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Myricetin is a flavonol with high antioxidant properties. In this research, the fluorescence emission of myricetin powder and its solutions in different solvents were measured and analyzed by comparing with the results of calculations. Comparison of the calculated and measured characteristic wavelengths allowed the identification of all the spectral features in the fluorescence spectra of myricetin powder and solutions with different concentrations. The computation was based on modeling the process of the excited state intermolecular proton transfer, which predicts the formation of tautomeric forms of the flavonol molecule. Characteristic emission wavelengths were obtained using TDDFT/M06-2X/6-31++G(d,p). To understand the influence of the hydroxyl groups in the B-ring of the flavonol molecule on the emission spectrum, we also compared the fluorescence spectra of myricetin with those of kaempferol and quercetin. Moreover, based on the analysis of the changes in the shape of the FL spectra with the concentration of the solution, a criterion for the complete dissolution of the flavonol powders was established, which is important for bioavailability of flavonoids.
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Quempferóis , Quercetina , Pós , Fluorescência , Flavonoides , FlavonóisRESUMO
SUMMARY OBJECTIVE: Cisplatin, a widely used anticancer agent, induces hepatotoxicity alongside organ damage. Understanding Cisplatin's toxicity mechanism and developing preventive measures are crucial. Our study explores Myricetin, a flavonoid, for its protective effects against Cisplatin-induced hepatotoxicity. METHODS: In our study, a total of 32 Wistar albino male rats were utilized, which were categorized into four distinct groups: Control, Myricetin, Cisplatin, and Myricetin+Cisplatin. For the histological assessment of hepatic tissues, hematoxylin-eosin and periodic acid Schiff staining were employed, alongside immunohistochemical measurements of TNF-α, interleukin-17, and interleukin-6 immunoreactivity. Additionally, aspartate transaminase and alanine transaminase values were examined by biochemical analysis. RESULTS: In the histological evaluation of the tissues, a normal healthy cell structure and a strong periodic acid Schiff (+) reaction were observed in the hepatocyte cells in the tissues of the Control and Myricetin groups, while intense eosinophilia, minimal vacuolization, congestion, and sinusoidal expansions were observed in the hematoxylin-eosin stainings, and a decrease in the positive reaction in the periodic acid Schiff staining was observed in the Cisplatin group. Consistent with these histological findings, an increase in TNF-α, interleukin-17, and interleukin-6 expressions (p<0.0001) and a concomitant increase in aspartate transaminase and alanine transaminase values were observed in the Cisplatin group. In the group protected by Myricetin, a significant improvement was observed in all these histological and biochemical values. CONCLUSION: Cisplatin induces notable histopathological alterations in the liver. In this context, Myricetin exhibits the potential to alleviate Cisplatin-induced damage by modulating histological parameters and biochemical processes.
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SUMMARY: The aim of this study is to reveal the gonadoprotective effects of myricetin (MYC), which has many biological properties, on cisplatin (CP)-induced testicular damage in rats. For this purpose, 40 male Wistar albino rats were divided into 4 groups as Control (group given no treatment), MYC (group given 5 mg/kg/i.p myricetin for 7 days), CP (group given 7 mg/kg/i.p cisplatin at 7th day) and MYC + CP (group given 5 mg/kg/i.p myricetin for 7 days before 7 mg/kg/i.p cisplatin injection). After administrations, testicular tissues of animals were extracted and processed according to tissue processing protocol. Hematoxylin & Eosin staining were performed to evaluate the histopathological changes and Johnsen'sTesticular Biopsy Score (JTBS) was applied and mean seminiferous tubule diameters (MSTD) were measured to compare experimental groups in terms of histopathological changes. Moreover, TLR4, NF-kB, HSP70 and HSP90 expression levels were detected by immunohistochemical staining and the density of immunoreactivity were measured to determine the difference in the expression levels of these factors among groups. Additionally, testicular apoptosis was detected via TUNEL assay. JTBS and MSTD data were significantly lower in CP group compared to other groups and MYC administrations significantly protects testicular tissue against CP-induced damage. Moreover, TLR4, NF-kB, HSP70 and HSP90 expressions and apoptotic cells significantly increased in the CP group (p<0.05). However, MYC administrations exerted a strong gonadoprotective effect on testicular tissue in terms of these parameters in MYC+CP group (p<0.05). According to our results, we suggested that MYC can be considered as a protective agent against cisplatin-induced testicular damage.
El objetivo de este estudio es revelar los efectos gonadoprotectores de la miricetina (MYC), que tiene muchas propiedades biológicas, sobre el daño testicular inducido por cisplatino (CP) en ratas. Para este propósito, se dividieron 40 ratas albinas Wistar macho en 4 grupos: Control (grupo que no recibió tratamiento), MYC (grupo que recibió 5 mg/kg/i.p de miricetina durante 7 días), CP (grupo que recibió 7 mg/kg/i.p de cisplatino al séptimo día) y MYC + CP (grupo que recibió 5 mg/ kg/i.p de miricetina durante 7 días antes de la inyección de 7 mg/ kg/i.p de cisplatino). Después de las administraciones, se extrajeron y procesaron tejidos testiculares de animales según el protocolo de procesamiento de tejidos. Se realizó tinción con hematoxilina y eosina para evaluar los cambios histopatológicos y se aplicó la puntuación de biopsia testicular de Johnsen (JTBS) y se midieron los diámetros medios de los túbulos seminíferos (MSTD) para comparar los grupos experimentales en términos de cambios histopatológicos. Además, los niveles de expresión de TLR4, NF-kB, HSP70 y HSP90 se detectaron mediante tinción inmunohistoquímica y se midió la densidad de inmunorreactividad para determinar la diferencia en los niveles de expresión de estos factores entre los grupos. Además, se detectó apoptosis testicular mediante el ensayo TUNEL. Los datos de JTBS y MSTD fueron significativamente más bajos en el grupo CP en comparación con otros grupos y las administraciones de MYC protegen significativamente el tejido testicular contra el daño inducido por CP. Además, las expresiones de TLR4, NF-kB, HSP70 y HSP90 y las células apoptóticas aumentaron significativamente en el grupo CP (p<0,05). Sin embargo, las administraciones de MYC ejercieron un fuerte efecto gonadoprotector sobre el tejido testicular en términos de estos parámetros en el grupo MYC+CP (p<0,05). Según nuestros resultados, sugerimos que MYC puede considerarse como un agente protector contra el daño testicular inducido por cisplatino.
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Animais , Masculino , Ratos , Testículo/efeitos dos fármacos , Testículo/lesões , Flavonoides/administração & dosagem , Cisplatino/toxicidade , Flavonoides/farmacologia , Imuno-Histoquímica , NF-kappa B , Ratos Wistar , Resposta ao Choque Térmico , Marcação In Situ das Extremidades Cortadas , Receptor 4 Toll-Like , Inflamação , Antineoplásicos/toxicidadeRESUMO
Understanding the role of 3CLpro protease for SARS-CoV-2 replication and knowing the potential of flavonoid molecules like rutin, myricetin, and baicalein against 3CLpro justify an investigation into their inhibition. This study investigates possible bonds and reactivity descriptors of rutin, myricetin, and baicalein through conformational and electronic properties. Density functional theory was used to determine possible interactions. Analyses were carried out through the molecular electrostatic potential, electron localization function, Fukui function descriptors based on frontier orbitals, and non-covalent interactions. A docking study was performed using a resolution of 1.55 Å for 3CLpro to analyze the interactions of rutin, myricetin, and baicalein. Scores of structures showed that rutin is the best ligand, followed by myricetin and baicalein. Docking studies showed that baicalein and rutin can establish effective interactions with residues of the catalytic dyad (Cys145 and His41), but just rutin forms a hydrogen bond. Myricetin, in turn, could not establish an effective interaction with Cys145. Baicalein interaction arose with active residues such as Arg188, Val186, Gln189, and Gln192. Interactions of rutin and myricetin with Arg188 and Gln189 were also found. A critical interaction was observed only for rutin with the hydroxyls of ring A with His41, and also for Cys145 with rings B and C, which is probably related to the highest score of rutin.
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Flavanonas , Rutina , Flavonoides/farmacologia , Simulação de Acoplamento Molecular , Inibidores de Proteases/química , Simulação de Dinâmica Molecular , Antivirais/farmacologiaRESUMO
The chikungunya virus (CHIKV) has produced epidemic outbreaks of significant public health impact. The clinical symptoms of this disease are fever, polyarthralgia, and skin rash, generally self-limiting, although patients may develop a chronic disabling condition or suffer lethal complications. Unfortunately, there is no specific treatment or vaccine available. Thus, the search for effective therapies to control CHIKV infection is an urgent need. This study evaluated the antiviral activity of flavonoids isolated from Marcetia taxifolia by in vitro and in silico analysis. Cytotoxicity of compounds was determined by MTT assay and viral load was assessed in cell substrates supernatants by plaque-forming and RT-qPCR assays. Selected molecules were analyzed by molecular docking assays. Myricetin 3-rhamnoside (MR) and myricetin 3-(6-rhamnosylgalactoside) (MRG) were tested for antiviral assays and analyzed by the TCID50 method and RT-qPCR. MR exhibited dose-dependent antiviral activity, reducing viral titer at concentrations of 150-18.8 µg/mL by at least 1-log. Similarly, MRG showed a significant decrease in viral titer at concentrations of 37.5, 9.4, and 2.3 µg/mL. RT-qPCR analysis also displayed a substantial reduction of CHIKV RNA for both flavonoids. Furthermore, molecular docking of the selected flavonoids proposed the nsP3 macrodomain as a possible target of action. Our study reveals that MR and MRG could be considered promising anti-CHIKV therapeutic agents. Molecular modeling studies showed MR and MRG ligands with a high affinity for the N-terminal region of the nsP3 macrodomain, postulating them as a potential target of action for the CHIKV control.
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The interest in the consumption of edible flowers has increased since they represent a rich source of bioactive compounds, which are significantly beneficial to human health. The objective of this research was to access the bioactive compounds and antioxidant and cytotoxic properties of unconventional alternative edible flowers of Hibiscus acetosella Welw. Ex Hiern. The edible flowers presented pH value of 2.8 ± 0.00, soluble solids content of 3.4 ± 0.0 °Brix, high moisture content of about 91.8 ± 0.3%, carbohydrates (6.9 ± 1.2%), lipids (0.90 ± 0.17%), ashes (0.4 ± 0.0%), and not detectable protein. The evaluation of the scavenging activity of free radicals, such as 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), of the flower extract was better than the results observed for other edible flowers (507.8 ± 2.7 µM TE and 783.9 ± 30.8 µM TE, respectively) as well as the total phenolic composition (TPC) value (568.8 ± 0.8 mg GAE/g). These flowers are rich in organic acids and phenolic compounds, mainly myricetin, and quercetin derivatives, kaempferol, and anthocyanins. The extract showed no cytotoxicity for the cell lineages used, suggesting that the extract has no directly harmful effects to cells. The important bioactive compound identified in this study makes this flower especially relevant in the healthy food area due to its nutraceutical potential without showing cytotoxicity.
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Antocianinas , Hibiscus , Humanos , Antocianinas/química , Antioxidantes/química , Fenóis/química , Extratos Vegetais/química , Flores/químicaRESUMO
High-performance counter-current chromatography (HPCCC) was used as a tool for the isolation and fractionation of phenolic compounds (PCs) in extracts from wine lees (WL) and grape pomace (GP). The biphasic solvent systems applied for HPCCC separation were n-butanol:methyl tert-butyl ether:acetonitrile:water (3:1:1:5) with 0.1% trifluoroacetic acid (TFA) and n-hexane:ethyl acetate:methanol:water (1:5:1:5). After refining the ethanol:water extracts of GP and WL by-products by ethyl acetate extraction, the latter system yielded an enriched fraction of the minor family of flavonols. Recoveries of 112.9 and 105.9 mg of purified flavonols (myricetin, quercetin, isorhamnetin, and kaempferol) in GP and WL, respectively, from 500 mg of ethyl acetate extract (equivalent to 10 g of by-product) were obtained. The HPCCC fractionation and concentration capabilities were also exploited for the characterization and tentative identification of constitutive PCs by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS). In addition to the isolation of the enriched flavonol fraction, a total of 57 PCs in both matrixes were identified, 12 of which were reported for the first time in WL and/or GP. The application of HPCCC to GP and WL extracts may be a powerful approach to isolate large amounts of minor PCs. The composition of the isolated fraction demonstrated quantitative differences in the individual compound composition of GP and WL, supporting the potential exploitation of these matrixes as sources of specific flavonols for technological applications.
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Rhus trilobata (RHTR) is a medicinal plant with cytotoxic activity in different cancer cell lines. However, the active compounds in this plant against ovarian cancer are unknown. In this study, we aimed to evaluate the antineoplastic activity of RHTR and identify its active metabolites against ovarian cancer. The aqueous extract (AE) and an active fraction (AF02) purified on C18-cartridges/ethyl acetate decreased the viability of SKOV-3 cells at 50 and 38 µg/mL, respectively, compared with CHO-K1 (>50 µg/mL) in MTT assays and generated changes in the cell morphology with apoptosis induction in Hemacolor® and TUNEL assays (p ≤ 0.05, ANOVA). The metabolite profile of AF02 showed a higher abundance of flavonoid and lipid compounds compared with AE by UPLC-MSE. Gallic acid and myricetin were the most active compounds in RHTR against SKOV-3 cells at 50 and 166 µg/mL, respectively (p ≤ 0.05, ANOVA). Antineoplastic studies in Nu/Nu female mice with subcutaneous SKOV-3 cells xenotransplant revealed that 200 mg/kg/i.p. of AE and AF02 inhibited ovarian tumor lesions from 37.6% to 49% after 28 days (p ≤ 0.05, ANOVA). In conclusion, RHTR has antineoplastic activity against ovarian cancer through a cytostatic effect related to gallic acid and myricetin. Therefore, RHTR could be a complementary treatment for this pathology.
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Data in this article are associated with our research article "Effect of Myricetin on Odontoblast-like Cells and its Potential to Preserve Resin-Dentin Bonds." Both a poor infiltration of resin monomers into the demineralized dentin matrix and hydrolytic degradation of the adhesive could lead to the instability of the resin-dentin interface. The degradation of collagen is caused by matrix metalloproteinases (MMP) and cysteine cathepsins. These collagenolytic enzymes are contained in their latent form as pro-MMPs in the dentinal structure, and undergo activation during the adhesive process. Given that the integrity of the collagen matrix is essential for the preservation of the dentin bond strength in both the medium and long term, the inhibition of these proteases is necessary to improve the durability of adhesive restorations. Among the different strategies suggested to improve both the behavior of the substrate against enzymatic degradation and the biomechanical behavior of the adhesive interface, the use of protease inhibitors and collagen crosslinking agents has been recommended, such as polyphenols. Research has focused on flavonoids such as proanthocyanidins (PAC), a class of phenolic compounds found in a variety of plants such as blueberry and grape whose chemical structure favors their action as cross-linking agents. However, the focus has recently shifted towards myricetin (MYR) due to its chemical structure: a greater amount of hydroxyl groups at the substitution positions, which form bonds with the carbonyl groups of the side chains of collagen amino acids and generate interfiber bonds. Our previous study has shown the efficacy of MYR both as a cross-linking agent and as a MMP inhibitor without any immediate effects on microtensile bond strength (µTBS) and preserving it for six months after storage, and maintaining the odontoblastic phenotype without affecting cell viability. The objective of this article is to present a dataset on the effect of flavonoids PAC and MYR on the resin-dentin interface. Given that durability of the resin-dentin bond holds great importance for the clinical longevity of adhesive restorations, our data aims to show the effects of these flavonoids on resin-dentin µTBS after 18-month storage. Test groups for the µTBS assay were set as follows: G1 (negative control), conventional adhesion technique; G2 (vehicle control), 100% ethanol (EtOH) for 120 s; G3, 0.2% chlorhexidine (CHX) for 60 s; G4, 1% glutaraldehyde (GA) for 60 s; and G5, 600 µM myricetin (MYR) for 120 s. Datasets were exported to SPSS software, version 21.0 (SPSS, Chicago, IL, USA) for analysis using the Shapiro-Wilk, a two-way analysis of variance including factor interactions (treatment and storage time). Data are presented as mean ± standard deviation (SD). Differences with p-values < 0.05 were considered significant. Our data can be used as a basis for comparison among other natural and synthetic substances that could work as MMP inhibitors and crosslinking agents. These findings could be useful for designing an effective strategy towards the stabilization of the hybrid layer in a relevant clinical protocol.
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The biological and pharmacological properties of natural polyphenols of the extract of Euterpe oleracea stone (EEOS) are associated with the central nervous system (CNS). To investigate the sedative and myorelaxant activity of EEOS in vivo, this study aimed to present the myorelaxant and sedative effects of EEOS in Wistar rats using spontaneous locomotor activity and motor electrophysiology. A total of 108 animals were used in the following experiments: a) behavioral tests (n = 27); b) electromyographic recordings of skeletal muscle (n = 27); c) respiratory muscle activity recordings (n = 27); d) cardiac muscle activity recordings (n = 27). The behavioral characteristics were measured according to the latency time of onset, the transient loss of posture reflex and maximum muscle relaxation. Electrodes were implanted in the gastrocnemius muscle and in the tenth intercostal space for electromyographic (EMG) signal capture to record muscle contraction, and in the D2 lead for electrocardiogram acquisition. After using the 300 mg/kg dose of EEOS intraperitoneally, a myorelaxant activity exhibited a lower frequency of contractility with an amplitude pattern of low and short duration at gastrocnemius muscle and intercostal muscle, which clearly describes a myorelaxant activity and changes in cardiac activity. The present report is so far the first study to demonstrate the myorelaxant activity of this extract, indicating an alternative route for açai stone valorization and its application in pharmaceutical fields.
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Staphylococcus aureus is an opportunistic pathogen involved in several human diseases and presents ability to produce many virulence factors and resistance to antibacterial agents. One of the current strategies to combat such multidrug resistant bacteria is the antibacterial combination therapy. Myricetin is a flavonoid capable of inhibiting several S. aureus virulence factors without influencing on bacterial growth. Therefore, the combination of antibacterials with the antivirulence compound myricetin may provide a positive interaction to control multidrug resistant-bacteria. This work aims to evaluate the effect of the combination of myricetin with oxacillin and vancomycin against methicillin resistant S. aureus (MRSA) and vancomycin intermediate resistant S. aureus (VISA) strains. Concentrations used in combination assays were determined according to the minimum inhibitory concentration (MIC) for antibacterials and to the biofilm minimum inhibitory concentration (BMIC) for myricetin. Checkerboard evaluations showed reduction in MIC for antibacterials in presence of myricetin and time-kill assays confirmed the synergism for these combinations, except for VISA strain when the flavonoid was combined with vancomycin. Importantly, when myricetin was combined with oxacillin, MRSA strain became susceptible to the antibacterial. Myricetin did not reduce staphyloxanthin production, indicating that the oxacillin susceptibility seems not to be related to this step of functional membrane microdomains. In vivo evaluations using Galleria mellonella confirmed the efficacy of oxacillin plus myricetin in treatment of MRSA infected-larvae when compared to the control groups, increasing in 20% host survival. The present work points out the potential of antibacterial and antivirulence compounds combinations as new alternative to control infections by multidrug resistant-bacteria.
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Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Sinergismo Farmacológico , Flavonoides/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Staphylococcus aureusRESUMO
Dental caries is a diet-biofilm-dependent disease. Streptococcus mutans contributes to cariogenic biofilms by producing an extracellular matrix rich in exopolysaccharides and acids. The study aimed to determine the effect of topical treatments with compound 1771 (modulates lipoteichoic acid (LTA) metabolism) and myricetin (affects the synthesis of exopolysaccharides) on S. mutans biofilms. In vitro S. mutans UA159 biofilms were grown on saliva-coated hydroxyapatite discs, alternating 0.1% sucrose and 0.5% sucrose plus 1% starch. Twice-daily topical treatments were performed with both agents alone and combined with and without fluoride: compound 1771 (2.6 µg/mL), myricetin (500 µg/mL), 1771 + myricetin, fluoride (250 ppm), 1771 + fluoride, myricetin + fluoride, 1771 + myricetin + fluoride, and vehicle. Biofilms were evaluated via microbiological, biochemical, imaging, and gene expression methods. Compound 1771 alone yielded less viable counts, biomass, exopolysaccharides, and extracellular LTA. Moreover, the combination 1771 + myricetin + fluoride decreased three logs of bacterium counts, 60% biomass, >74% exopolysaccharides, and 20% LTA. The effect of treatments on extracellular DNA was not pronounced. The combination strategy affected the size of microcolonies and exopolysaccharides distribution and inhibited the expression of genes linked to insoluble exopolysaccharides synthesis. Therefore, compound 1771 prevented the accumulation of S. mutans biofilm; however, the effect was more pronounced when it was associated with fluoride and myricetin.
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Biofilmes/efeitos dos fármacos , Flavonoides/farmacologia , Fluoretos/farmacologia , Saliva/microbiologia , Bibliotecas de Moléculas Pequenas/farmacologia , Streptococcus mutans/crescimento & desenvolvimento , Administração Tópica , Proteínas de Bactérias/genética , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Sinergismo Farmacológico , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Humanos , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/metabolismo , Modelos Biológicos , Polissacarídeos Bacterianos/antagonistas & inibidores , Polissacarídeos Bacterianos/metabolismo , Saliva/química , Saliva/efeitos dos fármacos , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/genética , Ácidos Teicoicos/antagonistas & inibidores , Ácidos Teicoicos/metabolismoRESUMO
Peptidoglycan (PGN) is a cell wall constituent in dental plaque bacteria that triggers inflammatory responses. PGN binds Toll-like receptors, leading to increases in prostaglandin E2 and interleukin-1ß, which play crucial roles in the inflammatory response and tissue destruction. Dental surgery can give plaque bacteria access to blood circulation, thereby creating a risk of septic inflammation of the endocardium. Plant-derived flavonoids have been reported to reduce inflammatory cytokine secretion by host cells. In the present study, we investigated the effects of flavonoid myricetin on expression of cyclooxygenase 2 (COX-2) in the H9c2 cells treated with PGN from Streptococcus sanguinis, a bacterial constituent of dental plaque associated with infective endocarditis. Myricetin exposure resulted in dose-dependent suppression of PGN-induced COX-2 expression, diminished phosphorylation of p38, extracellular signal regulated kinase 1/2, and c-Jun N-terminal kinase, and reduced IκB-α degradation, consistent with decreased COX-2 activity. In conclusion, the aforementioned results suggest that myricetin is useful for moderating the inflammatory response in infective endocarditis.
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The Myrtaceae is one of the most common plant families in Brazil, including >1000 species of native fruit spread from North to South, where around 50% of all species are endemic to the Atlantic Rain Forest Biome. Most Brazilian species belong to Eugenia, Campomanesia, Psidium and Myrciaria genera. In general, they are characterized by the presence of leaves opposite, simple, entire, with pellucid glands containing ethereal oils and produces berry-like, fleshy fruits with a wide diversity of beneficial characteristics. Several parts of these plants are widely used in regional folk medicine as an astringent, anti-inflammatory, antihypertensive, to treat gastrointestinal disorders, and so on. Some species have already been studied and most of their metabolic effects are attributed to the presence of polyphenols, carotenoids as well as sesquiterpenes and monoterpenes. In addition, the Myrtaceae family has great economic potential, because of the sensory characteristics which encourages their commercial exploitation plus the presence of phytochemicals which play an important role in managing several degenerative chronic diseases besides representing a hotspot of technological innovation for food, cosmetic and pharmaceutical purposes. In this context, this review discusses about the importance of some Eugenia genera representatives such as Eugenia uniflora, Eugenia stipitata, Eugenia brasiliensis, Eugenia pyriformis and Eugenia dysenterica, emphasizing its profile of bioactive compounds as well as the knowledge of the nutritional and functional fruit potential, providing information for further studies aiming to stimulate the cultivation of Brazilian wild berries, for consumption and new food ingredients.
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Eugenia , Frutas/química , Compostos Fitoquímicos , Extratos Vegetais , Animais , Brasil , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Camundongos , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/análise , Extratos Vegetais/química , Extratos Vegetais/farmacologiaRESUMO
In this work, we present a computational study on the antioxidant potential of myricetin 3-O-α-L-rhamnopyranoside (Compound M3) and myricetin 4'-O-α-L-rhamnopyranoside (Compound M4'). Structural parameters, bond dissociation enthalpies (BDEs), ionization potentials (IPs), proton dissociation enthalpies (PDEs), proton affinities (PAs), and electron transfer enthalpies (ETEs), which are properties connected with different mechanisms related to antioxidant activity, were determined using density functional theory (DFT) with B3LYP, LC-ωPBE, M06-2X, and BMK functionals along with the 6-311G(d,p) and 6-311+G(d,p) basis sets in the gas phase, water, and pentylethanoate. The values obtained were compared with results previously available in the literature for myricetin (the parent molecule and a well-known antioxidant) and myricetin 3,4'-di-O-α-L-rhamnopyranoside (Compound M3,4'). As the BDEs are considerably lower than the IPs, the HAT mechanism is preferred over SET for the compounds M3 and M4'. The present study indicates Compound M3 as having its lowest bond dissociation enthalpy from the several different OH groups with similar value to the lowest for myricetin (74.72 kcal/mol versus 74.8 kcal/mol, respectively, at the B3LYP/6-311G(d,p) level of theory in the gas phase) and, thus, presenting antioxidant potential as good as its parent molecule. On the other hand, Compound M4' presented 78.97 kcal/mol as the lowest BDE at the B3LYP/6-311G(d,p) level of theory in the gas phase, that is very close to the 78.34 kcal/mol computed using the same approach for Compound M3,4'. Therefore, the present investigation indicated Compound M4' as being a slightly inferior antioxidant (with antioxidant potential comparable to Compound M3,4') than Compound M3. In addition, the inclusion of the sugar moiety studied here in the position 4'-ArOH of myricetin seems to have a more marked impact (downward) on the antioxidant activity than the glycosylation in the position 3-ArOH.
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The grape is an important fruit regarding economic and health benefit parameters, because of its large consumption around the world and their bioactive phenolic compounds. The drying process of BRS Morena grapes, whether pre-treated or not with olive oil for producing raisins, resulted in qualitative and quantitative changes in their phenolic composition (anthocyanins, flavonols, stilbenes, hydroxycinammic acid derivatives, flavan-3-ols and proanthocyanidins). The raisins with the pre-treatment preserved more anthocyanins and proanthocyanidins than the raisins not pre-treated. Moreover, the total dehydration time accelerated by approximately 40% in the raisins pre-treated. Therefore, the production of raisins of BRS Morena grapes pre-treated with olive oil as a natural surfactant constitutes an interesting process from both the industrial and health points of view, because of the remarkable reduction in the processing time and the preservation of high concentrations of flavonoids, which have important claims to health benefits from biological activities.
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Dessecação , Frutas/química , Fenóis/análise , Vitis/química , Antocianinas/análise , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/análise , Flavonóis/análise , Extratos Vegetais/química , Proantocianidinas/análise , Estilbenos/análiseRESUMO
Myricetin is a flavonoid with several biological properties, including antioxidant and anti-inflammatory features. Its protective effect in chronic diseases may occur through the inhibition of protein kinases that trigger inflammation and carcinogenesis pathways. Considering the influence of kinases on such pathological disorders, it is crucial to study compounds that inhibit these proteins. This study aims to evaluate the inhibitory potential of 14 flavonoids on TNF-α release in human whole blood as well as the inhibitory potential of myricetin towards kinases involved in tumorigenesis. Our results showed that, out of all flavonoids, myricetin had the highest inhibitory effect on TNF-α level. In addition, myricetin showed potential as a multi-anti-kinase compound, reducing the activity of 7 kinases by >70% and of 9 kinases by >90%. Together these data demonstrate the great inhibitory activity of myricetin on tumorigenic kinases and potential for the development of new therapeutics.
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Carcinogênese/efeitos dos fármacos , Flavonoides/farmacologia , Inflamação/tratamento farmacológico , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Inflamação/sangue , Inflamação/imunologia , Neoplasias/sangue , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Plinia cauliflora is a plant species with edible fruits but its chemical composition is not totally known yet although former studies showed its potential as antifungal agent. This work aimed the chemical analysis of the leaves, the activity against fungi species and evaluated cytotoxicity. Extract was obtained with 70% ethanol. An ethyl acetate fraction was obtained and glycosylated quercetin and myricetin were isolated. Samples were tested against Candida species, dermatophytes and entomopathogenic fungi. Cytotoxicity was evaluated against fibroblast cells. Extract showed good activity against C. albicans (minimum inhibitory concentration at 156 µg/mL), C. parapsilosis (78 µg/mL), C. krusei (19 µg/mL), Trichophyton rubrum (78 µg/mL) and Microsporum canis (156 µg/mL). Isolated compounds were more active against C. krusei and T. rubrum. The extract, which was the more active sample, demonstrated low cytotoxic effect and encourage more studies against rising non-albicans species and dermatophyte T. rubrum.
Assuntos
Antifúngicos/isolamento & purificação , Flavonoides/isolamento & purificação , Myrtaceae/química , Folhas de Planta/química , Animais , Antifúngicos/farmacologia , Arthrodermataceae/efeitos dos fármacos , Candida/efeitos dos fármacos , Citotoxinas/isolamento & purificação , Citotoxinas/farmacologia , Fibroblastos/efeitos dos fármacos , Flavonoides/farmacologia , Humanos , Testes de Sensibilidade Microbiana , Microsporum/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Quercetina/isolamento & purificação , Quercetina/farmacologia , Trichophyton/efeitos dos fármacosRESUMO
In this study, the profile of the bioactive compounds of sapucaia nut (Lecythis pisonis Cambess) and its by-products have been investigated. The phenolic profile by LC-ESI-MS/MS, the total phenolic content, the condensed tannins and the antioxidant activity of the sapucaia nut and shell were determined. 14 phenolic compounds were identified in the sapucaia nut extract, primarily phenolic acids and flavonoids. Catechin, epicatechin, myricetin, ellagic acid and ferulic acid presented significant correlation to the antioxidant activity. The sapucaia shell contained 22 phenolic compounds, 13 of which were quantified. The sapucaia shell extract showed a high content of total phenolic compounds, a high condensed tannins content, and high antioxidant activity. The higher antioxidant activity of the shell can be associated with a higher content of phenolics. Overall, it can be concluded that the sapucaia nut is a raw material rich in phenolic compounds that present high antioxidant activity. The nuts and the cake may be used as a promising raw material for the food industry, while the shells could be an alternative source of natural antioxidants. Further use in the cosmetics and pharmaceutical industry may also be envisaged.
Assuntos
Antioxidantes/análise , Lecythidaceae/química , Nozes/química , Fenóis/análise , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/métodos , Manipulação de Alimentos/métodos , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
ABSTRACT Cyperus rotundus L. (Suada, Sueda, family: Cyperaceae) is vastly spread in several world's subtropical and tropical regions. It had variable traditional uses and bioactivities. A new flavonol derivative: cyperaflavoside (myricetin 3,3',5'-trimethyl ether 7-O-β-D-glucopyranoside) and five flavonoids: vitexin, orientin, cinaroside, quercetin 3-O-β-D-glucopyranoside, and myrcetin 3-O-β-D-glucopyranoside were separated from the methanolic extract of C. rotundus aerial parts. Their structures were verified based on UV, IR, NMR (1D and 2D), HRESIMS, and comparison with literature. All metabolites were assessed for their 5-lipoxygenase inhibitory potential. All compounds possessed 5-lipoxygenase inhibitory potentials with IC50s 5.1, 4.5, 5.9, 4.0, 3.7, and 2.3 µM, respectively, in comparison to indomethacin (IC50 0.98 µM). These results supported the traditional uses of C. rotundus in treating inflammation and its related symptoms.