Bioavailability and bioefficacy of polyphenols in humans. II. Review of 93 intervention studies

Epimedium polysaccharides mitigates Porphyromonas gingivalis-exacerbated intestinal inflammation by suppressing the Th17 pathway and modulating the gut microbiota

This study aimed to investigate the potential alleviating effect of Epimedium polysaccharide (EP) on intestinal inflammation aggravated by Porphyromonas gingivalis (Pg). P. gingivalis, an oral pathogen, may play a role in intestinal inflammation, highlighting the necessity to explore substances capable of inhibiting its pathogenicity. Initially, in vitro screening experiments utilizing co-culturing and quantitative polymerase chain reaction revealed that EP significantly inhibited the growth of P. gingivalis and the levels of virulence genes, including Kgp and RgpA. Subsequent mouse experiments demonstrated that EP notably ameliorated Pg-aggravated weight loss, disease activity index, histopathological lesions, and disruption of intestinal barrier integrity, evidenced by a reduction in tight junction protein levels. Flow cytometry analysis further illustrated that EP attenuated Pg-induced Th17 differentiation and Th17-related cytokines, such as IL-17 and IL-6. Additionally, 16S rRNA amplicon sequencing analysis elucidated that EP significantly mitigated Pg-induced gut microbiota dysbiosis, enriching potentially beneficial microbes, including Akkermansia and Bifidobacterium. The metabolomic analysis provided further insight, indicating that EP intervention altered the accumulation of relevant intestinal metabolites and exhibited correlations with disease indicators. In conclusion, our research suggested that EP holds promise as a prospective therapeutic agent for alleviating P. gingivalis-aggravated intestinal inflammation.

Flavonoids as modulators of miRNA expression in pancreatic cancer: Pathways, Mechanisms, And Therapeutic Potential

Pancreatic cancer (PC) is a complex malignancy, distinguished by its aggressive characteristics and unfavorable prognosis. Recent developments in understanding the molecular foundations of this disease have brought attention to the noteworthy involvement of microRNAs (miRNAs) in disease development, advancement, and treatment resistance. The anticancer capabilities of flavonoids, which are a wide range of phytochemicals present in fruits and vegetables, have attracted considerable interest because of their ability to regulate miRNA expression. This review provides the effects of flavonoids on miRNA expression in PC, explains the underlying processes, and explores the possible therapeutic benefits of flavonoid-based therapies. Flavonoids inhibit PC cell proliferation, induce apoptosis, and enhance chemosensitivity via the modulation of miRNAs involved in carcinogenesis. Additionally, this review emphasizes the significance of certain miRNAs as targets of flavonoid action. These miRNAs have a role in regulating important signaling pathways such as the phosphoinositide-3-kinase-protein kinase B/Protein kinase B (Akt), mitogen activated protein kinase (MAPK), Janus kinase/signal transducers and activators of transcription (JAK/STAT), and Wnt/β-catenin pathways. This review aims to consolidate current knowledge on the interaction between flavonoids and miRNAs in PC, providing a comprehensive analysis of how flavonoid-mediated modulation of miRNA expression could influence cancer progression and therapy. It highlights the use of flavonoid nanoformulations to enhance stability, increase absorption, and maximize anti-PC activity, improving patient outcomes. The review calls for further research to optimize the use of flavonoid nanoformulations in clinical trials, leading to innovative treatment strategies and more effective approaches for PC.

Effect of the Mediterranean Diet (MeDi) on the Progression of Retinal Disease: A Narrative Review

Worldwide, the number of individuals suffering from visual impairment, as well as those affected by blindness, is about 600 million and it will further increase in the coming decades. These diseases also seriously affect the quality of life in working-age individuals. Beyond the characterization of metabolic, genetic, and environmental factors related to ocular pathologies, it is important to verify how lifestyle may participate in the induction of the molecular pathways underlying these diseases. On the other hand, scientific studies are also contributing to investigations as to whether lifestyle could intervene in modulating pathophysiological cellular responses, including the production of metabolites and neurohormonal factors, through the intake of natural compounds capable of interfering with molecular mechanisms that lead to ocular diseases. Nutraceuticals are promising in ameliorating pathophysiological complications of ocular disease such as inflammation and neurodegeneration. Moreover, it is important to characterize the nutritional patterns and/or natural compounds that may be beneficial against certain ocular diseases. The adherence to the Mediterranean diet (MeDi) is proposed as a promising intervention for the prevention and amelioration of several eye diseases. Several characteristic compounds and micronutrients of MeDi, including vitamins, carotenoids, flavonoids, and omega-3 fatty acids, are proposed as adjuvants against several ocular diseases. In this review, we focus on studies that analyze the effects of MeDi in ameliorating diabetic retinopathy, macular degeneration, and glaucoma. The analysis of knowledge in this field is requested in order to provide direction on recommendations for nutritional interventions aimed to prevent and ameliorate ocular diseases.

The therapeutic potential and molecular mechanism of Alpha-pinene, Gamma-terpinene, and P-cymene against melanoma cells

The purpose of this study is to investigate the potential anticarcinogenic effects of three phytochemicals, namely Alpha-pinene (AP), Gamma-terpinene (GT), and P-cymene (PC), on melanoma cells (A2058 cell line). Additionally, the study aims to explore the synergistic activities of these phytochemicals with Dacarbazine, a chemotherapy drug. To understand the molecular mechanism involved in apoptosis induction in the A-2058 cell line, it was used AO/EB staining for apoptosis detection and cell cycle analysis, monitored through flow cytometry. It also determined the mRNA expression levels of different apoptosis-regulatory genes, including p53, Bax, NF-kB, Bcl-2, Bcl-xl, and caspase-3. The antitumor activities of these phytochemicals and their combinations were investigated in a subcutaneous mouse tumor model. The tumor diameter was 21.4 ± 1.1 mm in the Dacarbazine treatment group and 42.4 ± 3.1 mm in the control group. The antitumoral activities of AP and PC in the tumor model were similar to those of Dacarbazine. On the other hand, GT exhibited remarkable antitumoral activity, with a 1.75-fold reduction in tumor diameter compared to the Dacarbazine group. When different combinations of phytochemicals and Dacarbazine were used, the GT plus Dacarbazine treatment group was found to have a 3.5-fold reduction in tumor diameter compared to the Dacarbazine group. The tumor diameters in the Dacarbazine, AP plus GT, GT plus Dacarbazine, and AP plus Dacarbazine treatment groups were 21.4 ± 1.1, 7.6 ± 2.2, 8.6 ± 0.5, and 6.2 ± 1.9 mm, respectively.

Quercetin Attenuates Acetaldehyde-Induced Cytotoxicity via the Heme Oxygenase-1-Dependent Antioxidant Mechanism in Hepatocytes

It is still unclear whether or how quercetin influences the toxic events induced by acetaldehyde in hepatocytes, though quercetin has been reported to mitigate alcohol-induced mouse liver injury. In this study, we evaluated the modulating effect of quercetin on the cytotoxicity induced by acetaldehyde in mouse hepatoma Hepa1c1c7 cells, the frequently used cellular hepatocyte model. The pretreatment with quercetin significantly inhibited the cytotoxicity induced by acetaldehyde. The treatment with quercetin itself had an ability to enhance the total ALDH activity, as well as the ALDH1A1 and ALDH3A1 gene expressions. The acetaldehyde treatment significantly enhanced the intracellular reactive oxygen species (ROS) level, whereas the quercetin pretreatment dose-dependently inhibited it. Accordingly, the treatment with quercetin itself significantly up-regulated the representative intracellular antioxidant-related gene expressions, including heme oxygenase-1 (HO-1), glutamate-cysteine ligase, catalytic subunit (GCLC), and cystine/glutamate exchanger (xCT), that coincided with the enhancement of the total intracellular glutathione (GSH) level. Tin protoporphyrin IX (SNPP), a typical HO-1 inhibitor, restored the quercetin-induced reduction in the intracellular ROS level, whereas buthionine sulphoximine, a representative GSH biosynthesis inhibitor, did not. SNPP also cancelled the quercetin-induced cytoprotection against acetaldehyde. These results suggest that the low-molecular-weight antioxidants produced by the HO-1 enzymatic reaction are mainly attributable to quercetin-induced cytoprotection.

Dietary Flavonoids: Mitigating Air Pollution's Cardiovascular Risks

Air pollution significantly impacts cardiovascular health, yet pollution reduction strategies in cardiovascular disease prevention remain limited. Dietary flavonoids show promise in protecting cardiovascular health, but their potential to mitigate air-pollution-induced risks is unexplored. This study investigates this research gap. Following PRISMA-ScR guidelines, literature from 2014-2024 was searched across MedLine/PubMed, ScienceDirect, and MDPI databases. Of 463 identified studies, 53 were eligible for analysis based on PICO criteria. Findings revealed significant impacts of air pollution on cardiovascular health, including increased disease risks and mortality. Flavonoid intake demonstrated protective effects against these risks. Flavonoid mechanisms include improved endothelial function, antioxidant and anti-inflammatory effects, blood pressure regulation, antiplatelet effects, cardioprotection, and enhanced lipid and glucose metabolism. Higher flavonoid intake was consistently associated with reduced cardiovascular risks. While reducing pollution remains crucial, promoting flavonoid-rich diets is a promising complementary strategy. Public health initiatives should raise awareness about these benefits. Further research on direct interactions between flavonoid intake and air pollution exposure is needed. Current evidence supports integrating dietary interventions into broader strategies to reduce air pollution's cardiovascular impacts.

Flavonoids as Potential Therapeutics Against Neurodegenerative Disorders: Unlocking the Prospects

Neurodegeneration, the decline of nerve cells in the brain, is a common feature of neurodegenerative disorders (NDDs). Oxidative stress, a key factor in NDDs such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease can lead to neuronal cell death, mitochondria impairment, excitotoxicity, and Ca2+ stress. Environmental factors compromising stress response lead to cell damage, necessitating novel therapeutics for preventing or treating brain disorders in older individuals and an aging population. Synthetic medications offer symptomatic benefits but can have adverse effects. This research explores the potential of flavonoids derived from plants in treating NDDs. Flavonoids compounds, have been studied for their potential to enter the brain and treat NDDs. These compounds have diverse biological effects and are currently being explored for their potential in the treatment of central nervous system disorders. Flavonoids have various beneficial effects, including antiviral, anti-allergic, antiplatelet, anti-inflammatory, anti-tumor, anti-apoptotic, and antioxidant properties. Their potential to alleviate symptoms of NDDs is significant.

Effects of Anthocyanins on Cognition and Vascular Function: A Systematic Review

SCOPE

Good vascular function is crucial for cerebral blood flow and cognitive performance. Diets high in anthocyanins have been shown to improve vascular function and are associated with improvements in cognition. This systematic review investigates randomized controlled trials examining the impact of anthocyanin intake on both cognition and vascular function.

METHODS AND RESULTS

Of the 1486 studies identified through searching Ovid Medline and AMED, PsychInfo, Web of Science, and Scopus, 20 studies are selected which measured cognitive and vascular function. Overall, positive effects on verbal and working memory are observed, which are supported by studies using functional magnetic resonance imaging to demonstrate increased blood flow in brain regions related to these cognitive domains. However, effects of anthocyanins on blood pressure and markers of endothelial function are inconsistent.

CONCLUSION

This systematic review provides evidence for a positive effect of anthocyanins on cognition and insight into the relevance of endothelial function. Anthocyanins are widely available and can be easily consumed in a range of different fruits, vegetables, and other products. Further studies should establish the optimal daily intake of anthocyanins for cardiovascular and cognitive health.

Unlocking the potential of flavonoids: Natural solutions in the fight against colon cancer

Colorectal cancer (CRC) is a major cause of cancer-related deaths worldwide, underscoring the importance of understanding the diverse molecular and genetic underpinnings of CRC to improve its diagnosis, prognosis, and treatment. This review delves into the adenoma-carcinoma-metastasis model, emphasizing the "APC-KRAS-TP53" signature events in CRC development. CRC is categorized into four consensus molecular subtypes, each characterized by unique genetic alterations and responses to therapy, illustrating its complexity and heterogeneity. Furthermore, we explore the role of chronic inflammation and the gut microbiome in CRC progression, emphasizing the potential of targeting these factors for prevention and treatment. This review discusses the impact of dietary carcinogens and lifestyle factors and the critical role of early detection in improving outcomes, and also examines conventional chemotherapy options for CRC and associated challenges. There is significant focus on the therapeutic potential of flavonoids for CRC management, discussing various types of flavonoids, their sources, and mechanisms of action, including their antioxidant properties, modulation of cell signaling pathways, and effects on cell cycle and apoptosis. This article presents evidence of the synergistic effects of flavonoids with conventional cancer therapies and their role in modulating the gut microbiome and immune response, thereby offering new avenues for CRC treatment. We conclude by emphasizing the importance of a multidisciplinary approach to CRC research and treatment, incorporating insights from genetic, molecular, and lifestyle factors. Further research is needed on the preventive and therapeutic potential of natural compounds, such as flavonoids, in CRC, underscoring the need for personalized and targeted treatment strategies.

Metabolic, toxicological, chemical, and commercial perspectives on esterification of dietary polyphenols: a review

Molecular modifications have been practiced for more than a century and nowadays they are widely applied in food, pharmaceutical, or other industries to manipulate the physicochemical, bioactivity, metabolic/catabolic, and pharmacokinetic properties. Among various structural modifications, the esterification/O-acylation has been well-established in altering lipophilicity and bioactivity of parent bioactive compounds, especially natural polyphenolics, while maintaining their high biocompatibility. Meanwhile, various classic chemical and enzymatic protocols and other recently emerged cell factory technology are being employed as viable esterification strategies. In this contribution, the main motivations of phenolic esterification, including the tendency to replace synthetic alkyl phenolics with safer alternatives in the food industry to improve the bioavailability of phenolics as dietary supplements/pharmaceuticals, are discussed. In addition, the toxicity, metabolism, and commercial application of synthetic and natural phenolics are briefly introduced. Under these contexts, the mechanisms and reaction features of several most prevalent chemical and enzymatic esterification pathways are demonstrated. In addition, insights into the studies of esterification modification of natural phenolic compounds and specific pros/cons of various reaction systems with regard to their practical application are provided.

Gut-Brain Axis in Focus: Polyphenols, Microbiota, and Their Influence on α-Synuclein in Parkinson's Disease

With the recognition of the importance of the gut-brain axis in Parkinson's disease (PD) etiology, there is increased interest in developing therapeutic strategies that target α-synuclein, the hallmark abhorrent protein of PD pathogenesis, which may originate in the gut. Research has demonstrated that inhibiting the aggregation, oligomerization, and fibrillation of α-synuclein are key strategies for disease modification. Polyphenols, which are rich in fruits and vegetables, are drawing attention for their potential role in this context. In this paper, we reviewed how polyphenols influence the composition and functional capabilities of the gut microbiota and how the resulting microbial metabolites of polyphenols may potentially enhance the modulation of α-synuclein aggregation. Understanding the interaction between polyphenols and gut microbiota and identifying which specific microbes may enhance the efficacy of polyphenols is crucial for developing therapeutic strategies and precision nutrition based on the microbiome.

Higher habitual intakes of flavonoids and flavonoid-rich foods are associated with a lower incidence of type 2 diabetes in the UK Biobank cohort

AIM

To examine the associations of a diet high in flavonoid-rich foods, as reflected by a "Flavodiet Score" (FDS), the major individual food contributors to flavonoid intake, and flavonoid subclasses with type 2 diabetes (T2D) risk in the UK Biobank cohort.

MATERIALS AND METHODS

Flavonoid intakes were estimated from ≥2 dietary assessments among 113,097 study participants [age at enrolment: 56 ± 8 years; 57% female] using the U.S Department of Agriculture (USDA) databases. Multivariable Cox proportional hazards models were used to investigate associations between dietary exposures and T2D.

RESULTS

During 12 years of follow-up, 2628 incident cases of T2D were identified. A higher FDS (compared to lower [Q4 vs. Q1]), characterised by an average of 6 servings of flavonoid-rich foods per day, was associated with a 26% lower T2D risk [HR: 0.74 (95% CI: 0.66-0.84), ptrend = <0.001]. Mediation analyses showed that lower body fatness and basal inflammation, as well as better kidney and liver function partially explain this association. In food-based analyses, higher intakes of black or green tea, berries, and apples were significantly associated with 21%, 15%, and 12% lower T2D risk. Among individual flavonoid subclasses, 19-28% lower risks of T2D were observed among those with the highest, compared to lowest intakes.

CONCLUSIONS

A higher consumption of flavonoid-rich foods was associated with lower T2D risk, potentially mediated by benefits to obesity/sugar metabolism, inflammation, kidney and liver function. Achievable increases in intakes of specific flavonoid-rich foods have the potential to reduce T2D risk.

A View on the Chemical and Biological Attributes of Five Edible Fruits after Finishing Their Shelf Life: Studies on Caco-2 Cells

We studied five common perishable fruits in terms of their polyphenols dynamic, minerals distribution, scavenger activity and the effects of 50% ethanolic extracts on the viability of Caco-2 cells in vitro, over a period of time between T = 0 and T = 5/7 days, typically the end of their shelf life. Altogether, there were few changes found, consisting of either an increase or a decrease in their chemical and biological attributes. A slow decrease was found in the antioxidant activity in apricot (-11%), plum (-6%) and strawberry (-4%) extracts, while cherry and green seedless table grape extracts gained 7% and 2% antioxidant potency, respectively; IC50 values ranged from 1.67 to 5.93 μg GAE/μL test extract. The cytotoxicity MTS assay at 24 h revealed the ability of all 50% ethanol fruit extracts to inhibit the Caco-2 cell viability; the inhibitory effects ranged from 49% to 83% and were measured at 28 µg GAE for strawberry extracts/EES, from 22 µg to 45 µg GAE for cherry extracts/EEC, from 7.58 to 15.16 µg GAE for apricot extracts/EEA, from 12.50 to 25.70 µg GAE for plum extracts/EEP and from 21.51 to 28.68 µg GAE for green table grape extracts/EEG. The MTS anti-proliferative assay (72 h) also revealed a stimulatory potency upon the Caco-2 viability, from 34% (EEA, EEG) and 48% (EEC) to 350% (EES) and 690% (EEP); therefore fruit juices can influence intestinal tumorigenesis in humans.

Dysregulation of cellular membrane homeostasis as a crucial modulator of cancer risk

Cellular membranes serve as an epicentre combining extracellular and cytosolic components with membranous effectors, which together support numerous fundamental cellular signalling pathways that mediate biological responses. To execute their functions, membrane proteins, lipids and carbohydrates arrange, in a highly coordinated manner, into well-defined assemblies displaying diverse biological and biophysical characteristics that modulate several signalling events. The loss of membrane homeostasis can trigger oncogenic signalling. More recently, it has been documented that select membrane active dietaries (MADs) can reshape biological membranes and subsequently decrease cancer risk. In this review, we emphasize the significance of membrane domain structure, organization and their signalling functionalities as well as how loss of membrane homeostasis can steer aberrant signalling. Moreover, we describe in detail the complexities associated with the examination of these membrane domains and their association with cancer. Finally, we summarize the current literature on MADs and their effects on cellular membranes, including various mechanisms of dietary chemoprevention/interception and the functional links between nutritional bioactives, membrane homeostasis and cancer biology.

The Effects of Cranberry Consumption on Glycemic and Lipid Profiles in Humans: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This study aims to update the evidence and clarify whether cranberry possesses lipid-lowering and hypoglycemic properties in humans. PubMed, Web of Science, and Scopus were searched to identify relevant articles published up to December 2023. In total, 3145 publications were reviewed and 16 of them were included for qualitative synthesis and meta-analysis. Stata 15.0 and Review Manager 5.4 were applied for statistical analyses. The results revealed a significant decrease in the total cholesterol to high-density lipoprotein cholesterol ratio (TC/HDL-C) (MD = -0.24; 95% CI: -0.45, -0.04; peffect = 0.02) and homeostasis model assessment of insulin resistance (HOMA-IR) (MD = -0.59; 95% CI: -1.05, -0.14; peffect = 0.01) with cranberry consumption. However, it did not influence total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and fasting insulin. In subgroup analysis, cranberry consumption in dried form (capsules, powder, and tablets) was found to significantly decrease the fasting insulin level (three studies, one hundred sixty-five participants, MD = -2.16; 95% CI: -4.24, -0.07; peffect = 0.04), while intervention duration, health conditions, and dosage of polyphenols and anthocyanins had no impact on blood lipid and glycemic parameters. In summary, cranberry might have potential benefits in regulating lipid and glucose profiles.

An Update of Kaempferol Protection against Brain Damage Induced by Ischemia-Reperfusion and by 3-Nitropropionic Acid

Kaempferol, a flavonoid present in many food products, has chemical and cellular antioxidant properties that are beneficial for protection against the oxidative stress caused by reactive oxygen and nitrogen species. Kaempferol administration to model experimental animals can provide extensive protection against brain damage of the striatum and proximal cortical areas induced by transient brain cerebral ischemic stroke and by 3-nitropropionic acid. This article is an updated review of the molecular and cellular mechanisms of protection by kaempferol administration against brain damage induced by these insults, integrated with an overview of the contributions of the work performed in our laboratories during the past years. Kaempferol administration at doses that prevent neurological dysfunctions inhibit the critical molecular events that underlie the initial and delayed brain damage induced by ischemic stroke and by 3-nitropropionic acid. It is highlighted that the protection afforded by kaempferol against the initial mitochondrial dysfunction can largely account for its protection against the reported delayed spreading of brain damage, which can develop from many hours to several days. This allows us to conclude that kaempferol administration can be beneficial not only in preventive treatments, but also in post-insult therapeutic treatments.

Electrochemical decarboxylative alkylation of β-ketoacids with phenol derivatives

An electrochemical method for the decarboxylative alkylation of β-ketoacids with phenol derivatives has been developed. The protocol was carried out in readily available unseparated cells at room temperature in the absence of catalysts and oxidants. The corresponding aryl ketones were obtained in satisfactory yields without additional electrolytes, and were easy to produce in gram-scale synthesis. Based on control experiments and cyclic voltammetry, a plausible reaction mechanism was proposed.

New Labeling Rules for Wine: Wine Alcohol-Derived Calories and Polyphenol Consumption on Health

Alcohol content, proanthocyanins and anthocyanins influence wine quality. The composition of wine depends on the type of cultivar, location, environmental conditions, and management practices. Phenolic compounds have attracted considerable research interest due to their antioxidant properties and potential beneficial effects on human health. However, the low bioavailability of anthocyanins creates a major bottleneck in their ability to exert beneficial effects. Despite extensive research on the effects of wine on human health, no clear evidence has been obtained on the benefits of wine quality or geographic area of production on health conditions, such as metabolic syndrome. Five climatically and geologically distinct wines were evaluated. Based on recent studies, meta-analyses, and pooled analyses of wine composition, along with the predicted low bioavailability of polyphenol compounds, we estimated the efficacy of five geographically distinct wines according to gastrointestinal absorption and the effects of alcohol intake on both men and women, with a view to ascertaining whether geographical origin influences the antioxidant serum composition of wine. Data on the estimated consumption of wine suggest that the polyphenol contents are similar regardless of choice of wine/area, while different alcohol compositions affect the level of alcohol and calorie intake. Thus, moderate wine drinkers should be advised to control the habit, but without exceeding the dose considered a healthy threshold (up to 30-40 g of alcohol/day in men and 10-20 g of alcohol/day in women), given no medical contraindications are present. These results will add value to the framework of the last reform of the Common Agricultural Policy (CAP) adopted in December 2021, where the European Parliament and the Council introduced new labeling rules for the wine sector and aromatized wine products.

Combined effects of green tea supplementation and eccentric exercise on nuclear factor erythroid 2-related factor 2 activity

PURPOSE

This study investigated whether combining eccentric exercise and green tea supplementation synergistically increased nuclear factor erythroid 2-related factor 2 (NRF2) activity, a transcription factor responsible for coordinating endogenous antioxidant expression.

METHODS

In a double-blinded, randomized, between-subjects design, 24 males (mean [SD]; 23 [3] years, 179.6 [6.1] cm, 78.8 [10.6] kg) performed 100 drop jumps following a 6 days supplementation period with either green tea (poly)phenols (n = 12; 500 mg·d-1) or a placebo (n = 12; inulin). NRF2/antioxidant response element (ARE) binding in peripheral blood mononuclear cells (PBMCs), catalase (CAT) and glutathione reductase (GR) activity, 8-hydroxy-2'-deoxyguanosine (8-OHdG) excretion, and differential leukocyte counts were measured pre-, post-, 1 h and 24 h post-exercise.

RESULTS

Exercise did not increase NRF2/ARE binding (p = 0.12) (fold change vs rest: green tea = [post] 0.78 ± 0.45, [1 h] 1.17 ± 0.54, [24 h] 1.06 ± 0.56; placebo = [post] 1.40 ± 1.50, [1 h] 2.98 ± 3.70, [24 h] 1.04 ± 0.45). Furthermore, CAT activity (p = 0.12) and 8-OHdG excretion (p = 0.42) were unchanged in response to exercise and were not augmented by green tea supplementation (p > 0.05 for all). Exercise increased GR activity by 30% (p = 0.01), however no differences were found between supplement groups (p = 0.51). Leukocyte and neutrophil concentrations were only elevated post-exercise (p < 0.001 for all).

CONCLUSION

Eccentric exercise, either performed alone or in conjunction with green tea supplementation, did not significantly increase NRF2 activity in PBMCs.

TRIAL REGISTRATION NUMBER

osf.io/kz37g (registered: 15/09/21).

Role of Extracellular Vesicles in Absorption and Functional Mechanisms of Quercetin

SCOPE

Quercetin (QUE), a phytochemical found in various plant foods, has been shown to have a variety of physiological activities in vivo, though biological sites where it has activities and the mechanisms of transport have not been fully elucidated.

METHODS AND RESULTS

In the present study, intracellular uptake of QUE into HT-29 human colon adenocarcinoma cells is found to result in spontaneous release of extracellular vesicles (EVs), which are subsequently embedded with QUE. In addition, QUE-embedded EVs are detected in serum of QUE-administered Sprague-Dawley rats. Interestingly, the rate of cellular uptake of QUE-encapsulated EVs (EV-QUE) into RAW264.7 macrophages is markedly higher than that of free QUE. Moreover, EV-QUE suppresses lipopolysaccharide (LPS)-induced nitric oxide at a lower concentration than free QUE.

CONCLUSION

The present findings suggest that QUE may be embedded in EVs in the gastrointestinal tract, then become absorbed and enter the bloodstream to exhibit biological activities.

Variation, during Shelf Life, of Functional Properties of Biscuits Enriched with Fibers Extracted from Artichoke (Cynara scolymus L.)

To boost revaluation of industrial by-products of artichoke, this research tries to determine the stability throughout storage of phenolic compounds and their antioxidant activity in biscuits enriched with fiber-rich powders extracted from b y-products of artichokes (FRPA). To determine the most stable extraction method, biscuits were formulated with FRPA extracted by two different environmentally friendly extraction solvents: water (W) and a solution of 1% CaCl2∙5H2O (CA) and compared with biscuits made with pea fiber (P) and control biscuits (B) without fiber added. Initially and during storage, the biscuits enriched with FRPA (W, CA) showed a higher content of bioavailable polyphenols and antioxidant activity compared to the control biscuits (B) and the reference fiber (P, pea fiber). In conclusion, FRPA are an excellent source of bioavailable fiber with antioxidant activity, but especially the FRPA extracted with 1% CaCl2∙5H2O (CA), and they could present a good alternative to the use of pea fiber.

A Systematic Ex-Vivo Study of the Anti-Proliferative/Cytotoxic Bioactivity of Major Olive Secoiridoids' Double Combinations and of Total Olive Oil Phenolic Extracts on Multiple Cell-Culture Based Cancer Models Highlights Synergistic Effects

Several individual olive oil phenols (OOPs) and their secoiridoid derivatives have been shown to exert anti-proliferative and pro-apoptotic activity in treatments of human cancer cell lines originating from several tissues. This study evaluated the synergistic anti-proliferative/cytotoxic effects of five olive secoiridoid derivatives (oleocanthal, oleacein, oleuropein aglycone, ligstroside aglycone and oleomissional) in all possible double combinations and of total phenolic extracts (TPEs) on eleven human cancer cell lines representing eight cell-culture-based cancer models. Individual OOPs were used to treat cells for 72 h in half of their EC₅₀ values for each cell line and their synergistic, additive or antagonistic interactions were evaluated by calculating the coefficient for drug interactions (CDI) for each double combination of OOPs. Olive oil TPEs of determined OOPs' content, originating from three different harvests of autochthonous olive cultivars in Greece, were evaluated as an attempt to investigate the efficacy of OOPs to reduce cancer cell numbers as part of olive oil consumption. Most combinations of OOPs showed strong synergistic effect (CDIs < 0.9) in their efficacy, whereas TPEs strongly impaired cancer cell viability, better than most individual OOPs tested herein, including the most resistant cancer cell lines evaluated.

Dendrimers as Nanocarriers for the Delivery of Drugs Obtained from Natural Products

Natural products have proven their value as drugs that can be therapeutically beneficial in the treatment of various diseases. However, most natural products have low solubility and poor bioavailability, which pose significant challenges. To solve these issues, several drug nanocarriers have been developed. Among these methods, dendrimers have emerged as vectors for natural products due to their superior advantages, such as a controlled molecular structure, narrow polydispersity index, and the availability of multiple functional groups. This review summarizes current knowledge on the structures of dendrimer-based nanocarriers for natural compounds, with a particular focus on applications in alkaloids and polyphenols. Additionally, it highlights the challenges and perspectives for future development in clinical therapy.

Nanoformulations for the Delivery of Dietary Anthocyanins for the Prevention and Treatment of Diabetes Mellitus and Its Complications

Diabetes mellitus (DM) is a metabolic disease characterized by abnormal blood glucose levels-hyperglycemia, caused by a lack of insulin secretion, impaired insulin action, or a combination of both. The incidence of DM is increasing, resulting in billions of dollars in annual healthcare costs worldwide. Current therapeutics aim to control hyperglycemia and reduce blood glucose levels to normal. However, most modern drugs have numerous side effects, some of which cause severe kidney and liver problems. On the other hand, natural compounds rich in anthocyanidins (cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin) have also been used for the prevention and treatment of DM. However, lack of standardization, poor stability, unpleasant taste, and decreased absorption leading to low bioavailability have hindered the application of anthocyanins as therapeutics. Therefore, nanotechnology has been used for more successful delivery of these bioactive compounds. This review summarizes the potential of anthocyanins for the prevention and treatment of DM and its complications, as well as the strategies and advances in the delivery of anthocyanins using nanoformulations.

Potential of resveratrol in the treatment of interstitial lung disease

Interstitial lung disease (ILD) is a heterogeneous group of diseases characterized by lung injury caused by lung fibroblast proliferation, interstitial inflammation, and fibrosis. Different cell signal transduction pathways are activated in response to various proinflammatory or fibrotic cytokines, such as IL-6, and these cytokines are increased in different ILDs. The overexpressed cytokines and growth factors in ILD can activate TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways, promote the activation of immune cells, increase the release of pro-inflammatory and pro-fibrotic factors, differentiate fibroblasts into myofibroblasts, and promote the occurrence and development of ILD. This finding suggests the importance of signal transduction pathways in patients with ILD. Recent evidence suggests that resveratrol (RSV) attenuates excessive inflammation and pulmonary fibrosis by inhibiting the TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways and overactivation of immune cells. In this review, advances in lung protection and the underlying mechanisms of RSV are summarized, and the potential efficacy of RSV as a promising treatment option for ILD is highlighted.

Quercetin and Its Nano-Formulations for Brain Tumor Therapy—Current Developments and Future Perspectives for Paediatric Studies

The development of efficient treatments for tumors affecting the central nervous system (CNS) remains an open challenge. Particularly, gliomas are the most malignant and lethal form of brain tumors in adults, causing death in patients just over 6 months after diagnosis without treatment. The current treatment protocol consists of surgery, followed using synthetic drugs and radiation. However, the efficacy of these protocols is associated with side effects, poor prognosis and with a median survival of fewer than two years. Recently, many studies were focused on applying plant-derived products to manage various diseases, including brain cancers. Quercetin is a bioactive compound derived from various fruits and vegetables (asparagus, apples, berries, cherries, onions and red leaf lettuce). Numerous in vivo and in vitro studies highlighted that quercetin through multitargeted molecular mechanisms (apoptosis, necrosis, anti-proliferative activity and suppression of tumor invasion and migration) effectively reduces the progression of tumor cells. This review aims to summarize current developments and recent advances of quercetin’s anticancer potential in brain tumors. Since all reported studies demonstrating the anti-cancer potential of quercetin were conducted using adult models, it is suggested to expand further research in the field of paediatrics. This could offer new perspectives on brain cancer treatment for paediatric patients.

Honey polyphenols: regulators of human microbiota and health

A comprehensive review of research over the last decade was conducted to carry out this work. The main objective of this work is to present relevant evidence of the effect of honey intake on the human intestinal microbiota and its relationship with the improvement of various chronic diseases, such as cirrhosis, metabolic syndrome, diabetes, and obesity, among others. Therefore, this work focuses on the health-improving honey dietary supplementation implications associated with specific changes in the human microbiota and their biochemical mechanisms to enhance the proliferation of beneficial microorganisms and the inhibition of pathogenic microorganisms. Consumption of honey polyphenols significantly improves people's health conditions, especially in patients with chronic disease. Hence, honey intake unequivocally constitutes an alternative way to enhance health and could be used to prevent some relevant chronic diseases.

Gut Bacterial Indole-3-acetic Acid Induced Immune Promotion Mediates Preventive Effects of Fu Brick Tea Polyphenols on Experimental Colitis

Ulcerative colitis has been consistently associated with gut microbiota imbalance and disturbed immune system. Emerging research suggests a protective function of polyphenols on prevention and treatment of ulcerative colitis, yet underlying mechanisms remain unclear. Fu brick tea, a postfermented tea, contains abundant polyphenols with anti-inflammatory and antioxidant properties. In the present study, we found that prophylactic supplementation of polyphenols extracted from Fu brick tea (FBTP) dose-dependently alleviated colitis symptoms, immune cells infiltration, and pro-inflammatory cytokines secretion in mice suffering dextran sulfate sodium induced murine colitis. FBTP substantially reshaped gut microbiota and promoted microbial transformation of tryptophan into indole-3-acetic acid (I3A), thereafter leading to aryl hydrocarbon receptor (AHR)-mediated protection from colitis through enhanced expressions of IL-22 and tight junction proteins (i.e., ZO-1, occluding and claudin-1) in colon. Multiomics integration analyses revealed strong connections between I3A, tryptophan-metabolizing bacteria, AHR activity, and pathological phenotypes of colitis. Notably, FBTP failed to significantly alleviate colitis symptoms in the absence of gut microbiota, while intragastric administration of I3A could imitate benefits of FBTP on colitis alleviation and intestinal epithelial homeostasis through a direct enhancement in AHR activity in microbiota-depleted mice. These findings further determine the key role of gut microbiota controlled I3A-AHR signaling in mediating the FBTP on colitis alleviation. This study provides the first data proposing the FBTP as a natural prebiotic for colitis alleviation through the gut microbiota-dependent modulation of the AHR pathway. Most importantly, we also identified I3A as a key microbial metabolite targeted by FBTP for exhibiting health-promoting effects.

The effect of curcumin on blood pressure and cognitive impairment in spontaneously hypertensive rats

BACKGROUND/OBJECTIVES

It is known that the renin-angiotensin system (RAS) in the brain could regulate cognitive functions as well as blood pressure. Inhibition of RAS for the improvement of cognitive function may be a new strategy, but studies so far have mostly reported on the effects of RAS inhibition by drugs, and there is no research on cognitive improvement through RAS inhibition of food ingredients. Therefore, this study investigated the effect of curcumin on blood pressure and cognitive function and its related mechanism in spontaneously hypertensive rat/Izm (SHR/Izm).

MATERIALS/METHODS

Six-week-old SHR/Izm rats were divided into 5 groups: control group (CON), scopolamine group (SCO, drug for inducing cognitive deficits), positive control (SCO and tacrine [TAC]), curcumin 100 group (CUR100, SCO + Cur 100 mg/kg), and curcumin 200 group (CUR200, SCO + Cur 200 mg/kg). Changes in blood pressure, RAS, cholinergic system, and cognitive function were compared before and after cognitive impairment.

RESULTS

The SCO group showed increased blood pressure and significantly reduced cognitive function based on the y-maze and passive avoidance test. Curcumin treatments significantly improved blood pressure and cognitive function compared with the SCO group. In both the CUR100 and CUR200 groups, the mRNA expressions of angiotensin-converting enzyme (ACE) and angiotensin II receptor type1 (AT1), as well as the concentrations of angiotensin II (Ang II) in brain tissue were significantly decreased. The mRNA expression of the muscarinic acetylcholine receptors (mAChRs) and acetylcholine (ACh) content was significantly increased, compared with the SCO group.

CONCLUSIONS

The administration of curcumin improved blood pressure and cognitive function in SCO-induced hypertensive mice, indicating that the cholinergic system was improved by suppressing RAS and AT1 receptor expression and increasing the mAChR expression.

Protective Role of Natural Compounds under Radiation-Induced Injury

In recent years, evidence has shown the potential therapeutic effects of different natural compounds for the prevention and treatment of radiotherapy-induced mucositis (RIOM). RIOM represents one of the most frequent side effects associated with anti-neoplastic treatments affecting patients' quality of life and treatment response due to radiation therapy discontinuation. The innate radio-protective ability of natural products obtained from plants is in part due to the numerous antioxidants possessed as a part of their normal secondary metabolic processes. However, oxygen presence is a key point for radiation efficacy on cancer cells. The aim of this review is to describe the most recent evidence on radiation-induced injury and the emerging protective role of natural compounds in preventing and treating this specific damage without compromising treatment efficacy.

Quercetin Ameliorates Testicular Damage in Zucker Diabetic Fatty Rats through Its Antioxidant, Anti-Inflammatory and Anti-Apoptotic Properties

The aim of this study was to investigate the effects of quercetin (QUE) on the testicular architecture as well as markers of oxidative, inflammatory, and apoptotic profile of male gonads in Zucker diabetic fatty (ZDF) rats suffering from Type 2 diabetes mellitus in the absence or presence of obesity. QUE was administered orally at a dose of 20 mg/kg/day for 6 weeks. Morphometric analysis revealed that QUE treatment led to an improvement in testicular appearance, particularly in the case of Obese ZDF rats. Furthermore, a significant stabilization of the antioxidant capacity (p < 0.05), superoxide dismutase and catalase activity (p < 0.01), with a concomitant decrease in lipid peroxidation (p < 0.05) were observed in Obese ZDF animals exposed to QUE. Our data also indicate a significant decline in the levels of interleukin (IL)-1 (p < 0.05), IL-6 (p < 0.01) and tumor necrosis factor alpha (p < 0.001) following QUE supplementation to Obese ZDF rats in comparison with their respective control. Finally, a significant down-regulation of the pro-apoptotic BAX protein (p < 0.0001) was observed in Obese ZDF rats administered with QUE, while a significant Bcl-2 protein overexpression (p < 0.0001) was recorded in Lean ZDF animals when compared to their untreated control. As such, our results suggest that QUE is a potentially beneficial agent to reduce testicular damage in ZDF rats with Type 2 diabetes mellitus by decreasing oxidative stress, chronic inflammation, and excessive cell loss through apoptosis.

Tumor immunomodulatory effects of polyphenols

Polyphenols, commonly found in various plants, have attracted enormous attention due to their potential pharmacological activity, especially antitumor activity dependent on immune function. In recent years, the development of nanomedicine can counteract the low bioavailability of polyphenols and improve the effect of tumor treatment. Among them, metal-phenolic networks (MPNs), which utilize various metal ions and phenolic ligands for coordination binding, have now become candidates for polyphenol-based nanomedicine treatment of tumors. In this mini-review, we described the classification of polyphenols and their mechanisms in antitumor immune responses, and provided suggestions for the next steps of treating tumors with polyphenols.

Quercetin's Effects on Glutamate Cytotoxicity

The potentially therapeutic effects of the naturally abundant plant flavonoid quercetin have been extensively studied. An extensive body of literature suggests that quercetin's powerful antioxidant effects may relate to its ability to treat disease. Glutamate excitotoxicity occurs when a neuron is overstimulated by the neurotransmitter glutamate and causes dysregulation of intracellular calcium concentrations. Quercetin has been shown to be preventative against many forms of neuronal cell death resulting from glutamate excitotoxicity, such as oncosis, intrinsic apoptosis, mitochondrial permeability transition, ferroptosis, phagoptosis, lysosomal cell death, parthanatos, and death by reactive oxygen species (ROS)/reactive nitrogen species (RNS) generation. The clinical importance for the attenuation of glutamate excitotoxicity arises from the need to deter the continuous formation of tissue infarction caused by various neurological diseases, such as ischemic stroke, seizures, neurodegenerative diseases, and trauma. This review aims to summarize what is known concerning glutamate physiology and glutamate excitotoxic pathophysiology and provide further insight into quercetin's potential to hinder neuronal death caused by cell death pathways activated by glutamate excitotoxicity. Quercetin's bioavailability may limit its use clinically, however. Thus, future research into ways to increase its bioavailability are warranted.

Effect of geographical location, processing and simulated digestion on antioxidant characteristics of quince (Cydonia oblonga)

Quince fruit (Cydonia oblonga Miller) is an important source of bioactive compounds, especially of phenolic compounds, that's why it is considered a good source of antioxidants. However, it is known that the antioxidant characteristics and the beneficial effect of foods are affected by the variety, geographical origin, processing and gastrointestinal digestion. In this work, the effects of the geographical origin, processing, and simulated digestion of quince jam on its antioxidant characteristics were studied. Phenolic composition and antioxidant capacity were determined in quince fruit and jam from four different locations in San Juan, Argentina. The results showed that quince fruit samples from St. Lucia had the highest total phenolic content (5.13 mg GAE/g; p < 0.05) and in vitro antioxidant capacity measured by ferric-reducing antioxidant power assay (FRAP) and radical-scavenging capacity assay (DPPH· and ABTS·+ ). With regard to quince jam, a positive effect was observed on its antioxidant characteristics after processing. Twenty-one phenolics were detected in jam, being most of them derivatives of hydroxycinnamic acids (eg. 5-caffeoylquinic acid; 4-caffeoylquinic acid and quinic acid). Studies on stability and bioaccessibility of quince phenolics showed that less than 25% of the initial phenolics in jam were detected after digestion being quinic acid and hydroxycinnamic acids the most resistant. The in vitro antioxidant capacity showed, in general, a similar trend to the phenolics content throughout the digestion process. The results obtained showed that the antioxidant activity of quince and jam is related to the type and amount of phenolics in the samples, which depends on the geographical origin, processing, and gastrointestinal digestion. These variables are not always taken into account when studying the probable antioxidant activity of food, even though they should be considered for a complete nutritional evaluation of a food.

Apple Polyphenol Diet Extends Lifespan, Slows down Mitotic Rate and Reduces Morphometric Parameters in Drosophila Melanogaster: A Comparison between Three Different Apple Cultivars

Plant-derived polyphenols exhibit beneficial effects on physiological and pathological processes, including cancer and neurodegenerative disorders, mainly because of their antioxidant activity. Apples are highly enriched in these compounds, mainly in their peel. The Tuscia Red (TR) apple variety exhibits the peculiar characteristic of depositing high quantities of polyphenols in the pulp, the edible part of the fruit. Since polyphenols, as any natural product, cannot be considered a panacea per se, in this paper, we propose to assess the biological effects of TR flesh extracts, in comparison with two commercial varieties, in a model system, the insect Drosophila melanogaster, largely recognized as a reliable system to test the in vivo effects of natural and synthetic compounds. We performed a comparative, qualitative and quantitative analysis of the polyphenol compositions of the three cultivars and found that TR flesh shows the highest content of polyphenols, and markedly, anthocyanins. Then, we focused on their effects on a panel of physiological, morphometrical, cellular and behavioral phenotypes in wild-type D. melanogaster. We found that all the apple polyphenol extracts showed dose-dependent effects on most of the phenotypes we considered. Remarkably, all the varieties induced a strong relenting of the cell division rate.

Advancing quantification methods for polyphenols in brown seaweeds-applying a selective qNMR method compared with the TPC assay

INTRODUCTION

Brown seaweeds are a sustainable biomass with a potential for various industrial applications. Polyphenols are an important contributor to this potential.

OBJECTIVE

The aim was total quantification of polyphenols in brown seaweeds from different tidal zones, using a selective 1 H quantitative NMR (qNMR) method, comparing the results with the colorimetric Folin-Ciocalteu total phenolic content (TPC) assay.

METHOD

qNMR was performed with integration of selected peaks in the aromatic region (7-5.5 ppm). Deselection of non-polyphenolic 1 H signals was based on information from 2D (1 H-13 C, 1 H-15 N) NMR spectra. 13 C NMR phlorotannin characterisation facilitated the average number of protons expected to be found per aromatic ring used for the 1 H quantification.

RESULTS

Selective qNMR and the TPC assay showed similar results for the three sublittoral growing species from the Laminariaceae; lower amounts for Laminaria hyperborea and Laminaria digitata (qNMR: 0.4%-0.6%; TPC: 0.6%-0.8%, phloroglucinol equivalents (PGE), dry weight (DW)) and higher amounts for Saccharina latissima (qNMR: 1.2%; TPC: 1.5%, PGE, DW). For the eulittoral Fucaceae, Fucus vesiculosus (qNMR: 1.1%; TPC: 4.1%; PGE, DW) and Ascophyllum nodosum (qNMR: 0.9%; TPC: 2.0%; PGE, DW), the TPC results were found to be up to three times higher than the qNMR results. The 13 C NMR characterisation showed the highest phlorotannin polymerisation degree for F. vesiculosus.

CONCLUSION

The TPC assay provided similar polyphenolic amounts to the selective qNMR method for sublittoral species. For eulittoral growing species, the TPC method showed amounts up to three times higher than the qNMR method-most likely illustrating the lack of selectivity in the TPC assay.

The Anticancer Potential of Plant-Derived Nutraceuticals via the Modulation of Gene Expression

Current studies show that approximately one-third of all cancer-related deaths are linked to diet and several cancer forms are preventable with balanced nutrition, due to dietary compounds being able to reverse epigenetic abnormalities. An appropriate diet in cancer patients can lead to changes in gene expression and enhance the efficacy of therapy. It has been demonstrated that nutraceuticals can act as powerful antioxidants at the cellular level as well as anticarcinogenic agents. This review is focused on the best studies on worldwide-available plant-derived nutraceuticals: curcumin, resveratrol, sulforaphane, indole-3-carbinol, quercetin, astaxanthin, epigallocatechin-3-gallate, and lycopene. These compounds have an enhanced effect on epigenetic changes such as histone modification via HDAC (histone deacetylase), HAT (histone acetyltransferase) inhibition, DNMT (DNA methyltransferase) inhibition, and non-coding RNA expression. All of these nutraceuticals are reported to positively modulate the epigenome, reducing cancer incidence. Furthermore, the current review addresses the issue of the low bioavailability of nutraceuticals and how to overcome the drawbacks related to their oral administration. Understanding the mechanisms by which nutraceuticals influence gene expression will allow their incorporation into an “epigenetic diet” that could be further capitalized on in the therapy of cancer.

A look beyond dietary (poly)phenols: The low molecular weight phenolic metabolites and their concentrations in human circulation

A large number of epidemiological studies have shown that consumption of fruits, vegetables, and beverages rich in (poly)phenols promote numerous health benefits from cardiovascular to neurological diseases. Evidence on (poly)phenols has been applied mainly to flavonoids, yet the role of phenolic acids has been largely overlooked. Such phenolics present in food combine with those resulting from gut microbiota catabolism of flavonoids and chlorogenic acids and those produced by endogenous pathways, resulting in large concentrations of low molecular weight phenolic metabolites in human circulation. Independently of the origin, in human intervention studies using diets rich in (poly)phenols, a total of 137 low molecular weight phenolic metabolites have been detected and quantified in human circulation with largely unknown biological function. In this review, we will pinpoint two main aspects of the low molecular weight phenolic metabolites: (i) the microbiota responsible for their generation, and (ii) the analysis (quali- and quantitative) in human circulation and their respective pharmacokinetics. In doing so, we aim to drive scientific advances regarding the ubiquitous roles of low molecular weight phenolic metabolites using physiologically relevant concentrations and under (patho)physiologically relevant conditions in humans.

Tamarind Seed Coat: A Catechin-Rich Source with Anti-Oxidation, Anti-Melanogenesis, Anti-Adipogenesis and Anti-Microbial Activities

Tamarindus indica L. or tamarind seed is an industrial by-product of interest to be investigated for its potential and value-added application. An ethanolic tamarind seed coat (TS) extract was prepared using the maceration technique and used to determine the phytochemical composition and bioactivities. The total phenolic and flavonoid contents were determined using colorimetric methods; moreover, chemical constituents were identified and quantified compared to the standard compounds using the HPLC-UV DAD technique. Bioactivities were investigated using various models: antioxidative activity in a DPPH assay model, anti-melanogenesis in B16 melanoma cells, anti-adipogenesis in 3T3-L1 adipocytes, and anti-microbial activity against S. aureus, P. aeruginosa, E. coli, and C. albican using agar disc diffusion and microdilution methods. The results manifested a high content of catechin as a chemical constituent and multiple beneficiary bioactivities of TS extract, including superior antioxidation to ascorbic acid and catechin, comparable anti-melanogenesis to deoxyarbutin, and significant anti-adipogenesis through inhibition of pre-adipocyte differentiation and reduction of lipid and triglyceride accumulation, and a broad spectral anti-microbial activity with a selectively high susceptibility to S. aureus when compared to 1% Parabens. Conclusively, TS extract has been revealed as a potential bioactive agent as well as an alternative preservative for application in food, cosmetic, and pharmaceutical product development.

Plants as a Source of Anticancer Agents: From Bench to Bedside

Cancer is the second leading cause of death after cardiovascular diseases. Conventional anticancer therapies are associated with lack of selectivity and serious side effects. Cancer hallmarks are biological capabilities acquired by cancer cells during neoplastic transformation. Targeting multiple cancer hallmarks is a promising strategy to treat cancer. The diversity in chemical structure and the relatively low toxicity make plant-derived natural products a promising source for the development of new and more effective anticancer therapies that have the capacity to target multiple hallmarks in cancer. In this review, we discussed the anticancer activities of ten natural products extracted from plants. The majority of these products inhibit cancer by targeting multiple cancer hallmarks, and many of these chemicals have reached clinical applications. Studies discussed in this review provide a solid ground for researchers and physicians to design more effective combination anticancer therapies using plant-derived natural products.

Food-Grade Quercetin-Loaded Nanoemulsion Ameliorates Effects Associated with Parkinson's Disease and Cancer: Studies Employing a Transgenic C. elegans Model and Human Cancer Cell Lines

A nanosized food-grade quercetin-loaded nanoemulsion (QNE) system comprising capmul MCM NF (oil) and cremophor RH 40 (surfactant) was developed using a high-speed homogenization technique. The developed QNE was studied for its significant neuroprotective (anti-Parkinsonism) and cytotoxicity (anticancer) effects against Caenorhabditis elegans (C. elegans) strains and human cancer cells, respectively. HR-TEM studies revealed that the QNE was spherical with a mean globule size of ~50 nm. Selected area electron diffraction (SAED) studies results demonstrated that QNE was amorphous. In vivo results show that QNE potentially reduced the α-Syn aggregation, increased mitochondrial and fat content, and improved the lifespan in transgenic C. elegans strain NL5901. QNE significantly downregulated the reactive oxygen species (ROS) levels in wild-type C. elegans strain N2. In vitro results of the MTT assay show that QNE significantly exhibited chemotherapeutic effects in all treated human cancer cells in an order of cytotoxicity: HeLa cells > A549 cells > MIA PaCa-2 cells, based on the IC50 values at 24 h. Conclusively, the QNE showed improved solubility, targetability, and neuroprotective effects against the PD-induced C. elegans model, and also cytotoxicity against human cancer cells and could be potentially used as an anti-Parkinson’s or anticancer agent.

Investigating the interaction between dietary polyphenols, the SARS CoV-2 spike protein and the ACE-2 receptor

The global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has called for an urgent need for the identification of compounds able to control, prevent or slow down the global pandemic. Several dietary polyphenols were assayed against binding to the SARS CoV-2 S1 spike protein and the human ACE-2 receptor, the target of the SARS CoV-2 virus using nano differential scanning fluorimetry, suggesting interaction of dietary polyphenols with both proteins. Following this initial screening the two dietary polyphenols with the strongest affinity were evaluated in a second functional binding assay. The assay was based on the thermophoresis of a fluorescently labelled spike protein and the ACE-2 receptor in the presence of dietary concentrations of the polyphenol in question. It could be experimentally shown that 5-caffeoyl quinic acid and epicatechin reduce the binding constant between SARS CoV-2 spike protein of the alpha variant and the ACE-2 receptor by a factor of ten. The finding could as well be applied to black tea and a coffee beverage with dietary 5-CQA concentrations for the alpha variant Spike protein. Hence it can be speculated that a cup of coffee reduces binding of the virus to its human target, therefore reducing the likelihood of infection with SARS CoV-2, acting as a virus entry-inhibitor.

Inhibitory activities of flavonoids from Scutellaria baicalensis Georgi on amyloid aggregation related to type 2 diabetes and the possible structural requirements for polyphenol in inhibiting the nucleation phase of hIAPP aggregation

Human islet amyloid polypeptide (hIAPP)-mediated cytotoxicity is identified as a potential target for developing new anti-diabetic molecules. Herein, we investigated the effect of the major bioactive compounds of Scutellaria baicalensis Georgi (S. baicalensis), including baicalein, baicalin, wogonin and oroxylin A, on hIAPP aggregation. We found that all of these compounds inhibited hIAPP fibril formation in a dose-dependent manner. But baicalein and baicalin, especially baicalein are more effective than wogonin and oroxylin A in stabilizing hIAPP monomers and eliminating toxic hIAPP assembly, suggesting that flavonoids with ortho-hydroxyl group on the A-ring exhibited higher anti-hIAPP nucleation potential than those without this structure. This stimulated our interest in further studying the possible structure-activity relationship between polyphenol and hIAPP aggregation inhibition. Our results demonstrated that flavonoids with ortho-hydroxyl group on the B-ring are also more effective against hIAPP nucleation than those without this structure. These results suggest that the ortho-hydroxybenzene structure is a key structural feature required for polyphenols to effectively inhibit hIAPP nucleation. This was further confirmed by the effect of polyphenoland phenols in inhibiting hIAPP nucleation. The conclusion that pyrogallol-type polyphenols are potential lead inhibitors may provide a valuable structural template for the further development of polyphenol-based inhibitor of amyloid peptides.

Bioactive Compounds from Plants and their Immune Potential against Corona Virus

Background:

Corona virus is a contagious single-strand RNA virus affecting majorly the lungs causing severe acute respiratory disease. The viral pandemic has affected the world economy and posed new challenges to the scientific community. Due to high mutation rate, a lot of variants are occurring and persons who are vaccinated are also getting affected. In addition, vaccination trials for children aged below 18 are still going on. Moreover, the cost, shelf-life, success rate, no booster dose required, and the long-term complications associated with the vaccine are yet to be studied. Preservation and transportation of vaccines are another big challenge.

Objective:

Despite vaccination, the best alternative is to boost our immune system by administration of bioactive compounds which are safe and effective. Bioactive compounds have been found to be effective against several viral infections.

Methods:

Literature review has been performed using recently published research and review articles pertaining to the role of plant-derived bioactive compounds in regulating COVID-19 infection.

Result:

The current review will describe the role and mechanism of bioactive compounds derived from natural sources in disease management and boosting the immune system against COVID-19.

Conclusion:

In addition to vaccination, the administration of plant-derived bioactive compounds will help in regulating viral infection and boosting the immune response during COVID-19 infection.

Phytochemical Screening, Antioxidant and Antifungal Activities of Aconitum chasmanthum Stapf ex Holmes Wild Rhizome Extracts

Aconitum chasmanthum Stapf ex Holmes, an essential and critically endangered medicinal plant from Kashmir Himalayas, was studied for its antioxidant and antifungal properties. The shade-dried powdered rhizome was extracted sequentially with hexane, ethyl acetate, and methanol. These subsequent fractions were evaluated for total phenolic content (TPC); total flavonoid content (TFC); antioxidant assays, such as 1,1-diphenyl 1-2-picryl-hydrazyl (DPPH); ferric-reducing antioxidant power (FRAP); superoxide radical scavenging (SOR); hydroxyl radical scavenging (OH) and antifungal activity using the poisoned food technique. Highest TPC (5.26 ± 0.01 mg/g) and TFC (2.92 ± 0.04 mg/g) were reported from methanolic extracts. The highest values of radical scavenging activities were also observed in methanolic extracts with IC₅₀ values of 163.71 ± 2.69 μg/mL in DPPH, 173.69 ± 4.91 μg/mL in SOR and 159.64 ± 2.43 μg/mL in OH. The chemical profile of ethyl acetate extract was tested using HR-LCMS. Methanolic extracts also showed a promising inhibition against Aspergillus niger (66.18 ± 1.03), Aspergillus flavus (78.91 ± 1.19) and Penicillium notatum (83.14 ± 0.97) at a 15% culture filtrate concentration with minimum inhibitory concentration (MIC) values of 230 μg/mL, 200 μg/mL and 190 μg/mL, respectively. Overall, the methanolic fractions showed significant biological potential, and its pure isolates might be used to construct a potential new medicinal source.