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1.
Food Chem ; 298: 124987, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260962

RESUMO

In this study, subcritical water extraction (SWE), SWE in aqueous citric acid (pH 5.0) (SWEC), and ultrasound-assisted SWEC (USWEC) were used to extract soluble dietary fiber (SDF) from wheat bran. Results showed that SWE-based methods significantly influenced the physicochemical, functional, and biological properties of the SDF. The fraction SDF-III attained via USWEC had higher SDF yield (46.30%) and carbohydrate content (82.91%), and lower weight-average molecular weight (65.2 kDa) and particle size (1.17 µm), and looser and more porous surface structure, compared with the SDF-I and SDF-II obtained by SWE and SWEC, respectively. USWEC increased the thermal stability and homogeneity of SDF-III but decreased its apparent viscosity and dynamic viscoelasticity. Moreover, the SDF-III exhibited more significant antioxidant and α-amylase inhibitory activities in vitro than SDF-I and SDF-II. Therefore, the USWEC technique had a greater potential for the highly-efficient production of SDF from wheat bran.


Assuntos
Fracionamento Químico/métodos , Fibras na Dieta , Antioxidantes/química , Antioxidantes/farmacologia , Ácido Cítrico/química , Fibras na Dieta/farmacologia , Difusão Dinâmica da Luz , Inibidores Enzimáticos/farmacologia , Concentração de Íons de Hidrogênio , Peso Molecular , Monossacarídeos/análise , Tamanho da Partícula , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade , Água/química , alfa-Amilases/antagonistas & inibidores
2.
Food Chem ; 298: 125026, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260961

RESUMO

Roasted cotyledons of the Chilean hazelnut (Gevuina avellana) are appreciated as snacks. The aim of our work was to assess the fatty acid, oxylipin and phenolic composition using gas chromatography (GC) coupled to mass spectrometry (MS), ultra- high performance liquid chromatography (UHPLC) coupled to MS and HPLC coupled to diode array detector (HPLC-DAD). Additionally, various antioxidant activities were assessed. The inhibition of α-glucosidase, α-amylase, lipase, cyclooxygenases-1 and -2 (COX-1/COX-2), and lipoxygenase was determined. The main fatty acids were oleic and 7-hexadecenoic acids. Eight phytoprostanes and three phytofurans were identified and quantified. Hydroxybenzoic and hydroxycinnamic acids were the main phenolic compounds. Oils showed antioxidant activity determined by EPR, and inhibition of COX-1/COX-2. The statistical analysis showed that the roasting does not affect the composition of the samples. The occurrence of oxylipins in this species is reported for the first time. Chilean hazelnuts can be considered a source of health promoting compounds.


Assuntos
Antioxidantes/química , Corylus/química , Síndrome Metabólica/enzimologia , Oxilipinas/análise , Fenóis/análise , Chile , Ácidos Cumáricos/análise , Cromatografia Gasosa-Espectrometria de Massas , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/metabolismo
3.
J Photochem Photobiol B ; 197: 111541, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31272033

RESUMO

Here, we report the novel fabrication of ZnO nanoparticles using the Costus igneus leaf extract. Gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy to determine the bioactive components present in the plant extract. The synthesis of Ci-ZnO NPs (C. igneus- coated zinc oxide nanoparticles) was accomplished using a cost-effective and simple technique. Ci-ZnO NPs were specified using UV-visible spectroscopy, FTIR, XRD, and TEM. Ci-ZnO NPs was authenticated by UV-Vis and exhibited a peak at 365 nm. The XRD spectra proved the crystalline character of the Ci-ZnO NPs synthesized as hexagonal wurtzite. The FTIR spectrum illustrated the presence of possible functional groups present in Ci-ZnO NPs. The TEM micrograph showed evidence of the presence of a hexagonal organization with a size of 26.55 nm typical of Ci-ZnO NPs. The α-amylase and α-glucosidase inhibition assays demonstrated antidiabetic activity of Ci-ZnO NPs (74 % and 82 %, respectively), and the DPPH [2,2-diphenyl-1-picrylhydrazyl hydrate] assay demonstrated the antioxidant activity of the nanoparticles (75%) at a concentration of 100 µg/ml. The Ci-ZnO NPs exhibited promising antibacterial and biofilm inhibition activity against the pathogenic bacteria Streptococcus mutans, Lysinibacillus fusiformis, Proteus vulgaris, and Vibrio parahaemolyticus. Additionally, the Ci-ZnO NPs showed biocompatibility with mammalian RBCs with minimum hemolytic activity (0.633 % ±â€¯0.005 %) at a concentration of 200 µg/ml.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/química , Biofilmes/efeitos dos fármacos , Nanopartículas Metálicas/química , Extratos Vegetais/química , Óxido de Zinco/química , Antibacterianos/síntese química , Antibacterianos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Costus/química , Costus/metabolismo , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/fisiologia , Química Verde , Hemólise/efeitos dos fármacos , Humanos , Insulina/química , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
4.
Carbohydr Polym ; 219: 219-228, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151520

RESUMO

Coreopsis tinctoria is being widely cultivated in Xinjiang of China, whose consumption is known to prevent diabetes and neurodegenerative diseases. To elucidate the bioactive ingredients responsible for these benefits, the alkaline soluble crude polysaccharide (CTB) was isolated from C. tinctoria. In vitro experiments showed that the inhibition of α-amylase and α-glucosidase by CTB was 13407-fold and 906-fold higher than that by positive control, respectively. Then, a novel arabinogalactan, CTBP-1, was isolated and purified from CTB. Structural analysis showed that CTBP-1 possessed a 1,6-linked ß-d-Galp and 1,5-linked α-l-Araf backbone with branches substituted at the C-3 position of the 1,6-linked ß-d-Galp, and the side chains included 1,5-linked α-l-Araf, T-linked ß-d-Galp and T-linked α-l-Araf. The inhibitory effects of CTBP-1 on α-amylase and α-glucosidase were 2.7 and 17.9 times that of acarbose, respectively. CTBP-1 could avoid indigestion and similar side effects. In addition, CTBP-1 remarkably inhibited the release of nitric oxide (NO), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. In summary, CTBP-1 is a novel arabinogalactan with great potential as a treatment for type 2 diabetes and Alzheimer's disease.


Assuntos
Coreopsis/metabolismo , Galactanos , Inibidores de Glicosídeo Hidrolases/farmacologia , Microglia , Extratos Vegetais/química , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/metabolismo , Células Cultivadas , China , Galactanos/química , Galactanos/farmacologia , Interleucina-6/metabolismo , Lipopolissacarídeos/farmacologia , Microglia/citologia , Microglia/efeitos dos fármacos , Óxido Nítrico/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
5.
J Sci Food Agric ; 99(13): 6001-6010, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31225640

RESUMO

BACKGROUND: In this study, we aimed to evaluate the influence of different extraction procedures [decoction, homogenizer-assisted extraction (HAE), infusion, maceration, Soxhlet and ultrasound-assisted extraction (UAE)] on the chemical profiling and biological properties of methanol and water extracts of Pulicaria dysenterica (L.) Bernh. The chemical profiles of the extracts were evaluated by high-performance liquid chromatography coupled to electrospray ionization and time-of-flight mass spectrometry (HPLC-ESI-TOF-MS). The antioxidant properties and enzymes (lipase, α-amylase, α-glucosidase, tyrosinase and cholinesterases) inhibitory potential of the extracts were evaluated. RESULTS: The chemical profiles were dependent on the type of extraction methods as well as on the type of solvent. The methanolic extracts showed higher levels of total phenolic, flavonoid, and phenolic acid content, while the highest total flavonol content was observed in the HAE-water extract. Forty different compounds were identified from P. dysenterica. In relation to the potential in vitro anti-diabetic effects, the highest activity against the studied key enzymes was observed for the macerated extract (α-amylase: 0.58 ± 0.03 and α- glucosidase: 1.65 ± 0.03 mmol ACAE g-1 ). The HAE-methanol extract was the most potent inhibitor of cholisterases, whereas the highest activities against tyrosinase were observed for UAE-methanol extract, followed by macerated and Soxhlet. The inhibitory activity of the studied extracts against lipase were in the order: soxhlet > macerated> HAE-methanol > UAE-methanol. CONCLUSION: This study has established scientific baseline data on the therapeutic properties of P. dysentrica, thereby advocating the need for further investigations in an endeavour to develop novel pharmaceuticals from this plant. © 2019 Society of Chemical Industry.


Assuntos
Extratos Vegetais/química , Pulicaria/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flavonoides/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/química , Análise Multivariada , Fenóis/química , Fenóis/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Espectrometria de Massas por Ionização por Electrospray , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Glucosidases/química
6.
Food Chem ; 297: 125018, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253265

RESUMO

Different Ohmic heating conditions (OH, 10, 100, and 1000 Hz at 25 V; 45, 60, and 80 V at 60 Hz) were assessed to manufacture whey-raspberry flavored beverages. The inhibition of α-glucosidase, α-amylase, and angiotensin-converting I enzymes, antioxidant capacity, fatty acid profile, and volatile organic compounds (VOCs) were determined. OH treated samples presented lower anthocyanins content than the conventional treatment (2.91 ±â€¯0.23 mg/g), while the mild-intermediate conditions (10,100-Hz at 25 V and 45,60-V at 60 Hz) presented the highest chemical antioxidant activity when compared to the extreme processing conditions (1000 Hz-25 V and 80 V-60 Hz). OH led to an increase of 10% in both α-glucosidase (>99%) and α-amylase (≥70%). Among the VOCs, furfural and 5-hydroxymethylfurfural, a major intermediate Maillard reaction product was found in all treatments. Overall, OH can be used in the processing of whey-flavored raspberry beverages.


Assuntos
Bebidas/análise , Aromatizantes/química , Rubus/química , Soro do Leite/química , Antocianinas/análise , Antioxidantes/química , Culinária , Ácidos Graxos/análise , Cromatografia Gasosa-Espectrometria de Massas , Glucosidases/antagonistas & inibidores , Glucosidases/metabolismo , Ondas de Rádio , Temperatura Ambiente , Compostos Orgânicos Voláteis/análise , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
7.
J Chromatogr A ; 1600: 55-64, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31036362

RESUMO

Plant defense protein α-amylase trypsin inhibitors (ATIs) have been proposed as one of the triggers of non-coeliac gluten sensitivity, however there have been no focused studies on their optimal extraction and quantitation from cereal grains. The efficiency of extraction is of utmost interest for the downstream detection and characterisation. In the present study, three extraction buffers and two modified protocols were investigated using LC-MRM-MS in order to examine their ability to efficiently and repeatably extract ATIs from selected barley cultivars. Initially, three extraction buffers IPA/DTT, urea and Tris-HCl were used to extract ATIs from two selected barley cultivars, Commander and Hindmarsh. The results obtained from the preliminary study showed that IPA/DTT and urea-based buffer extraction could yield ∼70% and ∼45% more ATIs, respectively than a buffer based on Tris-HCl extraction, with all methods showing high repeatability (CV < 15%). A multi-step protocol, employing IPA/DTT and urea improved the extraction efficiency in comparison to the single buffer extraction protocols (p<0.0001). When solutions from parallel extractions using IPA/DTT and urea were combined, the results were comparable (p = 0.99) with a sequential multi-step IPA/DTT-urea protocol. However, the repeatability of the combined process was compromised, as discerned by greater variation (CV>30%). The optimised sequential two-step extraction protocol was successfully used to extract and quantify ATIs from 12 barley cultivars. LC-MS analysis revealed that cv Yagan and cv Scope contain the higher levels (∼143% relative to the average barley ATI content), whereas cultivars Fleet (61%), Baudin (77%) and Commander (79%) contained the lowest levels. The libraries of ATIs identified and the quantitative methods described here provide a foundation for the future application of MS-based quantitative methodologies to detect and quantify ATIs in barley varieties and in food products.


Assuntos
Análise de Alimentos/métodos , Hordeum/química , Proteômica/métodos , Inibidores da Tripsina/análise , Inibidores da Tripsina/isolamento & purificação , alfa-Amilases/antagonistas & inibidores , Cromatografia Líquida , Grão Comestível/química , Glutens/análise , Proteínas de Plantas/análise , Espectrometria de Massas em Tandem
8.
Phytochemistry ; 164: 94-101, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31103779

RESUMO

Diabetes mellitus is a widespread metabolic disorder that affects millions of people around the world. The disease is a major burden on both economic and social levels, and there is a need for improved drugs with fewer side effects in the management of the disease. Current methods for isolation of anti-diabetic lead compounds from complex mixtures suffer from low resolution and sensitivity, and there is a need for improved alternatives. In this work, magnetic ligand fishing combined with high-performance liquid chromatography - photodiode-array detection - high-resolution mass spectrometry - solid-phase extraction - nuclear magnetic resonance spectroscopy (HPLC-PDA-HRMS-SPE-NMR) was developed and validated, with the aim of accelerating discovery of natural products targeting α-amylase. The enzyme was successfully immobilized onto magnetic beads and retained its catalytic activity for a period of 75 days, and the specificity of this method was successfully validated by testing the N-terminus coupled α-amylase immobilized magnetic beads on an artificial mixture. A proof of concept experiment, using a crude ethyl acetate extract of Ginkgo biloba leaves, proved that it was possible to fish out four α-amylase ligands. HPLC-PDA-HRMS-SPE-NMR analysis confirmed the presence of bilobetin, isoginkgetin, ginkgetin and sciadopitysin in the solutions resulting from α-amylase ligand fishing with Ginkgo biloba. IC50 curves revealed a reversed relationship between concentration of sciadopitysin and inhibition of α-amylase activity, suggesting that this compound activated the enzyme instead of inhibiting it.


Assuntos
Ginkgo biloba/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Extratos Vegetais/farmacologia , alfa-Amilases/antagonistas & inibidores , Relação Dose-Resposta a Droga , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Humanos , Ligantes , Magnetismo , Microesferas , Conformação Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Relação Estrutura-Atividade , alfa-Amilases/metabolismo
9.
Molecules ; 24(8)2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30999646

RESUMO

A series of symmetrical salicylaldehyde-bishydrazine azo molecules, 5a-5h, have been synthesized, characterized by 1H-NMR and 13C-NMR, and evaluated for their in vitro α-glucosidase and α-amylase inhibitory activities. All the synthesized compounds efficiently inhibited both enzymes. Compound 5g was the most potent derivative in the series, and powerfully inhibited both α-glucosidase and α-amylase. The IC50 of 5g against α-glucosidase was 0.35917 ± 0.0189 µM (standard acarbose IC50 = 6.109 ± 0.329 µM), and the IC50 value of 5g against α-amylase was 0.4379 ± 0.0423 µM (standard acarbose IC50 = 33.178 ± 2.392 µM). The Lineweaver-Burk plot indicated that compound 5g is a competitive inhibitor of α-glucosidase. The binding interactions of the most active analogues were confirmed through molecular docking studies. Docking studies showed that 5g interacts with the residues Trp690, Asp548, Arg425, and Glu426, which form hydrogen bonds to 5g with distances of 2.05, 2.20, 2.10 and 2.18 Å, respectively. All compounds showed high mutagenic and tumorigenic behaviors, and only 5e showed irritant properties. In addition, all the derivatives showed good antioxidant activities. The pharmacokinetic evaluation also revealed promising results.


Assuntos
Inibidores de Glicosídeo Hidrolases , Simulação de Acoplamento Molecular , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Glucosidases/química , Animais , Inibidores de Glicosídeo Hidrolases/síntese química , Inibidores de Glicosídeo Hidrolases/química , Estrutura Molecular , Suínos
10.
Molecules ; 24(8)2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30991766

RESUMO

The edible and medicinal perennial herb dandelion is known to have antitumor, antioxidant, and anticomplement properties. However, the structural characterization and biological effects of its polysaccharides are not well understood. Here, we aimed to extract and investigate a novel polysaccharide from dandelion. A water-soluble polysaccharide, PD1-1, was successfully obtained from dandelion through ultrasonic-assisted extraction and purification using diethylaminoethyl (DEAE)-Sepharose fast flow and Sephadex G-75 columns. The results showed that PD1-1 is an inulin-type polysaccharide with a molecular weight of 2.6 kDa and is composed of glucose (52.39%), and mannose (45.41%). Glycosidic linkage analysis demonstrated that PD1-1 contains terminal α-d-Man/Glcp-(1→ and →1)-ß-d-Man/Glcf-(2→ glycosidic linkage conformations. A physicochemical analysis indicated that PD1-1 has a triple helix structure and exhibits important properties, including good swelling, water-holding, and oil-holding capacities. Furthermore, PD1-1 showed good antioxidant activities in DPPH and hydroxyl free radical scavenging abilities, with IC50 values of 0.23 mg/mL and 0.25 mg/mL, respectively, and good hypoglycemic activities in α-amylase and α-glucosidase inhibition, with IC50 values of 0.53 mg/mL and 0.40 mg/mL, respectively, in a concentration-dependent manner. Results suggest that PD1-1 possesses efficacious antioxidant and hypoglycemic properties and has potential applications as a functional food ingredient.


Assuntos
Antioxidantes/química , Inibidores de Glicosídeo Hidrolases/química , Polissacarídeos/química , Taraxacum/química , alfa-Amilases , alfa-Glucosidases/química , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química
11.
Biomed Res Int ; 2019: 3692605, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30993111

RESUMO

This study evaluated the biological activities of Eryngium planum and of Cnicus benedictus extracts enriched in polyphenols obtained by nanofiltration. The HPLC-MS analysis showed that E. planum contains mainly flavonoids, especially rutin, while in C. benedictus extracts show the high concentration of the phenolic acids, principally the chlorogenic acid and sinapic acid. Herein, there is the first report of ursolic acid, genistin, and isorhamnetin in E. planum and C. benedictus. C. benedictus polyphenolic-rich extract showed high scavenging activity (IC50=0.0081 mg/mL) comparable to that of standard compound (ascorbic acid) and a higher reducing power (IC50= 0.082 mg/mL), with IC50 having a significantly lower value than IC50 for ascorbic acid. Both extracts were nontoxic to NCTC cell line. Among the investigated herbs, E. planum polyphenolic-rich extract showed the highest inhibitory activities with the IC50 value of 31.3 µg/mL for lipoxygenase and 24.6 µg/mL for hyaluronidase. Both polyphenolic-rich extracts had a higher inhibitory effect on α-amylase and α-glucosidase than that of the acarbose. The synergistic effect of ursolic acid, rutin, chlorogenic acid, rosmarinic acid, genistin, and daidzein identified in polyphenolic-rich extracts could be mainly responsible for the pharmacological potentials of the studied extracts used in managing inflammation and diabetes.


Assuntos
Cnicus/química , Eryngium/química , Inibidores de Glicosídeo Hidrolases/química , Extratos Vegetais/química , Polifenóis/química , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Glucosidases/química , Animais , Linhagem Celular , Camundongos
12.
Chem Biodivers ; 16(6): e1900032, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30957403

RESUMO

The inhibition of carbohydrate-hydrolyzing enzymes in human digestive organs is crucial in controlling blood sugar levels, which is important in treating type 2 diabetes. In the current study, pahangensin A (1), a bis-labdanic diterpene characterized previously in the rhizomes of Alpinia pahangensis Ridl., was identified as an active dual inhibitor for α-amylase (IC50 =114.80 µm) and α-glucosidase (IC50 =153.87 µm). This is the first report on the dual α-amylase and α-glucosidase inhibitory activities of a bis-labdanic diterpene. The Lineweaver-Burk plots of compound 1 indicate that it is a mixed-type inhibitor with regard to both enzymes. Based on molecular docking studies, compound 1 docked in a non-active site of both enzymes. The dual inhibitory activity of compound 1 makes it a suitable natural alternative in the treatment of type 2 diabetes.


Assuntos
Alpinia/química , Diterpenos/química , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo , Alpinia/metabolismo , Sítios de Ligação , Domínio Catalítico , Diterpenos/isolamento & purificação , Diterpenos/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Cinética , Simulação de Acoplamento Molecular , Extratos Vegetais/química , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/química
13.
Molecules ; 24(6)2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30871172

RESUMO

Digestive enzymes and free radical inhibitors are used to prevent complications resulting from diabetes. Entada spiralis (family Leguminosae), which is a well-known medicinal plant in herbal medicine due to its various traditional and medicinal applications, was studied. Crude extracts were successively obtained from the stem bark using petroleum ether, chloroform and methanol as extracting solvents. The antioxidant activity of all the extracts, fractions and isolated compounds were estimated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ß-carotene and 2,2'-azinobis(-3-ethylbenzothiazine-6-sulfonic acid) (ABTS) assays, while digestive enzymes inhibitory activity was assessed using α-amylase and α-glucosidase inhibitory methods. Structure elucidation of pure compounds was achieved through different spectroscopic analysis methods. Fractionation and purification of the most active methanol extract resulted in the isolation of a ferulic ester namely; (e)-hexyl 3-(4-hydroxy-3-methoxyphenyl) acrylate (FEQ-2) together with five known phenolic constituents, identified as kaempferol (FEQ-3), 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (FEQ-2), gallic acid (FEQ-5), (+)-catechin (FEQ-7) and (-)-epicatechin (FEQ-8). FEQ-5 exhibited the strongest antioxidant and enzyme inhibitory activities followed by FEQ-3 and FEQ-4. FEQ-2 also displayed potent free radical scavenging activity with IC50 values of 13.79 ± 2.13 (DPPH) and 4.69 ± 1.25 (ABTS) µg/mL, respectively. All other compounds were found active either against free radicals or digestive enzymes.


Assuntos
Antioxidantes/química , Inibidores Enzimáticos/química , Fabaceae/química , Compostos Fitoquímicos/química , Antioxidantes/farmacologia , Fracionamento Químico , Inibidores Enzimáticos/farmacologia , Flavonoides/isolamento & purificação , Inibidores de Glicosídeo Hidrolases , Estrutura Molecular , Compostos Fitoquímicos/farmacologia , Casca de Planta/química , Caules de Planta/química , Plantas Medicinais/química , alfa-Amilases/antagonistas & inibidores
14.
Mar Drugs ; 17(3)2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30857204

RESUMO

Phlorotannins are phloroglucinol-based phenolic compounds, occurring particularly in brown macroalgae, that have been recognized for their promising bioactive properties. In this study, the extraction of phlorotannins from Fucus vesiculosus was evaluated with particular emphasis on the influential parameters, including the solvent concentration, solvent-solid ratio, extraction temperature and extraction time, using a single-factor design followed by a Box-Behnken design. The maximum total phlorotannin content, determined using the 2,4-dimethoxybenzaldehyde (DMBA) method, corresponded to 2.92 ± 0.05 mg of phloroglucinol equivalents/g dry seaweed (mg PGE/g DS), and was achieved for extracts carried out with acetone 67% (v/v), a solvent-solid ratio of 70 mL/g and temperature at 25 °C. This crude extract, together with a semi-purified phlorotannin fraction, were further evaluated for their anti-enzymatic capacity against α-glucosidase, α-amylase and pancreatic lipase, both showing promising inhibitory effects, particularly against α-glucosidase for which a greater inhibitory effect was observed compared to the pharmaceutical drug acarbose (IC50 = 4.5 ± 0.8 and 0.82 ± 0.3 µg/mL, respectively, against 206.6 ± 25.1 µg/mL). Additionally, the ultra-high-pressure liquid chromatography coupled to mass spectrometry (UHPLC-MS) analysis carried out on the ethyl acetate fraction revealed the presence of fucols, fucophlorethols, fuhalols and several other phlorotannin derivatives. Moreover, possible new phlorotannin compounds, including fucofurodiphlorethol, fucofurotriphlorethol and fucofuropentaphlorethol, have been tentatively identified in this extract. Overall, this study provides evidence that F. vesiculosus phlorotannin-rich extracts hold potential for the management of the activity of α-glucosidase, α-amylase and pancreatic lipase, which are well known to be linked to metabolic disorders such as diabetes and obesity.


Assuntos
Inibidores Enzimáticos/farmacologia , Fucus/química , Extratos Vegetais/farmacologia , Alga Marinha/química , Taninos/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Ensaios Enzimáticos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/uso terapêutico , Lipase/antagonistas & inibidores , Lipase/metabolismo , Espectrometria de Massas , Doenças Metabólicas/tratamento farmacológico , Doenças Metabólicas/metabolismo , Floroglucinol/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico , Taninos/química , Taninos/isolamento & purificação , Taninos/uso terapêutico , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo
15.
BMC Biotechnol ; 19(1): 15, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30849970

RESUMO

BACKGROUND: Insect resistance in crops represents a main challenge for agriculture. Transgenic approaches based on proteins displaying insect resistance properties are widely used as efficient breeding strategies. To extend the spectrum of targeted pathogens and overtake the development of resistance, molecular evolution strategies have been used on genes encoding these proteins to generate thousands of variants with new or improved functions. The cotton boll weevil (Anthonomus grandis) is one of the major pests of cotton in the Americas. An α-amylase inhibitor (α-AIC3) variant previously developed via molecular evolution strategy showed inhibitory activity against A. grandis α-amylase (AGA). RESULTS: We produced in a few days considerable amounts of α-AIC3 using an optimised transient heterologous expression system in Nicotiana benthamiana. This high α-AIC3 accumulation allowed its structural and functional characterizations. We demonstrated via MALDI-TOF MS/MS technique that the protein was processed as expected. It could inhibit up to 100% of AGA biological activity whereas it did not act on α-amylase of two non-pathogenic insects. These data confirmed that N. benthamiana is a suitable and simple system for high-level production of biologically active α-AIC3. Based on other benefits such as economic, health and environmental that need to be considerate, our data suggested that α-AIC3 could be a very promising candidate for the production of transgenic crops resistant to cotton boll weevil without lethal effect on at least two non-pathogenic insects. CONCLUSIONS: We propose this expression system can be complementary to molecular evolution strategies to identify the most promising variants before starting long-lasting stable transgenic programs.


Assuntos
Inibidores Enzimáticos/metabolismo , Expressão Gênica , Engenharia Genética/métodos , Tabaco/genética , alfa-Amilases/antagonistas & inibidores , Animais , Evolução Molecular Direcionada , Inibidores Enzimáticos/química , Inativação Gênica , Controle de Insetos/métodos , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Gorgulhos , alfa-Amilases/genética , alfa-Amilases/metabolismo
16.
Mar Drugs ; 17(3)2019 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-30832418

RESUMO

Marine organisms produce an array of biologically active natural products, many of which have unique structures that have not been found in terrestrial organisms. Hence, marine algae provide a unique source of bioactive compounds. The present study investigated 19 marine algae and one seagrass collected from Torquay beach, Victoria, Australia. High-performance thin-layer chromatography (HPTLC) hyphenated with microchemical (DPPH•, p-anisaldehyde, and Fast Blue B) and biochemical (α-amylase and acetylcholine esterase (AChE) enzymatic) derivatizations was used to evaluate antioxidant activity, presence of phytosterols and phenolic lipids, α-amylase and AChE inhibitory activities of extract components. Significant α-amylase and AChE inhibitory activities were observed in samples 2, 6, 8 and 10. Antioxidant activities in the samples were found to be correlated to phytosterol content (R² = 0.78), but was not found to be related to either α-amylase or AChE inhibitory activities. α-Amylase inhibitory activities were correlated to AChE inhibition (R² = 0.77) and attributed to the phytosterol content, based on the similar peak position in the chromatograms with the ß-sitosterol chromatogram. Samples 1, 8, and especially sample 20, were found to contain phenolic lipids (alkyl resorcinol derivatives) with significant antioxidant activities. The results suggest that these marine species have a significant number of bioactive compounds that warrant further investigation.


Assuntos
Produtos Biológicos/farmacologia , Extratos Vegetais/farmacologia , Alga Marinha/química , Acetilcolinesterase/metabolismo , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Austrália , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Compostos de Bifenilo/química , Compostos de Bifenilo/isolamento & purificação , Compostos de Bifenilo/farmacologia , Inibidores da Colinesterase/química , Inibidores da Colinesterase/isolamento & purificação , Inibidores da Colinesterase/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia em Camada Delgada/métodos , Ensaios Enzimáticos , Fitosteróis/química , Fitosteróis/isolamento & purificação , Fitosteróis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/metabolismo
17.
Protein Pept Lett ; 26(6): 403-413, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-30919765

RESUMO

BACKGROUND: Peptide-based therapeutics offer a unique avenue for the development of novel agents for the treatment of diabetes mellitus including α-glucosidase inhibitors. The peptide, SQSPA, was reported to possess to α -glucosidase inhibitory activity in addition to resistance to Gastrointestinal Tract (GIT) digestion. METHODS: In this study, the in silico and in vitro structure-activity analyses of the peptide was conducted using alanine scanning to identify key amino acid residues. RESULTS: The alanine scanning led to four analogs viz; AQSPA, SASPA, SQAPA and SQSAA which were GIT stable. Initially, the peptides were subjected to molecular docking on human α- glucosidase and α -amylase where the binding affinities to the enzymes were in the order; AQSPA>SASPA>SQSPA>SQAPA> SQSAA and AQSPA>SQSAA>SASPA>SQSPA> SQAPA, respectively. Hydrogen bond were important for the binding of all peptides but SASPA and AQSPA had the highest hydrogen bonds interactions with the α-glucosidase and α-amylase, respectively. In vitro analysis revealed that the α -glucosidase and α-amylase inhibitory activities of the peptides were in the order AQSPA>SQSPA>SQAPA>SASPA>SQSAA and AQSPA>SASPA> SQAPA>SQSPA>SQSAA, respectively. Using inhibition kinetics, SQSPA was a mixed inhibitor of α-glucosidase while AQSPA, SQAPA and SQSAA showed non-competitive inhibition. For α- amylase inhibition, SQSPA was a non-competitive inhibitor while AQSPA and SQSAA were mixed inhibitors; SASPA and SQAPA showed uncompetitive inhibition. CONCLUSION: The results indicated that P4 and Q2 are important requirements for the α-glucosidase and α-amylase inhibitory activities of the parent peptide, SQSPA. Furthermore, alanine scanning has led to the design of a novel α-glucosidase inhibitory peptide, AQSPA, with increased activities.


Assuntos
Inibidores Enzimáticos/química , Hipoglicemiantes/química , Simulação de Acoplamento Molecular/métodos , Peptídeos/química , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/metabolismo , Sítios de Ligação , Simulação por Computador , Humanos , Ligações de Hidrogênio , Cinética , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade
18.
J Ethnopharmacol ; 236: 196-204, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-30844488

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Hopea ponga (Dennst.) Mabb. Is used in traditional herbal formulations for diabetes complications. The aim of this study is to evaluate the antidiabetic effect of extracts and compounds from H. ponga. MATERIALS AND METHODS: Silica gel column chromatography was performed to identify various chemical components of the plant extract. Different extracts of H. ponga and isolated compounds were screened for their antidiabetic effect by modulation of digestive enzymes and protein glycation. The effect of glucose uptake by the compounds and the pathways through which the compounds mediate the glucose uptake potential were confirmed by fluorescent microscopy, flow cytometry and western blot analysis. RESULTS: Acetone and ethanol extracts of the stem bark of Hopea ponga (Dennst.) Mabb. Afforded six resveratrol oligomers namely, E-resveratrol (1), (-)-ε-viniferin (2), (-)-α-viniferin (3), trihydroxyphenanthrene glucoside (THPG) (4), vaticaphenol A (5), (-)-hopeaphenol (6), along with four phytosterols. The structures were determined on the basis of spectroscopic analyses including nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRMS) data. Compounds 1-5 and 7-10 were tested for their α-glucosidase, α-amylase and glycation inhibitiory activities. All the resveratrol oligomers (1-5) showed prominent α-glucosidase inhibition with IC50 values, 12.56 ±â€¯1.00, 23.98 ±â€¯1.11, 7.17 ±â€¯1.10, 31.74 ±â€¯0.42 and 16.95 ±â€¯0.39 µM, respectively. Molecular docking studies also supported the observed α-glucosidase inhibition. Compound 3 displayed IC50 values of 4.85 ±â€¯0.06 and 27.10 ±â€¯0.04 µM in α-amylase and glycation inhibitory assays activity. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay revealed that the compounds 3 and 4 were found to be less toxic at a concentration of 100 µM (<10%) and 25 µM (<20%), respectively. The effect of glucose uptake performed by 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG) in L6 myoblast were measured by fluorescent microscopy and flow cytometry. The compounds 3 and 4 showed 2-NBDG uptake of 49.6% and 38.8% respectively. By examining the molecular pathway through which the compounds elicit their glucose uptake potential, it was observed that both the compounds mainly act via AMPK pathway. CONCLUSION: This is the first report on the isolation of compounds from H. ponga. Altogether, the results of this study reveal the antidiabetic effects of H. ponga extracts and isolated compounds promoting traditional use of this plant in the treatment of diabetes.


Assuntos
Dipterocarpaceae/química , Hipoglicemiantes/farmacologia , Extratos Vegetais/farmacologia , Resveratrol/farmacologia , Acetona/química , Animais , Linhagem Celular , Diabetes Mellitus/tratamento farmacológico , Ensaios Enzimáticos , Etanol/química , Glicosilação/efeitos dos fármacos , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Concentração Inibidora 50 , Medicina Tradicional/métodos , Simulação de Acoplamento Molecular , Estrutura Molecular , Mioblastos , Casca de Planta/química , Extratos Vegetais/química , Caules de Planta/química , Ratos , Resveratrol/química , Resveratrol/isolamento & purificação , Testes de Toxicidade , alfa-Amilases/antagonistas & inibidores , alfa-Amilases/química , alfa-Amilases/metabolismo , alfa-Glucosidases/química , alfa-Glucosidases/metabolismo
19.
Cell Mol Biol (Noisy-le-grand) ; 65(2): 50-57, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30860471

RESUMO

Fumaria officinalis belongs to family papaveraceae and is traditionally used to treat hypertension, hepatitis and diabetes. The current study was conducted to evaluate in vitro and in vivo antidiabetic activity of Fumaria officinalis. Aerial parts of the plant were sequentially extracted with n-hexane, chloroform, methanol and water. Phytochemical analysis was carried out on all extracts. Antioxidant activity was determined by 2,2-diphenyl-1-picryl hydrazyl (DPPH) inhibition method. In vitro alpha-amylase inhibitory activity was performed on all extracts by using dinitrosalicylic acid. Effect of aqueous and methanolic extracts of F. officinalis on blood glucose was evaluated in normo-glycaemic rats and alloxan induced diabetic rats. Glimepiride 0.2 mg/kg was used as standard therapy in diabetic rats. Results showed that methanolic extract exhibited the maximum percentage inhibition of DPPH (86.30%) and alpha-amylase inhibition (94.01%) at 500 µg/ml and 16 mg/ml concentration respectively. Administration in normo-glycaemic rats did not show any significant decrease in blood glucose level at 500 and 750 mg/kg dosage. Aqueous and methanolic extracts exhibited a significant hypoglycaemic effect (p˂0.05) at all doses. A significant increase in the body weight and an improvement in liver and kidney function tests of diabetic rats were observed. These extracts also reduced the damage to the cells of glomeruli, interstitial inflammation, necrosis of tubular cells and thrombosis in the kidney, the enlargement of sinusoids and steatosis in the liver of diabetic rats. This study concludes that F. officinalis may have antidiabetic potential possibly due to its antioxidant and alpha-amylase inhibitory activities.


Assuntos
Antioxidantes/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Fumaria/química , Hipoglicemiantes/uso terapêutico , Extratos Vegetais/uso terapêutico , alfa-Amilases/antagonistas & inibidores , Animais , Biomarcadores/metabolismo , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Jejum/sangue , Feminino , Teste de Tolerância a Glucose , Rim/efeitos dos fármacos , Rim/patologia , Rim/fisiopatologia , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/fisiopatologia , Masculino , Compostos Fitoquímicos/análise , Extratos Vegetais/farmacologia , Ratos Wistar , alfa-Amilases/metabolismo
20.
Food Chem ; 288: 413-421, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30902312

RESUMO

An accurate high-performance anion-exchange chromatography (HPAEC) method is presented to measure the inhibition property of flavonoids against mammalian starch digestive enzymes, because flavonoids interfere with commonly used 3,5-dinitrosalicylic acid (DNS) and glucose oxidase/peroxidase (GOPOD) methods. Eriodictyol, luteolin, and quercetin increased absorbance values (without substrate) in the DNS assay and, with substrate, either overestimated or underestimated values in the DNS and GOPOD assays. Using a direct HPAEC measurement method, flavonoids showed different inhibition properties against α-amylase and α-glucosidases, showing different inhibition constants (Ki) and mechanisms. The double bond between C2 and C3 on the C-ring of flavonoids appeared particularly important to inhibit α-amylase, while the hydroxyl group (OH) at C3 of the C-ring was related to inhibition of α-glucosidases. This study shows that direct measurement of starch digestion products by HPAEC should be used in inhibition studies, and provides insights into structure-function aspects of polyphenols in controlling starch digestion rate.


Assuntos
Inibidores Enzimáticos/química , Flavonoides/química , Amido/metabolismo , alfa-Amilases/metabolismo , alfa-Glucosidases/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Colorimetria , Ensaios Enzimáticos , Inibidores Enzimáticos/metabolismo , Flavonoides/metabolismo , Cinética , Amido/análise , Especificidade por Substrato , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases/química
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