Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42.398
Filtrar
1.
Food Chem ; 366: 130605, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34311239

RESUMO

The Citrus genus is a good source of dietary flavonoids, which have many health benefits. As a representative citrus fruit, the flavonoids composition in Shatianyu (Citrus grandis L. Osbeck) pulp remains to be investigated. In the present study, 11 flavonoids were isolated and identified from Shatianyu pulp flavonoid extracts (SPFEs). Among them, 4 flavonoids were previously undescribed and 2 flavonoids were firstly isolated from pummelo. The cellular antioxidant activity (CAA) and oxygen radical absorbance capacity (ORAC) of isolated compounds were evaluated. Naringin and rhoifolin showed the highest ORAC activity, and the presence of a 3-hydroxy-3-methylglutaryl or a 4'-glucose decreased the ORAC activity of flavonoids. The contribution of isolated flavonoids to the holistic antioxidant activity of SPFEs was determined by an online knockout method. Melitidin, bergamjuicin and naringin contributed most to ORAC activity, while bergamjuicin, melitidin and apigenin-4'-O-ß-d-glucopyranosyl-7-O-α-l-rhamnopyranosyl-(1 â†’ 2)-[6″-O-(3- hydroxy-3-methylgltaryl)]-ß-d-glucopyranoside contributed most to CAA activity.


Assuntos
Citrus , Antioxidantes , Flavonoides , Extratos Vegetais , Polifenóis
2.
Food Chem ; 366: 130593, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34314928

RESUMO

It is a common belief in China that aging could improve the quality of white tea. However, the stored-induced compositional changes remain elusive. In this study, ten subsets of white tea samples, which had been stored for 1-, 2-, 3-, 4-, 5-, 6-, 7-, 10-, 11- and 13- years, were selected. Macro-compositions were quantified firstly. As the results showed, it was interesting to find total flavonoids, thearubigins (TRs), and theabrownines (TBs) increasing, accompanied with a gradual decrease of total polyphenols, which suggest a conversion of phenolic component in the aging process. Then, nontargeted metabolomics was further conducted on selected subsets of samples, including 1-, 7- and 13- years stored to profile their conversion. As a result, most different metabolites were related to flavonol glycosides and flavone glycosides, suggesting dynamic phenolic component changes were vital in aging. The partial least-squares-discriminant analysis (PLS-DA) also identified them as markers in distinguishing.


Assuntos
Metabolômica , Chá , Flavonoides/análise , Polifenóis/análise
3.
Food Chem ; 366: 130597, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34314935

RESUMO

We investigated the effect of bee species identity and harvesting methods on the chemical composition and antiradical activity of 53 honey samples, produced by six stingless bee species in western Kenya (Kakamega forest). Our results illustrate that none of the assayed parameters significantly varied between the honey samples harvested by "punching holes" (n = 25) and "squeezing" (n = 28) methods. By contrast, species identity drove significant differences in the assayed parameters. Positive correlations between the antiradical activity and the phytochemicals (phenols and flavonoids) were observed, and honeys from Liotrigona sp. exhibited the highest amounts of phenols (214 mg GAE/100 g), flavonoids (73.0 mg QE/100 g) and antiradical activity (76.2%). The physicochemical analyses confirm the need to establish separate stingless bee honey standards for moisture, free acidity, invertase, electrical conductivity, and HMF, as these parameters significantly diverged from the set limits for Apis mellifera honey.


Assuntos
Mel , Himenópteros , Animais , Abelhas , Flavonoides , Quênia , Simpatria
4.
Food Chem ; 366: 130689, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34343950

RESUMO

This research established the optimal conditions for infusion extraction (IE) and ultrasound-assisted extraction (UAE) of bioactive components from laver (Porphyra dentata) using response surface methodology (RSM) and artificial neural network coupled with genetic algorithm (RSM-ANN-GA). The variables, temperatures (60, 80, and 100 ℃) and times (10, 15, and 20 min) were designed to optimise total phenolic, total flavonoid, total amino acid, a* value, and R-phycoerythrin content of laver extract. The optimised condition for IE and UAE was achieved at 60 ℃ for 18.08 min and 80.66℃ for 14.76 min in RSM while showing 60 ℃ for 19 min and 80℃ for 15 min in the RSM-ANN-GA mode, respectively. Results revealed that RSM-ANN-GA provided better predictability and greater accuracy than the RSM model and laver extract from UAE gave the higher values of responses compared to those from IE. These findings highlight the high-efficient extraction method along with better statistical approach.


Assuntos
Porphyra , Flavonoides , Redes Neurais de Computação , Fenóis , Extratos Vegetais
5.
Food Chem ; 367: 130682, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34364147

RESUMO

Basil is an edible, aromatic plant, which makes the study of the ecotoxicity of metals in plant metabolism relevant. Given the above, the objective of this study was to evaluate the effects of metals, aluminum, lead, and cadmium, in the synthesis of phenolic compounds and in the dry mass of basil plants (O. basilicum L.) grown in a hydroponic system. The plants were subjected to four different concentrations of cadmium (0.2, 0.6, 1.2, and 1.8 mmol L-1), lead and aluminum (0.04, 0.08, 0.12, and 0.16 mmol L-1), and compared with the control. After desiccation of the plant material, the total dry mass was obtained and then, hydroethanolic extracts (43% distilled water and 57% ethanol) were made for biochemical analyzes, which consisted of the determination of caffeic acid (CA) and rosmarinic acid (RA) by high performance liquid chromatography analysis with a diode detector (HPLC-DAD); total phenolics (TP) and total flavonoids (TF) by spectrophotometry. The data were submitted to analysis of variance and multivariate analysis (principal component analysis-PCA and hierarchical cluster analysis-HCA) was applied for data association. The phenolic compounds showed a high positive correlation with each other, and the total dry mass showed low and negative correlations with the analyzed variables. The results showed that the metals aluminum, lead, and cadmium promoted a stress condition in basil plants, which resulted in the reduction of the dry matter mass and an increase in the synthesis of phenolic compounds, according to the type and concentration of the metal.


Assuntos
Ocimum basilicum , Antioxidantes , Cádmio , Ácidos Cafeicos , Cinamatos , Depsídeos , Flavonoides , Chumbo , Análise Multivariada
6.
Food Chem ; 367: 130744, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34384977

RESUMO

Conventional methods for determining phenolics and their bioactive properties are expensive, time-consuming, and laborious. This hinders the quality control of red propolis, recognized for having different types of phenolic constituents with different bioactive properties, for example, its antioxidant properties. In this sense, we present a new application of near and medium infrared spectroscopy to predict phenolic constituents, total flavonoids, gallic acid, kaempferol, pyrocatechin, quercetin, and different antioxidant tests (DPPH radical, reducing power and protection of the ß-carotene: linoleic acid system) of red propolis using chemometry. The optimized models showed good predictive capacity with a minimum correlation coefficient of 0.70, low associated error, and figures of merit that indicate the good predictive capacity in the validation of the models. These data show infrared spectroscopy as efficient to simultaneously predict nine quality analyzes of red propolis quickly and simply. This also avoids tedious procedures for traditional chromatographic and spectrophotometric tests.


Assuntos
Própole , Antioxidantes , Flavonoides , Análise Multivariada , Fenóis , Espectrofotometria Infravermelho
7.
BMC Complement Med Ther ; 21(1): 219, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470625

RESUMO

BACKGROUND: Pears have been world-widely used as a sweet and nutritious food and a folk medicine for more than two millennia. METHODS: We conducted a review from ancient literatures to current reports to extract evidence-based functions of pears. RESULTS: We found that pears have many active compounds, e.g., flavonoids, triterpenoids, and phenolic acids including arbutin, chlorogenic acid, malaxinic acid, etc. Most of researchers agree that the beneficial compounds are concentrated in the peels. From various in vitro, in vivo, and human studies, the medicinal functions of pears can be summarized as anti-diabetic,-obese, -hyperlipidemic, -inflammatory, -mutagenic, and -carcinogenic effects, detoxification of xenobiotics, respiratory and cardio-protective effects, and skin whitening effects. Therefore, pears seem to be even effective for prevention from Covid-19 or PM2.5 among high susceptible people with multiple underlying diseases. CONCLUSION: For the current or post Covid-19 era, pears have potential for functional food or medicine for both of communicable and non-communicable disease.


Assuntos
Frutas/química , Alimento Funcional , Compostos Fitoquímicos/farmacologia , Pyrus/química , COVID-19 , Flavonoides , Humanos , Fenóis , Triterpenos
8.
Molecules ; 26(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34500636

RESUMO

The African pumpkin (Momordica balsamina) contains bioactive phenolic compounds that may assist in reducing oxidative stress in the human body. The leaves are mainly consumed after boiling in water for a specific time; this hydrothermal process and conditions of the gastrointestinal tract may affect the presence and bioactivity of phenolics either positively or negatively. In this study, the effects of hydrothermal processing (boiling) and in vitro simulated human digestion on the phenolic composition, bioaccessibility and bioactivity in African pumpkin were investigated in comparison with those of spinach (Spinacia oleracea). A high-resolution ultra-performance liquid chromatography, coupled with diode array detection, quadrupole time-of-flight and mass spectrometer (UPLC-DAD-QTOF-MS) was used to profile phenolic metabolites. Metabolites such as 3-caffeoylquinic acid, 5-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid and 4,5-dicaffeoylquinic acid were highly concentrated in the boiled vegetable extracts compared to the raw undigested and all digested samples. The majority of African pumpkin and spinach extracts (non-digested and digested) protected Deoxyribonucleic acid (DNA), (mouse fibroblast) L929 and human epithelial colorectal adenocarcinoma (Caco-2) cells from 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced oxidative damage. From these results, the consumption of boiled African pumpkin leaves, as well as spinach, could be encouraged, as bioactive metabolites present may reduce oxidative stress in the body.


Assuntos
Cucurbita/química , Digestão/efeitos dos fármacos , Momordica/química , Fenóis/química , Fenóis/farmacologia , Folhas de Planta/química , Animais , Antioxidantes/química , Células CACO-2 , Linhagem Celular Tumoral , Flavonoides/química , Humanos , Camundongos , Oxirredução/efeitos dos fármacos , Extratos Vegetais/química , Polifenóis/química , Ácido Quínico/análogos & derivados , Ácido Quínico/química , Spinacia oleracea/química , Verduras/química
9.
Molecules ; 26(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34500647

RESUMO

Diabetes mellitus is a major health problem globally. The management of carbohydrate digestion provides an alternative treatment. Flavonoids constitute the largest group of polyphenolic compounds, produced by plants widely consumed as food and/or used for therapeutic purposes. As such, isoxazoles have attracted the attention of medicinal chemists by dint of their considerable bioactivity. Thus, the main goal of this work was to discover new hybrid molecules with properties of both flavonoids and isoxazoles in order to control carbohydrate digestion. Moreover, the trifluoromethyl group is a key entity in drug development, due to its strong lipophilicity and metabolic stability. Therefore, the present work describes the condensation of a previously synthesized trifluoromethylated flavonol with different aryl nitrile oxides, affording 13 hybrid molecules indicated as trifluoromethylated flavonoid-based isoxazoles. The structures of the obtained compounds were deduced from by 1H NMR, 13C NMR, and HRMS analysis. The 15 newly synthesized compounds inhibited the activity of α-amylase with an efficacy ranging from 64.5 ± 0.7% to 94.7 ± 1.2% at a concentration of 50 µM, and with IC50 values of 12.6 ± 0.2 µM-27.6 ± 1.1 µM. The most effective compounds in terms of efficacy and potency were 3b, 3h, 3j, and 3m. Among the new trifluoromethylated flavonoid-based isoxazoles, the compound 3b was the most effective inhibitor of α-amylase activity (PI = 94.7 ± 1.2% at 50 µM), with a potency (IC50 = 12.6 ± 0.2 µM) similar to that of the positive control acarbose (IC50 = 12.4 ± 0.1 µM). The study of the structure-activity relationship based on the molecular docking analysis showed a low binding energy, a correct mode of interaction in the active pocket of the target enzyme, and an ability to interact with the key residues of glycosidic cleavage (GLU-230 and ASP-206), explaining the inhibitory effects of α-amylase established by several derivatives.


Assuntos
Fármacos Antiobesidade/farmacologia , Diabetes Mellitus/tratamento farmacológico , Flavonoides/farmacologia , Hipoglicemiantes/farmacologia , Isoxazóis/farmacologia , alfa-Amilases/antagonistas & inibidores , Fármacos Antiobesidade/química , Diabetes Mellitus/metabolismo , Flavonoides/química , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Humanos , Hipoglicemiantes/química , Isoxazóis/química , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , alfa-Glucosidases/metabolismo
10.
Anal Chim Acta ; 1180: 338874, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34538332

RESUMO

Prenylated (iso)flavonoids are potent bioactive compounds found in the Fabaceae family. Analysis and quantification of this type of phytochemicals is challenging due to their large structural diversity. In this study, the fragmentation of prenylated (iso)flavonoids was investigated using electrospray ionization ion trap mass spectrometry (ESI-IT-MSn) with fragmentation by collision induced dissociation (CID) in combination and Orbitrap-MS (ESI-FT-MS2) with fragmentation by higher energy C-trap dissociation (HCD). With this combination of IT-MSn and high resolution MS (FT-MSn), it was possible to determine the fragmentation pathways and characteristic spectral features of different subclasses of prenylated (iso)flavonoid standards, as well as characteristic fragmentations and neutral losses of different prenyl configurations. Based on our findings, a decision guideline was developed to (i) identify (iso)flavonoid backbones, (ii) annotate prenyl number, (iii) configuration, and (iv) position of unknown prenylated (iso)flavonoids, in complex plant extracts. In this guideline, structural characteristics were identified based on: (i) UV absorbance of the compound, (ii) mass-to-charge (m/z) ratio of the parent compound; (iii) ratio of relative abundances between neutral losses 42 and 56 u in MSn; (iv) retro-Diels-Alder (RDA) fragments, neutral losses 54 and 68 u, and the ratio [M+H-C4H8]+/[M+H]+. Using this guideline, 196 prenylated (iso)flavonoids were annotated in a Glycyrrhiza glabra root extract. In total, 75 skeletons were single prenylated, 104 were double prenylated, and for merely 17 skeletons prenyl number could not unambiguously be annotated. Our prenylation guideline allows rapid screening for identification of prenylated (iso)flavonoids, including prenyl number, configuration, and position, in complex plant extracts. This guideline supports research on these bioactive compounds in the areas of plant metabolomics and natural products.


Assuntos
Flavonoides , Espectrometria de Massas por Ionização por Electrospray , Neopreno , Extratos Vegetais , Prenilação
11.
Molecules ; 26(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34500546

RESUMO

The present study aims to evaluate the chemical composition, metabolites secondary and pharmacology activities of methanolic extract of Marrubium vulgare collected from King Saudi Arabia. Moreover, the primary mode of action of the tested extract was studied here for the first time against E. coli and L. monocytogenes. HPLC analysis shows that the major components in the tested extract are luteolin-7-O-d-glucoside, ferulic acid and premarrubiin. Obtained data demonstrated that the investigated extract was richer in phenol (26.8 ± 0.01 mg/GAE g) than in flavonoids (0.61 ± 0.05 mg EC/mL). In addition, the methanolic extract showed an important antioxidant capacity against the DPPH (IC50 = 35 ± 0.01 µg/mL) and ABTS (IC50 = 25 ± 0.2 µg/mL) radical scavenging and a strong inhibition of acetylcholinesterase enzyme with an IC50 value corresponding to 0.4 mg/mL. The antibacterial activity demonstrated that the evaluated extract had significant activity against both Gram-positive and Gram-negative bacteria. The effect of time on cell integrity on E. coli and L. monocytogenes determined by time-kill and bacteriolysis tests showed that the M. vulgare extract reduced the viability of both strains after 8 and 10 h and had a bacteriolytic effect against two different categories of bacteria, Gram-positive and negative, which are not of the same potency. Based on obtained data, it can be concluded that Saudi M. vulgare has a high pharmacological importance and can be used in preparation of food or drugs.


Assuntos
Antibacterianos/farmacologia , Doenças Transmitidas por Alimentos/tratamento farmacológico , Marrubium/química , Extratos Vegetais/farmacologia , Antioxidantes/fisiologia , Cromatografia Líquida de Alta Pressão/métodos , Escherichia coli/efeitos dos fármacos , Flavonoides/farmacologia , Doenças Transmitidas por Alimentos/microbiologia , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Fenóis/farmacologia , Arábia Saudita
12.
Molecules ; 26(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34500597

RESUMO

Breast cancer persists as a diffuse source of cancer despite persistent detection and treatment. Flavonoids, a type of polyphenol, appear to be a productive option in the treatment of breast cancer, because of their capacity to regulate the tumor related functions of class of compounds. Plant polyphenols are flavonoids that appear to exhibit properties which are beneficial for breast cancer therapy. Numerous epidemiologic studies have been performed on the dynamic effect of plant polyphenols in the prevention of breast cancer. There are also subclasses of flavonoids that have antioxidant and anticarcinogenic activity. These can regulate the scavenging activity of reactive oxygen species (ROS) which help in cell cycle arrest and suppress the uncontrolled division of cancer cells. Numerous studies have also been performed at the population level, one of which reported a connection between cancer risk and intake of dietary flavonoids. Breast cancer appears to show intertumoral heterogeneity with estrogen receptor positive and negative cells. This review describes breast cancer, its various factors, and the function of flavonoids in the prevention and treatment of breast cancer, namely, how flavonoids and their subtypes are used in treatment. This review proposes that cancer risk can be reduced, and that cancer can be even cured by improving dietary intake. A large number of studies also suggested that the intake of fruit and vegetables is associated with reduced breast cancer and paper also includes the role and the use of nanodelivery of flavonoids in the healing of breast cancer. In addition, the therapeutic potential of orally administered phyto-bioactive compounds (PBCs) is narrowed because of poor stability and oral bioavailability of compounds in the gastrointestinal tract (GIT), and solubility also affects bioavailability. In recent years, creative nanotechnology-based approaches have been advised to enhance the activity of PBCs. Nanotechnology also offers the potential to become aware of disease at earlier stages, such as the detection of hidden or unconcealed metastasis colonies in patients diagnosed with lung, colon, prostate, ovarian, and breast cancer. However, nanoformulation-related effects and safety must not be overlooked. This review gives a brief discussion of nanoformulations and the effect of nanotechnology on herbal drugs.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Flavonoides/farmacologia , Nanopartículas/administração & dosagem , Animais , Antioxidantes/farmacologia , Disponibilidade Biológica , Neoplasias da Mama/metabolismo , Feminino , Frutas/química , Humanos , Polifenóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Verduras/química
13.
Zhongguo Zhong Yao Za Zhi ; 46(12): 2889-2899, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34467710

RESUMO

Sophorae Flavescentis Radix,derived from the root of Sophora flavescens in the Leguminosae family,has been widely used in the medicine,agriculture,animal husbandry,and daily chemical industry. A pharmacophore model-based method for rapid discovery of tyrosinase inhibitors( TIs) from S. flavescens was established by molecular docking under Lipinski rules,and verified by enzyme assays. Briefly,the chemical constituent database of S. flavescens( CDSF) was established based on the previous papers. Theoptimal pharmacophore model( OPM) was constructed by DS 2019 on the basis of known active TIs. Eighty-three hits predominated by flavonoids having higher fitting scores with OPM than the positive control were screened out,and subjected to molecular docking based on the three-dimensional structure of tyrosinase crystal protein. The potential TIs such as kurarinone and nor-kurarinone were rapidly discovered from the compounds with higher docking scores than the positive control under the Lipinski rules. The results were verified by the in vitro enzyme assays. The inhibition activities of tyrosinase from non-medicinal parts of S. flavescens were also tested to explore the relationship between the inhibition activity and chemical compositions. This study is expected to provide data support for the comprehensive application and development of S. flavescens and also a new method for the rapid discovery of active substances or functional constituents in the complex systems.


Assuntos
Sophora , Animais , Flavonoides , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase , Extratos Vegetais/farmacologia , Raízes de Plantas
14.
Zhongguo Zhong Yao Za Zhi ; 46(16): 4167-4174, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34467729

RESUMO

This study aimed to explore the effects of galangin on energy metabolism and autophagy in gastric cancer MGC803 cells and the underlying mechanism. Cell counting kit-8(CCK-8) was used to detect the effects of galangin at different concentrations on via-bility of MGC803 cells after 48 h intervention. Western blot was carried out to measure the effects of galangin on expression of proteins related to autophagy, nuclear factor-κB(NF-κB) pathway and energy metabolism, followed by the determination of its effects on mRNA expression of energy metabolism-related proteins by Real-time quantitative PCR(qPCR). The impact of galangin on autophagy was explored using AutophagyGreen dye reagent, with autophagosomes and lysosomes observed under the transmission electron microscope(TEM). Nude mice transplanted with gastric cancer MGC803 cells via subcutaneous injection were randomly divided into the following three groups: control(0.5% sodium carboxymethyl cellulose, once a day), 5-fluorouracil(5-FU, 50 mg·kg~(-1), twice a week), and galangin(120 mg·kg~(-1), once a day) groups. The body weight and tumor volume were measured once every three days with a vernier caliper at the same time point by the same person. After 21-d treatment, the tumor tissue was isolated and weighed for the calculation of the tumor-suppressing rate. The comparison with the control group revealed that galangin inhibited the viability of MGC803 cells, up-regulated the protein expression of microtuble-associated protein 1 light chain 3 B(LC3 B) Ⅱ, inhibited the phosphorylation of NF-κB pathway-related proteins, and promoted the formation of autophagosomes in MGC803 cells. However, it did not obviously affect the expression of energy metabolism-related proteins. Furthermore, galangin at 120 mg·kg~(-1) significantly reduced the tumor weight and volume in mice, enhanced LC3 BⅡ protein expression, and inhibited the phosphorylation of NF-κB pathway-related proteins. All these have suggested that galangin inhibited the growth of gastric cancer MGC803 cells both in vivo and in vitro, possibly by inhibiting the NF-κB pathway and enhancing autophagy.


Assuntos
NF-kappa B , Neoplasias Gástricas , Animais , Autofagia , Flavonoides , Camundongos , Camundongos Nus , NF-kappa B/genética , Transdução de Sinais , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética
15.
Enzyme Microb Technol ; 150: 109862, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34489021

RESUMO

Glycosylation and methylation of flavonoids are the main types of structural modifications and can endow flavonoids with greater stability, bioactivity, and bioavailability. In this study, five types of O-methyltransferases were screened for producing O-methylated luteolin, and the biosynthesis strategy of 3'-O-methylisoorientin from luteolin was determined. To improve the production of 3'-O-methylluteolin, the S-adenosyl-l-methionine synthesis pathway was reconstructed in the recombinant strain by introducing S-adenosyl-l-methionine synthetase genes. After optimizing the conversion conditions, maximal 3'-O-methylluteolin production reached 641 ± 25 mg/L with a corresponding molar conversion of 76.5 %, which was the highest titer of methylated flavonoids reported to date in Escherichia coli. 3'-O-Methylluteolin (127 mg) was prepared from 250 mL of the broth by silica gel column chromatography and preparative HPLC with a yield of 79.4 %. Subsequently, we used the biocatalytic cascade of Gentiana triflora C-glycosyltransferase (Gt6CGT) and Glycine max sucrose synthase (GmSUS) to biosynthesize 3'-O-methylisoorientin from 3'-O-methylluteolin in vitro. By optimizing the coupled reaction conditions and using the fed-batch operation, maximal 3'-O-methylisoorientin production reached 226 ± 8 mg/L with a corresponding molar conversion of 98 %. Therefore, this study provides an efficient method for the production of novel 3'-O-methylisoorientin and the biosynthesis strategy for methylated C-glycosylation flavonoids by selective O-methylation/C-glycosylation motif on flavonoids.


Assuntos
Flavonoides , Luteolina , Glicosilação , Metilação , Metiltransferases/metabolismo
16.
Talanta ; 235: 122734, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517603

RESUMO

Polyphenols are bioactive substances of vegetal origin with a significant impact on human health. The assessment of polyphenol intake and excretion is therefore important. In this work, a new electrochemical approach based on molecularly imprinted polymer extraction and preconcentration, combined with a disposable carbon screen-printed sensor and adsorptive transfer differential pulse voltammetry detection has been proposed for quantifying of 4-hydroxyphenylacetic acid (4-HPA), which is a biomarker of flavan-3-ols intake, and other phenolic acids. The simple experimental performance has allowed the rapid data collection with relevant information about the profile of catabolites extracted. The method was validated over a concentration range of 10-200 mg L-1, R2 > 0.999. In the optimized conditions, the recovery value was 94% with RSD 8%. The limits of detection and quantification were 2.38 mg L-1 and 7.21 mg L-1, respectively. The method was validated by means of a chromatographic method, being the differences between the values of the 4-HPA concentrations obtained by both methods under 1%. The proposed method showed high recoveries, low detection limit, and good accuracy, providing a fast, reliable, and cheap procedure to quantify phenolic metabolites in urine, and representing therefore a good and interesting alternative method. Also, the procedure offers other advantages, including the miniaturization, the low use of organic solvents, the ability to analyse small volumes of samples, in situ analysis and simple instrumentation requirement.


Assuntos
Impressão Molecular , Técnicas Eletroquímicas , Eletrodos , Flavonoides , Humanos , Limite de Detecção , Extração em Fase Sólida , Solventes
17.
Anticancer Res ; 41(9): 4377-4385, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34475057

RESUMO

BACKGROUND/AIM: Expression of pleckstrin homology-like domain family A member 2 (PHLDA2) has been reported to be suppressed or activated in several cases of malignant tumors. However, its apoptotic regulatory mechanism and role in gastric cancer are not understood. This study examined the role of PHLDA2 in apoptosis in gastric cancer. MATERIALS AND METHODS: We used cell culture, western blotting, semiquantitative reverse transcription polymerase chain reaction, MTT assays, and PHLDA2 knockdown with short hairpin RNA (shRNA). RESULTS: To identify the pathway associated with HGF-induced PHLDA2 up-regulation, the cells were treated with PI3-kinase inhibitor (LY294002), MEK inhibitor (PD098059), or p38 inhibitor (SB203580) and then analyzed by western blotting. HGF-mediated changes in PHLDA2 protein levels were only decreased by LY294002. PHLDA2-shRNA cells showed decreased levels of p53 and increased levels of pAKT. Furthermore, HGF-induced cell proliferation and in vitro invasion were increased in PHLDA2 knockdown cells and HGF-induced cell apoptosis was increased in PHLDA2 knockdown cells. CONCLUSION: PHLDA2 plays a role in gastric cancer tumorigenesis by inhibiting apoptosis through the PI3K/AKT pathway.


Assuntos
Fator de Crescimento de Hepatócito/metabolismo , Proteínas Nucleares/metabolismo , Neoplasias Gástricas/metabolismo , Regulação para Cima , Apoptose , Linhagem Celular Tumoral , Cromonas/farmacologia , Flavonoides/farmacologia , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Imidazóis , Morfolinas/farmacologia , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Piridinas
18.
Trop Biomed ; 38(3): 360-365, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34508344

RESUMO

COVID-19, caused by the SARS-CoV-2 virus, can lead to massive inflammation in the gastrointestinal tract causing severe clinical symptoms. SARS-CoV-2 infects lungs after binding its spike proteins with alveolar angiotensin-converting enzyme 2 (ACE2), and it also triggers inflammation in the gastrointestinal tract. SARS-CoV-2 invades the gastrointestinal tract by interacting with Toll-like receptor-4 (TLR4) that induces the expression of ACE2. The influx of ACE2 facilitates cellular binding of more SARS-CoV-2 and causes massive gastrointestinal inflammation leading to diarrhea. Diarrhea prior to COVID-19 infection or COVID-19-induced diarrhea reportedly ends up in a poor prognosis for the patient. Flavonoids are part of traditional remedies for gastrointestinal disorders. Preclinical studies show that flavonoids can prevent infectious diarrhea. Recent studies show flavonoids can inhibit the multiplication of SARS-CoV-2. In combination with vitamin D, flavonoids possibly activate nuclear factor erythroid-derived-2-related factor 2 that downregulates ACE2 expression in cells. We suggest that flavonoids have the potential to prevent SARS-CoV-2 induced diarrhea.


Assuntos
COVID-19/complicações , Diarreia/prevenção & controle , Flavonoides/uso terapêutico , SARS-CoV-2 , Enzima de Conversão de Angiotensina 2/fisiologia , Diarreia/etiologia , Humanos
19.
Braz J Biol ; 83: e243438, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34468509

RESUMO

Cisplatin (CP) is a commonly used, powerful antineoplastic drug, having numerous side effects. Casticin (CAS) is considered as a free radical scavenger and a potent antioxidant. The present research was planned to assess the curative potential of CAS on CP persuaded renal injury in male albino rats. Twenty four male albino rats were distributed into four equal groups. Group-1 was considered as a control group. Animals of Group-2 were injected with 5mg/kg of CP intraperitoneally. Group-3 was co-treated with CAS (50mg/kg) orally and injection of CP (5mg/kg). Group-4 was treated with CAS (50mg/kg) orally throughout the experiment. CP administration substantially reduced the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione S-transferase (GST), glutathione reductase (GSR), glutathione (GSH) content while increased thiobarbituric acid reactive substances (TBARS), and hydrogen peroxide (H2O2) levels. Urea, urinary creatinine, urobilinogen, urinary proteins, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels were substantially increased. In contrast, albumin and creatinine clearance was significantly reduced in CP treated group. The results demonstrated that CP significantly increased the inflammation indicators including nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), Interleukin-1ß (IL-1ß), Interleukin-6 (IL-6) levels and cyclooxygenase-2 (COX-2) activity and histopathological damages. However, the administration of CAS displayed a palliative effect against CP-generated renal toxicity and recovered all parameters by bringing them to a normal level. These results revealed that the CAS is an effective compound having the curative potential to counter the CP-induced renal damage.


Assuntos
Cisplatino , Peróxido de Hidrogênio , Animais , Antioxidantes , Cisplatino/toxicidade , Flavonoides , Masculino , Estresse Oxidativo , Ratos , Superóxido Dismutase/metabolismo
20.
Zhongguo Zhong Yao Za Zhi ; 46(15): 3806-3813, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34472253

RESUMO

Phytohormones play an important role at all stages of plant growth, influencing plant growth and development and regulating plant secondary metabolism, such as the synthesis of flavone, flavonol, anthocyanin, and other flavonoids. Flavonoids, a group of important secondary metabolites ubiquitous in plants, have antioxidative, anti-microbial, and anti-inflammatory activities and thus have a wide range of potential applications in Chinese medicine and food nutrition. With the development of biotechnology, phytohormones' regulation on flavonoids has become a research focus in recent years. This study reviewed the research progress on the mechanism of common phytohormones, such as abscisic acid, gibberellin, methyl jasmonate, and salicylic acid, in regulating flavonoid metabolism, and discussed the molecular mechanism of the synthesis and accumulation of flavonoids, aiming at clarifying the key role of phytohormones in modulating flavonoid metabolism. The result is of guiding significance for improving the content of flavonoids in plants through rational use of phytohormones and of reference value for exploring the mechanism of hormones in regulating flavonoid metabolism.


Assuntos
Giberelinas , Reguladores de Crescimento de Plantas , Ácido Abscísico , Flavonoides , Regulação da Expressão Gênica de Plantas , Desenvolvimento Vegetal
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...