Focus on the high therapeutic potentials of quercetin and its derivatives

Structural and Interactional Analysis of the Flavonoid Pathway Proteins: Chalcone Synthase, Chalcone Isomerase and Chalcone Isomerase-like Protein

Chalcone synthase (CHS) and chalcone isomerase (CHI) catalyze the first two committed steps of the flavonoid pathway that plays a pivotal role in the growth and reproduction of land plants, including UV protection, pigmentation, symbiotic nitrogen fixation, and pathogen resistance. Based on the obtained X-ray crystal structures of CHS, CHI, and chalcone isomerase-like protein (CHIL) from the same monocotyledon, Panicum virgatum, along with the results of the steady-state kinetics, spectroscopic/thermodynamic analyses, intermolecular interactions, and their effect on each catalytic step are proposed. In addition, PvCHI's unique activity for both naringenin chalcone and isoliquiritigenin was analyzed, and the observed hierarchical activity for those type-I and -II substrates was explained with the intrinsic characteristics of the enzyme and two substrates. The structure of PvCHS complexed with naringenin supports uncompetitive inhibition. PvCHS displays intrinsic catalytic promiscuity, evident from the formation of p-coumaroyltriacetic acid lactone (CTAL) in addition to naringenin chalcone. In the presence of PvCHIL, conversion of p-coumaroyl-CoA to naringenin through PvCHS and PvCHI displayed ~400-fold increased Vmax with reduced formation of CTAL by 70%. Supporting this model, molecular docking, ITC (Isothermal Titration Calorimetry), and FRET (Fluorescence Resonance Energy Transfer) indicated that both PvCHI and PvCHIL interact with PvCHS in a non-competitive manner, indicating the plausible allosteric effect of naringenin on CHS. Significantly, the presence of naringenin increased the affinity between PvCHS and PvCHIL, whereas naringenin chalcone decreased the affinity, indicating a plausible feedback mechanism to minimize spontaneous incorrect stereoisomers. These are the first findings from a three-body system from the same species, indicating the importance of the macromolecular assembly of CHS-CHI-CHIL in determining the amount and type of flavonoids produced in plant cells.

Therapeutic implications of quercetin and its derived-products in COVID-19 protection and prophylactic

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel human coronavirus, which has triggered a global pandemic of the coronavirus infectious disease 2019 (COVID-19). Outbreaks of emerging infectious diseases continue to challenge human health worldwide. The virus conquers human cells through the angiotensin-converting enzyme 2 receptor-driven pathway by mostly targeting the human respiratory tract. Quercetin is a natural flavonoid widely represented in the plant kingdom. Cumulative evidence has demonstrated that quercetin and its derivatives have various pharmacological properties including anti-cancer, anti-hypertension, anti-hyperlipidemia, anti-hyperglycemia, anti-microbial, antiviral, neuroprotective, and cardio-protective effects, because it is a potential treatment for severe inflammation and acute respiratory distress syndrome. Furthermore, it is the main life-threatening condition in patients with COVID-19. This article provides a comprehensive review of the primary literature on the predictable effectiveness of quercetin and its derivatives docked to multi-target of SARS-CoV-2 and host cells via in silico and some of validation through in vitro, in vivo, and clinically to fight SARS-CoV-2 infections, contribute to the reduction of inflammation, which suggests the preventive and therapeutic latency of quercetin and its derived-products against COVID-19 pandemic, multisystem inflammatory syndromes (MIS), and long-COVID.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

Chemical Constituents and Antioxidant Potential of Red Guava (Psidium cattleianum Sabine) from Southern Brazil in Different Edible Ripening Stages

Ripening and growing location are important factors that can impact fruit quality characteristics. In this study, the influence of these factors on physicochemical characteristics, carbohydrates, aliphatic organic acids, phenolic compounds, and antioxidant capacity of red guava (Psidium cattleianum Sabine) was evaluated. Fruit ripening increased fructose and glucose (up to 22.83 and 16.42 g 100 g- 1 dry matter (DM), respectively), and decreased citric acid, the major organic acid (up to 135.35 mg g- 1 DM). Ripening and growing location also influenced the concentration of phenolic compounds and antioxidant capacity of red guava, in which a dependency between both factors was observed in most cases. Apigenin, galangin, isoquercitrin, among other phenolic compounds were quantified for the first time in red guava, in which isoquercitrin was the major (up to 13409.81 mg kg- 1 DM). The antioxidant potential of red guava was also confirmed by ferric reducing antioxidant power assay (up to 82.63 µmol Fe+ 2 g- 1 DM), Folin-Ciocalteu reducing capacity assay (up to 17.79 mg gallic acid equivalent g- 1 DM), and DPPH free radical scavenging assay (up to 25.36 mg ascorbic acid equivalent g- 1 DM). These results especially demonstrated the bioactive potential of red guava and provided knowledge regarding the influence of ripening and growing location on chemical and bioactive components encouraging its industrial exploitation.

Effects of a Singular Dose of Mangiferin-Quercetin Supplementation on Basketball Performance: A Double-Blind Crossover Study of High-Level Male Players

Pre-exercise mangiferin-quercetin may enhance athletic performance. This study investigated the effect of mangiferin-quercetin supplementation on high-level male basketball players during a basketball exercise simulation test (BEST) comprising 24 circuits of 30 s activities with various movement distances. The participants were divided into two groups (EXP = 19 and CON = 19) and given a placebo one hour before the BEST (PRE-condition). The following week, the EXP group received mangiferin-quercetin (84 mg/140 mg), while the CON group received a placebo (POST-condition) before the BEST in a double-blind, cross-over design. The mean heart rate (HR) and circuit and sprint times (CT and ST) during the BEST were measured, along with the capillary blood lactate levels (La-), the subjective rating of muscle soreness (RPMS), and the perceived exertion (RPE) during a resting state prior to and following the BEST. The results showed significant interactions for the mean CT (p = 0.013) and RPE (p = 0.004); a marginal interaction for La- (p = 0.054); and non-significant interactions for the mean HR, mean ST, and RPMS. Moreover, the EXP group had significantly lower values in the POST condition for the mean CT (18.17 ± 2.08 s) and RPE (12.42 ± 1.02) compared to the PRE condition (20.33 ± 1.96 s and 13.47 ± 1.22, respectively) and the POST condition of the CON group (20.31 ± 2.10 s and 13.32 ± 1.16, respectively) (p < 0.05). These findings highlight the potential of pre-game mangiferin-quercetin supplementation to enhance intermittent high-intensity efforts in sports such as basketball.

Cytocompatibility, Antimicrobial and Antioxidant Activity of a Mucoadhesive Biopolymeric Hydrogel Embedding Selenium Nanoparticles Phytosynthesized by Sea Buckthorn Leaf Extract

Phytosynthesized selenium nanoparticles (SeNPs) are less toxic than the inorganic salts of selenium and show high antioxidant and antibacterial activity. Chitosan prevents microbial biofilm formation and can also determine microbial biofilm dispersal. Never-dried bacterial nanocellulose (NDBNC) is an efficient carrier of bioactive compounds and a flexible nanofibrillar hydrophilic biopolymer. This study aimed to develop a selenium-enriched hydrogel nanoformulation (Se-HNF) based on NDBNC from kombucha fermentation and fungal chitosan with embedded biogenic SeNPs phytosynthesized by an aqueous extract of sea buckthorn leaves (SbLEx)-SeNPsSb-in order to both disperse gingival dysbiotic biofilm and prevent its development. We determined the total phenolic content and antioxidant activity of SbLEx. Liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography (HPLC) were used for the identification of polyphenols from SbLEx. SeNPsSb were characterized by transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDX), dynamic light scattering (DLS), zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) in small- and wide-angle X-ray scattering (SAXS and WAXS). The hydrogel nanoformulation with embedded SeNPsSb was characterized by SEM, FTIR, XRD, rheology, mucin binding efficiency, contact angle and interfacial tension measurements. We also assessed the in vitro biocompatibility, antioxidant activity and antimicrobial and antibiofilm potential of SeNPsSb and Se-HNF. TEM, DLS and SAXS evidenced polydisperse SeNPsSb, whereas FTIR highlighted a heterogeneous biocorona with various biocompounds. The contact angle on the polar surface was smaller (52.82 ± 1.23°) than that obtained on the non-polar surface (73.85 ± 0.39°). The interfacial tension was 97.6 ± 0.47 mN/m. The mucin binding efficiency of Se-HNF decreased as the amount of hydrogel decreased, and the SEM analysis showed a relatively compact structure upon mucin contact. FTIR and XRD analyses of Se-HNF evidenced an interaction between BNC and CS through characteristic peak shifting, and the rheological measurements highlighted a pseudoplastic behavior, 0.186 N adhesion force and 0.386 adhesion energy. The results showed a high degree of cytocompatibility and the significant antioxidant and antimicrobial efficiency of SeNPsSb and Se-HNF.

Pharmacological and Chemical Analysis of Bauhinia divaricata L. Using an In Vitro Antiadipogenic Model

Obesity is characterized by an excessive and abnormal accumulation of fat. According to the 2022 National Health and Nutrition Survey, in Mexico, the prevalence of overweight and obesity-diagnosed if one's body mass index (BMI) was ≥25 kg/m2-in adults was 75.2%. A strong association between the amount of visceral fat and diseases such as diabetes mellitus type II has been recognized. Species of the Bauhinia genus have lipid-lowering and antidiabetic properties. The aim of this work was to evaluate the lipolytic and antiadipogenic activity of Bauhinia divaricata L. in 3T3-L1 cells and to identify the major compounds in the bioactive treatments. The extraction of aerial parts allowed us to obtain hexanic (BdHex), ethyl acetate (BdEAc), and hydroalcoholic (BdHA) extracts. Lipid levels were measured in 3T3-L1 cells differentiated into adipocytes. Our evaluation of cell viability identified an IC50 > 1000 μg/mL in all the extracts, and our evaluation of the antiadipogenic activity indicated that there was a significant reduction (p < 0.001) in the accumulation of lipids with hydroalcoholic (60%) and ethyl acetate (75%) extracts of B. divaricate compared with metformin at 30 mM (65%). The major compounds identified in these extracts were as follows: triacetin (1), 2,3-dihydroxypropyl acetate (2), (3E)-2-methyl-4-(1,3,3-trimethyl-7-oxabicyclo[4.1.0]hept-2-yl)-3-buten-2-ol (3), 2,5-dihydroxyphenylacetic acid (4), (3R)-3-hydroxydodecanoic acid (5), kaempferol-3-O-rhamnoside (6), and quercetin 3-O-rhamnoside (7). Some of these naturally occurring compounds have been related to the anti-obesity effects of other medicinal plants; therefore, these compounds isolated from B. divaricata could be responsible for inhibiting the differentiation process from preadipocytes to mature adipocytes.

Structural Similarities and Overlapping Activities among Dihydroflavonol 4-Reductase, Flavanone 4-Reductase, and Anthocyanidin Reductase Offer Metabolic Flexibility in the Flavonoid Pathway

Flavonoids are potent antioxidants that play a role in defense against pathogens, UV-radiation, and the detoxification of reactive oxygen species. Dihydroflavonol 4-reductase (DFR) and flavanone 4-reductase (FNR) reduce dihydroflavonols and flavanones, respectively, using NAD(P)H to produce flavan-(3)-4-(di)ols in flavonoid biosynthesis. Anthocyanidin reductase (ANR) reduces anthocyanidins to flavan-3-ols. In addition to their sequences, the 3D structures of recombinant DFR, FNR and ANR from sorghum and switchgrass showed a high level of similarity. The catalytic mechanism, substrate-specificity and key residues of three reductases were deduced from crystal structures, site-directed mutagenesis, molecular docking, kinetics, and thermodynamic ana-lyses. Although DFR displayed its highest activity against dihydroflavonols, it also showed activity against flavanones and anthocyanidins. It was inhibited by the flavonol quercetin and high concentrations of dihydroflavonols/flavonones. SbFNR1 and SbFNR2 did not show any activity against dihydroflavonols. However, SbFNR1 displayed activity against flavanones and ANR activity against two anthocyanidins, cyanidin and pelargonidin. Therefore, SbFNR1 and SbFNR2 could be specific ANR isozymes without delphinidin activity. Sorghum has high concentrations of 3-deoxyanthocyanidins in vivo, supporting the observed high activity of SbDFR against flavonols. Mining of expression data indicated substantial induction of these three reductase genes in both switchgrass and sorghum in response to biotic stress. Key signature sequences for proper DFR/ANR classification are proposed and could form the basis for future metabolic engineering of flavonoid metabolism.

Consideration for Flavonoid-Containing Dietary Supplements to Tackle Deficiency and Optimize Health

Randomized clinical trials (RCT) and observational studies have highlighted the importance of flavonoid consumption for human health. Several studies have associated a high intake of dietary flavonoids with (a) enhanced metabolic and cardiovascular health, (b) enhanced cognitive and vascular endothelial functions, (c) an improved glycemic response in type 2 diabetes mellitus, and (d) a reduced risk of breast cancer in postmenopausal women. Since flavonoids belong to a broad and diverse family of polyphenolic plant molecules-with more than 6000 compounds interspersed in the human diet-researchers are still uncertain whether the intake of single, individual polyphenols or a large combination of them (i.e., synergistic action) can produce the greatest health benefits for humans. Furthermore, studies have reported a poor bioavailability of flavonoid compounds in humans, which presents a major challenge for determining their optimal dosage, recommended intake, and, consequently, their therapeutic value. Especially because of their scarce bioavailability from foods-along with the overall declining food quality and nutrient density in foods-the role of flavonoid supplementation may become increasingly important for human health. Although research shows that dietary supplements can be a highly useful tool to complement diets that lack sufficient amounts of important nutrients, some caution is warranted regarding possible interactions with prescription and non-prescription drugs, especially when taken concurrently. Herein, we discuss the current scientific basis for using flavonoid supplementation to improve health as well as the limitations related to high intakes of dietary flavonoids.

Phytochemical Profile, Antioxidant, Antimicrobial, and Antidiabetic Activities of Ajuga iva (L.)

In Morocco, many applications in ethnomedicine on Ajuga iva (L.) have been recognized as able to treat various pathologies such as diabetes, stress, and microbial infections. The objective of this work is to carry out phytochemical, biological, and pharmacological investigations on the extracts of Ajuga iva leaves in order to confirm its therapeutic effects. The phytochemical screening carried out on the different extracts of Ajuga iva showed its richness in primary (lipids and proteins) and secondary metabolites (flavonoids, tannins, reducing compounds, oses, and holoside. The best contents of polyphenols, flavonoids, and tannins evaluated by spectrophotometric methods were found in the hydroethanolic extract (69.850 ± 2.783 mg EAG/g DE, 17.127 ± 0.474 mg EQ/g DE, 5.566 ± 0.000 mg EQC/g DE), respectively. Analysis of the chemical composition of the aqueous extract by LC/UV/MS revealed 32 polyphenolic compounds including ferulic acid (19.06%), quercetin (10.19%), coumaric acid (9.63%), and apigenin-7-(2-O-apiosylglucoside) (6.8%). The antioxidant activity of Ajuga iva extracts was evaluated by three methods (DPPH*, FRAP, CAT). The hydroethanolic extract recorded the strongest reducing power: DPPH* (IC₅₀ = 59.92 ± 0.7 µg/mL), FRAP (EC₅₀ = 196.85 ± 1.54 (µg/mL), and CAT (199.21 ± 0.37 mg EAG/gE). A strong correlation between phenolic compounds and antioxidant activities was confirmed by the determination of Pearson's coefficient. The antimicrobial activity of Ajuga iva studied by the microtiter method revealed potent antifungal and antibacterial qualities against Candida parapsilosis and Staphylococcus aureus BLACT. An in vivo oral glucose tolerance test (OGTT) using normal rats revealed that the antihyperglycemic action of the aqueous extract significantly reduced postprandial hyperglycaemia at (30 min, p < 0.01) and area under the curve (AUC glucose), p < 0.01. Similarly, the aqueous extract, tested on pancreatic α-amylase enzyme activity in vitro and in vivo significantly inhibited pancreatic α-amylase activity with IC₅₀ = 1.52 ± 0.03 mg/mL. In conclusion, the extract from Ajuga iva could be a good source of bioactive molecules, which exhibit potent antioxidant and antimicrobial activity, as well as strong antidiabetic activity, for applications in the pharmaceutical industry.

Bioprospecting phytochemicals of Rosmarinus officinalis L. for targeting SARS-CoV-2 main protease (Mpro): a computational study

CONTEXT

The persistent spread of highly contagious COVID-19 disease is one of the deadliest occurrences in the history of mankind. Despite the distribution of numerous efficacious vaccines and their extensive usage, the perpetual effectiveness of immunization is being catechized. Therefore, discovering an alternative therapy to control and prevent COVID-19 infections has become a top priority. The main protease (M^pro) plays a key role in viral replication, making it an intriguing pharmacological target for SARS-CoV-2.

METHODS

In this context, virtual screening of thirteen bioactive polyphenols and terpenoids of Rosmarinus officinalis L. was performed using several computational modules including molecular docking, ADMET, drug-likeness characteristics, and molecular dynamic simulation to predict the potential inhibitors against SARS-CoV-2 M^pro (PDB: 6LU7). The results suggest that apigenin, betulinic acid, luteolin, carnosol, and rosmarinic acid may emerge as potential inhibitors of SARS-CoV-2 with acceptable drug-likeness, pharmacokinetics, ADMET characteristics, and binding interactions comparable with remdesivir and favipiravir. These findings imply that some of the active components of Rosmarinus officinalis L. can serve as an effective antiviral source for the development of therapeutics for SARS-CoV-2 infection.

Inhibitory effect of quercetin-3-O-α-rhamnoside, p-coumaric acid, phloridzin and 4-O-β-glucopyranosyl-cis-coumaric acid on rats liver microsomes cytochrome P450 enzyme activities

P-coumaric acid, phloridzin, quercetin-3-O-α-rhamnoside and 4-O-β-glucopyranosyl-cis-coumaric acid isolated in Malus micromalus Makino fruit were investigated the inhibitory activity of cytochrome CYP450 enzyme by the probe test method of rat liver microsomes in vitro, and determined the role in drug metabolism and/or toxicology. Enzymatic kinetics method was used to determine the inhibition type of these components and corresponding inhibition constants. The results demonstrated that all the 4 compounds had no significance to inhibit the activities of CYP2E1 and CYP2C11. P-coumaric acid, phloridzin and quercetin-3-O-α-rhamnoside had a weak inhibitory effect on CYP3A4, which belonged to the competitive inhibitory type with inhibitory constants of 10.56, 30.79 and 40.29 μmol L-1, respectively. 4-O-β-glucopyranosyl-cis-coumaric acid had a moderate inhibitory effect on CYP3A4, which belonged to the anti-competitive inhibition type and the inhibition constant was 5.56 μmol L-1. The CYP1A2 could be weakly inhibited by p-coumaric acid in the competitive type, and the inhibition constant is 25.20 μmol L-1 4-O-β-glucopyranosyl-cis-coumaric acid exhibited anti-competitive inhibition of CYP1A2 with an inhibition constant of 19.91 μmol L-1, and the inhibition effect was weak. The results will be useful to optimize the clinical dosage regimen and avoid drug-drug interactions when it is utilized comminating with other medicines in the clinic.

Enhanced Bioavailability and Pharmacokinetics of a Natural Self-Emulsifying Reversible Hybrid-Hydrogel System of Quercetin: A Randomized Double-Blinded Comparative Crossover Study

Despite the vast array of health beneficial pharmacological effects, the bioavailability of the dietary flavonoid quercetin was found to be poor due to insolubility, incompatibility, and rapid biotransformation. Herein, we investigated the solubility, morphology, particle size, stability, in vitro release, and human pharmacokinetics of a hybrid-hydrogel formulation of quercetin (FQ-35) using fenugreek galactomannans as the hydrogel scaffold. Physicochemical characterization revealed that the crystalline quercetin was well encapsulated in the hydrogel matrix to form translucent microgel particles of FQ-35 with enhanced solubility (96-fold). The mean particle size was found to be 183.6 ± 42.7 nm with a zeta potential of 35.1 ± 3.8 mV. Pharmacokinetic investigation on healthy volunteers (N = 16) employing tandem mass spectrometric (ultra-performance liquid chromatography-electrospray tandem mass spectrometry) measurements of the concentration of free (unconjugated) and conjugated quercetin metabolites revealed an 18.6-fold improvement in free (unconjugated) quercetin bioavailability and 62-fold improvement in total quercetin (sum of free and conjugated) bioavailability, compared to the unformulated quercetin extracted from Sophora japonica. In summary, the natural self-emulsifying reversible hybrid-hydrogel delivery system was found to offer significant solubility, stability, and bioavailability of quercetin upon single-dose oral administration.

Quercetin Derivatives in Combating Spinal Cord Injury: A Mechanistic and Systematic Review

Spinal cord injury (SCI) possesses a complicated etiology. There is no FDA-approved treatment for SCI, and the majority of current interventions focus on reducing symptoms. During SCI, inflammation, oxidative stress, apoptosis, and autophagy are behind the secondary phase of SCI and cause serious consequences. It urges the need for providing multi-targeting agents, that possess lower side effects and higher efficacy. The plant secondary metabolites are multi-targeting agents and seem to provide new roads in combating diseases. Flavonoids are phytochemicals of continual interest to scientists in combating neurodegenerative diseases (NDDs). Flavonoids are being studied for their biological and pharmacological effects, particularly as antioxidants, anti-inflammatory agents, anti-apoptotic, and autophagy regulators. Quercetin is one of the most well-known flavonols known for its preventative and therapeutic properties. It is a naturally occurring bioactive flavonoid that has recently received a lot of attention for its beneficial effects on NDDs. Several preclinical evidence demonstrated its neuroprotective effects. In this systematic review, we aimed at providing the biological activities of quercetin and related derivatives against SCI. Detailed neuroprotective mechanisms of quercetin derivatives are also highlighted in combating SCI.

Quercetin Ameliorates Renal Injury and Pyroptosis in Lupus Nephritis through Inhibiting IL-33/ST2 Pathway In Vitro and In Vivo

Lupus nephritis (LN) is a common and serious symptom in patients with systemic lupus erythematosus (SLE). Tubular interstitial fibrosis is a common underlying mechanism in the development of lupus nephritis to end-stage renal failure (ESRD). Quercetin is widely proven to prevent tissue fibrosis. Therefore, the purpose of this study is to investigate the beneficial effects of quercetin on the inhibition of fibrosis and inflammation pathways in in vitro and in vivo lupus nephritis models. In the current study, MRL/lpr mice as animal models, and HK-2 human renal tubular epithelial cells were stimulated by interleukin-33 (IL-33) to mimic the cellular model of lupus nephritis. Immunohistochemical staining, immunoblotting assay, immunofluorescence staining, and quantitative real-time polymerase chain reaction assay were used. The in vivo results showed that quercetin improved the renal function and inhibited both fibrosis- and inflammation-related markers in MRL/lpr mice animal models. The in vitro results indicated that quercetin ameliorated the accumulation of fibrosis- and inflammation-related proteins in IL-33-induced HK-2 cells and improved renal cell pyroptosis via the IL33/ST2 pathway. Overall, quercetin can improve LN-related renal fibrosis and inflammation, which may offer an effective potential therapeutic strategy for lupus nephritis.

Polyphenols as Potent Epigenetics Agents for Cancer

Human diseases such as cancer can be caused by aberrant epigenetic regulation. Polyphenols play a major role in mammalian epigenome regulation through mechanisms and proteins that remodel chromatin. In fruits, seeds, and vegetables, as well as food supplements, polyphenols are found. Compounds such as these ones are powerful anticancer agents and antioxidants. Gallic acid, kaempferol, curcumin, quercetin, and resveratrol, among others, have potent anti-tumor effects by helping reverse epigenetic changes associated with oncogene activation and tumor suppressor gene inactivation. The role dietary polyphenols plays in restoring epigenetic alterations in cancer cells with a particular focus on DNA methylation and histone modifications was summarized. We also discussed how these natural compounds modulate gene expression at the epigenetic level and described their molecular targets in cancer. It highlights the potential of polyphenols as an alternative therapeutic approach in cancer since they modulate epigenetic activity.

Targeting Oxidative Stress in Intracerebral Hemorrhage: Prospects of the Natural Products Approach

Intracerebral hemorrhage (ICH), the second most common subtype of stroke, remains a significant cause of morbidity and mortality worldwide. The pathological mechanism of ICH is very complex, and it has been demonstrated that oxidative stress (OS) plays an important role in the pathogenesis of ICH. Previous studies have shown that OS is a therapeutic target after ICH, and antioxidants have also achieved some benefits in the treatment of ICH. This review aimed to explore the promise of natural products therapy to target OS in ICH. We searched PubMed using the keywords “oxidative stress in intracerebral hemorrhage” and “natural products in intracerebral hemorrhage”. Numerous animal and cell studies on ICH have demonstrated the potent antioxidant properties of natural products, including polyphenols and phenolic compounds, terpenoids, alkaloids, etc. In summary, natural products such as antioxidants offer the possibility of treatment of OS after ICH. However, researchers still have a long way to go to apply these natural products for the treatment of ICH more widely in the clinic.

Effect of Dietary Polyphenols on Osteoarthritis—Molecular Mechanisms

Osteoarthritis is a common crippling and degenerative disease resulting in irreversible functional changes due to damage of the cartilage and other tissues of the joint. With limited safe and effective pharmaceutical treatments, the demand and use for alternative therapeutic approaches with symptomatic relief for OA patients have increased. Clinical, pre-clinical, and in vitro studies have demonstrated that polyphenols can exert pain-relieving symptoms coupled with increased functional capacity in OA models. This review will highlight studies carried out in the last five years to define the efficacies and underlying mechanisms in polyphenols such as quercetin, resveratrol, curcumin, epigallocatechin-3-gallate, rosmarinic acid, genistein, ginger, berries, silver fir, pine bark, and Boswellia. Most of these studies indicate that polyphenols exhibit their beneficial roles through regulating changes at the biochemical and molecular levels, inducing or inhibiting various signaling pathways related to inflammation and oxidative stress. Polyphenols have also been implicated in modulating microRNA at the posttranscriptional level to counteract OA pathogenesis.