Myricetin: A Dietary Molecule with Diverse Biological Activities

Impact of nutraceuticals on immunomodulation against viral infections-A review during COVID-19 pandemic in Indian scenario

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China, in early December 2019 is a censorious global emergency after World War II. Research on the coronavirus uncovered essential information that aided in the development of the vaccine, and specific coronavirus disease 2019 (COVID-19) vaccines were later developed and were approved for usage in humans. But then, mutations in the coronavirus gave rise to new variants and questioned the vaccine's efficacy against them. On the other hand, the investigation of traditional medicine was also on its path to find a novel outcome against COVID-19. On a comparative analysis between India and the United States, India had low death rate and high recovery rate than the latter. The dietary regulation of immunity may be the factor that makes the above difference. The immunity gained from the regular diet of Indian culture nourishes Indian people with essential phytochemicals that support immunity and metabolism. Dietary phytochemicals or nutraceuticals possess antioxidant, anti-inflammatory, and anticancer properties, out of which our concern will be on immune-boosting phytochemicals from our daily nutritional supplements. In several case studies, dietary substance like lemon, ginger, and spinach was reported in the recovery of COVID-19 patients. Thus in this review, we discuss coronavirus and its available variants, vaccines, and the effect of nutraceuticals against the coronavirus. Further, we denote that the immunity of the Indian population may be high because of their diet, which adds natural phytochemicals to boost their immunity and metabolism.

Novel Antioxidant Insights of Myricetin on the Performance of Broiler Chickens and Alleviating Experimental Infection with Eimeria spp.: Crosstalk between Oxidative Stress and Inflammation

In the modern poultry industry, the application of novel phytogenic bioactive compounds with antioxidant potential aims to enhance productivity and quality and to minimize the stress of associated diseases. Herein, myricetin, a natural flavonoid, was evaluated for the first time on broiler chickens' performance, antioxidants and immune modulating functions, and tackling avian coccidiosis. A total of 500 one-day-old chicks were divided into five groups. The negative (NC) and infected control (IC) groups were fed a control diet without additives, and the latter was infected with Eimeria spp. Groups supplemented with myricetin (Myc) were fed a control diet of Myc (200, 400 and 600 mg/kg diet each). On d 14, all chicks except those in NC were challenged with oocysts of mixed Eimeria spp. Significant improvements in the overall growth rate and feed conversion ratio were detected in the group that was fed 600 mg/kg, unlike the IC group. Notably, groups that were fed 400 and 600 mg/kg showed higher total meat antioxidant capacity with an inverse reduction in oxidative and lipid peroxidation biomarkers (hydrogen peroxide: H₂O₂; reactive oxygen species: ROS; Malondialdehyde: MDA). Of note, the upregulation of glutathione peroxidase; GSH-Px, catalase; CAT, superoxide dismutase; SOD, heme oxygenase-1; HO-1 and NAD(P)H dehydrogenase quinone 1 NQO1 genes in jejunum and muscle were prominently observed with increasing levels of supplemental Myc. At 21 dpi, the severity of coccoidal lesions (p < 0.05) induced by mixed Eimeria spp. and oocyst excretion were greatly reduced in the group that was fed 600 mg/kg of Myc. In the IC group, higher serum levels of C-reactive protein; CRP and nitric oxide; and NO and the upregulated expression of inflammatory biomarkers (interleukin-1β; IL-1β, interleukin-6; IL-6, tumor necrosis factor-α; TNF-α, chemotactic cytokines; CCL20, stromal cell-derived factor-1; CXCL13, and avian defensins; AvBD612) were subsided in higher levels in the Myc-fed groups. Taken together, these findings indicate the promising antioxidant role of Myc in modulating immune responses and reducing growth depression associated with coccidia challenges.

In Vitro and In Silico Protocols for the Assessment of Anti-Tick Compounds from Pinus roxburghii against Rhipicephalus (Boophilus) microplus Ticks

Pinus roxburghii, also known by the name "Himalayan chir pine," belongs to the Pinaceae family. Rhipicephalus (Boophilus) microplus tick is one of the most significant bovine ectoparasites, making it a major vector of economically important tick-borne diseases. The researchers conducted adult immersion tests (AIT) and larval packet tests (LPT) to investigate the acaricidal effect of P. roxburghii plant extract on R. (B.) microplus and its potential modulatory function when used with cypermethrin. Eggs were also assessed for their weight, egg-laying index (IE), hatchability rate, and control rate. After exposure to essential extract concentrations ranging from 2.5 to 40 mg/mL for 48 h, adult female ticks' oviposition inhibition and unfed R. (B.) microplus larvae's mortality rates were analyzed. Engorged females exposed to P. roxburghii at 40 mg/mL had reduced biological activity (oviposition, IE) compared to positive and negative controls. A concentration of 40 mg/mL of P. roxburghii caused 90% mortality in R. (B.) microplus larvae, whereas cypermethrin (the positive control) caused 98.3% mortality in LPT. In AIT, cypermethrin inhibited 81% of oviposition, compared to the 40 mg/mL concentration of P. roxburghii, which inhibited 40% of the ticks' oviposition. Moreover, this study assessed the binding capacity of selected phytocompounds with the targeted protein. Three servers (SWISS-MODEL, RoseTTAFold, and TrRosetta) recreated the target protein RmGABACl's 3D structure. The modeled 3D structure was validated using the online servers PROCHECK, ERRAT, and Prosa. Molecular docking using Auto Dock VINA predicted the binding mechanisms of 20 drug-like compounds against the target protein. Catechin and myricetin showed significant interactions with active site residues of the target protein, with docking scores of -7.7 kcal/mol and -7.6 kcal/mol, respectively. In conclusion, this study demonstrated the acaricidal activity of P. roxburghii extract, suggesting its potential as an alternative natural acaricide for controlling R. (B.) microplus.

The convergent application of metabolites from Avena sativa and gut microbiota to ameliorate non-alcoholic fatty liver disease: a network pharmacology study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a serious public health issue globally, currently, the treatment of NAFLD lies still in the labyrinth. In the inchoate stage, the combinatorial application of food regimen and favorable gut microbiota (GM) are considered as an alternative therapeutic. Accordingly, we integrated secondary metabolites (SMs) from GM and Avena sativa (AS) known as potent dietary grain to identify the combinatorial efficacy through network pharmacology.

METHODS

We browsed the SMs of AS via Natural Product Activity & Species Source (NPASS) database and SMs of GM were retrieved by gutMGene database. Then, specific intersecting targets were identified from targets related to SMs of AS and GM. The final targets were selected on NAFLD-related targets, which was considered as crucial targets. The protein-protein interaction (PPI) networks and bubble chart analysis to identify a hub target and a key signaling pathway were conducted, respectively. In parallel, we analyzed the relationship of GM or AS─a key signaling pathway─targets─SMs (GASTM) by merging the five components via RPackage. We identified key SMs on a key signaling pathway via molecular docking assay (MDA). Finally, the identified key SMs were verified the physicochemical properties and toxicity in silico platform.

RESULTS

The final 16 targets were regarded as critical proteins against NAFLD, and Vascular Endothelial Growth Factor A (VEGFA) was a key target in PPI network analysis. The PI3K-Akt signaling pathway was the uppermost mechanism associated with VEGFA as an antagonistic mode. GASTM networks represented 122 nodes (60 GM, AS, PI3K-Akt signaling pathway, 4 targets, and 56 SMs) and 154 edges. The VEGFA-myricetin, or quercetin, GSK3B-myricetin, IL2-diosgenin complexes formed the most stable conformation, the three ligands were derived from GM. Conversely, NR4A1-vestitol formed stable conformation with the highest affinity, and the vestitol was obtained from AS. The given four SMs were no hurdles to develop into drugs devoid of its toxicity.

CONCLUSION

In conclusion, we show that combinatorial application of AS and GM might be exerted to the potent synergistic effects against NAFLD, dampening PI3K-Akt signaling pathway. This work provides the importance of dietary strategy and beneficial GM on NAFLD, a data mining basis for further explicating the SMs and pharmacological mechanisms of combinatorial application (AS and GM) against NAFLD.

Phenolic Biotransformations in Wheatgrass Juice after Primary and Secondary Fermentation

Fermented wheatgrass juice was prepared using a two-stage fermentation process by employing Saccharomyces cerevisiae and recombinant Pediococcus acidilactici BD16 (alaD⁺). During fermentation, a reddish-brown hue appeared in wheatgrass juice due to production of different types of red pigments. The fermented wheatgrass juice has considerably higher content of anthocyanins, total phenols and beta-carotenes as compared to unfermented wheatgrass juice. It has low ethanol content, which might be ascribed to the presence of certain phytolignans in wheatgrass juice. Several yeast-mediated phenolic transformations (such as bioconversion of coumaric acid, hydroxybenzoic acid, hydroxycinnamic acid and quinic acid into respective derivatives; glycosylation and prenylation of flavonoids; glycosylation of lignans; sulphonation of phenols; synthesis of carotenoids, diarylnonanoids, flavanones, stilbenes, steroids, quinolones, di- and tri-terpenoids and tannin) were identified in fermented wheatgrass juice using an untargeted liquid chromatography (LC)-mass spectrometry (MS)-matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF)/time-of-flight (TOF) technique. The recombinant P. acidilactici BD16 (alaD⁺) also supported flavonoid and lignin glycosylation; benzoic acid, hydroxycoumaric acid and quinic acid derivatization; and synthesis of anthraquinones, sterols and triterpenes with therapeutic benefits. The information presented in this manuscript may be utilized to elucidate the importance of Saccharomyces cerevisiae and P. acidilactici BD16 (alaD⁺) mediated phenolic biotransformations in developing functional food supplements such as fermented wheatgrass juice.

Flavonols in Action: Targeting Oxidative Stress and Neuroinflammation in Major Depressive Disorder

Major depressive disorder is one of the most common mental illnesses that highly impairs quality of life. Pharmacological interventions are mainly focused on altered monoamine neurotransmission, which is considered the primary event underlying the disease's etiology. However, many other neuropathological mechanisms that contribute to the disease's progression and clinical symptoms have been identified. These include oxidative stress, neuroinflammation, hippocampal atrophy, reduced synaptic plasticity and neurogenesis, the depletion of neurotrophic factors, and the dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis. Current therapeutic options are often unsatisfactory and associated with adverse effects. This review highlights the most relevant findings concerning the role of flavonols, a ubiquitous class of flavonoids in the human diet, as potential antidepressant agents. In general, flavonols are considered to be both an effective and safe therapeutic option in the management of depression, which is largely based on their prominent antioxidative and anti-inflammatory effects. Moreover, preclinical studies have provided evidence that they are capable of restoring the neuroendocrine control of the HPA axis, promoting neurogenesis, and alleviating depressive-like behavior. Although these findings are promising, they are still far from being implemented in clinical practice. Hence, further studies are needed to more comprehensively evaluate the potential of flavonols with respect to the improvement of clinical signs of depression.

Engineered production of bioactive polyphenolic O-glycosides

Polyphenolic compounds (such as quercetin and resveratrol) possess potential medicinal values due to their various bioactivities, but poor water solubility hinders their health benefits to humankind. Glycosylation is a well-known post-modification method to biosynthesize natural product glycosides with improved hydrophilicity. Glycosylation has profound effects on decreasing toxicity, increasing bioavailability and stability, together with changing bioactivity of polyphenolic compounds. Therefore, polyphenolic glycosides can be used as food additives, therapeutics, and nutraceuticals. Engineered biosynthesis provides an environmentally friendly and cost-effective approach to generate polyphenolic glycosides through the use of various glycosyltransferases (GTs) and sugar biosynthetic enzymes. GTs transfer the sugar moieties from nucleotide-activated diphosphate sugar (NDP-sugar) donors to sugar acceptors such as polyphenolic compounds. In this review, we systematically review and summarize the representative polyphenolic O-glycosides with various bioactivities and their engineered biosynthesis in microbes with different biotechnological strategies. We also review the major routes towards NDP-sugar formation in microbes, which is significant for producing unusual or novel glycosides. Finally, we discuss the trends in NDP-sugar based glycosylation research to promote the development of prodrugs that positively impact human health and wellness.

Synthesis and physicochemical characterization of acyl myricetins as potential anti-neuroexocytotic agents

Acyl myricetins (monopropionyl-, dipropionyl-, and monooctanoyl-myricetin, termed as MP₁, MP₂, and MO₁, respectively) were synthesized through enzymatic or non-enzymatic esterification reaction of myricetin aglycone. Structure study indicated the hydroxyl group at C4' in B-ring was highly susceptible to acylation. Over its parental myricetin, acylated compounds showed enhanced lipophilicity (from 7.4- to 26.3-fold) and oxidative stability (from 1.9- to 3.1-fold) on the basis of logP and decay rate, respectively. MO₁, presenting the physicochemical superiority compared to the others, provided lowest EC₅₀ value of 2.51 μM on inhibition of neutrotransmitter release and CC₅₀ value of 59.0 μM, leading to widest therapeutic window. All myricetin esters did not show any irritation toxicity when assessed with a chicken embryo assay. This study describes information on acylation of myricetin that has not yet been explored, and suggests that MO₁ has membrane fusion-arresting and anti-neuroexocytotic potential for industrial application due to its enhanced biological properties.

Antimicrobial potential of myricetin-coated zinc oxide nanocomposite against drug-resistant Clostridium perfringens

BACKGROUND

Clostridium perfringens (C. perfringens) is an important pathogen in livestock animals and humans causing a wide array of systemic and enteric diseases. The current study was performed to investigate the inhibitory activity of myricetin (MYR), polyvinyl alcohol (PVA), and zinc oxide (ZnO) nanocomposite against growth and α-hemolysin of C. perfringens isolated from beef meat and chicken sources.

RESULTS

The overall occurrence of C. perfringens was 29.8%. The prevalence of C. perfringens was higher in chicken (38.3%) than in beef meat products (10%). The antimicrobial susceptibility testing revealed that C. perfringens isolates exhibited high resistance levels for metronidazole (93%), bacitracin (89%), penicillin G (84%), and lincomycin (76%). Of note, 1% of C. perfringens isolates were pandrug-resistant (PDR), 4% were extensive drug-resistant (XDR), while 91% were multidrug-resistant. The results of broth microdilution technique revealed that all tested C. perfringens isolates were susceptible to MYR-loaded ZnO/PVA with minimum inhibitory concentrations (MICs) ranged from 0.125 to 2 µg/mL. Moreover, the MYR either alone or combined with the nanocomposite had no cytotoxic activities on chicken red blood cells (cRBCs). Transcriptional modifications of MYR, ZnO, ZnO/PVA, and ZnO/PVA/MYR nanocomposite were determined, and the results showed significant down-regulation of α-hemolysin fold change to 0.5, 0.7, 0.6, and 0.28, respectively compared to the untreated bacteria.

CONCLUSION

This is an in vitro study reporting the antimicrobial potential of MYR-coated ZnO nanocomposite as an effective therapeutic candidate against C. perfringens. An in vivo approach is the next step to provide evidence for applying these alternatives in the treatment and prevention of C. perfringens-associated diseases.

Efficacy of Two Moroccan Cistus Species Extracts against Acne Vulgaris: Phytochemical Profile, Antioxidant, Anti-Inflammatory and Antimicrobial Activities

BACKGROUND

The genus Cistus L. (Cistaceae) includes several medicinal plants growing wild in the Moroccan area. Acne vulgaris (AV) is a chronic skin disorder treated with topical and systemic therapies that often lead to several side effects in addition to the development of antimicrobial resistance. Our study aimed to investigate the bioactivity of extracts of two Moroccan Cistus species, Cistus laurifolius L. and Cistus salviifolius L., in view of their use as potential coadjuvants in the treatment of mild acne vulgaris.

METHODS

Targeted phytochemical profiles obtained by HPLC-DAD and HPLC-ESI/MS analyses and biological activities ascertained by several antioxidants in vitro chemical and cell-based assays of the leaf extracts. Moreover, antimicrobial activity against Gram-positive and Gram-negative bacteria, and Candida albicans was evaluated.

RESULTS

Analyses revealed the presence of several polyphenols in the studied extracts, mainly flavonoids and tannins. Cistus laurifolius L. and Cistus salviifolius L. possessed good biological properties and all extracts showed antibacterial activity, particularly against Staphylococcus aureus, S. epidermidis, and Propionibacterium acnes, identified as the main acne-causing bacteria.

CONCLUSION

The results suggest that examined extracts are promising agents worthy of further studies to develop coadjuvants/natural remedies for mild acne treatment.

Separation of flavonoids with significant biological activity from Acacia mearnsii leaves

Acacia mearnsii leaves, which are a rich source of flavonoids, were used to separate and purify myricitrin (W3) and myricetin-3-O-glucoside (W1). Further, the antioxidant and hypoglycemic activities of the two purified flavonoids were evaluated. The flavonoids were separated using solvent partition, macroporous adsorbent resin column, and Sephadex column chromatography, and purified using preparative reverse-phase high-performance liquid chromatography (HPLC). The purified flavonoids were characterized using HPLC, mass spectrometry, and nuclear magnetic resonance methods. A high yield (7.3 mg g-1 of crude extract) of W3 was obtained, with a high purity of 98.4%. Furthermore, the purity of W1 was over 95%. W1 and W3 showed strong antioxidant activity and significantly inhibited α-glucosidase. W3 also demonstrated substantial α-amylase inhibitory capacity. This study indicated that A. mearnsii leaves, which are discarded in significant amounts, can be used as a source of myricitrin, thus providing more adequate material for the production of antioxidants and type II diabetes inhibitors. Hence, A. mearnsii leaves have the potential to create great market economic value and environmental benefits.

A Study on the Interactions of Proteinase K with Myricetin and Myricitrin by Multi-Spectroscopy and Molecular Modeling

Myricetin (MYR) and myricitrin (MYT) are well recognized for their nutraceutical value, such as antioxidant, hypoglycemic, and hypotensive effects. In this work, fluorescence spectroscopy and molecular modeling were adopted to investigate the conformational and stability changes of proteinase K (PK) in the presence of MYR and MYT. The experimental results showed that both MYR and MYT could quench fluorescence emission via a static quenching mechanism. Further investigation demonstrated that both hydrogen bonding and van der Waals forces play significant roles in the binding of complexes, which is consistent with the conclusions of molecular modeling. Synchronous fluorescence spectroscopy, Förster resonance energy transfer, and site-tagged competition experiments were performed to prove that the binding of MYR or MYT to PK could alter its micro-environment and conformation. Molecular docking results revealed that either MYR or MYT spontaneously interacted with PK at a single binding site via hydrogen bonding and hydrophobic interactions, which is consistent with the results of spectroscopic measurements. A 30 ns molecular dynamics simulation was conducted for both PK-MYR and PK-MYT complexes. The calculation results showed that no large structural distortions or interaction changes occurred during the entire simulation time span. The average RMSD changes of PK in PK-MYR and PK-MYT were 2.06 and 2.15 Å, respectively, indicating excellent stability of both complexes. The molecular simulation results suggested that both MYR and MYT could interact with PK spontaneously, which is in agreement with spectroscopic results. This agreement between experimental and theoretical results indicates that the method herein could be feasible and worthwhile for protein–ligand complex studies.

Myricetin Nanofibers Enhanced Water Solubility and Skin Penetration for Increasing Antioxidant and Photoprotective Activities

Excessive exposure to ultraviolet radiation (UV) can induce oxidative stress through the over-production of reactive oxygen species (ROS) on the skin. Myricetin (MYR), a natural flavonoid compound, significantly inhibited UV-induced keratinocyte damage; however, its bioavailability is limited by its poor water solubility and inefficient skin penetration ability, which subsequently influences its biological activity. The purpose of the study was to develop a myricetin nanofibers (MyNF) system of hydroxypropyl-β-cyclodextrin (HPBCD)/polyvinylpyrrolidone K120 (PVP)-loaded with MYR that would enhance the water solubility and skin penetration by changing the physicochemical characteristics of MYR, including reducing the particle size, increasing the specific surface area, and amorphous transformation. The results also revealed that the MyNF can reduce cytotoxicity in HaCaT keratinocytes when compared with MYR; additionally, MyNF had better antioxidant and photoprotective activity than raw MYR for the UVB-induced HaCaT keratinocytes damage model due to the MyNF increased water solubility and permeability. In conclusion, our results demonstrate that MyNF is a safe, photostable, and thermostable topical ingredient of antioxidant nanofibers to enhance the skin penetration of MYR and prevent UVB-induced skin damage.

Identification of MAP Kinase Kinase 3 as a protein target of myricetin in non-small cell lung cancer cells

Myricetin is a typical flavonol with various pharmacological effects which shows favorable biological activities in cancer. However, the underlying mechanisms and potential targets of myricetin in NSCLC (non-small cell lung cancer) cells remain unclear. First, we demonstrated that myricetin not only inhibited the proliferation, migration and invasion, but also induced apoptosis in A549 and H1299 cells in a dose-dependent manner. Then, we confirmed myricetin may play an anti-NSCLC effect through modulating MAPK-related functions and signaling pathway by Network pharmacology. Furthermore, MKK3 (MAP Kinase Kinase 3) was identified and confirmed as a potential target of myricetin by biolayer interferometry (BLI) and molecular docking, revealing that myricetin directly bound to MKK3. Moreover, three mutations (D208, L240, and Y245) of key amino acids predicted by molecular docking obviously decreased the affinity between myricetin and MKK3. Finally, enzyme activity assay was utilized to determine the effect of myricetin on MKK3 activity in vitro, and the result showed that myricetin attenuated MKK3 activity. Subsequently, myricetin decreased the phosphorylation of p38 MAPK. Furthermore, knockdown of MKK3 reduced the susceptibility of A549 and H1299 cells to myricetin. These results suggested that myricetin inhibited the growth of NSCLC cells via targeting MKK3 and influencing the downstream p38 MAPK signaling pathway. The findings revealed that MKK3 is a potential target of myricetin in the NSCLC and myricetin is considered to be a small-molecular inhibitor of MKK3, which can improve comprehension of the molecular mechanisms of myricetin pharmacological effects in cancer and further development of MKK3 inhibitors.

Myricetin improves apoptosis after ischemic stroke via inhibiting MAPK-ERK pathway

BACKGROUND

Neuronal apoptosis is the main cause for the disabilities and deaths of patients suffered with stroke. Neuroprotectants are clinically used to reduce neuronal apoptosis in ischemic stroke. However, the current neuroprotectants have multiple limitations. Myricetin is beneficial for multiple neurodegenerative diseases, but the role of myricetin as a neuroprotective agent in ischemic stroke is still not fully understood.

METHODS AND RESULTS

Middle cerebral artery occlusion, Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining and Western blots were used to explore the anti-apoptotic effects of myricetin in vivo. Flow cytometry, Western blots and Ca²⁺ staining were used to study the neuroprotective effects of myricetin in vitro. In this study, we first demonstrated that myricetin reduced neuronal apoptosis after ischemia in vivo and in vitro. And, among the factors of apoptosis after ischemic stroke, excitotoxicity, oxidative stress and inflammation-induced apoptosis can be alleviated by myricetin. Moreover, we further demonstrated that myricetin was able to improve neuronal intrinsic apoptosis by inhibiting the phosphorylation of extracellular signal-regulated kinase in the oxygen and glucose deprivation in vitro.

CONCLUSIONS

Summarily, our results support myricetin as a novel neuroprotectant for the prevention or treatment of ischemic stroke via MAPK-ERK signaling pathway.

Exploring the interaction of myricetin with human alpha-2-macroglobulin: biophysical and in-silico analysis

Myricetin (MYR) is a bioactive secondary metabolite found in plants that is recognized for its nutraceutical value and is an essential constituent of various foods and beverages. It is reported to exhibit a plethora of activities, including antioxidant, antimicrobial, antidiabetic, anticancer, and anti-inflammatory. Alpha-2-macroglobulin (α2M) is a major plasma anti-proteinase that can inhibit proteinases of both human and non-human origin, regardless of their specificity and catalytic mechanism. Here, we explored the interaction of MYR-α2M using various biochemical and biophysical techniques. It was found that the interaction of MYR brings subtle change in its anti-proteolytic potential and thereby alters its structure and function, as can be seen from absorbance and fluorescence spectroscopy. UV spectroscopy of α2M in presence of MYR indicated the occurrence of hyperchromism, suggesting complex formation. Fluorescence spectroscopy reveals that MYR reduces the fluorescence intensity of native α2M with a shift in the wavelength maxima. At 318.15 K, MYR binds to α2M with a binding constant of 2.4 × 10³ M^-1, which indicates significant binding. The ΔG value was found to be - 7.56 kcal mol^-1 at 298.15 K, suggesting the interaction to be spontaneous and thermodynamically favorable. The secondary structure of α2M does not involve any major change as was confirmed by CD analysis. The molecular docking indicates that Asp-146, Ser-172, Glu-174, and Tyr-180 were the key residues involved in α2M-MYR complex formation. This study contributes to our understanding of the function and mechanism of protein and flavonoid binding by providing a molecular basis of the interaction between MYR and α2M.

Myricetin treatment has ameliorative effects in DNFB-induced atopic dermatitis mice under high-fat conditions

Atopic dermatitis (AD) is a chronic, inflammatory cutaneous disorder. Obesity is associated with increased prevalence and severity of AD for reasons that remain poorly understood. Myricetin, a dietary flavonoid found in fruits and vegetables, is known to have anti-inflammatory effects, but its role in AD is unclear. Thus, we investigated the effects of obesity on exacerbation AD lesions and evaluated the effects of myricetin on obese AD. Mice were fed normal diet (ND) or high-fat diet, and then 2,4-dinitrofluorobenzene was used to induce AD-like lesions. We found that obesity exacerbated AD lesions, and myricetin topical administration ameliorated symptoms and skin lesions of obsess AD mice, such as dermatitis scores, scratching behavior, epidermal thickness, and mast cell infiltration. In addition, myricetin reduced the levels of immunoglobulin E and histamine, inhibited the infiltration of CD4+T cells, and modulated the expression of Th1, Th2, Th17, and Th22 cytokines and pro-inflammatory factors (CCL17, CCL22, IL-1β, and TGF-β). Moreover, myricetin restored impaired barrier function by reducing transepidermal water loss, increasing lamellar body secretion, as well as upregulating the mRNA and protein expression of filaggrin. Western blot results showed that significantly increased levels of phosphorylated IκB and NF-κB p65 was observed in the obese AD mice compared with the AD mice fed ND, whereas the myricetin could downregulated the phosphorylations of IκB and NF-κB, and inhibited mRNA expression of iNOS and COX2. Taken together, our results suggest that myricetin treatment exhibits potentially protective effects against the obeseassociated AD by inhibiting inflammatory response and restoring skin barrier function.

Dihydromyricetin supplementation during in vitro culture improves porcine oocyte developmental competence by regulating oxidative stress

Dihydromyricetin (DHM), a dihydroflavonoid compound, exhibits a variety of biological activities, including antitumor activity. However, the effects of DHM on mammalian reproductive processes, especially during early embryonic development, remain unclear. In this study, we added DHM to porcine zygotic medium to explore the influence and underlying mechanisms of DHM on the developmental competence of parthenogenetically activated porcine embryos. Supplementation with 5 μM DHM during in vitro culture (IVC) significantly improved blastocyst formation rate and increased the total number of cells in porcine embryos. Further, DHM supplementation also improved glutathione levels and mitochondrial membrane potential; reduced natural reactive oxygen species levels in blastomeres and apoptosis rate; upregulated Nanog, Oct4, SOD1, SOD2, Sirt1, and Bcl2 expression; and downregulated Beclin1, ATG12, and Bax expression. Collectively, DHM supplementation regulated oxidative stress during IVC and could act as a potential antioxidant during in vitro porcine oocytes maturation.

Myricetin derivative-rich fraction from Syzygium malaccense prevents high-fat diet-induced obesity, glucose intolerance and oxidative stress in C57BL/6J mice

AIM

A high-fat diet (HFD) can lead to obesity and related metabolic disorders. This study evaluated the preventive efficacy of myricetin derivative-rich fraction (MD) from Syzygium malaccense leaf extract against HFD-induced obesity, hyperglycaemia, and oxidative stress in C57BL/6J mice.

METHODS

HFD-fed mice were administered MD (50 mg/kg, 100 mg/kg, and 150 mg/kg) or 2 mg/kg metformin (positive control) orally for 16 weeks. Normal diet and HFD-fed control groups received normal saline.

RESULTS

MD dose of 50 mg/kg was better than 100 mg/kg and 150 mg/kg in significantly reducing weight-gain, glucose intolerance, insulin resistance, lipid accumulation in liver and kidney, and improving the serum lipid profile. Lowered protein carbonyls and lipid hydroperoxides in urine and tissue homogenates and elevated reduced glutathione, ferric reducing antioxidant power (FRAP), and Trolox equivalent antioxidant capacity (TEAC) levels in tissue homogenates indicated amelioration of oxidative stress.

CONCLUSION

MD has therapeutic value in the prevention and management of obesity, hyperglycaemia, and oxidative stress.

Dietary Corn Silk (Stigma maydis) Extract Supplementation Modulate Production Performance, Immune Response and Redox Balance in Corticosterone-Induced Oxidative Stress Broilers

Immunosuppression is a serious consequence of oxidative stress exposure that negatively affects the productivity and profitability of birds, as well as their well-being. Thus, the present investigation was designed to evaluate the potential of corn silk extract (CSE) supplementation to overcome the negative impacts of oxidative stress induced by corticosterone administration (CORT) in broiler chickens. A total of 280 one day old Cobb 500 male chicks were divided into four groups in 2 × 2 factorial arrangements. The experimental groups included CSE supplementation (0 or 500 mg/kg diet, from 20 to 35 days of age) and CORT administration (0 or 25 mg/kg diet, from 22 to 35 days of age) as independent factors. At the end of week five of age, production performance parameters were measured. The humoral and cell-mediated immune response parameters, redox status, and stress markers were determined. Data revealed deleterious effects of CORT administration on the broilers' body weight, body weight gain, and feed conversion ratio. Moreover, an exponential increase in stress marker levels, in addition to immunosuppression and redox imbalance, were associated with CORT administration. However, CSE supplementation, with its high total phenols content, partially alleviated the negative impacts of CORT administration, as shown by a significant improvement in immune response parameters and antioxidant activity, as well as a reduction in stress marker levels. Furthermore, CSE supplementation to non-stressed birds even significantly improved total antioxidant activity, total white blood cells (TWBCs) count, T-lymphocyte stimulating index, and wattle thickness. It can be concluded that, under stress conditions in commercial broiler farms, dietary CSE supplementation can strongly be recommended to modulate the negative impacts of stress. Therefore, CSE can be used as an effective immunomodulator and antioxidant agent to increase commercial broiler farm productivity and profitability.

The Effect of Selected Flavonoids and Lipoic Acid on Natural and Model Cell Membranes: Langmuir and Microelectrophoretic Methods

The influence of kaempferol (K), myricetin (M) and lipoic acid (LA) on the properties of natural erythrocytes, isolated from animal blood and biological membrane models (monolayers and liposomes) made of phosphatidylcholine (PC), cholesterol (CHOL), and sphingomyelin (SM), CHOL in a ratio of 10:9, was investigated. The Langmuir method, Brewster angle microscopy (BAM) and microelectrophoresis were used. The presented results showed that modification of liposomes with kaempferol, myricetin and lipoic acid caused changes in the surface charge density and the isoelectric point value. Comparing the tested systems, several conclusions were made. (1) The isoelectric point for the DPPC:Chol:M (~2.2) had lower pH values compared to lipoic acid (pH~2.5) and kaempferol (pH~2.6). (2) The isoelectric point for the SM-Chol with myricetin (~3.0) had lower pH values compared to kaempferol (pH~3.4) and lipoic acid (pH~4.7). (3) The surface charge density values for the DPPC:Chol:M system in the range of pH 2-9 showed values from 0.2 to -2.5 × 10^-2 C m^-2. Meanwhile, for the DPPC:Chol:K and DPPC:Chol:LA systems, these values were higher at pH~2 (0.7 × 10^-2 C m^-2 and 0.8 × 10^-2 C m^-2) and lower at pH~9 (-2.1 × 10^-2 C m^-2 and -1.8 × 10^-2 C m^-2), respectively. (4) The surface charge density values for the SM:Chol:M system in the range of pH 2-9 showed values from 0.5 to -2.3 × 10^-2 C m^-2. Meanwhile, for the DPPC:Chol:K and DPPC:Chol:LA systems, these values were higher at pH~2 (0.8 × 10^-2 C m^-2), and lower at pH~9 (-1.0 × 10^-2 C m^-2 and -1.8 × 10^-2 C m^-2), respectively. (5) The surface charge density values for the erythrocytes with myricetin in the range of pH 2-9 showed values from 1.0 to -1.8 × 10^-2 C m^-2. Meanwhile, for the erythrocytes:K and erythrocytes:LA systems, these values, at pH~2, were 1.3 × 10^-2 C m^-2 and 0.8 × 10^-2 C m^-2 and, at pH~9, -1.7 × 10^-2 C m^-2 and -1.0 × 10^-2 C m^-2, respectively.

Myricetin alleviated immunologic contact urticaria and mast cell degranulation via the PI3K/Akt/NF-κB pathway

Immunologic contact urticaria (ICU) is characterized by the wheal and flare reaction from direct contact with a chemical or protein agent, which involves a type I hypersensitivity mediated by allergen-specific immunoglobulin E (sIgE). Myricetin (Myr), a bioactive flavonoid, exhibits antiinflammatory activities. Our results showed that treatment with Myr could alleviate ICU symptoms, including a decrease in the number of wheals and scratching, and inhibit ear swelling in the IgE/DNFB-induced mice. The serum level of IgE, histamine, interleukin (IL)-4, TNF-α, and MCP-1 were reduced in Myr-treated mice. Myr also attenuated mast cells (MCs) degranulation and H-PGDS, TSLP, IL-33, PI3K, Akt, and NF-κB mRNA levels in ICU model. The IgE-mediated anaphylaxis mouse models demonstrated anti-allergic effects of Myr. In vitro analysis showed that Myr reduced IgE-induced calcium (Ca²⁺ ) influx, suppressed degranulation, and chemokine release in LAD2 cells (human primary mast cells). Myr can significantly inhibited PLCγ1, Akt, NF-κB, and p38 phosphorylation. In conclusion, the study demonstrated that Myr alleviate ICU symptoms and inhibit mast cell activation via PI3K/Akt/NF-κB signal pathway.

Assembly-Induced Emission Enhancement in Glutathione-Capped Bimetallic Gold and Copper Nanoclusters by Al3+ Ions and Further Application in Myricetin Determination

A significant emission enhancement (>100-fold) of glutathione-capped bimetallic gold and copper nanoclusters (AuCuNC@GSH) was achieved by assembling with Al3+ ions and by assembly-induced emission enhancement (AIEE). Further chelation of myricetin to Al3+ resulted in emission quenching of AuCuNC-Al3+, which was applied to specifically detect myricetin. Two linear responses were shown in the range of 0−1.5 μM and 1.5−50 μM, separately, leading to a low limit of detection at 8.7 nM. The method was successfully and accurately applied to myricetin determination in grape juice, which showed good application for real samples. Finally, the in-depth mechanism revealed that both the chelation of myricetin and Al3+ and the inner filter effect (IFE) between myricetin-Al3+ and AuCuNC-Al3+ greatly contributed to the quenching response of myricetin. Therefore, the present study provides an easy way to improve the fluorescence property of metal nanoclusters. Additionally, it supplies a cost-effective and easily performed approach to detect myricetin with high selectivity and sensitivity.

Inhibitory effect of phytochemicals towards SARS-CoV-2 papain like protease (PLpro) proteolytic and deubiquitinase activity

Recent studies have shown that RNA-dependent RNA polymerase (RdRp), 3-chymotrypsin-like protease (3CLpro), and papain-like protease (PLpro) are necessary for SARS-CoV-2 replication. Among these three enzymes, PLpro exhibits both proteolytic and deubiquitinase (DUB) activity and is responsible for disrupting the host's innate immune response against SARS-CoV-2. Because of this unique property of PLpro, we investigated the inhibitory effects of phytochemicals on the SARS-CoV-2 PLpro enzyme. Our data indicates that the phytochemicals such as catechin, epigallocatechin gallate (EGCG), mangiferin, myricetin, rutin, and theaflavin exhibited inhibitory activity with IC₅₀ values of 14.2, 128.4, 95.3, 12.1, and 43.4, and 7.3 μM, respectively, towards PLpro proteolytic activity. However, the IC₅₀ values of quercetin, oleuropein, and γ-mangostin are ambiguous. We observed that EGCG, mangiferin, myricetin, oleuropein, rutin, and theaflavin have also inhibited the DUB activity with IC₅₀ values of 44.7, 104.3, 29.2, 131.5, 61.7, and 13.2 μM, respectively. Mechanistically, the ligand-protein interaction structural modeling suggests that mangiferin, EGCG, theaflavin, and oleuropein shows that these four ligands interact with Glu¹⁶⁷, and Tyr²⁶⁸, however mangiferin and oleuropein showed very weak interaction with Glu¹⁶⁷ as compared to EGCG, and theaflavin which reflects their low IC₅₀ values for DUB activity. Our data indicate that the phytochemicals mentioned above inhibit the proteolytic and DUB activity of SARS-CoV-2 PLpro, thus preventing viral replication and promoting host innate immune response. However, the therapeutic potential of these phytochemicals needs to be validated by pre-clinical and clinical studies.

A Comprehensive Review on Anti-Inflammatory Response of Flavonoids in Experimentally-Induced Epileptic Seizures

Flavonoids, a group of natural compounds with phenolic structure, are becoming popular as alternative medicines obtained from plants. These compounds are reported to have various pharmacological properties, including attenuation of inflammatory responses in multiple health issues. Epilepsy is a disorder of the central nervous system implicated with the activation of the inflammatory cascade in the brain. The aim of the present study was to summarize the role of various neuroinflammatory mediators in the onset and progression of epilepsy, and, thereafter, to discuss the flavonoids and their classes, including their biological properties. Further, we highlighted the modulation of anti-inflammatory responses achieved by these substances in different forms of epilepsy, as evident from preclinical studies executed on multiple epilepsy models. Overall, the review summarizes the available evidence of the anti-inflammatory potential of various flavonoids in epilepsy.

The Role of the JAK/STAT Signaling Pathway in the Pathogenesis of Alzheimer's Disease: New Potential Treatment Target

Alzheimer's disease is characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. However, emerging evidence suggests that neuroinflammation, mediated notably by activated neuroglial cells, neutrophils, and macrophages, also plays an important role in the pathogenesis of Alzheimer's disease. Therefore, understanding the interplay between the nervous and immune systems might be the key to the prevention or delay of Alzheimer's disease progression. One of the most important mechanisms determining gliogenic cell fate is the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway that is influenced by the overactivation of microglia and astrocytes. The JAK/STAT signaling pathway is one of the critical factors that promote neuroinflammation in neurodegenerative diseases such as Alzheimer's disease by initiating innate immunity, orchestrating adaptive immune mechanisms, and finally, constraining neuroinflammatory response. Since a chronic neuroinflammatory environment in the brain is a hallmark of Alzheimer's disease, understanding the process would allow establishing the underlying role of neuroinflammation, then estimating the prognosis of Alzheimer's disease development and finding a new potential treatment target. In this review, we highlight the recent advances in the potential role of JAK/STAT signaling in neurological diseases with a focus on discussing future research directions regarding novel therapeutic approaches and predictive biomarkers for Alzheimer's disease.

Pesticides as a risk factor for cognitive impairment: Natural substances are expected to become alternative measures to prevent and improve cognitive impairment

Pesticides are the most effective way to control diseases, insects, weeds, and fungi. The central nervous system (CNS) is damaged by pesticide residues in various ways. By consulting relevant databases, the systemic relationships between the possible mechanisms of pesticides damage to the CNS causing cognitive impairment and related learning and memory pathways networks, as well as the structure-activity relationships between some natural substances (such as polyphenols and vitamins) and the improvement were summarized in this article. The mechanisms of cognitive impairment caused by pesticides are closely related. For example, oxidative stress, mitochondrial dysfunction, and neuroinflammation can constitute three feedback loops that interact and restrict each other. The mechanisms of neurotransmitter abnormalities and intestinal dysfunction also play an important role. The connection between pathways is complex. NMDAR, PI3K/Akt, MAPK, Keap1/Nrf2/ARE, and NF-κB pathways can be connected into a pathway network by targets such as Ras, Akt, and IKK. The reasons for the improvement of natural substances are related to their specific structure, such as polyphenols with different hydroxyl groups. This review's purpose is to lay a foundation for exploring and developing more natural substances that can effectively improve the cognitive impairment caused by pesticides.

Thymus linearis Extracts Ameliorate Indices of Metabolic Syndrome in Sprague Dawley Rats

Materials and Methods

The extract library (n-hexane (NH), ethyl acetate (EA), methanol (M), distilled water (DW), and combined extract (CE)) was standardized using in vitro phytochemical, antioxidant, and α-amylase inhibition assays, after which the protective effect of selected "hit," i.e., CE against metabolic syndrome, was determined in vivo, using rats fed a high-fat diet supplemented with additional cholesterol administration. CE was administered to Sprague Dawley rats in high dose as 100 mg/kg in carboxymethyl cellulose (CMC) (1 ml; 0.75% in DW) and low-dose group as 50 mg/kg in CMC (0.5 ml; 0.75% in DW). After 10 weeks, the effects of CE on insulin resistance, lipid metabolism, nonalcoholic fatty liver disease (NAFLD), oxidative stress, and genotoxicity were assessed through histological, biochemical, and hematological investigations.

Results

Phytochemical analysis including RP-HPLC analysis of the extracts showed that flavonoids and phenolics (myricetin, kaempferol, and apigenin), previously known to be effective against obesity and diabetes, are present in the extracts. Antioxidant studies revealed that the plant possesses a highly significant (p < 0.05) concentration of antioxidants. Satisfactory α-amylase inhibitory activity was also observed in in vitro experiments. In vivo studies showed that CE-administered animals had significantly (p < 0.05) lower weight gain and smaller adipocytes than the control group. Moreover, CE resisted any significant (p < 0.05) change in the organ weights. Analogous to findings from its traditional use, the plant extract had a positive modulatory effect on insulin resistance and hyperglycemia. The study also indicated that CE resisted high-fat diet-induced disturbance in lipid profile and countered any pathological changes in liver enzymes caused by fat-infused diet. Furthermore, a study on endogenous antioxidant levels indicated that CE was effective in maintaining catalase and peroxidase levels within the normal range and resisted the effects of lipid peroxidation of thiobarbituric acid reactive substances.

Conclusion

In principle, the current study's findings scientifically validate the implication of T. linearis in metabolic syndrome and recommend further studies on molecular insights of the observed therapeutic activity.

Myricetin attenuates hypoxic-ischemic brain damage in neonatal rats via NRF2 signaling pathway

Introduction: Hypoxic-ischemic encephalopathy (HIE) is a crucial cause of neonatal death and neurological sequelae, but currently there is no effective therapy drug for HIE. Both oxidative stress and apoptosis play critical roles in the pathological development of HIE. Myricetin, a naturally extracted flavonol compound, exerts remarkable effects against oxidative stress, apoptosis, and inflammation. However, the role and underlying molecular mechanism of myricetin on HIE remain unclear. Methods: In this study, we established the neonatal rats hypoxic-ischemic (HI) brain damage model in vivo and CoCl₂ induced PC1₂ cell model in vitro to explore the neuroprotective effects of myricetin on HI injury, and illuminate the potential mechanism. Results: Our results showed that myricetin intervention could significantly reduce brain infarction volume, glia activation, apoptosis, and oxidative stress marker levels through activating NRF2 (Nuclear factor-E2-related factor 2) and increase the expressions of NRF2 downstream proteins NQO-1 and HO-1. In addition, the NRF2 inhibitor ML385 could significantly reverse the effects of myricetin. Conclusion: This study found that myricetin might alleviate oxidative stress and apoptosis through NRF2 signaling pathway to exert the protective role for HI injury, which suggested that myricetin might be a promising therapeutic agent for HIE.

Current Naturopathy to Combat Alzheimer's Disease

Neurodegeneration is the progressive loss of structure or function of neurons, which may ultimately involve cell death. The most common neurodegenerative disorder in the brain happens with Alzheimer's disease (AD), the most common cause of dementia. It ultimately leads to neuronal death, thereby impairing the normal functionality of the central or peripheral nervous system. The onset and prevalence of AD involve heterogeneous etiology, either in terms of genetic predisposition, neurometabolomic malfunctioning, or lifestyle. The worldwide relevancies are estimated to be over 45 million people. The rapid increase in AD has led to a concomitant increase in the research work directed towards discovering a lucrative cure for AD. The neuropathology of AD comprises the deficiency in the availability of neurotransmitters and important neurotrophic factors in the brain, extracellular betaamyloid plaque depositions, and intracellular neurofibrillary tangles of hyperphosphorylated tau protein. Current pharmaceutical interventions utilizing synthetic drugs have manifested resistance and toxicity problems. This has led to the quest for new pharmacotherapeutic candidates naturally prevalent in phytochemicals. This review aims to provide an elaborative description of promising Phyto component entities having activities against various potential AD targets. Therefore, naturopathy may combine with synthetic chemotherapeutics to longer the survival of the patients.

Microarray Expression Profile of Myricetin-Treated THP-1 Macrophages Exhibits Alterations in Atherosclerosis-Related Regulator Molecules and LXR/RXR Pathway

Atherosclerosis is a chronic inflammation characterized by macrophage infiltration, lipid deposition, and arterial wall thickening. Prevention of atherosclerosis by nutraceuticals is gaining attention. Myricetin, a dietary flavonol, is claimed to possess anti-atherosclerosis properties. We studied myricetin's effect on the atherosclerosis-associated molecular mechanism. Cytotoxicity and proliferation testing to check the viability of myricetin-treated THP-1 macrophages and monocyte migration study in the presence and absence of myricetin was performed. The whole transcriptome analysis was conducted using the Affymetrix microarray platform. The Partek genomics suite for detecting differentially expressed genes (DEGs) and ingenuity pathway analysis was used to identify canonical pathways. Cytotoxicity assays exhibited no significant toxicity in THP-1 macrophages treated with different myricetin concentrations (10-200 μM). Genome-wide expression profiling revealed 58 DEGs (53 upregulated and 5 downregulated) in myricetin-treated THP-1 macrophages. Pathway analysis revealed inhibition of LXR/RXR activation and angiogenesis inhibition by thrombospondin-1 and activated phagocytosis in myricetin-treated THP-1 macrophages. The cytotoxicity assay shows myricetin as a safe phytochemical. In vitro and in silico pathway studies on THP-1 macrophages showed that they can inhibit THP-1 monocyte migration and alter the cholesterol efflux mediated via LXR/RXR signaling. Therefore, myricetin could help in the prevention of cell infiltration in atherosclerotic plaque with reduced risk of stroke or brain damage.

The Neuroprotective Potentiality of Flavonoids on Alzheimer's Disease

Alzheimer's disease (AD), due to its spread, has become a global health priority, and is characterized by senile dementia and progressive disability. The main cause of AD and other neurodegenerations (Huntington, Parkinson, Amyotrophic Lateral Sclerosis) are aggregated protein accumulation and oxidative damage. Recent research on secondary metabolites of plants such as polyphenols demonstrated that they may slow the progression of AD. The flavonoids' mechanism of action in AD involved the inhibition of acetylcholinesterase, butyrylcholinesterase, Tau protein aggregation, β-secretase, oxidative stress, inflammation, and apoptosis through modulation of signaling pathways which are implicated in cognitive and neuroprotective functions, such as ERK, PI3-kinase/Akt, NFKB, MAPKs, and endogenous antioxidant enzymatic systems. This review focuses on flavonoids and their role in AD, in terms of therapeutic potentiality for human health, antioxidant potential, and specific AD molecular targets.

Role of potential bioactive metabolites from traditional Chinese medicine for type 2 diabetes mellitus: An overview

Type 2 diabetes mellitus (T2DM) is a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR). The number of diabetic patients globally has been rising over the past decades. Although significant progress has been made in treating diabetes mellitus (DM), existing clinical drugs for diabetes can no longer fully meet patients when they face complex and huge clinical treatment needs. As a traditional and effective medical system, traditional Chinese medicine (TCM) has a unique understanding of diabetes treatment and has developed many classic and practical prescriptions targeting DM. With modern medicine and pharmacy advancements, researchers have discovered that various bioactive metabolites isolated from TCM show therapeutic on DM. Compared with existing clinical drugs, these bioactive metabolites demonstrate promising prospects for treating DM due to their excellent biocompatibility and fewer adverse reactions. Accordingly, these valuable metabolites have attracted the interest of researchers worldwide. Despite the abundance of research works and specialized-topic reviews published over the past years, there is a lack of updated and systematic reviews concerning this fast-growing field. Therefore, in this review, we summarized the bioactive metabolites derived from TCM with the potential treatment of T2DM by searching several authoritative databases such as PubMed, Web of Science, Wiley Online Library, and Springer Link. For the convenience of readers, the content is divided into four parts according to the structural characteristics of these valuable compounds (flavonoids, terpenoids, alkaloids, and others). Meanwhile, the detailed mechanism and future directions of these promising compounds curing DM are also summarized in the related sections. We hope this review inspires increasingly valuable and significant research focusing on potential bioactive metabolites from TCM to treat DM in the future.

Antibacterial and Antiproliferative Activities of Azadirachta indica Leaf Extract and Its Effect on Oil-in-Water Food Emulsion Stability

The present study aims to identify and quantify the phenolic compounds of Azadirachta indica leaf extract using HPLC-MS and to evaluate the antioxidant, antibacterial (against different Gram-positive and negative bacteria) and in vitro anti-proliferative activities of this extract (against breast, human liver and cervix adenocarcinoma-derived cells). The application of this extract as a natural antioxidant for food preservation was also tested on oil-in-water food emulsions for the first time in the present work in order to determine the use of Azadirachta indica leaves as a natural additive to preserve the food against lipid oxidation and rancidity. The results obtained revealed that 50%-aqueous ethanol leaf extract showed the best extraction yield (25.14%), which was characterized by a high content in phenolic compounds and strong antioxidant activity. Moreover, this leaf extract inhibited the growth of the bacterial strains tested (Staphylococcus aureus, Escherichia coli, Salmonella paratyphi and Micrococcus luteus) and showed better anti-proliferative activity against breast and cervix adenocarcinoma-derived cells than human liver cancer cells after 48 h of treatment. Additionally, Azadirachta indica leaf extract showed almost similar effects as gallic acid solutions (0.25% and 0.5%) in preserving the oxidation of oil-in-water food emulsions and prevented the formation of secondary oxidation products (malondialdehyde) as well. The results obtained suggested that extracts of Azadirachta indica leaves are a potential source of antioxidant and antibacterial compounds and pointed to the potential of these natural extracts as therapeutic agents.

Plant based food bioactives: A boon or bane for neurological disorders

Neurological disorders are the foremost occurring diseases across the globe resulting in progressive dysfunction, loss of neuronal structure ultimately cell death. Therefore, attention has been drawn toward the natural resources for the search of neuroprotective agents. Plant-based food bioactives have emerged as potential neuroprotective agents for the treatment of neurodegenerative disorders. This comprehensive review primarily focuses on various plant food bioactive, mechanisms, therapeutic targets, in vitro and in vivo studies in the treatment of neurological disorders to explore whether they are boon or bane for neurological disorders. In addition, the clinical perspective of plant food bioactives in neurological disorders are also highlighted. Scientific evidences point toward the enormous therapeutic efficacy of plant food bioactives in the prevention or treatment of neurological disorders. Nevertheless, identification of food bioactive components accountable for the neuroprotective effects, mechanism, clinical trials, and consolidation of information flow are warranted. Plant food bioactives primarily act by mediating through various pathways including oxidative stress, neuroinflammation, apoptosis, excitotoxicity, specific proteins, mitochondrial dysfunction, and reversing neurodegeneration and can be used for the prevention and therapy of neurodegenerative disorders. In conclusion, the plant based food bioactives are boon for neurological disorders.

The recovery from agro-industrial wastes provides different profiles of anti-inflammatory polyphenols for tailored applications

Food and agro-industrial processing produce a great amount of side-stream and waste materials that are excellent sources of functional bioactive molecules such as phenolic compounds that recover them can be beneficial not only for food sustainability but also to human for many industrial applications such as flavor compounds and therapeutic applications such as antimicrobial and anti-inflammatory. The treatments and extraction techniques have major effects on the recovery of bioactive compounds. Along with the conventional extraction methods, numerous innovative techniques have been evolved and have been optimized to facilitate bioactive extraction more efficiently and sustainably. In this work, we have summarized the state-of-the-art technological approaches concerning novel extraction methods applied for five most produced crops in Italy; Grape Pomace (GP), Tomato Pomace (TP), Olive Pomace (OP), Citrus Pomace (CP), and Spent Coffee Grounds (SCG), presenting the extraction yield and the main class of phenolic classes, with the focus on their biological activity as an anti-inflammatory in vitro and in vivo studies via describing their molecular mechanism of action.

Myricetin prevents sleep deprivation-induced cognitive impairment and neuroinflammation in rat brain via regulation of brain-derived neurotropic factor

Memory formation in the hippocampus is formed and maintained by circadian clock genes during sleep. Sleep deprivation (SD) can lead to memory impairment and neuroinflammation, and there remains no effective pharmacological treatment for these effects. Myricetin (MYR) is a common natural flavonoid that has various pharmacological activities. In this study, we investigated the effects of MYR on memory impairment, neuroinflammation, and neurotrophic factors in sleep-deprived rats. We analyzed SD-induced cognitive and spatial memory, as well as pro-inflammatory cytokine levels during SD. SD model rats were intraperitoneally injected with 10 and 20 mg/kg/day MYR for 14 days. MYR administration significantly ameliorated SD-induced cognitive and spatial memory deficits; it also attenuated the SD-induced inflammatory response associated with nuclear factor kappa B activation in the hippocampus. In addition, MYR enhanced the mRNA expression of brain-derived neurotropic factor (BDNF) in the hippocampus. Our results showed that MYR improved memory impairment by means of anti-inflammatory activity and appropriate regulation of BDNF expression. Our findings suggest that MYR is a potential functional ingredient that protects cognitive function from SD.

Antimicrobial and Antioxidant Activity of Apricot (Mimusopsis comersonii) Phenolic-Rich Extract and Its Application as an Edible Coating for Fresh-Cut Vegetable Preservation

Edible coatings have several advantages in preserving foods, such as avoiding water loss, controlling microbial growth, and reducing the need for preservatives added directly to the product. Antimicrobial action can be obtained by adding antimicrobial substances including phenolic compounds commonly found in plant extracts. This study evaluated the phenolic compounds content, antioxidant and antimicrobial activity of pulp, and seed extracts of Mimusopsis comersonii (popularly known in Brazil as abrico), besides the phenolic compounds were identified and quantified in the pulp extract. Edible coatings were incorporated with pulp extract in order to evaluate the preservation of minimally processed apples and baroa potatoes against foodborne bacteria, and enzymatic browning was also determined. Myricetin-3-glucoside, quercetin-3-glucoside, and kaempferol-3-glucoside were identified as major flavonoids in the apricot pulp extract. The seed and pulp extracts inhibited all tested microorganisms, especially Staphylococcus aureus and Salmonella Typhimurium. Edible coatings added with 9% of phenolic extract showed in vitro antimicrobial activity, in addition to being effective in preventing enzymatic browning in minimally processed apples and baroa potatoes for up to 15 days of storage. They were also effective in reducing up to 2 log CFU/g of aerobic mesophiles after 15 days of storage for apples, even though no microbial inhibition in baroa potatoes was observed under the same conditions. The addition of pulp phenolic extract in edible coatings proved to be an alternative in the preservation of apples and in the antibrowning activity of minimally processed baroa potatoes.

Relative evaluation of in-vitro antioxidant potential and phenolic constituents by HPLC-DAD of Brassica vegetables extracted in different solvents

Cabbage, cauliflower and broccoli are well-known vegetables from the Brassica family having functional effects on human health. This study was carried out to identify different antioxidant properties and to quantify phenolic compounds by HPLC-DAD in different extracts (methanol, ethanol and water: acetic acid: acetone) of these vegetables. The results showed that, the methanolic dry extract of cabbage possessed the highest antioxidant activity (549 ± 7.30 μg/g) and IC₅₀ was 90 ± 2.52 μg/mL than others. Whereas the ethanolic dry extract of cauliflower had 348 ± 5.20 μg/g of flavonoid, which was the highest among all. The maximum levels of total tannin (414 ± 5.20 μg/g) and total phenolic content (465 ± 3.25 μg/g) was found in broccoli dry extract. Several polyphenolic compounds were identified in different extracts of the vegetables and they were Cauliflower (8) > Cabbage (10) > Broccoli (9) in total. Therefore, the use of total vegetables rather than extracts in the food industry would be more appropriate to get greater health benefit.

Morphology characterization and phytochemical overview of the Moluccan Ironwood Intsia bijuga (Colebr.) Kuntze, a living collection of Purwodadi Botanic Garden, Indonesia

As one of the ex situ conservation sites, Purwodadi Botanic Garden (PBG) has Intsia bijuga as its collection with high economic value for its high quality wood. It is categorised as Near Threatened in the IUCN Red List. Its efficacy as herb is due to the presence of its various chemical compounds. The purpose of this study was to characterize the morphology of I. bijuga cultivated in PBG and to reveal its phytochemical compounds, as well as their health benefits. This research was conducted at the PBG in April–May 2020. The plant material was obtained from PBG collection. The plant morphology was characterized by direct observation in the field, while information regarding phytochemical compounds of I. bijuga along with their benefits was obtained by literature review. The data obtained was analyzed descriptively. The results showed that I. bijuga collected by PBG came from Maluku and Java. Both have morphological characteristics that are not very different, i.e., they are trees, they have compound leaves, pale stems with lenticels on their surface, panicle flowers, pod-shaped fruits, and buttress roots. I. bijuga contains polyphenol compounds that have medicinal benefits, such as anti-bacterial, anti-cancer, and anti-viral, hence it has enormous medicinal potential. Due to habitat shrinkage of the species, an effort to have it conserved ex situ is critical.

Myricetin as a Potential Adjuvant in Chemotherapy: Studies on the Inhibition of Human Glutathione Transferase A1–1

Glutathione transferases (GSTs) are a family of Phase II detoxification enzymes that are involved in the development of multi-drug resistance (MDR) phenomena toward chemotherapeutic agents. GST inhibitors are considered candidate compounds able to chemomodulate and reverse MDR. The natural flavonoid myricetin (MYR) has been shown to exhibit a wide range of pharmacological functions, including antitumor activity. In the present work, the interaction of MYR with human glutathione transferase A1–1 (hGSTA1–1) was investigated by kinetics inhibition analysis and molecular modeling studies. The results showed that MYR binds with high affinity to hGSTA1–1 (IC50 2.1 ± 0.2 μΜ). It functions as a non-competitive inhibitor towards the electrophile substrate 1-chloro−2,4-dinitrobenzene (CDNB) and as a competitive inhibitor towards glutathione (GSH). Chemical modification studies with the irreversible inhibitor phenethyl isothiocyanate (PEITC), in combination with in silico molecular docking studies allowed the prediction of the MYR binding site. MYR appears to bind at a distinct location, partially overlapping the GSH binding site (G-site). The results of the present study show that MYR is a potent inhibitor of hGSTA1–1 that can be further exploited towards the development of natural, safe, and effective GST-targeted cancer chemosensitizers.

Myricetin alleviates the formaldehyde-enhanced Warburg effect in tumor cells through inhibition of HIF-1α

Myricetin is a flavonoid widely-distributed in foods with many beneficial health effects, which has been marketed in health products. Formaldehyde is an environmental carcinogen which can enhance the Warburg effect through the induction of human hypoxia-inducible factor 1 subunit alpha (HIF-1α), the primary regulator of cellular glycolysis. HIF-1α was verified as an important target in lung and ovarian tumors, which was also identified as a receptor for myricetin via molecular docking. The reinforced HIF-1α signaling, the Warburg effect and T cell suppression induced by 50 μM formaldehyde in both A549 and Caov-3 cells were dose-dependently attenuated by myricetin from 20 to 100 μM, and the attenuative effects were diminished by the stabilization of HIF-1α with deferoxamine. Exposure to 2.0 mg/m³ formaldehyde also stimulated tumor growth and elevated HIF-1α expression in tumor tissues of A549 xenograft mice, which were also alleviated by oral administration of 100 mg/kg myricetin. These results demonstrated that myricetin alleviated formaldehyde-enhanced Warburg effect in tumor cells through HIF-1α inhibition, which could be further developed as a therapeutic or complementary agent for formaldehyde-induced carcinogenesis.

Myricetin inhibits pseudorabies virus infection through direct inactivation and activating host antiviral defense

Myricetin, a polyhydroxyflavone compound, is one of the main ingredients of various human foods and therefore also known as dietary flavonoids. Due to the continuous emergence of resistant strains of herpesviruses, novel control measures are required. In the present study, myricetin exhibited potent antiviral activity against pseudorabies virus (PRV), a model organism of herpesvirus. The suppression rate could reach up to 96.4% at a concentration of 500 μM in cells, and the 50% inhibitory concentration (IC₅₀) was 42.69 μM. Moreover, the inhibitory activity was not attenuated by the increased amount of infective dose, and a significant reduction of intracellular PRV virions was observed by indirect immunofluorescence. A mode of action study indicated that myricetin could directly inactivate the virus in vitro, leading to inhibition of viral adsorption, penetration and replication in cells. In addition to direct killing effect, myricetin could also activate host antiviral defense through regulation of apoptosis-related gene expressions (Bcl-2, Bcl-xl, Bax), NF-κB and MAPK signaling pathways and cytokine gene expressions (IL-1α, IL-1β, IL-6, c-Jun, STAT1, c-Fos, and c-Myc). In PRV-infected mouse model, myricetin could enhance the survival rate by 40% at 5 days post infection, and viral loads in kidney, liver, lung, spleen, and brain were significantly decreased. The pathological changes caused by PRV infection were improved by myricetin treatment. The gene expressions of inflammatory factors (MCP-1, G-CSF, IL-1α, IL-1β, and IL-6) and apoptotic factors (Bcl-xl, Bcl-2, and Bax) were regulated by myricetin in PRV-infected mice. The present findings suggest that myricetin can effectively inhibit PRV infection and become a candidate for development of new anti-herpesvirus drugs.

A Comprehensive Review of Natural Compounds for Wound Healing: Targeting Bioactivity Perspective

Wound healing is a recovering process of damaged tissues by replacing dysfunctional injured cellular structures. Natural compounds for wound treatment have been widely used for centuries. Numerous published works provided reviews of natural compounds for wound healing applications, which separated the approaches based on different categories such as characteristics, bioactivities, and modes of action. However, current studies provide reviews of natural compounds that originated from only plants or animals. In this work, we provide a comprehensive review of natural compounds sourced from both plants and animals that target the different bioactivities of healing to promote wound resolution. The compounds were classified into four main groups (i.e., anti-inflammation, anti-oxidant, anti-bacterial, and collagen promotion), mostly studied in current literature from 1992 to 2022. Those compounds are listed in tables for readers to search for their origin, bioactivity, and targeting phases in wound healing. We also reviewed the trend in using natural compounds for wound healing.

Reduction of Weed Growth under the Influence of Extracts and Metabolites Isolated from Miconia spp

Weeds pose a problem, infesting areas and imposing competition and harvesting difficulties in agricultural systems. Studies that provide the use of alternative methods for weed control, in order to minimize negative impacts on the environment, have intensified. Native flora represents a source of unexplored metabolites with multiple applications, such as bioherbicides. Therefore, we aimed to carry out a preliminary phytochemical analysis of crude extracts and fractions of Miconia auricoma and M. ligustroides and to evaluate these and the isolated metabolites phytotoxicity on the growth of the target species. The growth bioassays were conducted with Petri dishes with lettuce, morning glory, and sourgrass seeds incubated in germination chambers. Phytochemical analysis revealed the presence of flavonoids, isolated myricetin, and a mixture of quercetin and myricetin. The results showed that seedling growth was affected in a dose-dependent manner, with the root most affected and the seedlings of the lettuce, morning glory, and sourgrass as the most sensitive species, respectively. Chloroform fractions and myricetin were the most inhibitory bioassays evaluated. The seedlings showed structural changes, such as yellowing, nonexpanded cotyledons, and less branched roots. These results indicate the phytotoxic potential of Miconia allelochemicals, since there was the appearance of abnormal seedlings and growth reduction.

Microtubule-affinity regulating kinase 4: A potential drug target for cancer therapy

The human genome encodes more than 500 protein kinases that work by transferring the γ-phosphate group from ATP to serine, threonine, or tyrosine (Ser/Thr/Tyr) residues. Various kinases are associated with the onset of cancer and its further progression. The recent advancements in developing small-molecule kinase inhibitors to treat different cancer types have shown noticeable results in clinical therapies. Microtubule-affinity regulating kinase 4 (MARK-4) is a Ser/Thr protein kinase that relates structurally to AMPK/Snf1 subfamily of the CaMK kinases. The protein kinase modulates major signalling pathways such as NF-κB, mTOR and the Hippo-signalling pathway. MARK4 is associated with various cancer types due to its important role in regulating microtubule dynamics and subsequent cell division. Aberrant expression of MARK4 is linked with several pathologies such as cancer, Alzheimer's disease, obesity, etc. This review provides detailed information on structural aspects of MARK4 and its role in various signalling pathways related to cancer. Several therapeutic molecules were designed to inhibit the MARK4 activity from controlling associated diseases. The review further highlights kinase-targeted drug discovery and development in oncology and cancer therapies. Finally, we summarize the latest findings regarding the role of MARK4 in cancer, diabetes, and neurodegenerative disease path to provide a solid rationale for future investigation and therapeutic intervention.

Bridelia ferruginea Benth.; An ethnomedicinal, phytochemical, pharmacological and toxicological review

Ethnopharmacological relevance

Bridelia ferruginea belonging to the family Euphorbiaceae, identified as an important commonly growing shrub, is used in traditional medicine for managing arthritis, dysentery, constipation, chronic diabetes, skin diseases, bladder and intestinal disorders, oral infections, thrush, bites and as an arrow poison antidote. This review aims at providing information on the traditional medicinal uses, pharmacological activities, phytochemistry and toxicity studies of Bridelia ferruginea to bridge the gap between traditional medicinal uses and preclinical studies on B. ferruginea and subsequently lead to the development of valued added medicines from B. ferruginea.

Materials and methods

Data in this review were compiled using databases such as Google Scholar, Science Direct, Scopus, PubMed, Springer link, Elsevier and Taylor and Francis, articles from peer reviewed journals and other grey literature (short notes, book chapters, short communications) to access all the relevant information available on B. ferruginea.

Results

B. ferruginea contains different phytochemicals including flavonoids, phenolics, phytosterols, triterpenes, saponins, alkaloids and cardiac glycosides. Gallocatechin-(4′-O-7)-epigallocatechin, 3,5-dicaffeoylquinic acid, 1,3,4,5-tetracaffeoylquinic acid and some derivatives of 3-methoxyflavone, such as quercetin-3-methyl ether, quercetin 3-,7,3′,4′-tetramethyl ether, myricetin 3′,4′,5′-trimethyl ether, myricetin 3,3′,4′,5′-tetramethyl ether, myricetin and quercetin 3-O-glucoside specific flavonoids and biflavonoids like apigenin, kaempferol and glycosides of both have been isolated and further characterized from B. ferruginea. B. ferruginea has several pharmacologically beneficial properties including anti-inflammatory, anti-diabetic, antioxidant, antimicrobial, anti-infective, antipyretic, analgesic, diuretic and natriuretic activities.

Conclusion

The wide distribution, traditional medicinal uses and wealth of phytochemicals present in B. ferruginea suggests that the plant can be useful in lead compound discovery. Although B. ferruginea has been widely studied, further studies on the mechanism of action, bioavailability, pharmacokinetics, toxicity and side effects in humans need to be investigated.