Proanthocyanidins against Oxidative Stress: From Molecular Mechanisms to Clinical Applications

Biombalance™, an Oligomeric Procyanidins-Enriched Grape Seed Extract, Prevents Inflammation and Microbiota Dysbiosis in a Mice Colitis Model

Inflammatory bowel disease (IBD) results from genetic factors, environmental factors, and intestinal microbiota interactions. This study investigated the effects of Biombalance™ (BB) in dextran sulphate sodium (DSS)-induced colitis in mice. BB extract exhibits high antioxidant activity, as determined by DPPH and ORAC tests. Mice were fed a standard diet, and BB was administered by gavage for ten days, before administration of 2.75% DSS in drinking water. BB significantly protected mice against DSS effects, as assessed by colon length, disease activity index (DAI) scores and colonic pathological damage. In addition, BB inhibited the expression of proinflammatory markers, such as IL-6, IL-17, CXCL1 and TNF-α, and the inflammatory mediators iNOS, TGF-β, FoxP3 and F4/80, while increasing IL-10 expression in the colon. BB modified microbiota composition, attenuating the microbial diversity lost due to DSS, increasing beneficial bacteria like Muribaculum, Lactobacillus, Muscispirillum, Roseburia and Bifidobacterium, and decreasing potentially harmful bacteria such as Proteobacteria and Enterococcus. Interestingly, microbiota-predicted functions using PICRUSt revealed that BB extract increases the antioxidant superpathway of ubiquinol biosynthesis, including ubiquinol-7, 8, 9 and 10 (CoenzymesQ). These findings suggest that Biombalance™ administration may help to reduce gut inflammation and oxidation, at least partly through modifications of the microbiota and its metabolites.

Myricetin Modulates Matrix Metalloproteinases Expression Induced by TEGDMA in Human Odontoblast-Like Cells

The activity of matrix metalloproteinases (MMPs) plays a crucial role in the aging of the resin-dentin interface. The in situ action of MMP-2 and MMP-9 has been confirmed in the process of dentin-collagen degradation. However, the involvement of dental pulp cells in MMP secretion as a response to oxidative stress induced by contact with resin monomers has not been fully elucidated. Myricetin (MYR), like proanthocyanidin (PAC), has antioxidant properties and may help prevent extracellular matrix degradation. The objective was to evaluate the effect of MYR on the MMP expression and activity in response to reactive oxygen species (ROS) increase induced by triethylene glycol dimethacrylate (TEGDMA) in human odontoblast-like cells (hOLCs). hOLCs differentiated from dental pulp mesenchymal stem cells were exposed to TEGDMA released from dentin blocks using a barrier model with transwell inserts for 18, 24, and 36 h. Intracellular oxidation was evaluated using the 2',7'-dichlorofluorescein probe. The effect of 600 μM MYR on the MMP-2 and MMP-9 expression was determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The extracellular MMP levels were quantified using enzyme-linked immunosorbent assay, and their activation by means of a proteolytic fluorometric assay. The results were analyzed by one-way analysis of variance and Tukey's post hoc test, p ≤ 0.05. TEGDMA exposure increased intracellular ROS and upregulated MMP-2 and MMP-9 mRNA in hOLCs (p < 0.001). The levels of MMPs increased significantly 24 h after TEGDMA exposure (p = 0.013). These secreted proteases exhibited high activation ability. MYR reduced ROS production and downregulated MMP expression and activity at both mRNA and protein levels, similar to the effect found for PAC, which was used as a control. A relationship was observed between MMP-2 and MMP-9 expression, secretion, and early activation with ROS increase due to TEGDMA exposure. MYR showed potential as a therapeutic strategy to control MMP expression and modulate redox imbalance, offering a protective effect on cellular response.

Optimization of Ultrasonic-Enzyme Synergistic Extraction of Proanthocyanidins from Jujube: Purification, Characterization, and Bioactivity Study

Proanthocyanidins have received extensive attention due to their high functional value, but their sources are limited. Therefore, this experiment studied the preparation, biological activities, and characterization of proanthocyanidins from Chinese jujube (Ziziphus jujuba Mill. cv. Muzao) at different periods, aiming to explore a new source of proanthocyanidins and enhance their utilization value. Through ultrasonic-assisted enzymatic extraction, the optimal extraction conditions for PC from Muzao were determined, yielding a proanthocyanidin content of 2.01%. Purification using AB-8 macroporous resin increased the proanthocyanidin content by 11 times. The bioactivity results indicated that proanthocyanidins demonstrated significant in vitro antioxidant activity (scavenging rate ≥ 83.4%) and blood glucose-lowering activity (inhibition rate ≥ 84.7%). Both activities decreased with maturity, while the degree of polymerization also exhibited a positive effect. Mass spectrometry identified a total of 102 compounds, with cyanidin-based compounds being the most abundant, comprising 28 species. The comprehensive research results indicate that the oligomeric proanthocyanidins extracted, purified, and isolated from Muzao during the young fruit stage exhibit diverse biological activities and are abundant in content. They can be utilized for the extraction and purification of proanthocyanidins, offering a reference for the expansion of natural sources of proanthocyanidins and the development of functional foods.

Combined treatment with Aronia berry extract and oligomeric proanthocyanidins exhibit a synergistic anticancer efficacy through LMNB1-AKT signaling pathways in colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent and highly recurrent malignancies worldwide and currently ranks as the second leading cause of cancer-related deaths. The high degree of morbidity and mortality associated with CRC is primarily attributed to the limited effectiveness of current therapeutic approaches and the emergence of chemoresistance to standard treatment modalities. Recent research indicates that several natural products, including Aronia berry extracts (ABE) and oligomeric proanthocyanidins (OPCs), might offer a safe, cost-effective, and multitargeted adjunctive role to cancer treatment. Herein, we hypothesized a combined treatment with ABE and OPCs could synergistically modulate multiple oncogenic pathways in CRC, thereby enhancing their anticancer activity. We initially conducted a series of in vitro experiments to assess the synergistic anticancer effects of ABE and OPCs on CRC cell lines. We demonstrate that these two compounds exhibited a superior synergistic anticancer potential versus individual treatments in enhancing the ability to inhibit cell viability, suppress colony formation, and induce apoptosis (p < 0.05). Consistent with our in vitro findings, we validated this combinatorial anticancer effect in tumor-derived 3D organoids (PDOs; p < 0.01). Using genome-wide transcriptomic profiling, we identified that a specific gene, LMNB1, associated with the cell apoptosis pathway, was found to play a crucial role in exhibiting anticancer effects with these two products. Furthermore, the combined treatment of ABE and OPCs significantly impacted the expression of key proteins involved in apoptosis, including suppressed expression levels of LMNB1 in CRC cell lines (p < 0.05), which resulted in inhibiting downstream AKT phosphorylation. In conclusion, our study provides novel evidence of the synergistic anticancer effects of ABE and OPCs in CRC cells, partially mediated through the regulation of apoptosis and the oncogene LMNB1 within the AKT signaling pathway. These findings have the potential to better appreciate the anticancer potential of natural products in CRC and help improve treatment outcomes in this malignancy.

Gut aging: A wane from the normal to repercussion and gerotherapeutic strategies

Globally, age-related diseases represent a significant public health concern among the elderly population. In aging, healthy organs and tissues undergo structural and functional changes that put the aged adults at risk of diseases. Some of the age-related diseases include cancer, atherosclerosis, brain disorders, muscle atrophy (sarcopenia), gastrointestinal (GIT) disorders, etc. In organs, a decline in stem cell function is the starting point of many conditions and is extremely important in GIT disorder development. Many studies have established that aging affects stem cells and their surrounding supportive niche components. Although there is a significant advancement in treating intestinal aging, the rising elderly population coupled with a higher occurrence of chronic gut ailments necessitates more effective therapeutic approaches to preserve gut health. Notable therapeutic strategies such as Western medicine, traditional Chinese medicine, and other health-promotion interventions have been reported in several studies to hold promise in mitigating age-related gut disorders. This review highlights findings across various facets of gut aging with a focus on aging-associated changes of intestinal stem cells and their niche components, thus a deviation from the normal to repercussion, as well as essential therapeutic strategies to mitigate intestinal aging.

In Vitro Mechanistic Studies of a Standardized Sustainable Grape Seed Extract for Potential Application as a Mood-Modulating and Cognition-Enhancing Supplement

BACKGROUND

Grape seed extract (GSE) from Vitis vinifera L. is rich in polyphenols and oligomeric proanthocyanidin complexes (OPCs), and it has shown potential benefits in managing low mood and cognitive function. In this study, we investigated the potential bioactivities of Enovita®, a standardized GSE extract (GSEe herein) rich in OPCs, in key mechanistic pathways related to low mood conditions and cognitive function.

METHODS

In vitro assays were conducted to assess GSEe's inhibitory effects on γ-aminobutyric acid transaminase (GABA-T) and monoamine oxidase A (MAO-A), its binding affinity to the GABA site of GABA-A receptors, and its effects on acetylcholinesterase (AChE). Its neuroprotective effects on human SH-SY5Y neuroblastoma cells under oxidative stress (induced by H2O2) were assessed using MTT and LDH release assays. Its antioxidant activities were evaluated using DPPH, ABTS, FRAP, ORAC, HORAC, total phenolic content, and TAS assays. Its cytotoxicity was also evaluated.

RESULTS

GSEe showed significant GABA-T inhibitory activity. It also exhibited MAO-A and AChE inhibition, along with moderate binding affinity to the GABA-A receptor. In neuroprotective assays, GSEe provided significant protection to SH-SY5Y cells against oxidative stress. GSEe demonstrated robust antioxidant activity in all assays, including scavenging of DPPH and ABTS radicals, high ferric-reducing power, high polyphenolic contents, and a substantial total antioxidant capacity.

CONCLUSIONS

GSEe exhibits promising bioactivities, highlighting its potential as a supplement for modulating mood and enhancing cognitive function. Overall, the promising results from these in vitro studies provide a strong foundation for the continued exploration and development of GSEe as a viable natural supplement for enhancing mental health and cognitive function.

Effects of Acute Guarana (Paullinia cupana) Ingestion on Mental Performance and Vagal Modulation Compared to a Low Dose of Caffeine

Guarana (GUA), a Brazilian seed extract, contains caffeine and other bioactive compounds that may have psychoactive effects. To assess the acute effects of GUA compared to a low dose of caffeine (CAF) on cognitive and mood parameters, twenty participants completed a double-blind, crossover experiment where they ingested capsules containing the following: (1) 100 mg CAF, (2) 500 mg GUA containing 130 mg caffeine, or (3) placebo (PLA). Cognitive tests (Simon and 2N-Back Task) were performed at the baseline (pre-ingestion) and 60 min after ingestion. The response time for the cognitive tests and heart rate variability were unaffected (p > 0.05) by treatment, although 2N-Back was overall faster (p = 0.001) across time. The accuracy in the 2N-Back Task showed a significant interaction effect (p = 0.029) due to higher post-ingestion versus pre-ingestion levels (p = 0.033), but only with the PLA. The supplements also had no effect on cognitive measures following physical fatigue (n = 11). There was an interaction effect on perceived mental energy, where the pre-ingestion of GUA had lower mental pep ratings compared to post-ingestion (p = 0.006) and post-exercise (p = 0.018) levels. Neither the acute ingestion of GUA nor low dose of CAF influenced cognitive performance or provided consistent benefit on mood or mental workload through vagal modulation. Additional investigations are beneficial to determining the lowest effective dose for CAF or GUA to influence mood and/or cognitive performance.

Advancements in Litchi chinensis Peel Processing: A Scientific Review of Drying, Extraction, and Isolation of Its Bioactive Compounds

This article systematically reviews the advancements in processing litchi peel (Litchi chinensis), emphasizing drying, extraction, purification methods, and the potential of bioactive compounds obtained from litchi peel. This work also highlights the impact of various drying techniques on phytochemical profiles, focusing on how methods such as hot air and freeze-drying affect the preservation of bioactive compounds. The study delves into extraction methods, detailing how different solvents and techniques influence the efficiency of extracting bioactive compounds from litchi peel. Furthermore, the purification and characterization of active compounds, showcasing the role of chromatographic techniques in isolating specific bioactive molecules, is discussed. Biological properties and mechanisms of action, such as antioxidant, antihyperglycemic, cardioprotective, hepatoprotective, anti-atherosclerotic, and anticancer activities, are reviewed, providing insight into the potential health benefits of litchi peel compounds. This review highlights the importance of optimizing and selecting accurate drying and extraction methods to maximize the therapeutic effects of litchi peel and its bioactive compounds. This review also reveals the broad pharmacological potential of the isolated compounds, underscoring the need for further research to discover their specific actions and health benefits.

Proanthocyanidins Ameliorate LPS-Inhibited Osteogenesis of PDLSCs by Restoring Lysine Lactylation

Periodontitis is a bacteria-induced inflammatory disease characterized by the progressive destruction of periodontal supporting tissues. Periodontal ligament stem cells (PDLSCs) are capable of differentiating into osteoblasts, which is an important stem cell source for endogenous periodontal tissue regeneration. Lysine lactylation (Kla) is a novel post-translational modification of proteins that is recently thought to be associated with osteogenic differentiation. Here, we found that lactylation levels are reduced both in the periodontal tissue of rats with periodontitis and lipopolysaccharide (LPS)-stimulated human PDLSCs. Proanthocyanidins were able to promote the osteogenesis of inflamed PDLSCs by restoring lactylation levels. Mechanistically, proanthocyanidins increased lactate production and restored the lactylation levels of PDLSCs, which recovered osteogenesis of inflamed PDLSCs via the Wnt/β-catenin pathway. These results provide evidence on how epigenetic regulation by pharmacological agents influence the osteogenic phenotype of stem cells and the process of periodontal tissue repair. Our current study highlights the valuable potential of natural product proanthocyanidins in the regenerative engineering of periodontal tissues.

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

Objective

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

Materials and methods

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

Results

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

Conclusion

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

Research progress of procyanidins in repairing cartilage injury after anterior cruciate ligament tear

Anterior cruciate ligament (ACL) tear is a common sports-related injury, and cartilage injury always emerges as a serious complication following ACL tear, significantly impacting the physical and psychological well-being of affected individuals. Over the years, efforts have been directed toward finding strategies to repair cartilage injury after ACL tear. In recent times, procyanidins, known for their anti-inflammatory and antioxidant properties, have emerged as potential key players in addressing this concern. This article focuses on summarizing the research progress of procyanidins in repairing cartilage injury after ACL tear. It covers the roles, mechanisms, and clinical significance of procyanidins in repairing cartilage injury following ACL tear and explores the future prospects of procyanidins in this domain. This review provides novel insights and hope for the repair of cartilage injury following ACL tear.

Effects and Mechanisms of Fisetin against Ischemia-reperfusion Injuries: A Systematic Review

BACKGROUND

Ischemia-reperfusion injury (IRI) is a well-known ailment that can disturb organ function.

OBJECTIVES

This systematic review study investigated fisetin's effects and possible mechanisms in attenuating myocardial, cerebral, renal, and hepatic IRIs.

METHODS

This systematic review included studies earlier than Sep 2023 by following the PRISMA statement 2020. After determining inclusion and exclusion criteria and related keywords, bibliographic databases, such as Cochrane Library, PubMed, Web of Science, Embase, and Scopus databases, were used to search the relevant studies. Studies were imported in End- Note X8, and the primary information was recorded in Excel.

RESULTS

Fisetin reduced reactive oxygen species (ROS) generation and upregulated antioxidant enzymes, such as superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), and glutathione peroxidase (GPx), in ischemic tissues. Moreover, fisetin can attenuate oxidative stress by activating phosphoinositide-3-kinase-protein kinase B/Akt (PI3K/Akt) and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways. Fisetin has been indicated to prevent the activation of several pro-inflammatory signaling pathways, including NF-κB (Nuclear factor kappa-light-chain-enhancer of activated B cells) and MAPKs (Mitogen-activated protein kinases). It also inhibits the production of pro-inflammatory cytokines and enzymes like tumor necrosis factor-a (TNF-α), inducible-NO synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), interleukin-1β (IL-1β), IL-1, and IL-6. Fisetin attenuates IRI by improving mitochondrial function, anti-apoptotic effects, promoting autophagy, and preserving tissues from histological changes induced by IRIs.

CONCLUSION

Fisetin, by antioxidant, anti-inflammatory, mitochondrial protection, promoting autophagy, and anti-apoptotic properties, can reduce cell injury due to myocardial, cerebral renal, and hepatic IRIs without any significant side effects.

Multi-Omics Analysis to Understand the Effects of Dietary Proanthocyanidins on Antioxidant Capacity, Muscle Nutrients, Lipid Metabolism, and Intestinal Microbiota in Cyprinus carpio

Proanthocyanidins (Pros), a natural polyphenolic compound found in grape seed and other plants, have received significant attention as additives in animal feed. However, the specific mechanism by which Pros affect fish health remains unclear. Therefore, the aim of this study was to investigate the potential effects of dietary Pro on common carp by evaluating biochemical parameters and multi-omics analysis. The results showed that Pro supplementation improved antioxidant capacity and the contents of polyunsaturated fatty acids (n-3 and n-6) and several bioactive compounds. Transcriptomic analysis demonstrated that dietary Pro caused an upregulation of the sphingolipid catabolic process and the lysosome pathway, while simultaneously downregulating intestinal cholesterol absorption and the PPAR signaling pathway in the intestines. Compared to the normal control (NC) group, the Pro group exhibited higher diversity in intestinal microbiota and an increased relative abundance of Cetobacterium and Pirellula. Furthermore, the Pro group had a lower Firmicutes/Bacteroidetes ratio and a decreased relative abundance of potentially pathogenic bacteria. Collectively, dietary Pro improved antioxidant ability, muscle nutrients, and the diversity and composition of intestinal microbiota. The regulation of lipid metabolism and improvement in muscle nutrients were linked with changes in the intestinal microbiota.

Proanthocyanidins: A novel approach to Henoch‑Schonlein purpura through balancing immunity and arresting oxidative stress via TLR4/MyD88/NF‑κB signaling pathway (Review)

Henoch-Schonlein purpura (HSP), a recurrent and immunoglobulin (Ig)A-mediated vasculitis, presents not only as skin lesions but also as systemic involvement that can be life-threatening. Although the etiology of HSP remains unknown, immune imbalance and oxidative stress (OS) are primary contributors to its pathogenesis, alongside the abnormal activation of Toll-like receptor (TLR)/myeloid differentiation primary response gene 88 (MyD88)/nuclear factor-κB (NF-κB) pathway. TLRs, especially TLR4, stimulate downstream signaling molecules such as NF-κB and proinflammatory cytokines, which are released when TLRs combine with the key adapter molecule MyD88. This leads to the activation of T helper (Th) cell 2/Th17 and overproduction of reactive oxygen species (ROS). The function of regulatory T (Treg) cells is suppressed in the process. Th17/Treg imbalance then produces various inflammatory cytokines to promote proliferation and differentiation of B cells and the secretion of antibodies. IgA is secreted, and it binds to vascular endothelial surface receptors where the complex induces injury of the vascular endothelial cells. Additionally, excessive ROS creates OS that leads to an inflammatory response and vascular cell apoptosis or necrosis, thereby contributing to vascular endothelial damage and HSP occurrence. Proanthocyanidins are active compounds naturally enriched in fruits, vegetables and plants. Proanthocyanidins have diverse properties, including anti-inflammatory, antioxidant, antibacterial, immunoregulatory, anticarcinogenic and vascular protective effects. Proanthocyanidins are used in the management of various diseases. Proanthocyanidins regulate T cells, equilibrate immunity and arrest OS by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Considering the pathogenesis of HSP and the properties of proanthocyanidins, the present study hypothesized that these compounds may potentially lead to HSP recovery through modulating the immune equilibrium and preventing OS by inhibiting the TLR4/MyD88/NF-κB pathway. To the best of our knowledge, however, little is known about the positive effects of proanthocyanidins against HSP. The present review summarizes the potential of proanthocyanidins to treat HSP.

The effect of grape seed procyanidins extract on cognitive function in elderly people with mild cognitive impairment: A randomized, double-blind, placebo-controlled clinical trial

Background

Procyanidins have antioxidative properties that may protect against age-related brain oxidative stress. Previous studies indicated that procyanidin-rich foods could improve cognitive function and prevent neurodegenerative diseases. This study hypothesized that grape seed procyanidins extract (GSPE) would have a favorable effect on cognitive function in elderly people with mild cognitive impairment (MCI).

Methods

A community-based, randomized, double-blind, placebo-controlled trial was conducted. Participants aged 60 years or older with MCI were randomly assigned into the GSPE group (n = 35, 320 mg/d) or placebo group (n = 36), and received capsules for 6 months. Cognitive function was assessed using the Montreal Cognitive Assessment Scale (MoCA). The change in MoCA scores between groups were tested by the time ✕ treatment interaction in mixed-design ANOVA.

Results

After 6 months of intervention, the MoCA score was higher than the baseline both in the intervention group and placebo control group, while the there was no significant difference for mean change in MoCA score from baseline between the intervention group and the placebo group (2.35 ± 3.20 vs. 1.28 ± 2.93, P = 0.192).

Conclusions

Present study showed that 6-month supplementation with GSPE did not significantly improve cognitive function in subjects with MCI. Further investigations regarding the longer-term intervention effect of procyanidins extract on mild or moderate cognitive disorders are needed.

The effect of grape products on liver enzymes: A systematic review and meta-analysis of randomized controlled trials

The favorable influence of grape consumption on metabolic diseases has previously been shown in studies. We sought to assess the effects of grape intake on liver enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), in adults. We performed literature search in online databases, to find eligible randomized controlled trials (RCTs). we considered RCTs that met the following criteria: RCTs consisted of use of grape products on ALT, AST, and ALP in adults (≥18 years) with at least 2 weeks intervention duration. Pooling data from 11 trials showed that grape products intake significantly reduced ALP (p = .010), without any significant changes in ALT (p = .234) and AST (p = .300). In subgroup analysis, we found a significant reduction in ALP, ALT, and AST when the duration of intervention was ≥12 weeks, and when grape seed extract (GSE) was administered. The variable duration and dosage of intervention was one of the sources of bias in our meta-analysis. Additionally, participants involved in included studies had different physiological status and various age groups. Grape products administration may significantly improve ALT, AST, and ALP in adults in long-term interventions and/or when GSE is administered. It should be noted that the favorable effects of grape consumption were small and may not reach clinical importance.

Proanthocyanidins attenuated liver damage and suppressed fibrosis in CCl4-treated rats

Liver damage and fibrosis are serious health problems without effective treatment. Proanthocyanidins (PAs) are flavonoids with several biological effects. We investigated the potential anti-fibrotic effect of proanthocyanidins on carbon tetrachloride (CCl₄)-induced liver injury and fibrosis. Liver fibrosis was induced by oral administration of CCl₄ three times a week for 5 and 9 weeks. PAs were daily administered in a dose of 500 mg/kg bw. Animals were divided into five groups: control groups, olive oil-treated group, Pas-treated group, CCl4-treated animals, and PAs + CCl4-treated rats. CCl4 and PAs were administered by gavage. Administration of CCl₄ caused a significant elevation in alanine aminotransferase and aspartate aminotransferase activities, the concentration of alpha-2-macroglobulin, and bilirubin concentration. In addition, the protein and apolipoprotein contents were significantly decreased in the serum of CCl4-treated rats. These results were accompanied by histopathological alterations and increased inflammation, apoptosis, and DNA damage. Treatment with PAs caused remarkable regression of fibrosis and alpha-2-macroglobulin with improvement in histological characteristics of the liver after 5 and 9 weeks of intoxication. PAs could also maintain redox balance, evidenced by the prevention of lipid peroxidation and mitigation of the decrease in antioxidants. Treatment of intoxicated rats with PAs resulted in a significant decline in pro-inflammatory cytokines, including IL-6, IL-1β, and TNF-α in serum. This is associated with a remarkable decrease in apoptosis of hepatic cells shown by decreased levels of Bax, caspase-3, and -9, with increased Bcl-2. The protective effect of PAs was also evident by protecting DNA integrity in the intoxicated rats. PAs suppressed hepatic fibrosis, improved liver function and structure via modulating the interdependence between oxidative stress, inflammation, apoptosis, and DNA integrity in CCl₄-treated rats.

Effect of Procyanidin on Canine Sperm Quality during Chilled Storage

Procyanidin (PC) is a polyphenolic compound with antioxidant activity. The purpose of this study was to determine the influence of PC on canine sperm quality after 72 h of storage at 4 °C. The collected ejaculates were separated into four equal aliquots and treated with various concentrations of PC (0, 10, 30, and 50 μg/mL) in Tris-citric-fructose-egg yolk (TCFE) extender and stored at 4 °C for 72 h. The findings revealed that 30 μg/mL PC was the optimum concentration for significantly improving sperm motility (p < 0.05). Sperm samples treated with 30 μg/mL PC had substantially greater plasma membrane integrity, acrosome integrity, and mitochondrial membrane potential than the control group (p < 0.05). Furthermore, T-AOC and the expression levels of superoxide dismutase 1 (SOD1), catalase (CAT), and glutathione peroxidase 1 (GPx1) genes were significantly higher in sperm treated with 30 μg/mL PC than those in control (p < 0.05). In summary, this study discovered that adding PC to the TCFE extender enhanced sperm quality and that 30 μg/mL PC was the optimal concentration for canine sperm when stored at 4 °C.

Flavonoids in vegetables: improvement of dietary flavonoids by metabolic engineering to promote health

Flavonoids are the most abundant polyphenols in plants, and have antioxidant effects as well as other bioactivities (e.g., anti-inflammatory, anti-cancer, anti-allergic, and neuroprotective effects). Vegetables are rich in flavonoids and are indispensable in our daily diet. Moreover, the vegetables as chassis for producing natural products would emerge as a promising means for cost-effective and sustainable production of flavonoids. Understanding the metabolic engineering of flavonoids in vegetables allows us to improve their nutrient composition. In this review, a comprehensive overview of flavonoids in vegetables, including the characterized types and distribution, health-promoting effects, associated metabolic pathways, and applied metabolic engineering are provided. We also introduce breakthroughs in multi-omics approaches that pertain to the elucidation of flavonoids metabolism in vegetables, as well as prospective and potential genome-editing technologies. Based on the varied composition and content of flavonoids among vegetables, dietary suggestions are further provided for human health.

Chemical Profiling, Formulation Development, In Vitro Evaluation and Molecular Docking of Piper nigrum Seeds Extract Loaded Emulgel for Anti-Aging

Emulgel is a new innovatory technique for drug development permitting controlled release of active ingredients for topical administration. We report a stable emulgel of 4% Piper nigrum extract (PNE) prepared using 80% ethanol. The PNE-loaded formulation had an antioxidant activity of 84% and tyrosinase inhibition was 82%. Prepared formulation rendered spherical-shaped globules with high zeta potential (−45.5 mV) indicative of a stable system. Total phenolic contents were 58.01 mg GAE/g of dry extract whereas total flavonoid content was 52.63 mg QE/g of dry extract. Sun protection factor for PNE-loaded emulgel was 7.512 and formulation was stable without any evidence of physical and chemical changes following 90 days of storage. Gas chromatography-mass spectroscopy (GC-MS) revealed seventeen bioactive compounds in the PNE including monoterpenoids, triterpenoids, a tertiary alcohol, fatty acid esters, and phytosterols. In silico studies of GC-MS identified compounds show higher binding affinity in comparison to standard kojic acid indicating tyrosinase inhibition. It can be concluded that PNE-loaded emulgel had prominent antioxidant and tyrosinase inhibition and can be utilized as a promising topical system for anti-aging skin formulation.

Food for healthier aging: power on your plate

Inflammageing is a persistent low-level inflammatory burden that accompanies age-related dysregulation of the immune system during normative aging and within the diseasome of aging. A healthy diet containing a balanced amount of macronutrients, vitamins and minerals, adequate in calories and rich in poly(phenols), has an essential role in mitigating the effects of inflammageing and extending healthspan through modulation of the activity of a range of factors. These include transcription factors, such as nuclear factor erythroid-derived 2 related factor 2 (Nrf2) and nuclear factor-κB (NF-kB), the inflammasome and the activities of the gut microbiota. The aim of this narrative review is to discuss the potential of food to ameliorate the effects of the diseasome of aging.

Broad-spectrum antiviral activity of Spatholobus suberectus Dunn against SARS-CoV-2, SARS-CoV-1, H5N1, and other enveloped viruses

The current COVID-19 pandemic caused by SARS-Cov-2 is responsible for more than 6 million deaths globally. The development of broad-spectrum and cost-effective antivirals is urgently needed. Medicinal plants are renowned as a complementary approach in which antiviral natural products have been established as safe and effective drugs. Here, we report that the percolation extract of Spatholobus suberectus Dunn (SSP) is a broad-spectrum viral entry inhibitor against SARS-CoV-1/2 and other enveloped viruses. The viral inhibitory activities of the SSP were evaluated by using pseudotyped SARS-CoV-1 and 2, HIV-1_{ADA and HXB2} , and H5N1. SSP effectively inhibited viral entry and with EC₅₀ values ranging from 3.6 to 5.1 μg/ml. Pre-treatment of pseudovirus or target cells with SSP showed consistent inhibitory activities with the respective EC₅₀ value of 2.3 or 2.1 μg/ml. SSP blocked both SARS-CoV-2 spike glycoprotein and the host ACE2 receptor. In vivo studies indicated that there was no abnormal toxicity and behavior in long-term SSP treatment. Based on these findings, we concluded that SSP has the potential to be developed as a drug candidate for preventing and treating COVID-19 and other emerging enveloped viruses.

Ultrasonic treatment of Dendrobium officinale polysaccharide enhances antioxidant and anti-inflammatory activity in a mouse D-galactose-induced aging model

Utilization of the biological macromolecule Dendrobium officinale polysaccharide (DOP) as a functional ingredient is limited by its high intrinsic viscosity and molecular weight. The goal of the present study was to improve rheological properties of DOP by ultrasonic treatment. Such a treatment resulted in the degradation of DOP and consequent reduction of rheological properties. Among DOP samples treated with ultrasonication at low (L), medium (M), and high (H) power intensities (25, 50, 75 w/cm2), M-DOP displayed the highest reactive oxygen species (ROS) and reactive nitrogen species (RNS) radical scavenging activity in vitro. In a mouse D-galactose (D-Gal)-induced aging model, M-DOP significantly increased activities of antioxidant enzymes and reduced levels of pro-inflammatory cytokines in liver. Real-time polymerase chain reaction (RT-PCR) analysis indicated that M-DOP upregulated messenger RNA (mRNA) expression of anti-inflammatory/antioxidant proteins such as Nrf2 (nuclear factor erythroid 2-related factor), hemeoxygenase-1 (HO-1), and NAD(P)H:quinone oxidoreductase (NQO1) in liver. In summary, M-DOP displayed a strong radical scavenging activity in vitro, and ameliorated liver injury in the mouse aging model through the promotion of Nrf2/HO-1/NQO1 signaling pathway.

Proanthocyanidins alleviate pentylenetetrazole-induced epileptic seizures in mice via the antioxidant activity

The role of oxidative stress in the initiation and progress of epilepsy is well established. Proanthocyanidins (PACs), a naturally occurring polyphenolic compound, have been reported to possess a broad spectrum of pharmacological and therapeutic properties against oxidative stress. However, the protective effects of proanthocyanidins against epilepsy have not been clarified. In the present study, we used the pentylenetetrazole (PTZ)-induced epilepsy mouse model to explore whether proanthocyanidins could help to reduce oxidative stress and protect against epilepsy. Mice were allocated into four groups (n = 14 per each group): control, PTZ (60 mg/kg, intraperitoneally), PACs + PTZ (200 mg/kg, p.o.) and sodium valproate (VPA) + PTZ (200 mg/kg, p.o.). PTZ injection caused oxidative stress in the hippocampal tissue as represented by the elevated lipid peroxidation and NO synthesis and increased expression of iNOS. Furthermore, depleted levels of anti-oxidants, GSH, GR, GPx, SOD, and CAT also indicate that oxidative stress was induced in mice exposed to PTZ. Additionally, a state of neuroinflammation was recorded following the developed seizures. Moreover, neuronal apoptosis was recorded following the development of epileptic convulsions as confirmed by the elevated Bax and caspase-3 and the decreased Bcl2 protein. Moreover, AChE activity, DA, NE, 5-HT, brain-derived neurotrophic factor levels, and gene expression of Nrf2 have decreased in the hippocampal tissue of PTZ exposed mice. However, pre-treatment of mice with PACs protected against the generation of oxidative stress, apoptosis, and neuroinflammation in the PTZ exposed mice brain as the biomarkers for all these conditions was bought to control levels. In addition, the gene expression of Nrf2 was significantly upregulated following PACs treatment. These results suggest that PACs can ameliorate oxidative stress, neuroinflammation, and neuronal apoptosis by activating the Nrf2 signaling pathway in PTZ induced seizures in mice.

An Emerging Role of Proanthocyanidins on Psoriasis: Evidence from a Psoriasis-Like Mouse Model

Background

Psoriasis is an immune-mediated, chronic inflammatory disease, and genetic, immune, oxidative stress (OS), and environmental factors are all thought to contribute to its occurrence. Proanthocyanidins (PCs) are natural flavonoids consisting of catechins and epicatechins which have anti-inflammatory and anti-OS activities. PCs have been widely used to treat various diseases, but reports regarding psoriasis are rare.

Objective

To investigate the therapeutic effect and potential mechanisms of action of PCs in a psoriasis-like mouse model.

Methods

Thirty male BALB/c hairless mice were assigned to six groups (n = 5): normal, model, low-dose PCs, medium-dose PCs, high-dose PCs, and control groups. The final five groups were dorsally exposed to 5% imiquimod (IMQ) cream once a day for 6 consecutive days, while the normal group received no intervention. Following the first day of IMQ application, mice in the PC-treated group were dosed with different amounts of PCs daily by oral gavage for six days, whereas mice in the control group received normal saline in the same way. One week later, skin lesions were evaluated by the severity of scoring system based on psoriasis area and severity index (PASI), and pathological alterations were assessed by hematoxylin-eosin (HE) staining. Indicators of inflammation or OS, such as interleukin- (IL-) 17, IL-23, phosphorylated-phosphatidylinositol 3-kinase (p-PI3K), phosphorylated-signal transducer and activator of transcription 3 (p-STAT3), superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), catalase (CAT), vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), reactive oxygen species (ROS), and heme oxygenase-1 (HO-1), were determined by ELISA, RT-PCR, western blot, and immunohistochemistry (IHC) analysis.

Results

IMQ administration induced the formation of large dark red plaques with thickly layered scales on the dorsal skin of mice; nevertheless, the lesions were substantially alleviated by PC administration. Histopathological alterations were observed in both model and control groups with epidermal hyperkeratosis, granulosa layer thinning, acanthosis, downward extension of rete ridges, dermal papillae expansion, capillary hyperplasia, and infiltration by inflammatory cells around blood vessels. These pathological changes, however, were restored by a range of doses of PCs, high-dose PCs in particular. Different doses of PCs significantly lowered the spleen index, levels of inflammatory or oxidative proteins (IL-17, IL-23, MDA, ROS, p-PI3K, and p-STAT3), and the mRNA expression of Il-17, Il-23, Vegf, and iNos. Protein and mRNA levels of anti-OS and anti-inflammatory biomarkers, including SOD, CAT, GSH, and HO-1, greatly increased after PC treatment, especially at the highest dose.

Conclusions

Our findings reveal that PCs ameliorate psoriasis-like symptoms, suppressing the inflammatory response and mitigating OS damage in an IMQ-induced psoriasis-like mouse model. These effects are probably related to the inactivation of STAT3 and PI3K and activation of HO-1 signaling.

Antioxidant and Antimicrobial Biofoil Based on Chitosan and Japanese Knotweed (Fallopia japonica, Houtt.) Rhizome Bark Extract

A 70% ethanol_(aq) extract of the rhizome bark of the invasive alien plant species Japanese knotweed (JKRB) with potent (in the range of vitamin C) and stable antioxidant activity was incorporated in 1% w/v into a chitosan biofoil, which was then characterized on a lab-scale. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay confirmed the antioxidant activity of the JKRB biofoil upon contact with the food simulants A, B, C, and D1 (measured half-maximal inhibitory concentrations—IC₅₀) and supported the Folin–Ciocalteu assay result. The migration of the antioxidant marker, (−)-epicatechin, into all food simulants (A, B, C, D1, D2, and E) was quantified using liquid chromatography hyphenated to mass spectrometry (LC-MS). Calculations showed that 1 cm² of JKRB biofoil provided antioxidant activity to ~0.5 L of liquid food upon 1 h of contact. The JKRB biofoil demonstrated antimicrobial activity against Gram-positive bacteria. The incorporation of JKRB into the chitosan biofoil resulted in improved tensile strength from 0.75 MPa to 1.81 MPa, while elongation decreased to 28%. JKRB biofoil’s lower moisture content compared to chitosan biofoil was attributed to the formation of hydrogen bonds between chitosan biofoil and JKRB compounds, further confirmed with attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The JKRB biofoil completely degraded in compost in 11 days. The future upscaled production of JKRB biofoil from biowastes for active packaging may support the fights against plastic waste, food waste, and the invasiveness of Japanese knotweed, while greatly contributing to the so-called ‘zero-waste’ strategy and the reduction in greenhouse gas emissions.

Polyphenolic Extracts of Coffee Cherry Husks Alleviated Colitis-Induced Neural Inflammation via NF-κB Signaling Regulation and Gut Microbiota Modification

Coffee cherry husks, the main byproduct of coffee production, contain an abundance of polyphenols. In this study, dextran sodium sulfate (DSS)-induced colitis mice were used to study the protective effects of polyphenolic extracts of coffee cherry husks (CCHP) on inflammation. The results indicated that CCHP administration alleviated the histological changes of DSS-induced colitis in mice and downregulated the mRNA level of TNF-α, IL-1β, IL-6 and Cox-2. Interestingly, CCHP inhibited the activation of microglia and suppressed neural inflammation in the brain. The TLR4/Myd88/NF-κB signaling pathway was examined and found to be inhibited by CCHP. Furthermore, a determination of the gut microbiota showed that an alteration of microbiota induced by DSS was restored by CCHP, including the decrease of the relative abundance of Proteobacteria and the increase of Bacteroidota. In conclusion, our results revealed the great potential of CCHP to alleviate brain inflammation in colitis mice by inhibiting the NF-κB signaling pathway and regulating gut microbiota.

In Vitro Antioxidant and Anticancer Properties of Various E. senegalensis Extracts

Although Erythrina senegalensis is a plant widely used in traditional medicine in sub-Saharan Africa, its biological properties have been poorly investigated to date. We first characterized by conventional reactions the composition of several stem bark extracts and evaluated in acellular and cellular assays their pro- or antioxidant properties supported by their high phenolic and flavonoid content, particularly with the methanolic extract. The pro- or antioxidant effects observed did not correlate with their IC₅₀ concentrations against five cancer cell lines determined by MTT assay. Indeed, the CH₂Cl₂ extract and its ethyl acetate (EtOAc) subfraction appeared more potent although they harbored lower pro- or antioxidant effects. Nevertheless, at equipotent concentration, both extracts induced ER- and mitochondria-derived vacuoles observed by fluorescent microscopy that further led to non-apoptotic cell death. LC coupled to high resolution MS investigations have been performed to identify chemical compounds of the extracts. These investigations highlighted the presence of compounds formerly isolated from E. senegalensis including senegalensein that could be retrieved only in the EtOAc subfraction but also thirteen other compounds, such as 16:3-Glc-stigmasterol and hexadecanoic acid, whose anticancer properties have been previously reported. Nineteen other compounds remain to be identified. In conclusion, E. senegalensis appeared rich in compounds with antioxidant and anticancer properties, supporting its use in traditional practice and its status as a species of interest for further investigations in anticancer drug research.

Nuts as a Part of Dietary Strategy to Improve Metabolic Biomarkers: A Narrative Review

Background

Nuts are in the spotlight because of their association with improved health outcomes. We aimed to summarize the findings of previous studies to evaluate the impact of nuts consumption on glycaemic and lipid profile, inflammation, and oxidative stress.

Methods

Electronic searches for observational and intervention studies were undertaken in PubMed, Embase, Web of Science, and Science Direct until 2022 for searching the studies aiming the application of different types of nuts and the beneficial effects of nuts in improving glycemia, dyslipidemia, inflammation, and oxidative stress.

Results

Results from 56 interventional, 9 narrative and 3 systematic reviews, and 12 meta-analysis studies, aiming at the evaluating beneficial effects of different types of nuts on metabolic markers, showed that nut consumption could improve metabolic markers, including glycaemic factors, lipid profile, and inflammatory and oxidative stress parameters in both healthy and individuals with metabolic disorders in a type-, dose- and duration-dependent manner. According to their unique nutrient components, nuts can be known as a part of a healthy diet, resulting in improved metabolic biomarkers.

Conclusion

Considering the efficacy of nuts in improving metabolic markers, incorporation of, incorporating nuts the effectiveness of nuts in improving metabolic markers, incorporating nuts in the diet may prevent the incidence or aggravation of chronic metabolic diseases. Considering the health benefits of the nuts' components, including essential micronutrients, if consumed in the appropriate dose and duration to provide the necessary amount of effective micronutrients to improve health, we will see an improvement in metabolic factors. At the same time, more research is required to determine the optimal type, dose, and duration of nut intervention with regards to metabolic control and reducing the risk of developing metabolic disorders.

The Activity of Purple Sweet Potato Extract on Antituberculosis-Induced Liver Toxicity

BACKGROUND: The proportion of antituberculosis-induced liver injury on tuberculosis patients showed a relatively high incidence in many countries. Hepatic damage induced by antituberculosis drugs might potentially fatal. Isoniazid (INH) and rifampicin (RIF) are two main components of antituberculosis with crucial role for the incidence of liver injury. One of the herbal remedies that pose hepatoprotective action is purple sweet potato. Hepatoprotective action of purple sweet potato extract has been proved to pose antioxidant and anti-inflammatory activity. AIM: This study was designed to analyze the effect of purple sweet potato extract on rat interleukin-6 (IL-6) and tumor necrosis factor-α _(TNF-α) level, as well as liver histopathology feature in hepatic injury induced by INH-RIF. METHODS: This study was a randomized posttest-only control group design. Male Wistar rats (Rattus norvegicus), age 8–12 weeks, weight 180–220 g were included in this research (divided into three groups). Purple sweet potato extract was produced by maceration technique. IL-6 and TNF-α _level was measured by enzyme-linked immunosorbent assay, whereas liver histopathology examination was performed with hematoxylin and eosin staining. Statistical analysis was performed using one-way ANOVA and post hoc test. RESULTS: Liver IL-6 level in the normal, control, and treatment groups was 2.272±0.473, 3.315 ± 0.536, and 2.548 ± 0.304, respectively (p < 0.001). Liver TNF-α _level in the normal, control, and treatment groups was 26.476 ± 1.681, 48.584 ± 1.359, and 32.547 ± 1.528, respectively (p < 0.05). Histopathology feature of the liver in the control group showed significant liver congestion, liver degeneration, liver necrosis, and infiltration of inflammatory cell. Otherwise, histopathology feature of the liver in the treatment group showed minimal lesion. CONCLUSIONS: Purple sweet potato ethanol extract lowered the liver concentration of IL-6 and TNF-α, as well as improving liver damage in Wistar rats induced with isoniazid and rifampicin.

The Role of Nutraceutical Containing Polyphenols in Diabetes Prevention

Research in pharmacological therapy has led to the availability of many antidiabetic agents. New recommendations for precision medicine and particularly precision nutrition may greatly contribute to the control and especially to the prevention of diabetes. This scenario greatly encourages the search for novel non-pharmaceutical molecules. In line with this, the daily and long-term consumption of diets rich in phenolic compounds, together with a healthy lifestyle, may have a protective role against the development of type 2 diabetes. In the framework of the described studies, there is clear evidence that the bio accessibility, bioavailability, and the gut microbiota are indeed affected by: the way phenolic compounds are consumed (acutely or chronically; as pure compounds, extracts, or in-side a whole meal) and the amount and the type of phenolic compounds (ex-tractable or non-extractable/macromolecular antioxidants, including non-bioavailable polyphenols and plant matrix complexed structures). In this review, we report possible effects of important, commonly consumed, phenolic-based nutraceuticals in pre-clinical and clinical diabetes studies. We highlight their mechanisms of action and their potential effects in health promotion. Translation of this nutraceutical-based approach still requires more and larger clinical trials for better elucidation of the mechanism of action toward clinical applications.

Optimization of the Extraction of Proanthocyanidins from Grape Seeds Using Ultrasonication-Assisted Aqueous Ethanol and Evaluation of Anti-Steatosis Activity In Vitro

Conventional extraction methods of proanthocyanidins (PAC) are based on toxic organic solvents, which can raise concerns about the use of extracts in supplemented food and nutraceuticals. Thus, a PAC extraction method was developed for grape seeds (GS) and grape seed powder using food-grade ethanol by optimizing the extraction conditions to generate the maximum yield of PAC. Extraction parameters, % ethanol, solvent: solid (s:s) ratio, sonication time, and temperature were optimized by the central composite design of the response surface method. The yields of PAC under different extraction conditions were quantified by the methylcellulose precipitable tannin assay. The final optimum conditions were 47% ethanol, 10:1 s:s ratio (v:w), 53 min sonication time, and 60 °C extraction temperature. High-performance liquid chromatography analysis revealed the presence of catechin, procyanidin B2, oligomeric and polymeric PAC in the grape seed-proanthocyanidin extracts (GS-PAC). GS-PAC significantly reduced reactive oxygen species and lipid accumulation in the palmitic-acid-induced mouse hepatocytes (AML12) model of steatosis. About 50% of the PAC of the GS was found to be retained in the by-product of wine fermentation. Therefore, the developed ethanol-based extraction method is suitable to produce PAC-rich functional ingredients from grape by-products to be used in supplemented food and nutraceuticals.

Protective Effects of Grape Seed Oligomeric Proanthocyanidins in IPEC-J2–Escherichia coli/Salmonella Typhimurium Co-Culture

Intestinal epithelium provides the largest barrier protecting mammalian species from harmful external factors; however, it can be severely compromised by the presence of bacteria in the gastrointestinal (GI) tract. Antibiotics have been widely used for the prevention and treatment of GI bacterial infections, leading to antimicrobial resistance in human and veterinary medicine alike. In order to decrease antibiotic usage, natural substances, such as flavonoids, are investigated to be used as antibiotic alternatives. Proanthocyanidins (PAs) are potential candidates for this purpose owing to their various beneficial effects in humans and animals. In this study, protective effects of grape seed oligomeric proanthocyanidins (GSOPs) were tested in IPEC-J2 porcine intestinal epithelial cells infected with Escherichia coli and Salmonella enterica ser. Typhimurium of swine origin. GSOPs were able to alleviate oxidative stress, inflammation and barrier integrity disruption inflicted by bacteria in the co-culture. Furthermore, GSOPs could decrease the adhesion of both bacteria to IPEC-J2 cells. Based on these observations, GSOPs seem to be promising candidates for the prevention and treatment of gastrointestinal bacterial infections.

Condensed Tannins as Antioxidants in Ruminants-Effectiveness and Action Mechanisms to Improve Animal Antioxidant Status and Oxidative Stability of Products

Condensed tannins (CTs) are widely distributed in plants, and due to their recognized antioxidant activity are considered as possible natural antioxidants for application in ruminant diets. A wide range of CT-rich sources has been tested in ruminant diets, and their effects on animal antioxidant status and oxidative stability of their products are reviewed in the present work. Possible mechanisms underlying the CT antioxidant effects in ruminants are also discussed, and the CT chemical structure is briefly presented. Utilization of CT-rich sources in ruminant feeding can improve the animals' antioxidant status and oxidative stability of their products. However, the results are still inconsistent. Although poorly understood, the evidence suggests that CTs can induce an antioxidant effect in living animals and in their products through direct and indirect mechanisms, which can occur by an integrated and synergic way involving: (i) absorption of CTs with low molecular weight or metabolites, despite CTs' poor bioavailability; (ii) antioxidant action on the gastrointestinal tract; and (iii) interaction with other antioxidant agents. Condensed tannins are alternative dietary antioxidants for ruminants, but further studies should be carried out to elucidate the mechanism underlying the antioxidant activity of each CT source to design effective antioxidant strategies based on the use of CTs in ruminant diets.

Polyphenols as Antitumor Agents Targeting Key Players in Cancer-Driving Signaling Pathways

Polyphenols constitute an important group of natural products that are traditionally associated with a wide range of bioactivities. These are usually found in low concentrations in natural products and are now available in nutraceuticals or dietary supplements. A group of polyphenols that include apigenin, quercetin, curcumin, resveratrol, EGCG, and kaempferol have been shown to regulate signaling pathways that are central for cancer development, progression, and metastasis. Here, we describe novel mechanistic insights on the effect of this group of polyphenols on key elements of the signaling pathways impacting cancer. We describe the protein modifications induced by these polyphenols and their effect on the central elements of several signaling pathways including PI3K, Akt, mTOR, RAS, and MAPK and particularly those affecting the tumor suppressor p53 protein. Modifications of p53 induced by these polyphenols regulate p53 gene expression and protein levels and posttranslational modifications such as phosphorylation, acetylation, and ubiquitination that influence stability, subcellular location, activation of new transcriptional targets, and the role of p53 in response to DNA damage, apoptosis control, cell- cycle regulation, senescence, and cell fate. Thus, deep understanding of the effects that polyphenols have on these key players in cancer-driving signaling pathways will certainly lead to better designed targeted therapies, with less toxicity for cancer treatment. The scope of this review centers on the regulation of key elements of cancer signaling pathways by the most studied polyphenols and highlights the importance of a profound understanding of these regulations in order to improve cancer treatment and control with natural products.

Screening for the Active Anti-Inflammatory and Antioxidant Polyphenols of Gaultheria procumbens and Their Application for Standardisation: From Identification through Cellular Studies to Quantitative Determination

Aerial parts, leaves, and stems of Gaultheria procumbens are polyphenol-rich herbal medicines with anti-inflammatory and antioxidant effects. The present study focused on identifying active markers of the G. procumbens extracts in an integrated approach combining phytochemical and biological capacity tests. The target compounds, representing all classes of Gaultheria polyphenols, were pre-selected by LC-ESI-PDA-MS/MS. For unambiguous identification, the key analytes, including a rare procyanidin trimer (cinnamtannin B-1), miquelianin potassium salt, and two new natural products: quercetin and kaempferol 3-O-β-d-xylopyranosyl-(1→2)-β-d-glucuronopyranosides, were isolated by preparative HPLC and investigated by spectroscopy (HR-ESI-MS, UV-vis, CD, 1D- and 2D-NMR), thiolysis, flame photometry, optical rotation experiments, and absolute configuration studies. The significant contribution of the pre-selected compounds to the biological effects of the extracts was confirmed in vitro: the analytes significantly and in a dose-dependent manner down-regulated the pro-oxidant and pro-inflammatory functions of human neutrophils ex vivo (inhibited the release of reactive oxygen species, IL-1β, TNF-α, and neutrophils elastase, ELA-2), inhibited two key pro-inflammatory enzymes (cyclooxygenase, COX-2, and hyaluronidase), and most of them, except gaultherin, exerted potent direct antioxidant activity (ferric reducing antioxidant power and superoxide anion scavenging capacity). Moreover, cellular safety was confirmed for all compounds by flow cytometry. Eventually, as these mechanisms have been connected to the health benefits of G. procumbens, 11 polyphenols were accepted as active markers, and a simple, accurate, reproducible, and fully validated RP-HPLC-PDA method for standardisation of the target extracts was proposed.

Role of Polyphenols on Gut Microbiota and the Ubiquitin-Proteasome System in Neurodegenerative Diseases

Today, neurodegenerative diseases have become a remarkable public health challenge due to their direct relation with aging. Accordingly, understanding the molecular and cellular mechanisms occurring in the pathogenesis of them is essential. Both protein aggregations as a result of the ubiquitin-proteasome system (UPS) inefficiency and gut microbiota alternation are the main pathogenic hallmarks. Polyphenols upregulating this system may decrease the developing rate of neurodegenerative diseases. Most of the dietary intake of polyphenols is converted into other microbial metabolites, which have completely different biological properties from the original polyphenols and should be thoroughly investigated. Herein, several prevalent neurodegenerative diseases are pinpointed to explain the role of gut microbiota alternations and the role of molecular changes, especially UPS down-regulation in their pathogenesis. Some of the most important polyphenols found in our diet are explained along with their microbial metabolites in the body.

Emerging biological therapies for the treatment of age-related macular degeneration

INTRODUCTION

Age-related macular degeneration (AMD) is the leading cause of blindness in individuals over age 50 in developed countries. Current therapy for nonexudative AMD (neAMD) is aimed at modifying risk factors and vitamin supplementation to slow progression, while intravitreal anti-vascular endothelial factor (VEGF) injections are the mainstay for treatment of choroidal neovascularization in exudative AMD (eAMD).

AREAS COVERED

Over the past decade, promising therapies have emerged that aim to improve the current standard of care for both diseases. Clinical trials for neAMD are investigating targets in the complement cascade, vitamin A metabolism, metformin, and tetracycline, whereas clinical trials for eAMD are aiming to decrease treatment burden through novel port delivery systems, increasing drug half-life, and targeting new sites of the VEGF cascade. Stem cell and gene therapy are also being evaluated for treatment of neAMD and eAMD.

EXPERT OPINION

With an aging population, the need for effective, long term, low burden treatment options for AMD will be in increasingly high demand. Current investigations aim to address the shortcomings of current treatment options with breakthrough treatment approaches. Therapeutics in the pipeline hold promise for improving the treatment of AMD, and are on track for widespread use within the next decade.

The Effects of Cold Atmospheric Pressure Plasma on Germination Parameters, Enzyme Activities and Induction of DNA Damage in Barley

Climate change, environmental pollution and pathogen resistance to available chemical agents are part of the problems that the food industry has to face in order to ensure healthy food for people and livestock. One of the promising solutions to these problems is the use of cold atmospheric pressure plasma (CAPP). Plasma is suitable for efficient surface decontamination of seeds and food products, germination enhancement and obtaining higher yields in agricultural production. However, the plasma effects vary due to plasma source, treatment conditions and seed type. In our study, we tried to find the proper conditions for treatment of barley grains by diffuse coplanar surface barrier discharge, in which positive effects of CAPP, such as enhanced germination or decontamination effects, would be maximized and harmful effects, such as oxidation and genotoxic potential, minimized. Besides germination parameters, we evaluated DNA damage and activities of various germination and antioxidant enzymes in barley seedlings. Plasma exposure resulted in changes in germination parameters and enzyme activities. Longer exposures had also genotoxic effects. As such, our findings indicate that appropriate plasma exposure conditions need to be carefully optimized in order to preserve germination, oxidation balance and genome stability, should CAPP be used in agricultural practice.

Grape Seed Extract Positively Modulates Blood Pressure and Perceived Stress: A Randomized, Double-Blind, Placebo-Controlled Study in Healthy Volunteers

It is well established that maintaining healthy blood pressure is fundamental in order to avoid disorders to the heart and blood vessels. In prevention, and alongside pharmacological therapy, the use of natural substances has been proven to be extremely helpful for pre- and mild hypertensive subjects. Our study was therefore focused on the effects, both in vitro and in humans, of a grape seed extract, Enovita (GSEe), a highly standardized extract in polyphenols of Vitis vinifera L. The in vitro human umbilical vein endothelial cells (HUVEC) model was chosen to explore the extract properties related to vascular inflammation/vasodilation. A significant reduction of both soluble Inter-Cellular Adhesion Molecule-1 (sICAM) and endothelin-1 secretion/release was induced by GSEe in HUVEC cells. A randomized, double-blind, placebo-controlled clinical study in healthy volunteers was further performed to investigate GSEe benefits. In healthy volunteers, both supplementations significantly modulated blood pressure, with a pronounced effect after GSEe tablets (300 mg/day for 16 weeks) in respect to placebo. In the male gender subgroup, no placebo effect was observed as it was for the female group. As an additional outcome, an overall GSEe positive modulation emerged on mood related to stress perception. Thus, GSEe resulted in a benefit of modulating endothelial functionality and blood pressure. It was noteworthy that GSEe relieved the perceived stress, promising new future perspectives on mood comfort.

Rind from Purple Mangosteen (Garcinia mangostana) Attenuates Diet-Induced Physiological and Metabolic Changes in Obese Rats

The pulp of the purple mangosteen, Garcinia mangostana, is a popular tropical fruit but the rind containing xanthones such as α-mangostin together with procyanidins and anthocyanidins is usually discarded as waste. However, this rind has been used in South-East Asia for diarrhoea, dysentery, skin infections and wounds. As xanthones have reported anti-inflammatory and antioxidant responses, this study has determined the bioactive compounds and evaluated the effects of G. mangostana rind on physiological, metabolic, liver and cardiovascular parameters in rats with diet-induced metabolic syndrome. Rats fed a diet with increased simple sugars and saturated fats developed obesity, hypertension, increased left ventricular stiffness, dyslipidaemia and fatty liver. Administration of G. mangostana rind as 5% of the food to rats with diet-induced metabolic syndrome gave a dose of 168 mg/kg/day α-mangostin, 355 mg/kg/day procyanidins, 3.9 mg/kg/day anthocyanins and 11.8 mg/kg/day hydroxycitric acid for 8 weeks which reduced body weight and attenuated physiological and metabolic changes in rats including decreased abdominal fat deposition, decreased abdominal circumference and whole-body fat mass, improved liver structure and function and improved cardiovascular parameters such as systolic blood pressure, left ventricular stiffness and endothelial function. These responses were associated with decreased infiltration of inflammatory cells, decreased deposition of collagen in both heart and liver and decreased mean adipocyte size in retroperitoneal adipose tissues. We conclude that, in rats with diet-induced metabolic syndrome, chronic intake of G. mangostana rind decreased infiltration of inflammatory cells which decreased physiological, metabolic, liver and cardiovascular symptoms.

Proanthocyanidins as a Potential Novel Way for the Treatment of Hemangioma

Hemangioma, the most common benign vascular tumor, not only affects the appearance and psychology but also has a life-threatening potential. It is considered that clonal vascular endothelial cell proliferation and excessive angiogenesis are responsible for hemangioma pathogenesis, in which abnormal cytokines/pathways are closely implicated, primarily including high expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) as well as their downstream pathways, especially phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt). These further stimulate the migration and proliferation of vascular endothelial cells and promote the formation of new vessels, ultimately leading to the occurrence and development of hemangioma. Proanthocyanidins are naturally active substance from plants and fruits. They possess multiple functions like antiproliferation, antiangiogenesis, and antitumor. It has been demonstrated that proanthocyanidins effectively work in various diseases via inhibiting the expression of various factors, e.g., HIF-1α, VEGF, PI3K, and Akt. Considering the pathogenesis of hemangioma and the effect of proanthocyanidins, we hold a hypothesis that proanthocyanidins would be applied in hemangioma via downregulating cytokine/pathway expression, suppressing vascular cell proliferation and arrest abnormal angiogenesis. Taken together, proanthocyanidins may be a potential novel way for the treatment of hemangioma.

The Diverse Efficacy of Food-Derived Proanthocyanidins for Middle-Aged and Elderly Women

Middle-aged and elderly women are affected by various symptoms and diseases induced by estrogen deficiency. Proanthocyanidins, widely present in many kinds of fruits and berries, have many beneficial effects, such as antioxidative, anti-inflammatory, and antimicrobial activities. We researched the effects of proanthocyanidins for middle-aged and elderly women, finding that it has been revealed in many clinical trials and cohort studies that proanthocyanidins contribute to the prevention of cardiovascular disease, hypertension, obesity, cancer, osteoporosis, and urinary tract infection, as well as the improvement of menopausal symptoms, renal function, and skin damage. Thus, proanthocyanidins can be considered one of the potent representatives of complementary alternative therapy.

Anti-Inflammatory Activity of Oligomeric Proanthocyanidins Via Inhibition of NF-κB and MAPK in LPS-Stimulated MAC-T Cells

Oligomeric proanthocyanidins (OPCs), classified as condensed tannins, have significant antioxidation, anti-inflammation and anti-cancer effects. This study was performed to investigate the anti-inflammatory effects of OPCs and the mechanism underlying these effects in lipopolysaccharide (LPS)-stimulated bovine mammary epithelial cells (MAC-T). Real-time PCR and ELISA assays indicated that OPC treatment at 1, 3 and 5 μg/ml significantly reduced the mRNA and protein, respectively, of oxidant indicators cyclooxygenase-2 (COX-2) (p < 0.05) and inducible nitric oxide synthase (iNOS) (p < 0.01) as well as inflammation cytokines interleukin (IL)-6 (p < 0.01), IL-1β (p < 0.01) and tumor necrosis factor-α (TNF-α) (p < 0.05) in LPS-induced MAC-T cells. Moreover, OPCs downregulated LPSinduced phosphorylation of p65 and inhibitor of nuclear factor kappa B (NF-κB) (IκB) in the NF-κB signaling pathway (p < 0.01), and they inhibited p65 translocation from the cytoplasm to the nucleus as revealed by immunofluorescence test and western blot. Additionally, OPCs decreased phosphorylation of p38, extracellular signal regulated kinase and c-jun NH₂-terminal kinase in the MAPK signaling pathway (p < 0.01). In conclusion, the anti-inflammatory and antioxidant activities of OPCs involve NF-κB and MAPK signaling pathways, thus inhibiting expression of pro-inflammatory factors and oxidation indicators. These findings provide novel experimental evidence for the further practical application of OPCs in prevention and treatment of bovine mastitis.

Is There Such a Thing as "Anti-Nutrients"? A Narrative Review of Perceived Problematic Plant Compounds

Plant-based diets are associated with reduced risk of lifestyle-induced chronic diseases. The thousands of phytochemicals they contain are implicated in cellular-based mechanisms to promote antioxidant defense and reduce inflammation. While recommendations encourage the intake of fruits and vegetables, most people fall short of their target daily intake. Despite the need to increase plant-food consumption, there have been some concerns raised about whether they are beneficial because of the various ‘anti-nutrient’ compounds they contain. Some of these anti-nutrients that have been called into question included lectins, oxalates, goitrogens, phytoestrogens, phytates, and tannins. As a result, there may be select individuals with specific health conditions who elect to decrease their plant food intake despite potential benefits. The purpose of this narrative review is to examine the science of these ‘anti-nutrients’ and weigh the evidence of whether these compounds pose an actual health threat.

Grape seed proanthocyanidins ameliorate neuronal oxidative damage by inhibiting GSK-3β-dependent mitochondrial permeability transition pore opening in an experimental model of sporadic Alzheimer's disease

Mitochondria-associated oxidative stress plays a crucial role in Alzheimer’s disease (AD). Grape seed proanthocyanidins (GSPs) have been reported to prevent oxidative stress. In this study, we investigated the underlying mechanisms of GSPs in protecting neurons against oxidative injury in an experimental model of sporadic AD. Primary mouse cortical neurons were subjected to streptozotocin (STZ) to mimic neuronal oxidative damage in vitro, and mice were subjected to intracerebroventricular (ICV) injection of STZ as an in vivo sporadic AD model. GSPs not only significantly ameliorated neuron loss and mitochondrial dysfunction in mouse cortical neurons pretreated of STZ, but also reduced cognitive impairments, apoptosis and mitochondrial oxidative stress in the cerebral cortex and hippocampus of sporadic AD mice. Moreover, GSPs increased phosphorylation levels of phosphatidylinositol 3-kinase (PI3K), Akt and glycogen synthase kinase 3β (GSK-3β) at its Ser9. Notably, GSPs inhibited STZ-induced mitochondrial permeability transition pore (mPTP) opening via enhancing phosphorylated GSK-3β (p-GSK-3β) binds to adenine nucleotide translocator (ANT), thereby reducing the formation of the complex ANT-cyclophilin D (CypD). In conclusion, GSPs ameliorate neuronal oxidative damage and cognitive impairment by inhibiting GSK-3β-dependent mPTP opening in AD. Our study provides new insights into that GSPs may be a new therapeutic candidate for treatment of AD.

Effect of germination environment on the biochemical compounds and anti-inflammatory properties of soybean cultivars

In this study, we investigated changes in the isoflavone content, total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities (DPPH, ABTS), and anti-inflammatory activities of small-seeded and large-seeded soybean cultivars during germination (light/dark conditions). Total isoflavone content was higher at the seed stage in large-seeded soybeans, while it increased after 7 days of germination in small-seeded soybeans, particularly in response to light conditions, under which they had high TPC, TFC, and antioxidant activities. In large-seeded soybeans, the germination environment did not significantly affect TFC or DPPH inhibition, whereas TPC and ABTS inhibition were high under dark germination conditions. Extracts of sprouts exhibited superior anti-inflammatory activities. Nitric oxide production was slightly lower in small-seeded and large-seeded soybeans germinated under light and dark conditions, respectively. Our findings indicate that germinated soybeans improved nutritionally, and that enhancement of bioactivity under different germination environments could contribute to the selection of appropriate soybean cultivars.

Oxidative Stress Biomarkers, Nut-Related Antioxidants, and Cardiovascular Disease

Atherosclerosis is related to fat accumulation in the arterial walls and vascular stiffening, and results in acute coronary syndrome which is commonly associated with acute myocardial infarction. Oxidative stress participates in the pathogenesis of atherosclerosis. Thus, the inclusion of food sources of dietary antioxidants, such as different kinds of nuts, may improve biomarkers related to oxidative stress, contributing to a possible reduction in atherosclerosis progression. This article has briefly highlighted the interaction between oxidative stress, atherosclerosis, and cardiovascular disease, in addition to the effect of the consumption of different nuts and related dietary antioxidants—like polyphenols and vitamin E—on biomarkers of oxidative stress in primary and secondary cardiovascular prevention. Studies in vitro suggest that nuts may exert antioxidant effects by DNA repair mechanisms, lipid peroxidation prevention, modulation of the signaling pathways, and inhibition of the MAPK pathways through the suppression of NF-κB and activation of the Nrf2 pathways. Studies conducted in animal models showed the ability of dietary nuts in improving biomarkers of oxidative stress, such as oxLDL and GPx. However, clinical trials in humans have not been conclusive, especially with regards to the secondary prevention of cardiovascular disease.

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 Seeds Proanthocyanidins: An Overview of In Vivo Bioactivity in Animal Models

Over the last decade, proanthocyanidins (PACs) are attracting attention not only from the food industry but also from public health organizations due to their health benefits. It is well-known that grapes are a good source of PACs and for that reason, the industry is also focused on grape by-products identification and bioactivity evaluation. Grape seeds extract (GSPE) is a rich source of PACs, mainly composed of monomeric catechin and epicatechin, gallic acid and polymeric and oligomeric proanthocyanidins. Thus, this review encompasses the state-of-art structure and the most recent evidence about the impact of GSPE on chronic diseases, with a focus on oxidative stress, inflammation and metabolic syndrome (MeS)-related disorders such as obesity, diabetes and cardiovascular risk disease in vivo to offer new perspectives in the field that allow further research. Despite the controversial results, is undeniable that PACs from grape seeds are highly antioxidants, thus, the capacity of GSPE to improve oxidative stress might mediate the inflammation process and the progress of MeS-related pathologies. However, further well-design animal studies with standardized dosages and GSPE composition are necessary to shed light into the cause-effect relationship in a more accurate way to later allow a deeper study of the effect of GSPE in humans.