activity. Furthermore, substantial changes were observed in the composition and content of individual phenolic compounds in the soluble fraction, with significantly heightened levels of specific phenolics such as chlorogenic acid, syringic acid, ferulic acid, epicatechin gallate, and resveratrol. Notably, during M. anka SSF, positive correlations were identified between the soluble phenolic content and hydrolase activities. In particular, there is a strong positive correlation between glycosidase and soluble phenols (r = 0.900). The findings present an effective strategy for improving the soluble phenolic profiles and bioactivities of grape pomace seeds through fungal SSF, thereby facilitating the valorization of winemaking by-products.

Effect of Pretreatment and Drying on the Nutritional and Functional Quality of Raisins Produced with Seedless Purple Grapes

Raisins, known for their delicious taste and high nutritional value, are among the most widely consumed dried fruits globally. The natural waxy layer on the surface of grapes impedes water migration, making pretreatment necessary before drying. This study evaluated the effects of various pretreatment methods on the nutritional and functional quality of seedless purple raisins. By using non-pretreated dry seedless purple raisins as a control, the impact of physical and chemical pretreatment methods on the nutritional and functional qualities of seedless purple raisins was assessed through the analysis of nutrient content, phenolic compounds, and antioxidant activity. Our results demonstrate that physical pretreatment significantly increases the levels of vitamin C, fructose, glucose, total acid, total phenolics, total flavonoids, total anthocyanins, and antioxidant activity compared to chemical pretreatment and the control group. The correlation analysis revealed that phenolic substances were closely linked to antioxidant capacity. Additionally, phenolic compounds, including resveratrol, ferulic acid, chlorogenic acid, ethyl coumarate, and cinnamic acid, were more abundant following physical pretreatment. The OPLS-DA model effectively differentiated the three groups of processed samples, showing that different pretreatments significantly affect the nutritional and functional quality of seedless purple raisins. These findings suggest that physical pretreatment offers considerable potential for improving the drying quality of seedless purple raisins.

The multiple actions of grape and its polyphenols on female reproductive processes with an emphasis on cell signalling

Grapes are an economically important fruit crop, and their polyphenols (mainly phenolic acids, flavanols, flavonols, anthocyanins, proanthocyanidins, and stilbenes) can exert a wide range of health benefits as an interesting and valuable dietary supplement for natural complementary therapy. However, their potential physiological and therapeutic actions on reproductive processes have not been sufficiently elucidated. This evidence-based study presents current knowledge of grape extracts and polyphenols, as well as their properties and therapeutical actions in relation to female reproduction in a nutshell. Grape extract, and its polyphenols such as resveratrol, proanthocyanidin B2 or delphinidin may influence female reproductive physiology and pathology, as well as regulate multiple signaling pathways related to reproductive hormones, steroid hormones receptors, intracellular regulators of oxidative stress and subsequent inflammation, apoptosis, and proliferation. Their role in the management of ovarian cancer, age-related reproductive insufficiency, ovarian ischemia, PCOS, or menopausal syndrome has been indicated. In particular, the potential involvement of grapeseed extracts and/or proanthocyanidin B2 and delphinidin on ovarian steroidogenesis, oocyte maturation, and developmental capacity has been implicated, albeit at different regulatory levels. Grape polyphenols exert a wide range of health benefits posing grape extract as an interesting and valuable dietary supplement for natural complementary therapy. This evidence-based study focuses on the actions of grapeseed extract and grape polyphenols on female reproductive processes at various regulatory levels and multiple signalling pathways by regulating reproductive hormones (GnRH, gonadotropins, prolactin, steroid hormones, IGFBP), steroid receptors, markers of proliferation and apoptosis. However, lack of knowledge of standardized dosages so far limits their clinical application despite the wide range of their biological and therapeutic potentials.

Biopolymeric nanofibrous scaffolds of poly(3-hydroxybuthyrate)/chitosan loaded with biogenic silver nanoparticle synthesized using curcumin and their antibacterial activities

The increasing prevalence of multi-drug resistant bacteria poses a significant threat to public health, especially in wound infections. Developing new bactericidal agents and treatment strategies is crucial to address this issue. In this study, biopolymeric nanofibrous scaffolds containing green-synthesized silver nanoparticles (AgNPs) with curcumin (CUR) were evaluated as antimicrobial materials for wound healing therapy. Firstly, CUR was utilized to synthesize AgNPs, which were then analyzed using various analytical methods. The microstructural analysis revealed that the biogenic AgNPs, which had a spherical shape and an average size of 19.83 nm, were uniformly anchored on PHB/CTS nanofibers. Then, the AgNPs with various content (0.25-1%wt) were incorporated into PHB/CTS matrix to enhance its wettability, thermal and bactericidal behaviors. The nanofibrous scaffolds were characterized by FT-IR, FE-SEM, TGA analysis and water contact angle measurement. Overall, the addition of CUR-AgNPs to the PHB/CTS matrix led to a reduction in fiber diameter, enhanced hydrophilicity and improved thermal properties. Additionally, antibacterial activity against Staphylococcus aureus and Escherichia coli was performed on samples of AgNPS and PHB/CTS/CUR-Ag. The synthesized AgNPs showed antibacterial activity against both microorganisms, especially against S. aureus. Higher concentrations of AgNPs in nanofibers led to a significant reduction in bacterial colony formation. The results displayed that PHB/CTS/CUR-AgNPs nanofibrous scaffolds could be a promising material for the biomedical applications such as wound healing.

ZnO nanostructured matrix as nexus catalysts for the removal of emerging pollutants

Water pollution stands as a pressing global environmental concern, elevating the significance of innovative, dependable, and sustainable solutions. This study represents an extensive review of the use of photocatalytic zinc oxide nanoparticles (ZnO NPs) for the removal of emerging pollutants from water and wastewater. The study examines ZnO NPs' different preparation methods, including physical, chemical, and green synthesis, and emphasizes on advantages, disadvantages, preparation factors, and investigation methods for the structural and morphological properties. ZnO NPs demonstrate remarkable properties as photocatalysts; however, their small dimensions pose an issue, leading to potential post-use environmental losses. A strategy to overcome this challenge is scaling up ZnO NP matrices for enhanced stability and efficiency. The paper introduces novel ZnO NP composites, by incorporating supports like carbon and clay that serve as photocatalysts in the removal of emerging pollutants from water and wastewater. In essence, this research underscores the urgency of finding innovative, efficient, and eco-friendly solutions for the removal of emerging pollutants from wastewater and highlights the high removal efficiencies obtained when using ZnO NPs obtained from green synthesis as a photocatalyst. Future research should be developed on the cost-benefit analysis regarding the preparation methods, treatment processes, and value-added product regeneration efficiency.

Polyphenol Composition by HPLC-DAD-(ESI-)MS/MS and Bioactivities of Extracts from Grape Agri-Food Wastes

BACKGROUND

Grape agri-food wastes, such as skin, seeds, and other discarded by-products, contain phytochemical compounds that offer potential health benefits.

METHODS

This study aimed to investigate the polyphenol composition and bioactivities of different extracts obtained from grape marc and seeds, with the goal of exploring their potential for application as natural food additives.

RESULTS

Regardless of the extraction method used (dynamic maceration, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE)), all extracts exhibited relatively high concentrations of phenolic compounds. The chemical characterization of the extracts revealed the presence of specific compounds and chemical groups associated with each extraction methodology. Moreover, the extracts displayed satisfactory antioxidant activities, especially in inhibiting lipoperoxidation as assessed by the TBARS assay. Additionally, the extracts demonstrated effective inhibition against different strains of bacteria and fungi known as food contaminants. Taken together, these findings indicate that those extracts have the potential to be tested as natural antioxidants and preservatives with sustainable origins in food and beverage systems. Among the extraction methods evaluated, traditional maceration and UAE provided extracts with the highest antioxidant and antimicrobial activities.

CONCLUSIONS

Our results suggest the opportunity to explore grape marc and seeds discarded by the winery industry in Portugal as natural sources of bioactive compounds, which could be employed as functional food ingredients or technological additives. The valorization of grape biowastes offers a promising strategy to reduce waste and harness their potential health benefits.

Cirsiliol and Quercetin Inhibit ATP Synthesis and Decrease the Energy Balance in Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin-Resistant Staphylococcus epidermidis (MRSE) Strains Isolated from Patients

Polyphenols have attracted attention in the fight against antibiotic-resistant bacteria, as they show antibacterial action. Considering that polyphenols inhibit F1Fo-ATP synthase (ATP synthase) and that bacteria need a constant energy production to maintain their homeostasis, we evaluated the effect of two flavones, cirsiliol (tri-hy-droxy-6,7-dimethoxyflavone) and quercetin (3,3,4,5,7-pentahydroxyflavone), on energy production and intracellular ATP content in a methicillin-resistant Staphylococcus aureus (MRSA) strain and a methicillin-resistant Staphylococcus epidermidis (MRSE) strain isolated from patients, comparing the results to those obtained by treating the bacteria with oligomycin, a specific ATP synthase Fo moiety inhibitor. Real-time quantitative ATP synthesis and total ATP content of permeabilized Gram-positive bacteria were assayed by luminometry. The results showed that cirsiliol and quercetin inhibited ATP synthase and decreased the intracellular ATP levels in both strains, although the effect was higher in MRSE. In addition, while cirsiliol and quercetin acted immediately after the treatment, oligomycin inhibited ATP synthesis only after 30 min of incubation, suggesting that the different responses may depend on the different permeability of the bacterial wall to the three molecules. Thus, cirsiliol and quercetin could be considered potential additions to antibiotics due to their ability to target ATP synthase, against which bacteria cannot develop resistance.

In Vitro Bioaccessibility Assessment of Phenolic Compounds from Encapsulated Grape Pomace Extract by Ionic Gelation

Grape pomace is a by-product of winemaking characterized by a rich chemical composition from which phenolics stand out. Phenolics are health-promoting agents, and their beneficial effects depend on their bioaccessibility, which is influenced by gastrointestinal digestion. The effect of encapsulating phenol-rich grape pomace extract (PRE) with sodium alginate (SA), a mixture of SA with gelatin (SA-GEL), and SA with chitosan (SA-CHIT) on the bioaccessibility index (BI) of phenolics during simulated digestion in vitro was studied. A total of 27 individual phenolic compounds (IPCs) were quantified by UHPLC. The addition of a second coating to SA improved the encapsulation efficiency (EE), and the highest EE was obtained for SA-CHIT microbeads (56.25%). Encapsulation affected the physicochemical properties (size, shape and texture, morphology, crystallinity) of the produced microbeads, which influenced the delivery of phenolics to the intestine and their BI. Thus, SA-GEL microbeads had the largest size parameters, as confirmed by scanning electron microscopy (SEM), and the highest BI for total phenolic compounds and IPCs (gallic acid, 3,4-dihydroxybenzoic acid and o-coumaric acid, epicatechin, and gallocatechin gallate) ranged from 96.20 to 1011.3%. The results suggest that encapsulated PRE has great potential to be used as a functional ingredient in products for oral administration.

Nontargeted Screening for Flavonoids in Salicornia Plant by Reversed-Phase Liquid Chromatography–Electrospray Orbitrap Data-Dependent MS2/MS3

The Salicornia genus has great potential in agrifood industries because of its nutritional benefits related to its high content of antioxidant compounds, including flavonoids. A nontargeted method based on reversed-phase liquid chromatography–electrospray orbitrap data-dependent MS2/MS3 and the fragment ion search (FISh) strategy was developed to screen flavonoids in Salicornia plants. An extensive study of fragmentation of a set of flavonoid standards allowed for the definition of 15 characteristic fragment ions for flagging flavonoids in the plant matrix. The nontargeted analysis was applied to Salicornia europaea species and allowed for the annotation of 25 candidate flavonoids, including 14 that had not been reported previously. Structural prediction of two unreported flavonoids and their isomeric forms was based on an advanced data processing method using an in silico approach and in-house databases compiling flavonoid-specific chemical substitution. Finally, the method developed allowed for the optimization of extraction yields of flavonoids from the plant matrix.

Coupling Hydrophilic Interaction Chromatography and Reverse-Phase Chromatography for Improved Direct Analysis of Grape Seed Proanthocyanidins

Acid-catalyzed depolymerization is recognized as the most practical method for analyzing subunit composition and the polymerization degree of proanthocyanidins, involving purification by removing free flavan-3-ols, as well as acid-catalyzed cleavage and the identification of cleavage products. However, after the removal of proanthocyanidins with low molecular weights during purification, the formation of anthocyanidins from the extension subunits accompanying acid-catalyzed cleavage occurred. Thus, grape seed extract other than purified proanthocyanidins was applied to acid-catalyzed depolymerization. Hydrophilic interaction chromatography was developed to quantify free flavan-3-ols in grape seed extract to distinguish them from flavan-3-ols from terminal subunits of proanthocyanidins. Reverse-phase chromatography was used to analyze anthocyanidins and cleavage products at 550 and 280 nm, respectively. It is found that the defects of the recognized method did not influence the results of the subunit composition, but both altered the mean degree of polymerization. The established method was able to directly analyze proanthocyanidins in grape seed extract for higher accuracy and speed than the recognized method.

Exploration and Comparison of the Behavior of Some Indigenous and International Varieties (Vitis vinifera L.) Grown in Climatic Conditions of Herzegovina: The Influence of Variety and Vintage on Physico-Chemical Characteristics of Grapes

Viticulture is of great economic importance in the southern part of Bosnia and Herzegovina, thanks to favorable climatic conditions and a long-standing tradition of growing vines. The assortment is dominated by international varieties, as well as some autochthonous and domesticated varieties. The subject of the research is the analysis of the quality of Cabernet Sauvignon, Merlot, Vranac, and Blatina varieties at two localities in Herzegovina during the period 2020-2021. The paper examined the most important economic and technological characteristics, grape quality, and berry phenolic profile. A particularly pronounced variation of the tested characteristics during the research period was observed in the Merlot and Blatina varieties, while the Cabernet Sauvignon and Vranac varieties showed a slightly higher stability of the tested characteristics. Poorer grape quality during the research period was registered with the Blatina variety, which can be considered a varietal characteristic to some extent. The analyzed grape varieties were rich in polyphenols, and the impact of grape variety on the berry phenolic profiles was confirmed. The most abundant polyphenols in the analyzed grape samples were quercetin 3-O-glucoside and catechin gallate, followed by kaempferol 3-O-glucoside. The highest values of polyphenols were found mainly in the samples originating from Trebinje. Indigenous Balkan grape varieties (Vranac and Blatina) stood out with particularly high contents of some phenolics. Research has shown that climatic conditions have a significant influence on the most important characteristics of grapes, which are conditioned by genotypic specificities. The conditions for growing vines in the conditions of Herzegovina enable high quality in the production of grapes, especially the Cabernet Sauvignon and Vranac varieties. The autochthonous variety Blatina shows significant variations in grape quality during the test period, which was confirmed by the results of a larger number of studies in the previous period.

Inflammation and Obesity: The Pharmacological Role of Flavonoids in the Zebrafish Model

A Mediterranean-style diet is highly encouraged thanks to its healthy food pattern, which includes valuable nutraceuticals such as polyphenols. Among these, flavonoids are associated with relevant biological properties through which they prevent or fight the onset of several human pathologies. Globally, the enhanced incidence of overweight and obese people has caused a dramatic increase in comorbidities, raising the need to provide better therapies. Therefore, the development of sophisticated animal models of metabolic dysregulation has allowed for a deepening of knowledge on this subject. Recent advances in using zebrafish (Danio rerio) as model for metabolic disease have yielded fundamental insights into the potential anti-obesity effects of flavonoids. Chronic low-grade inflammation and immune system activation seem to characterize the pathogenesis of obesity; thus, their reduction might improve the lipid profile of obese patients or prevent the development of associated metabolic illnesses. In this review, we highlight the beneficial role of flavonoids on obesity and related diseases linked to their anti-inflammatory properties. In light of the summarized studies, we suggest that anti-inflammatory therapies could have a relevant place in the prevention and treatment of obesity and metabolic disorders.

Biocosmetics: technological advances and future outlook

The paper provides an overview of biocosmetics, which has tremendous potential for growth and is attracting huge business opportunities. It emphasizes the immediate need to replace conventional fossil-based ingredients in cosmetics with natural, safe, and effective ingredients. It assembles recent technologies viable in the production/extraction of the bioactive ingredient, product development, and formulation processes, its rapid and smooth delivery to the target site, and fosters bio-based cosmetic packaging. It further explores industries that can be a trailblazer in supplying raw material for extraction of bio-based ingredients for cosmetics, creating biodegradable packaging, or weaving innovation in fashion clothing. Lastly, the paper discusses what it takes to become the first generation of a circular economy and supports the implementation of strict regulatory guidelines for any cosmetic sold globally.

Processing Stabilization of Polyethylene with Grape Peel Extract: Effect of Extraction Technology and Composition

Dry grape peel powder was extracted by three different techniques, stirred tank reactor, Soxhlet and ultrasound extraction. The composition, physical and chemical structure and inherent stability of the extracts were characterized by various methods. The extracts and reference compounds were added to polyethylene and their stabilization efficiency was determined in multiple extrusion experiments. The composition of the extracts was quite similar. Ten main compounds were identified in the extracts, which contained a considerable number of polyphenols, but only small amounts of quercetin and trans-resveratrol. The extracts proved to be more efficient processing stabilizers than trans-resveratrol and the commercial stabilizer, Irganox 1010, irrespective of the extraction technology used. In spite of their good processing stabilization effect, polymers containing the extracts had poor residual stability. The differences in processing and long-term stabilization must be related to the different structures of the polyphenols contained by the extracts and the reference compounds. The results clearly prove that the IC50 value determined by the DPPH assay is not suitable for the estimation of the efficiency of a compound as a stabilizer for polymers.

Endoplasmic reticulum as a target in cardiovascular diseases: Is there a role for flavonoids?

Flavonoids are found in natural health products and plant-based foods. The flavonoid molecules contain a 15-carbon skeleton with the particular structural construction of subclasses. The most flavonoid's critical subclasses with improved health properties are the catechins or flavonols (e.g., epigallocatechin 3-gallate from green tea), the flavones (e.g., apigenin from celery), the flavanones (e.g., naringenin from citrus), the flavanols (e.g., quercetin glycosides from berries, onion, and apples), the isoflavones (e.g., genistein from soya beans) and the anthocyanins (e.g., cyanidin-3-O-glucoside from berries). Scientific data conclusively demonstrates that frequent intake of efficient amounts of dietary flavonoids decreases chronic inflammation and the chance of oxidative stress expressing the pathogenesis of human diseases like cardiovascular diseases (CVDs). The endoplasmic reticulum (ER) is a critical organelle that plays a role in protein folding, post-transcriptional conversion, and transportation, which plays a critical part in maintaining cell homeostasis. Various stimuli can lead to the creation of unfolded or misfolded proteins in the endoplasmic reticulum and then arise in endoplasmic reticulum stress. Constant endoplasmic reticulum stress triggers unfolded protein response (UPR), which ultimately causes apoptosis. Research has shown that endoplasmic reticulum stress plays a critical part in the pathogenesis of several cardiovascular diseases, including diabetic cardiomyopathy, ischemic heart disease, heart failure, aortic aneurysm, and hypertension. Endoplasmic reticulum stress could be one of the crucial points in treating multiple cardiovascular diseases. In this review, we summarized findings on flavonoids' effects on the endoplasmic reticulum and their role in the prevention and treatment of cardiovascular diseases.

Physicochemical characteristics and biological activities of grape polysaccharides collected from different cultivars

In this study, four wine grape polysaccharides were extracted and optimized by using an efficient ultrasound-assisted extraction. A three-level, three-factor Box Behnken Design (BBD) combining with response surface methodology (RSM) was employed to optimize the extraction conditions including ultrasonic power, ultrasonic time and liquid-to-solid ratio. Furthermore, their physicochemical structures, antioxidant and liver protective activity were investigated and compared. Results revealed that the functional groups and monosaccharide compositions of these grape polysaccharides collected from different varieties were similar. Nevertheless, their molecular weights, molar ratios of monosaccharide compositions and surface morphological features were different. And the antioxidant activities of these polysaccharides were screened by free radical scavenging test. 'Beichun' (BC) and 'Benni fuji' (BF) polysaccharides possessed better antioxidant function. Further, the in vivo evaluation indicated that the polysaccharides of BC and BF have a protective effect against myocardial I/R injury in mice by inhibiting myocardial necroptosis mediated by mitochondrial ROS generation. Therefore, BC and BF grapes have potential applications in the medical and food industries.

Extraction of Anthocyanins from Black Grape By-Products and Improving Their Stability Using Cobalt(II) Complexation

This study was conducted to investigate the effect of cobalt complexation on the spectral properties of anthocyanins (AC) extracted from black grape pomace (Black Magic) and the effect of complexation on the pH stability of AC during storage. Initially, cobalt acetate tetrahydrate aqueous solution was complexed with AC crude extract and diluted separately in buffer solutions with different pH (3.5, 4.5, 5.5, and 6.5). Afterward, spectral changes were determined spectrophotometrically. pH stability was investigated using the same buffer solutions and stored for 7 days in the dark at room temperature, and the absorbance of each solution was measured daily using a spectrophotometer. Results indicated that complexation caused similar hypsochromic and hyperchromic shifts in λ_max at all pH values. With regard to pH stability, the degradation of complexed AC followed first-order reaction kinetics causing half-lives to increase up to 80-fold as compared with noncomplexed AC, which was due to the sharp decrease in K (per day), indicating an improved pH stability as compared with noncomplexed AC. Therefore, Co(II) could be used in the stabilization of grape AC for the coloration of a wide range of foods and food products at near-neutral pH environments considering the health benefits of grape AC and the maximum nontoxic dose of Co(II) salt.

Selected Seeds as Sources of Bioactive Compounds with Diverse Biological Activities

Seeds contain a variety of phytochemicals that exhibit a wide range of biological activities. Plant-derived compounds are often investigated for their antioxidant, anti-inflammatory, immunomodulatory, hypoglycemic, anti-hypercholesterolemic, anti-hypertensive, anti-platelet, anti-apoptotic, anti-nociceptive, antibacterial, antiviral, anticancer, hepatoprotective, or neuroprotective properties. In this review, we have described the chemical content and biological activity of seeds from eight selected plant species-blackberry (Rubus fruticosus L.), black raspberry (Rubus coreanus Miq.), grape (Vitis vinifera L.), Moringa oleifera Lam., sea buckthorn (Hippophae rhamnoides L.), Gac (Momordica cochinchinensis Sprenger), hemp (Cannabis sativa L.), and sacha inchi (Plukenetia volubilis L). This review is based on studies identified in electronic databases, including PubMed, ScienceDirect, and SCOPUS. Numerous preclinical, and some clinical studies have found that extracts, fractions, oil, flour, proteins, polysaccharides, or purified chemical compounds isolated from the seeds of these plants display promising, health-promoting effects, and could be utilized in drug development, or to make nutraceuticals and functional foods. Despite that, many of these properties have been studied only in vitro, and it's unsure if their effects would be relevant in vivo as well, so there is a need for more animal studies and clinical trials that would help determine if they could be applied in disease prevention or treatment.

Properties of Winemaking By-products of Feteasca Neagra Grape Seeds

The composition of the lipophilic and hydrophilic extracts from the Feteasca Neagra ground seeds, grown in three different vineyards, was studied. The physicochemical indicators of the seeds, the oil quality indicators and the total content of polyphenols and flavonoids in the extracts were determined. Some phenolic and flavanol constituents were identified and quantified using reversed-phase HPLC by gradient-elution. The Trolox equivalent antioxidant capacity assay proved the increased antioxidant activity of the hydrophilic extracts, with the highest DPPH• scavenging effect of almost 91.70 and 93.81%, an equivalent of 281.66 and 288.27 µM/L Trolox. It was concluded that the seeds recovered from Feteasca Neagra by-products are a rich source of functional compounds, with significant antioxidant properties.

Purple grape juice improves performance of recreational runners, but the effect is genotype dependent: a double blind, randomized, controlled trial

Background

We examined the influence of superoxide dismutase 3 (SOD3) Arg213Gly and Peroxisome Proliferator-Activated α-Receptor (PPARα) 7G/C polymorphisms to a single dose of purple grape juice supplementation on time-to-exhaustion running test, redox balance and muscle damage in recreational runners.

Methods

Forty-seven male recreational runners performed a running test until exhaustion after supplementation with grape juice or a control drink. Serum total antioxidant capacity (TAC), malondialdehyde (MDA), plasma nitrite (NO), creatine kinase (CK) and lactate dehydrogenase (LDH) were measured pre and post exercise. Also, polymorphisms were analyzed in DNA extracted from the oral mucosa.

Results

Grape juice improved the time-to-exhaustion. When analyzed by genotype, the recreational runners with GG+CG genotypes of the SOD3 gene had greater time-to-exhaustion than the CC genotype, but was no different for the PAPRα gene. A slight difference was noted in TAC, since the CC genotype of the SOD3 gene showed higher TAC values in the post-exercise compared to the baseline and with pre-exercise, but these values did not increase compared to the CG+GG group, respectively. The SOD3 and PPARα genes were similar at all times for the other biochemical variables.

Conclusion

The ergogenic effect of grape juice was genotype-dependent for SOD3 Arg213Gly. However, biochemical redox balance markers did not explain this difference.

Bioactive Phytochemical Composition of Grape Pomace Resulted from Different White and Red Grape Cultivars

Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, antiatherosclerotic, antimutagenic, anticarcinogenic, antibacterial, antiviral, and antimicrobial activity. The winemaking of the grapes generates significant amounts of waste. These wastes contain bioactive compounds in their biomass that can be used as a source of food improvement or as a source of nutrition supplementation. This study looks at the content of bioactive compounds, the polyphenolic profile, and the antioxidant activity in different white and red grape pomaces. The investigation of bioactive characteristics (total polyphenols, total flavonoids, catechins, tannins, and antioxidant activity) was carried out by UV-Vis spectrophotometric methods, while the individual polyphenolic composition was investigated by target and screening UHPLC-HRMS/MS analysis. Principal components (PCA) and the heat maps analysis allows the discrimination between the grape pomace resulted from white grape cultivars (Muscat Ottonel and Tamaioasa Romaneasca) and red grape pomaces (Cabernet Sauvignon, Merlot, Feteasca Neagra, Burgund Mare, Pinot Nore), with the identification of the specific phenolic compounds for each grape pomace type.

Light Quality Modulates Growth, Triggers Differential Accumulation of Phenolic Compounds, and Changes the Total Antioxidant Capacity in the Red Callus of Vitis davidii

Light quality is one of the key elicitors that directly affect plant cell growth and biosynthesis of secondary metabolites. In this study, the red callus of spine grape was cultured under nine light qualities (namely, dark, white, red, yellow, blue, green, purple, warm-yellow, and warm-white light). The effects of different light qualities were studied on callus growth, accumulation of phenolic compounds, and total antioxidant capacity of the red callus of spine grape. The results showed that blue and purple light induced increased red coloration in the callus, whereas yellow light induced the greatest callus proliferation. Among all of the light quality treatments, darkness treatment downregulated the contents of phenolic compounds, whereas blue light was the treatment most conducive to the accumulation of total phenolics. White, blue, and purple light induced increased anthocyanin accumulation. Mixed-wavelength light was beneficial to the accumulation of flavonoids. Blue and purple light were conducive to the accumulation of proanthocyanidins. A further study showed that cyanidin 3-glucoside (Cy3G) and peonidin 3-glucoside (P3G) were the main anthocyanin components in the callus, and blue, purple, and white light treatments promoted their accumulation, whereas flavan-3-ols and flavonols were the main components of non-anthocyanin phenolics, and their accumulation changed in response to not only light quality but also culture duration. The total antioxidant capacity of the callus cultures changed significantly in response to different light qualities. These results will provide evidence for an abiotic elicitor strategy to stimulate callus growth and enhance the accumulation of the main phenolic compounds in the red callus of spine grape.

Biocontrol yeast T-2 improves the postharvest disease resistance of grape by stimulation of the antioxidant system

Table grapes are susceptible to external pathogens during postharvest storage. The resulting continuous oxidative stress causes damage and aging, thereby reducing the defense against disease. In this study, the effect of biocontrol yeast T-2 on the storage performance of grapes was evaluated. After T-2 treatment, the grapefruits rot rate and lesion diameter caused by Botrytis cinerea (B. cinerea) were significantly decreased at 2-5 days after inoculation (DAI). Additionally, the browning rate and shedding rate of grapefruit during storage were significantly reduced at 2-5 DAI, and the weight loss rate was significantly reduced at 3-5 DAI. The decreased malondialdehyde (MDA) content in grapefruits at 1-5 DAI with T-2 indicated a reduction in oxidative damage. Furthermore, the activities of antioxidant enzymes such as peroxidase (POD), catalase (CAT), phenylalanin ammonia-lyase (PAL) were significantly increased during most storage time after being treated with T-2. Moreover, the contents of total phenolics and flavonoids and the expression levels of key enzyme genes in metabolic pathways were increased after T-2 treatment during most postharvest storage time, providing evidence that T-2 changed the biological process of phenolic flavonoid metabolism. The increase in enzymatic and nonenzymatic antioxidants after treatment with T-2 reflected the strengthening of the antioxidant system, hence postponing fruit senescence and promoting storage performance under the stress of B. cinerea.

Therapeutic and Nutraceutical Effects of Polyphenolics from Natural Sources

The prevalence of cardiovascular disease, oxidative stress-related complications, and chronic age-related illnesses is gradually increasing worldwide. Several causes include the ineffectiveness of medicinal treatment therapies, their toxicity, their inability to provide radical solutions in some diseases, and the necessity of multiple drug therapy in certain chronic diseases. It is therefore necessary for alternative treatment methods to be sought. In this review, polyphenols were identified and classified according to their chemical structure, and the sources of these polyphenol molecules are indicated. The cardioprotective, ROS scavenging, anti-aging, anticancer properties of polyphenolic compounds have been demonstrated by the results of many studies, and these natural antioxidant molecules are potential alternative therapeutic agents.

Microbial cell factories for the production of flavonoids-barriers and opportunities

Flavonoids are natural plant products with important nutritional value, health-promoting benefits, and therapeutic potential. The use of microbial cell factories to generate flavonoids is an appealing option. The microbial biosynthesis of flavonoids is compared to the classic plant extract approach in this review, and the pharmaceutical applications were presented. This paper summarize approaches for effective flavonoid biosynthesis from microorganisms, and discuss the challenges and prospects of microbial flavonoid biosynthesis. Finally, the barriers and strategies for industrial bio-production of flavonoids are highlighted. This review offers guidance on how to create robust microbial cell factories for producing flavonoids and other relevant chemicals.

Transcriptomic and metabolomic profiling of flavonoid biosynthesis provides novel insights into petals coloration in Asian cotton (Gossypium arboreum L.)

BACKGROUND

Asian cotton (Gossypium arboreum L.), as a precious germplasm resource of cotton with insect resistance and stress tolerance, possesses a broad spectrum of phenotypic variation related to pigmentation. Flower color affects insect pollination and the ornamental value of plants. Studying flower color of Asian cotton varieties improves the rate of hybridization and thus enriches the diversity of germplasm resources. Meanwhile, it also impacts the development of the horticultural industry. Unfortunately, there is a clear lack of studies concerning intricate mechanisms of cotton flower-color differentiation. Hereby, we report an integrative approach utilizing transcriptome and metabolome concerning flower color variation in three Gossypium arboreum cultivars.

RESULTS

A total of 215 differentially accumulated metabolites (DAMs) were identified, including 83 differentially accumulated flavonoids (DAFs). Colorless kaempferol was more abundant in white flowers, while gossypetin-fer showed specificity in white flowers. Quercetin and gossypetin were the main contributors to yellow petal formation. Pelargonidin 3-O-beta-D-glucoside and cyanidin-3-O-(6''-Malonylglucoside) showed high accumulation levels in purple petals. Quercetin and gossypetin pigments also promoted purple flower coloration. Moreover, 8178 differentially expressed genes (DEGs) were identified by RNA sequencing. The correlation results between total anthocyanins and DEGs were explored, indicating that 10 key structural genes and 29 transcription factors promoted anthocyanin biosynthesis and could be candidates for anthocyanin accumulation. Ultimately, we constructed co-expression networks of key DAFs and DEGs and demonstrated the interactions between specific metabolites and transcripts in different color flowers.

CONCLUSION

This study provides new insights into elucidating the regulatory mechanisms of cotton flower color and lays a potential foundation for generate cotton varieties with highly attractive flowers for pollinators.

The Effect on Hemostasis of Gelatin-Graphene Oxide Aerogels Loaded with Grape Skin Proanthocyanidins: In Vitro and In Vivo Evaluation

Using in vitro and in vivo models, this study investigated the hemostatic potential to control bleeding of both unloaded gelatin-graphene oxide aerogels and the same loaded with proanthocyanidins (PAs) from Vitis vinifera grape skin extract. Our results showed that the physicochemical and mechanical properties of the aerogels were not affected by PA inclusion. In vitro studies showed that PA-loaded aerogels increased the surface charge, blood absorption capacity and cell viability compared to unloaded ones. These results are relevant for hemostasis, since a greater accumulation of blood cells on the aerogel surface favors aerogel–blood cell interactions. Although PAs alone were not able to promote hemostasis through extrinsic and intrinsic pathways, their incorporation into aerogels did not affect the in vitro hemostatic activity of these composites. In vivo studies demonstrated that both aerogels had significantly increased hemostatic performance compared to SpongostanTM and gauze sponge, and no noticeable effects of PA alone on the in vivo hemostatic performance of aerogels were observed; this may have been related to its poor diffusion from the aerogel matrix. Thus, PAs have a positive effect on hemostasis when incorporated into aerogels, although further studies should be conducted to elucidate the role of this extract in the different stages of hemostasis.

Attempts to Create Products with Increased Health-Promoting Potential Starting with Pinot Noir Pomace: Investigations on the Process and Its Methods

A process for using grape (Pinot noir) pomace to produce products with improved health-promoting effects was investigated. This process integrated a solid–liquid extraction (SLE) method and a method to acylate the polyphenolics in the extract. This report describes and discusses the methods used, including the rationale and considerations behind them, and the results obtained. The study begins with the work to optimize the SLE method for extracting higher quantities of (+)-catechin, (−)-epicatechin and quercetin by trialing 28 different solvent systems on small-scale samples of Pinot noir pomace. One of these systems was then selected and used for the extraction of the same flavonoids on a large-scale mass of pomace. It was found that significantly fewer quantities of flavonoids were observed. The resultant extract was then subject to a method of derivatization using three different fatty acylating agents. The antiproliferative activities of these products were measured; however, the resulting products did not display activity against the chosen cancer cells. Limitations and improvements to the methods in this process are also discussed.

Design of experiments (DoE) to model phenolic compounds recovery from grape pomace using ultrasounds

Grape processing by-products (particularly grape pomace) are known to contain high amounts of phenolic compounds. To improve the extraction of phenols from this by-product, it is necessary to develop a method and set and model optimal conditions for their extraction. By applying the design of experiments (DoE) approach, optimal experimental factors of Ultrasound-assisted extraction (USAE) were determined to obtain grape pomace extracts with a satisfactory yield of phenols anthocyanins, as well as extracts with high antioxidant capacity using reagents approved in the food industry. Initial method optimization covered two experimental factors: solvent concentration and the weight ratio of the sample and solvent using fixed USAE conditions from literature. For the final method optimization, the three investigated experimental factors were: pH value, the temperature of extraction, and extraction time. The optimal experimental conditions for the development of the method were 55% ethanol, sample/solvent ratio 1:40, pH 4.5, T 55 °C, and 30 min. Depending on the primary goal of the extraction process (the antioxidant activity, total phenolic content, content of individual phenols, or content of individual anthocyanins), these parameters can easily be modified to obtain the desired recovery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05317-9.

A Comprehensive Review on Grape Juice Beverage in Context to Its Processing and Composition with Future Perspectives to Maximize Its Value

Red and purple grape juices (GJs) have long been consumed worldwide for their unique taste and nutritive value. Moreover, grape is postulated to play an important role in the improvement of cardiovascular risk factors owing to its rich polyphenol content. Little is known regarding GJ’s holistic chemistry and functionality as compared to those of other fruit juices. This review aims to compile the state-of-the art chemistry of colored grape juices and in context to its analysis and nutritional values. Further, a review of potential contaminants to be introduced during manufacturing and other factors that influence juice quality and or health effects are presented to help maximize GJ’s quality. A comparison between analytical methods for juice QC establishment is presented employing hyphenated platforms versus direct spectroscopic techniques. The enrichment of the colored skin with a myriad of phenolics poses it as a functional beverage compared to that of skinless juice.

Graphical abstract

Gret1 retrotransposon and VvmybA1 gene sequences in somatic mutants of new table grape varieties ‘Brasil’ and –Black Star’ (Vitis vinifera L.)

Somatic mutations in grapes are relatively frequent and associated with diversity in grape skin color and berry morphology. Mutations that occur on a side branch of the ‘Benitaka’ cultivar with rosy-red berry skin color generated the ‘Brasil’ cultivar, and mutations that occurred on a side branch of ‘Brasil’ generated the ‘Black Star’ cultivar, both showing a black color in the berry skin. Therefore, genetic characterization of the Gret1 retrotransposon and the VvmybA1 gene in ‘Italia’, ‘Rubi’, ‘Benitaka’, ‘Brasil’, and ‘Black Star’ was started to find whether the altered coloration of berries in ‘Brasil’ and ‘Black Star’ is a product of different mutation patterns in the investigated sequences. Six primer combinations were used for the amplification of different sequences of the Gret1 retrotransposon and VvmybA1 gene of the five cultivars. Polymerase chain reaction (PCR) of the Gret1 retrotransposon and the VvmybA1 gene and sequencing of the amplified products using six primer combinations showed no different alleles or different nucleotide sequences in ‘Brasil’ and ‘Black Star’. The sequencing of the VvmybA1 gene in the present study showed that the mutations that occurred in the cultivar ‘Italia’ for generating the ‘Benitaka’ cultivar persisted in the ‘Brasil’ and ‘Black Star’ cultivars.

Polyphenol Characterization and Antioxidant Activity of Grape Seeds and Skins from Sicily: A Preliminary Study

The interest in the consumption of health-promoting foods has led to identifying derivatives of the wine industry as products to increase the functional properties of different foods or to design new functional foods. The main goal of this study is to characterize and valorize byproducts and wastes of Sicilian grapes as new sources of bioactive components, from the perspective of a circular economy and a biorefinery approach. In particular, this research investigated: 1. the total phenolic content and antioxidant activities and 2. the phenolic profiles of free and bound fractions of defatted grape seeds and red grape skins from Sicily. Defatted grape seeds (DGS) and red grape skins (RGSK) are rich in phenolic compounds. Twenty biophenols were found in the defatted seeds and red grape skins. Particularly interesting were the results obtained after basic hydrolysis, which allowed the release of biophenols from the matrix. The degreased grape seeds showed p-coumaric acid levels at 4641.65 µg g−1, gallic acid at 2649.23 µg g−1, and caffeic acid at 1474.13 µg g−1, along with appreciable quantities of myricetin, epicatechin, and quercetin. As a sustainable approach, the reuse and the value added of the byproducts and wastes of grapes grown in Sicily is shown, which makes possible new applications in different fields, i.e., nutraceuticals.

Regulation mechanisms of flavonoids biosynthesis of Hancheng Dahongpao peels (Zanthoxylum bungeanum Maxim) at different development stages by integrated metabolomics and transcriptomics analysis

BACKGROUND

Flavonoids have strong free radical scavenging and antioxidant capacity. The high abundance of flavonoids in Chinese prickly ash peels have many benefits to human health. In this study, 'Hancheng Dahongpao', a main cultivar, was taken as materials to investigate the flavonoids biosynthesis mechanism of Zanthoxylum bungeanum Maxim at three key development stages by integration of metabolomics and transcriptomics analysis.

RESULTS

A total of 19 differentially accumulated metabolites were identified, the key flavonoids compounds were kaempferol, quercetin and their glycoside derivatives, and two major anthocyanins (peonidin O-hexoside and peonidin 3-O-glucoside). 5 gene networks/modules including 15 important candidate genes were identified, which was highly correlated with flavonoids. Among these genes, ZM-163828 and ZM-184209 were strongly correlated with kaempferol and quercetin, and ZM-125833 and ZM-97481 were controlled the anthocyanins biosynthesis. Moreover, it was shown that MYB-ZM1, MYB-ZM3, MYB-ZM5, MYB-ZM6 and MYB-ZM7 coordinately controlled flavonoids accumulation through regulating the structural genes.

CONCLUSIONS

Generally, this study systematically revealed the flavonoids metabolic pathways and candidate genes involved in flavonoids biosynthesis and laid a foundation for the potential targets for the breeding of new valuable Chinese prickly ash cultivars.

Flavonoid Synthesis and Metabolism During the Fruit Development in Hickory (Carya cathayensis)

Hickory (Carya cathayensis) kernel is rich in powerful bioactive flavonoids, which can remove excess free radicals in the human body and play an important role in regulating the physiological metabolism of the plant. This study investigated the changes of flavonoids in hickory exocarp and embryo during development. In this study, 72 DEGs involved in the regulation of flavonoid biosynthesis in fruits were identified, and TT4, CCoAOMT1, UGT71D1, C4H, F3H, TT8, FLS1, and LDOX were identified as the core genes of flavonoid biosynthesis. A total of 144 flavonoid-related metabolites were detected by metabolite analysis. Transcriptome and metabolome analysis combined to construct the flavonoid biosynthesis regulatory pathway in the development stage of hickory fruit. Our results provide a theoretical basis for the exploration and regulation of functional genes related to flavonoid biosynthesis and metabolism in hickory and other plants and the breeding of new walnut varieties.

COVID-19 and Retinal Degenerative Diseases: Promising link “Kaempferol”

Coronavirus disease (COVID-19) outbreak has caused unprecedented global disruption since 2020. Approximately 238 million people are affected worldwide where the elderly succumb to mortality. Post-COVID syndrome and its side effects have popped up with several health hazards, such as macular degeneration and vision loss. It thus necessitates better medical care and management of our dietary practices. Natural flavonoids have been included in traditional medicine and have also been used safely against COVID-19 and several other diseases. Kaempferol is an essential flavonoid that has been demonstrated to influence several vital cellular signaling pathways involved in apoptosis, angiogenesis, inflammation, and autophagy. In this review, we emphasize the plausible regulatory effects of Kaempferol on hallmarks of COVID-19 and macular degeneration.

Grape Pomace Extract Attenuates Inflammatory Response in Intestinal Epithelial and Endothelial Cells: Potential Health-Promoting Properties in Bowel Inflammation

Inflammatory bowel disease (IBD) implies the chronic inflammation of the gastrointestinal tract, combined with systemic vascular manifestations. In IBD, the incidence of cardiovascular disease appears to be related to an increase of oxidative stress and endothelial dysfunction. Grape pomace contains high levels of anti-oxidant polyphenols that are able to counteract chronic inflammatory symptoms. The aim of this study was to determine whether grape pomace polyphenolic extract (GPE) was able to mitigate the overwhelming inflammatory response in enterocyte-like cells and to improve vascular function. Intestinal epithelial Caco-2 cells, grown in monolayers or in co-culture with endothelial cells (Caco-2/HMEC-1), were treated with different concentrations of GPE (1, 5, 10 µg/mL gallic acid equivalents) for 2 h and then stimulated with lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α for 16 h. Through multiple assays, the expression of intestinal and endothelial inflammatory mediators, intracellular reactive oxygen species (ROS) levels and NF-κB activation, as well as endothelial-leukocyte adhesion, were evaluated. The results showed that GPE supplementation prevented, in a concentration-dependent manner, the intestinal expression and release of interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, and matrix metalloproteinases (MMP)-9 and MMP-2. In Caco-2 cells, GPE also suppressed the gene expression of several pro-inflammatory markers, such as IL-1β, TNF-α, macrophage colony-stimulating factor (M-CSF), C-X-C motif ligand (CXCL)-10, intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and cyclooxygenase (COX)-2. The GPE anti-inflammatory effect was mediated by the inhibition of NF-κB activity and reduced intracellular ROS levels. Furthermore, transepithelial GPE suppressed the endothelial expression of IL-6, MCP-1, VCAM-1, and ICAM-1 and the subsequent adhesion of leukocytes to the endothelial cells under pro-inflammatory conditions. In conclusion, our findings suggest grape pomace as a natural source of polyphenols with multiple health-promoting properties that could contribute to the mitigation of gut chronic inflammatory diseases and improve vascular endothelial function.

Inhibitory activities of grape bioactive compounds against enzymes linked with human diseases

A quest for identification of novel, safe and efficient natural compounds, as additives in the modern food and cosmetic industries, has been prompted by concerns about toxicity and side effects of synthetic products. Plant phenolic compounds are one of the most documented natural products due to their multifarious biological applications. Grape (Vitis vinifera) is an important source of phenolic compounds such as phenolic acids, tannins, quinones, coumarins and, most importantly, flavonoids/flavones. This review crisply encapsulates enzyme inhibitory activities of various grape polyphenols towards different key human-ailment-associated enzymes: xanthine oxidase (gout), tyrosinase (hyperpigmentation), α-amylase and α-glucosidase (diabetes mellitus), pancreatic lipase (obesity), cholinesterase (Alzheimer's disease), angiotensin i-converting enzymes (hypertension), α-synuclein (Parkinson's disease) and histone deacetylase (various diseases). The review also depicts the enzyme inhibitory mechanism of various grape polyphenols and briefly discusses their stature as potential therapeutic and drug development candidates. KEY POINTS: • Nineteen major bioactive polyphenols from the grape/grape products and their disease targets are presented • Sixty-two important polyphenols as enzyme inhibitors from grape/grape products are presented • A thorough description and graphical presentation of biological significance of polyphenols against various diseases.

In Vitro Evaluation of Biological Activities of Canes and Pomace Extracts from Several Varieties of Vitis vinifera L. for Inclusion in Freeze-Drying Mouthwashes

In this study, the biological activities of four extracts from Vitis vinifera by-products: two pomace extracts, white (WPE) and red (RPE), a canes extract (CE), and their combination (CoE), were evaluated, to be included in freeze-drying mouthwashes formulations. The cytocompatibility and anticancerous potential of the four extracts were tested on three cancerous cell lines, as well as the cytoprotective activity against nicotine-induced cytotoxicity and the antioxidant potential determined on a human gingival fibroblasts (HGF) cell line. Additionally, the anti-inflammatory activity and the antimicrobial activity against several microorganisms from the oral microbiome were tested. Freeze-dried mouthwashes with CoE were prepared and characterized, both as lyophilizates and after reconstitution. The four tested extracts showed the highest cytotoxicity on MDA-kb2 cell line. The antioxidant potential was demonstrated for WPE, RPE, CE, and CoE, both in non-stimulated and H₂O₂ stimulated conditions. The four extracts reduced the levels of proinflammatory cytokines (IL-6, IL-8, and IL-1β) in a dose-dependent manner, confirming their anti-inflammatory activity. The antimicrobial activity of tested extracts was shown against pathogenic bacteria from the oral microbiome. Mouthwashes of CoE with poloxamer-407, xylitol, and different ratios of mannitol were prepared by freeze-drying leading to porous formulations with interesting mechanical properties and reconstitution times.

Systematic analysis reveals O-methyltransferase gene family members involved in flavonoid biosynthesis in grape

O-methyltransferases (OMTs) are an important group of enzymes involved in the methylation of various secondary metabolites, including flavonoids. However, the features and functions of OMTs have not been comprehensively studied in grape (Vitis vinifera), a rich source of methylated flavonoids. Here, 47 OMT members were identified in grape genome. They were unevenly distributed on grape chromosomes and some genes were tandem duplicated, indicating the role of duplication processes in the expansion of this gene family. Based on the phylogenetic relationship, these OMTs were clustered into CCoAOMT and COMT subclades, which were further supported by the results of conserved motif and gene structure analysis. Correlation analysis revealed that three members (VvCCoAOMT1, VvCCoAOMT4, and VvCOMT1) were potentially involved in the synthesis of most methylated flavonoids in the berry skins. Expression profiling based on RNA-seq data and qRT-PCR experiments indicated that VvCCoAOMT1 and VvCCoAOMT4 had specific and high expression in berry skins, and responded to abscisic acid and high temperature treatments; and that VvCOMT1 expression was significantly induced during berry development and UVC treatment. Cis-regulatory element analysis suggested important roles of OMTs in growth, development, and defense against stresses. We further demonstrated the transcriptional regulation of VvCCoAOMT4 by VvMYBA1, a master regulator of grape berry anthocyanin, and verified the protein localization of VvCCoAOMT4 in membrane and nucleus. These findings facilitate a better understanding of the characteristics of OMT gene family, especially of the potential members involved in the formation of O-methylated flavonoids in grape.