RESUMO
D-xylose utilization by yeasts is an essential feature for improving second-generation ethanol production. However, industrial yeast strains are incapable of consuming D-xylose. Previous analyzes of D-xylose-consuming or fermenting yeast species reveal that the genomic features associated with this phenotype are complex and still not fully understood. Here we present a previously neglected yeast enzyme related to D-xylose metabolism, D-xylose dehydrogenase (XylDH), which is found in at least 105 yeast genomes. By analyzing the XylDH gene family, we brought evidence of gene evolution marked by purifying selection on codons and positive selection evidence in D-xylose-consuming and fermenting species, suggesting the importance of XylDH for D-xylose-related phenotypes in yeasts. Furthermore, although we found no putative metabolic pathway for XylDH in yeast genomes, namely the absence of three bacterial known pathways for this enzyme, we also provide its expression profile on D-xylose media following D-xylose reductase for two yeasts with publicly available transcriptomes. Based on these results, we suggest that XylDH plays an important role in D-xylose usage by yeasts, likely being involved in a cofactor regeneration system by reducing cofactor imbalance in the D-xylose reductase pathway.
Assuntos
Aldeído Redutase , Xilose , Xilose/metabolismo , Fermentação , Aldeído Redutase/metabolismo , Leveduras/genéticaRESUMO
In the modern diet, excessive fructose intake (>50 g/day) had been driven by the increase, in recent decades, of the consumption of sugar-sweetened beverages. This phenomenon has dramatically increased within the Caribbean and Latin American regions. Epidemiological studies show that chronic high intake of fructose related to sugar-sweetened beverages increases the risk of developing several non-communicable diseases, such as chronic obstructive pulmonary disease and asthma, and may also contribute to the exacerbation of lung diseases, such as COVID-19. Evidence supports several mechanismssuch as dysregulation of the renin−angiotensin system, increased uric acid production, induction of aldose reductase activity, production of advanced glycation end-products, and activation of the mTORC1 pathwaythat can be implicated in lung damage. This review addresses how these pathophysiologic and molecular mechanisms may explain the lung damage resulting from high intake of fructose.
Assuntos
Frutose , Pneumopatias , Aldeído Redutase , Frutose/efeitos adversos , Humanos , Pneumopatias/epidemiologia , Pneumopatias/fisiopatologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Edulcorantes/efeitos adversos , Ácido ÚricoRESUMO
Lignocellulose hydrolysates are rich in fermentable sugars such as xylose, cellobiose and glucose, with high potential in the biotechnology industry to obtain bioproducts of higher economic value. Thus, it is important to search for and study new yeast strains that co-consume these sugars to achieve better yields and productivity in the processes. The yeast Clavispora lusitaniae CDBB-L-2031, a native strain isolated from mezcal must, was studied under various culture conditions to potentially produce ethanol and xylitol due to its ability to assimilate xylose, cellobiose and glucose. This yeast produced ethanol under microaerobic conditions with yields of 0.451 gethanol/gglucose and 0.344 gethanol/gcellobiose, when grown on 1% glucose or cellobiose, respectively. In mixtures (0.5% each) of glucose:xylose and glucose:xylose:cellobiose the yields were 0.367 gethanol/gGX and 0. 380 gethanol/gGXC, respectively. Likewise, in identical conditions, C. lusitaniae produced xylitol from xylose with a yield of 0.421 gxylitol/gxylose. In 5% glucose or xylose, this yeast had better ethanol and xylitol titers and yields, respectively. However, glucose negatively affected xylitol production in the mixture of both sugars (3% each), producing only ethanol. Xylose reductase (XR) and xylitol dehydrogenase (XDH) activities were evaluated in cultures growing on xylose or glucose, obtaining the highest values in cultures on xylose at 8 h (25.9 and 6.22 mU/mg, respectively). While in glucose cultures, XR and XDH activities were detected once this substrate was consumed (4.06 and 3.32 mU/mg, respectively). Finally, the XYL1 and XYL2 genes encoding xylose reductase and xylitol dehydrogenase, respectively, were up-regulated by xylose, whereas glucose down-regulated their expression.
Assuntos
Xilitol , Xilose , Aldeído Redutase/genética , Aldeído Redutase/metabolismo , Celobiose/metabolismo , D-Xilulose Redutase/genética , D-Xilulose Redutase/metabolismo , Etanol/metabolismo , Fermentação , Glucose/metabolismo , Saccharomyces cerevisiae/genética , Saccharomycetales , Xilitol/metabolismo , Xilose/metabolismoRESUMO
Sugar alcohols are major photosynthetic products in plant species from the Apiaceae and Plantaginaceae families. Mannose-6-phosphate reductase (Man6PRase) and aldose-6-phosphate reductase (Ald6PRase) are key enzymes for synthesizing mannitol and glucitol in celery (Apium graveolens) and peach (Prunus persica), respectively. In this work, we report the first crystal structures of dimeric plant aldo/keto reductases (AKRs), celery Man6PRase (solved in the presence of mannonic acid and NADP+) and peach Ald6PRase (obtained in the apo form). Both structures displayed the typical TIM barrel folding commonly observed in proteins from the AKR superfamily. Analysis of the Man6PRase holo form showed that residues putatively involved in the catalytic mechanism are located close to the nicotinamide ring of NADP+, where the hydride transfer to the sugar phosphate should take place. Additionally, we found that Lys48 is important for the binding of the sugar phosphate. Interestingly, the Man6PRase K48A mutant had a lower catalytic efficiency with mannose-6-phosphate but a higher catalytic efficiency with mannose than the wild type. Overall, our work sheds light on the structure-function relationships of important enzymes to synthesize sugar alcohols in plants.
Assuntos
Fosfatos , Álcoois Açúcares , Oxirredutases do Álcool/metabolismo , Aldeído Redutase/metabolismo , Sequência de Aminoácidos , Humanos , Manosefosfatos , NADP/metabolismo , Plantas/metabolismo , AçúcaresRESUMO
ABSTRACT Objective: The AKR1B1 gene encodes an enzyme that catalyzes the reduction of glucose into sorbitol. Chronic hyperglycemia in patients with diabetes mellitus (DM) leads to increased AKR1B1 affinity for glucose and, consequently, sorbitol accumulation. Elevated sorbitol increases oxidative stress, which is one of the main pathways related to chronic complications of diabetes, including diabetic kidney disease (DKD). Accordingly, some studies have suggested the rs759853 polymorphism in the AKR1B1 gene is associated with DKD; however, findings are still contradictory. The aim was to investigate the association of the rs759853 polymorphism in the AKR1B1 gene and DKD. Materials and methods: The sample comprised 695 patients with type 2 DM (T2DM) and DKD (cases) and 310 patients with T2DM of more than 10 years' duration, but no DKD (controls). The polymorphism was genotyped by real-time PCR. Results: Allelic and genotype frequencies of this polymorphism did not differ significantly between groups. However, the A/A genotype was associated with risk for DKD after adjustment for gender, triglycerides, BMI, presence of hypertension and diabetic retinopathy, and duration of DM, under both recessive (P = 0.048) and additive (P = 0.037) inheritance models. Conclusion: Our data suggest an association between the AKR1B1 rs759853A/A genotype and risk for DKD in Brazilians T2DM patients.
Assuntos
Humanos , Aldeído Redutase/genética , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Alelos , Frequência do Gene , GenótipoRESUMO
OBJECTIVE: The AKR1B1 gene encodes an enzyme that catalyzes the reduction of glucose into sorbitol. Chronic hyperglycemia in patients with diabetes mellitus (DM) leads to increased AKR1B1 affinity for glucose and, consequently, sorbitol accumulation. Elevated sorbitol increases oxidative stress, which is one of the main pathways related to chronic complications of diabetes, including diabetic kidney disease (DKD). Accordingly, some studies have suggested the rs759853 polymorphism in the AKR1B1 gene is associated with DKD; however, findings are still contradictory. The aim was to investigate the association of the rs759853 polymorphism in the AKR1B1 gene and DKD. METHODS: The sample comprised 695 patients with type 2 DM (T2DM) and DKD (cases) and 310 patients with T2DM of more than 10 years' duration, but no DKD (controls). The polymorphism was genotyped by real-time PCR. RESULTS: Allelic and genotype frequencies of this polymorphism did not differ significantly between groups. However, the A/A genotype was associated with risk for DKD after adjustment for gender, triglycerides, BMI, presence of hypertension and diabetic retinopathy, and duration of DM, under both recessive (P = 0.048) and additive (P = 0.037) inheritance models. CONCLUSION: Our data suggest an association between the AKR1B1 rs759853A/A genotype and risk for DKD in Brazilians T2DM patients.
Assuntos
Aldeído Redutase , Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Aldeído Redutase/genética , Alelos , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Nefropatias Diabéticas/complicações , Nefropatias Diabéticas/genética , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
In recent studies, we found that compounds derived from phenolic acids (CAFs) prevent the formation of the tubulin/aldose reductase complex and, consequently, may decrease the occurrence or delay the development of secondary pathologies associated with aldose reductase activation in diabetes mellitus. To verify this hypothesis, we determined the effect of CAFs on Na+,K+-ATPase tubulin-dependent activity in COS cells, ex vivo cataract formation in rat lenses and finally, to evaluate the antidiabetic effect of CAFs, diabetes mellitus was induced in Wistar rats, they were treated with different CAFs and four parameters were determinates: cataract formation, erythrocyte deformability, nephropathy and blood pressure. After confirming that CAFs are able to prevent the association between aldose reductase and tubulin, we found that treatment of diabetic rats with these compounds decreased membrane-associated acetylated tubulin, increased NKA activity, and thus reversed the development of four AR-activated complications of diabetes mellitus determined in this work. Based on these results, the existence of a new physiological mechanism is proposed, in which tubulin is a key regulator of aldose reductase activity. This mechanism can explain the incorrect functioning of aldose reductase and Na+,K+-ATPase, two key enzymes in the pathogenesis of diabetes mellitus. Moreover, we found that such alterations can be prevented by CAFs, which are able to dissociate tubulin/aldose reductase complex.
Assuntos
Diabetes Mellitus Experimental , Cristalino , Aldeído Redutase , Animais , Diabetes Mellitus Experimental/complicações , Ratos , Ratos Wistar , Tubulina (Proteína)RESUMO
Apple pomace was studied as a raw material for the production of xylitol and 2G ethanol, since this agroindustrial residue has a high concentration of carbohydrate macromolecules, but is still poorly studied for the production of fermentation bioproducts, such as polyols. The dry biomass was subjected to dilute-acid hydrolysis with H2SO4 to obtain the hemicellulosic hydrolysate, which was concentrated, detoxified and fermented. The hydrolyzate after characterization was submitted to submerged fermentations, which were carried out in Erlenmeyer flasks using, separately, the yeasts Candida guilliermondii and Kluyveromyces marxianus. High cellulose (32.62%) and hemicellulose (23.60%) contents were found in this biomass, and the chemical hydrolysis yielded appreciable quantities of fermentable sugars, especially xylose. Both yeasts were able to metabolize xylose, but Candida guilliermondii produced only xylitol (9.35 g L-1 in 96 h), while K. marxianus produced ethanol as the main product (10.47 g L-1 in 24 h) and xylitol as byproduct (9.10 g L-1 xylitol in 96 h). Maximum activities of xylose reductase and xylitol dehydrogenase were verified after 24 h of fermentation with C. guilliermondii (0.23 and 0.53 U/mgprot, respectively) and with K. marxianus (0.08 e 0.08 U/mgprot, respectively). Apple pomace has shown potential as a raw material for the fermentation process, and the development of a biotechnological platform for the integrated use of both the hemicellulosic and cellulosic fraction could add value to this residue and the apple production chain.
Assuntos
Biotecnologia/métodos , Etanol/química , Malus/metabolismo , Xilitol/química , Aldeído Redutase/química , Biomassa , Reatores Biológicos , Candida , Celulose/metabolismo , D-Xilulose Redutase/química , Fermentação , Glucose/metabolismo , Hidrólise , Kluyveromyces , Polímeros/química , Polissacarídeos/química , Saccharomycetales , Fatores de Tempo , Xilose/metabolismoRESUMO
O Informe Diário de Evidências é uma produção do Ministério da Saúde que tem como objetivo acompanhar diariamente as publicações científicas sobre tratamento farmacológico e vacinas para a COVID-19. Dessa forma, são realizadas buscas estruturadas em bases de dados biomédicas, referente ao dia anterior desse informe. Não são incluídos estudos pré-clínicos (in vitro, in vivo, in silico). A frequência dos estudos é demonstrada de acordo com a sua classificação metodológica (revisões sistemáticas, ensaios clínicos randomizados, coortes, entre outros). Para cada estudo é apresentado um resumo com avaliação da qualidade metodológica. Essa avaliação tem por finalidade identificar o grau de certeza/confiança ou o risco de viés de cada estudo. Para tal, são utilizadas ferramentas já validadas e consagradas na literatura científica, na área de saúde baseada em evidências. Cabe ressaltar que o documento tem caráter informativo e não representa uma recomendação oficial do Ministério da Saúde sobre a temática. Foram encontrados 17 artigos.
Assuntos
Humanos , Pneumonia Viral/tratamento farmacológico , Infecções por Coronavirus/tratamento farmacológico , Betacoronavirus/efeitos dos fármacos , Avaliação da Tecnologia Biomédica , gama-Globulinas/uso terapêutico , Imunoglobulinas/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Vacinas/uso terapêutico , Cloroquina/uso terapêutico , Interferon beta/uso terapêutico , Aldeído Redutase/antagonistas & inibidores , Corticosteroides/uso terapêutico , Azitromicina/uso terapêutico , Sulfato de Zinco/uso terapêutico , Ritonavir/uso terapêutico , Oseltamivir/uso terapêutico , Lopinavir/uso terapêutico , Hidroxicloroquina/uso terapêuticoRESUMO
Aflatoxin B1 aldehyde reductase (AFAR) enzyme activity has been associated to a higher resistance to the aflatoxin B1 (AFB1) toxicity in ethoxyquin-fed rats. However, no studies about AFAR activity and its relationship with tolerance to AFB1 have been conducted in poultry. To determine the role of AFAR in poultry tolerance, the hepatic in vitro enzymatic activity of AFAR was investigated in liver cytosol from four commercial poultry species (chicken, quail, turkey and duck). Specifically, the kinetic parameters Vmax, Km and intrinsic clearance (CLint) were determined for AFB1 dialdehyde reductase (AFB1-monoalcohol production) and AFB1 monoalcohol reductase (AFB1-dialcohol production). In all cases, AFB1 monoalcohol reductase activity saturated at the highest aflatoxin B1 dialdehyde concentration tested (66.4 µM), whereas AFB1 dialdehyde reductase did not. Both activities were highly and significantly correlated and therefore are most likely catalyzed by the same AFAR enzyme. However, it appears that production of the AFB1 monoalcohol is favored over the AFB1 dialcohol. The production of alcohols from aflatoxin dialdehyde showed the highest enzymatic efficiency (highest CLint value) in chickens, a species resistant to AFB1; however, it was also high in the turkey, a species with intermediate sensitivity; further, CLint values were lowest in another tolerant species (quail) and in the most sensitive poultry species (the duck). These results suggest that AFAR activity is related to resistance to the acute toxic effects of AFB1 only in chickens and ducks. Genetic selection of ducks for high AFAR activity could be a means to control aflatoxin sensitivity in this poultry species.
Assuntos
Aflatoxina B1/análogos & derivados , Aldeído Redutase/metabolismo , Aves Domésticas/metabolismo , Aflatoxina B1/química , Aflatoxina B1/toxicidade , Animais , Feminino , Cinética , MasculinoRESUMO
Aldo-keto reductases (AKRs) are nicotinamide-dependent enzymes that catalyze the transformation of aldehydes and ketones into alcohols. They are spread across all phyla, and those from microbial origin have proved to be highly robust and versatile biocatalysts. In this work, we have discovered and characterized a microbial AKR from the yeast Rhodotorula mucilaginosa by combining genome-mining and expression assays. The new enzyme, named AKR3B4, was expressed by a simple protocol in very good amounts. It displays a selective substrate profile exclusively transforming aldehydes into alcohols. Also, AKR3B4 shows very good stability at medium temperatures, in a broad range of pH values and in the presence of green organic solvents. Conversion assays demonstrate it is an excellent biocatalyst to be used in the synthesis of aromatic alcohols, and also to produce furan-3-ylmethanol and the valuable sweetener xylitol. These results show that AKR3B4 displays attractive features so as to be used in chemoenzymatic processes.
Assuntos
Aldo-Ceto Redutases/genética , Aldo-Ceto Redutases/metabolismo , Rhodotorula/enzimologia , Rhodotorula/genética , Oxirredutases do Álcool/metabolismo , Álcoois/metabolismo , Aldeído Redutase/metabolismo , Aldeídos/metabolismo , Clonagem Molecular , Enzimas , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Especificidade por SubstratoRESUMO
Recently repeated heat stress and dehydration have been reported to cause oxidative stress and kidney damage that is enhanced by rehydrating with fructose solutions. We hypothesized that antioxidants might provide a novel way to prevent kidney damage. To test this hypothesis, mild heat stress was induced by exposing rats to 37 °C during 1 h in a closed chamber. The supplementation with water-soluble antioxidants (Antiox), ascorbic acid 1% plus N-acetyl cysteine 600 mg/L was done either in the 10% fructose 2 h rehydration fluid immediately after heat stress (Fructose 10% + Antiox), and/or in the tap water (Water + Antiox) for the remainder of the day, or in both fluids. After 4 weeks, control rats exposed to heat with fructose rehydration developed impaired renal function, tubular injury, intrarenal oxidative stress, a reduction in Nrf2-Keap1 antioxidant pathway, stimulation of vasopressin and the intrarenal polyol-fructokinase pathway. In contrast, dosing the antioxidants in the tap water (i.e., before the heat exposure and rehydration with fructose) preserved renal function, prevented renal tubule dysfunction and avoided the increase in systemic blood pressure. These effects were likely due to the amplification of the antioxidant defenses through increased Nrf2 nuclear translocation stimulated by the antioxidants and by the prevention of polyol fructokinase pathway overactivation. More studies to understand the mechanisms implicated in this pathology are warranted as there is recent evidence that they may be operating in humans as well.
Assuntos
Antioxidantes/farmacologia , Bebidas , Frutose/efeitos adversos , Resposta ao Choque Térmico , Nefropatias/metabolismo , Transporte Ativo do Núcleo Celular , Aldeído Redutase/metabolismo , Animais , Antioxidantes/administração & dosagem , Pressão Sanguínea , Núcleo Celular/metabolismo , Desidratação , Hidratação , Frutoquinases/metabolismo , Glutationa/metabolismo , Masculino , Óxido Nítrico Sintase Tipo III/metabolismo , Polímeros/metabolismo , Transporte Proteico , Ratos , Ratos WistarRESUMO
This chapter describes the use of lenses obtained from rats as a model of cataractogenesis. At the molecular level, this is visualized as reduced activity of oxidative reductive enzymes such as aldose reductase and increased proteolysis of lens structural proteins including vimentin. In this chapter, protocols for assessment of these two pathways are presented. Specifically, this analysis shows a comparison of aldose reductase activity and vimentin cleavage in male and female rat lenses. This is because female rats are more susceptible to cataract formation compared to males.
Assuntos
Aldeído Redutase/química , Catarata/fisiopatologia , Cristalinas/isolamento & purificação , Biologia Molecular/métodos , Aldeído Redutase/genética , Animais , Catarata/etiologia , Catarata/genética , Cristalinas/química , Feminino , Humanos , Cristalino/química , Masculino , Estresse Oxidativo/genética , Ratos , Vimentina/química , Vimentina/genéticaRESUMO
In this work we demonstrate that aldose reductase (AR) interacts directly with tubulin and, was subjected to microtubule formation conditions, enzymatic AR activity increased more than sixfold. Since AR interacts mainly with tubulin that has 3-nitro-tyrosine in its carboxy-terminal, we evaluated whether tyrosine and other phenolic acid derivatives could prevent the interaction tubulin/AR and the enzymatic activation. The drugs evaluated have two characteristics in common: the presence of an aromatic ring and a carboxylic substituent. The 9 drugs tested were able to prevent both the interaction tubulin/AR and the enzymatic activation. In addition, we found that the induction of microtubule formation by high concentrations of glucose and the consequent activation of AR in cultured cells can be inhibited by phenolic acid derivates that prevent the interaction tubulin/AR. These results suggest that tubulin regulates the activation of AR through a direct interaction which can be controlled with phenolic derivates of carboxylic acids.
Assuntos
Aldeído Redutase/metabolismo , Hidroxibenzoatos/metabolismo , Tubulina (Proteína)/metabolismo , Animais , Encéfalo/enzimologia , Células COS , Células Cultivadas , Chlorocebus aethiops , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática , Hidroxibenzoatos/química , Oxirredução , Ligação Proteica , Ratos , Proteínas Recombinantes/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismoRESUMO
BACKGROUND: The intrinsic heterogeneity of hepatocellular carcinoma (HCC) represents a great challenge for its molecular classification and for detecting predictive biomarkers. Aldo-keto reductase (Akr) family members have shown differential expression in human HCC, while AKR1B10 overexpression is considered a biomarker; AKR7A3 expression is frequently reduced in HCC. AIMS: To investigate the time-course expression of Akr members in the experimental hepatocarcinogenesis. METHODS: Using DNA-microarray data, we analyzed the time-course gene expression profile from nodules to tumors (4-17 months) of 17 Akr members induced by the resistant hepatocyte carcinogenesis model in the rat. RESULTS: The expression of six members (Akr1c19, Akr1b10, Akr7a3, Akr1b1, Akr1cl1, and Akr1b8) was increased, comparable to that of Ggt and Gstp1, two well-known liver cancer markers. In particular, Akr7a3 and Akr1b10 expression also showed a time-dependent increment at mRNA and protein levels in a second hepatocarcinogenesis model induced with diethylnitrosamine. We confirmed that aldo-keto reductases 7A3 and 1B10 were co-expressed in nine biopsies of human HCC, independently from the presence of glypican-3 and cytokeratin-19, two well-known HCC biomarkers. Because it has been suggested that expression of Akr members is regulated through NRF2 activity at the antioxidant response element (ARE) sequences, we searched and identified at least two ARE sites in Akr1b1, Akr1b10, and Akr7a3 from rat and human gene sequences. Moreover, we observed higher NRF2 nuclear translocation in tumors as compared with non-tumor tissues. CONCLUSIONS: Our results demonstrate that Akr7a3 mRNA and protein levels are consistently co-expressed along with Akr1b10, in both experimental liver carcinogenesis and some human HCC samples. These results highlight the presence of AKR7A3 and AKR1B10 from early stages of the experimental HCC and introduce them as a potential application for early diagnosis, staging, and prognosis in human cancer.
Assuntos
Aldeído Redutase/metabolismo , Membro B10 da Família 1 de alfa-Ceto Redutase/metabolismo , Aldo-Ceto Redutases/metabolismo , Carcinoma Hepatocelular/enzimologia , Neoplasias Hepáticas/enzimologia , Aldeído Redutase/genética , Membro B10 da Família 1 de alfa-Ceto Redutase/genética , Aldo-Ceto Redutases/genética , Animais , Biomarcadores/metabolismo , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/patologia , Modelos Animais de Doenças , Humanos , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/patologia , RNA Mensageiro/metabolismo , Ratos Endogâmicos F344RESUMO
We have synthesized a small series of five 3-[4-arylmethoxy)phenyl]propanoic acids employing an easy and short synthetic pathway. The compounds were tested in vitro against a set of four protein targets identified as key elements in diabetes: G protein-coupled receptor 40 (GPR40), aldose reductase (AKR1B1), peroxisome proliferator-activated receptor gama (PPARγ) and solute carrier family 2 (facilitated glucose transporter), member 4 (GLUT-4). Compound 1 displayed an EC50 value of 0.075 µM against GPR40 and was an AKR1B1 inhibitor, showing IC50 = 7.4 µM. Compounds 2 and 3 act as slightly AKR1B1 inhibitors, potent GPR40 agonists and showed an increase of 2 to 4-times in the mRNA expression of PPARγ, as well as the GLUT-4 levels. Docking studies were conducted in order to explain the polypharmacological mode of action and the interaction binding mode of the most active molecules on these targets, showing several coincidences with co-crystal ligands. Compounds 1-3 were tested in vivo at an explorative 100 mg/kg dose, being 2 and 3 orally actives, reducing glucose levels in a non-insulin-dependent diabetes mice model. Compounds 2 and 3 displayed robust in vitro potency and in vivo efficacy, and could be considered as promising multitarget antidiabetic candidates. This is the first report of a single molecule with these four polypharmacological target action.
Assuntos
Desenho de Fármacos , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Fenilpropionatos/química , Fenilpropionatos/farmacologia , Aldeído Redutase/antagonistas & inibidores , Animais , Sítios de Ligação , Linhagem Celular , Células Cultivadas , Técnicas de Química Sintética , Transportador de Glucose Tipo 4/agonistas , Transportador de Glucose Tipo 4/química , Transportador de Glucose Tipo 4/metabolismo , Humanos , Hipoglicemiantes/síntese química , Ligantes , Camundongos , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Terapia de Alvo Molecular , PPAR gama/antagonistas & inibidores , PPAR gama/química , Fenilpropionatos/síntese química , Ligação Proteica , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/químicaRESUMO
This study investigates in vitro targets related to diabetes in 30 herbal extracts from Peru, for the first time, using α-glucosidase, aldose reductase (AR) inhibitory assays and 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging assays. Among the 30 herbal extracts, Hypericum laricifolium Juss. (HL) was the herb which showed more than 50% inhibition in all assays, presenting 97.2 ± 2.0%, 56.9 ± 5.6%, 81.9 ± 2.5%, and 58.8 ± 4.6% inhibition for the α-glucosidase, AR, DPPH, and ABTS assays, respectively. Finally, six bioactive compounds, namely, protocatechuic acid, chlorogenic acid, caffeic acid, kaempferol 3-O-glucuronide, quercetin, and kaempferol were identified in HL by offline high-performance liquid chromatography (HPLC). Quercetin exhibited the strongest inhibition in all enzyme assays and the strongest antioxidant activity. The results suggest that HL shows great potential for the complementary treatment of diabetes and its complications.
Assuntos
Sequestradores de Radicais Livres/química , Inibidores de Glicosídeo Hidrolases/química , Hypericum/química , Hipoglicemiantes/química , Extratos Vegetais/química , Aldeído Redutase/antagonistas & inibidores , Animais , Ácidos Cafeicos/análise , Sequestradores de Radicais Livres/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Hidroxibenzoatos/análise , Hipoglicemiantes/farmacologia , Cristalino/efeitos dos fármacos , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: Understanding the effects of oxygen levels on yeast xylose metabolism would benefit ethanol production. In this work, xylose fermentative capacity of Scheffersomyces stipitis, Spathaspora passalidarum, Spathaspora arborariae and Candida tenuis was systematically compared under aerobic, oxygen-limited and anaerobic conditions. RESULTS: Fermentative performances of the four yeasts were greatly influenced by oxygen availability. S. stipitis and S. passalidarum showed the highest ethanol yields (above 0.44 g g-1) under oxygen limitation. However, S. passalidarum produced 1.5 times more ethanol than S. stipitis under anaerobiosis. While C. tenuis showed the lowest xylose consumption rate and incapacity to produce ethanol, S. arborariae showed an intermediate fermentative performance among the yeasts. NAD(P)H xylose reductase (XR) activity in crude cell extracts correlated with xylose consumption rates and ethanol production. CONCLUSIONS: Overall, the present work demonstrates that the availability of oxygen influences the production of ethanol by yeasts and indicates that the NADH-dependent XR activity is a limiting step on the xylose metabolism. S. stipitis and S. passalidarum have the greatest potential for ethanol production from xylose. Both yeasts showed similar ethanol yields near theoretical under oxygen-limited condition. Besides that, S. passalidarum showed the best xylose consumption and ethanol production under anaerobiosis.
Assuntos
Fermentação , Oxigênio/análise , Saccharomycetales/metabolismo , Xilose/metabolismo , Aldeído Redutase/metabolismo , Anaerobiose , Etanol/metabolismo , Oxigênio/metabolismo , Saccharomycetales/enzimologiaRESUMO
In the present study, the antioxidant and aldose reductase inhibitory activities of 24 Peruvian infusion tea plants were investigated by 2,2'-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and aldose reductase assays. Phoradendron sp. showed the highest inhibition of aldose reductase (IC50, 1.09±0.06µg/mL) and considerable antioxidant (IC50 of DPPH, 58.36±1.65µg/mL; IC50 of ABTS, 9.91±0.43µg/mL) effects. In order to identify the antioxidants and aldose reductase inhibitors of Phoradendron sp., DPPH-high performance liquid chromatography (HPLC) and ultrafiltration-HPLC assays were performed. Chlorogenic acid, 3,5-di-O-caffeoylquinic acid, and 1,3,5-tri-O-caffeoylquinic acid were identified as the antioxidants and aldose reductase inhibitors; apigenin was identified as the antioxidant. Finally, Phoradendron sp. and its aldose reductase inhibitors also showed a dose-dependent anti-inflammatory effect without cellular toxicity. These results suggested that Phoradendron sp. can be a potent functional food ingredient as an antioxidant, aldose reductase inhibitor and anti-inflammatory agent.