RESUMO
Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants ubiquitous in coastal ecosystems. The white shrimp Penaeus vannamei naturally inhabits in coastal areas and is cultivated in farms located nearby the oceans. PAHs can damage shrimp health, endanger natural populations, and lower shrimp aquaculture productivity. However, crustaceans have enzymes capable of metabolizing organic xenobiotics as PAHs and to neutralize reactive oxygen species (ROS) produced during xenobiotics metabolism. An important superfamily of xenobiotic-metabolizing and antioxidant enzymes are glutathione S-transferases (GSTs). In white shrimp, some GSTs are known, but they have been scarcely studied in response to PAHs. In this study we report the molecular cloning and bioinformatic characterization of two novel nucleotide sequences corresponding to cytosolic GSTs belonging the Delta and Theta classes (GSTD and GSTT). Both proteins genes have tissue-specific patterns of expression under normal conditions, that do not necessarily relate to GST activity and glutathione content. The expression of the GSTD and GSTT, GST activity and glutathione content was analyzed in juvenile P. vannamei exposed to two PAHs, naphthalene (NAP) and phenanthrene (PHE) in sub-lethal concentrations for 96 h. GSTD expression was up-regulated by the two PAHs, while GSTT expression was only induced by NAP. In contrast, GST activity towards CDNB was only up-regulated by PHE, suggesting differential effects of PAHs at gene and protein level. On the other hand, lower reduced glutathione content (GSH) caused by PAHs indicates its utilization for detoxification or antioxidant defenses. However, the GSH/GSSG did not change by PAHs treatment, indicating that shrimp can maintain redox balance during short-term sub-lethal exposure to NAP and PHE. Despite the variations in the responses to NAP and PHE, all these results suggest that the GSTD and GSTT genes could be useful biomarkers for PAH exposure in P. vannamei.
Assuntos
Glutationa Transferase , Glutationa , Naftalenos , Penaeidae , Fenantrenos , Poluentes Químicos da Água , Animais , Penaeidae/genética , Penaeidae/efeitos dos fármacos , Fenantrenos/toxicidade , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Poluentes Químicos da Água/toxicidade , Naftalenos/toxicidade , Glutationa/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Sequência de AminoácidosRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Different parts of Eugenia dysenterica have been popularly used in Brazil for treating diabetes mellitus and its complications. The present study aimed to screen extracts from E. dysenterica fruit pulp, peel, seed and leaf for carbohydrate digestive enzymes inhibitors with antioxidant and anti-glycation capacities. MATERIALS AND METHODS: Ethanol extracts of E. dysenterica were subjected to a liquid-liquid fractionation and the fractions were used to evaluate their antioxidant properties and inhibitory potential against the formation of advanced glycation end-products (AGEs) and α-amylase and α-glucosidase. RESULTS: The ethyl acetate fraction (EtOAcF) from seed and the dichloromethane fraction (CH2Cl2F) and EtOAcF from leaf had high antioxidant capacities (ORAC >5500 µmol trolox eq g-1, FRAP >1500 µmol trolox eq g-1 and DPPH IC50 < 35 µg mL-1) and showed exceptional inhibitory activities against AGEs formation (glycation inhibition above 80% at 10 µg mL-1) and α-amylase and α-glucosidase (inhibition above 50% at 10 µg mL-1). The gallated B-types proanthocyanidins were the most active ingredients found in the leaf of E. dysenterica (CH2Cl2 and EtOAcF), being responsible for the notorious inhibitory effects against glycation and glycoside hydrolases due to their ortho-hydroxyl groups, which play role in scavenge and quench free radicals and glycated products, and may occupy the enzymes' substrate binding pocket. Furthermore, gallic acid, quercetin and its glycoside derivatives were detected by the first time in the E. dysenterica fruit seed (EtOAcF). CONCLUSIONS: The results strongly contribute to the understanding of the antidiabetic potential of seeds and leaves from E. dysenterica, a species from a global biodiversity hotspot, which appears to be linked to the prevention of oxidative stress, AGEs production and postprandial hyperglycemia.
Assuntos
Eugenia/química , Flavonoides/química , Frutas/química , Folhas de Planta/química , Proantocianidinas/química , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Produtos Finais de Glicação Avançada , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Polifenóis/química , Polifenóis/farmacologia , alfa-Amilases/genética , alfa-Amilases/metabolismo , alfa-Glucosidases/genética , alfa-Glucosidases/metabolismoRESUMO
Acetylcholinesterase (AChE; EC 3.1.1.7) from aquatic organisms have been used to evaluate the exposure of specimens to pesticides and heavy metals at sublethal levels in environmental samples. AChE of Mytella charruana was extracted to characterize its physicochemical and kinetic properties as well as the effect of organophosphate (dichlorvos, diazinon, chlorpyrifos, methyl-parathion and temephos), carbamates (carbaryl, carbofuran and aldicarb), benzoylureas (diflubenzuron and novaluron), pyrethroid (cypermethrin) and juvenile hormone analog - JHA (pyriproxyfen) and the effect of metal ions: Hg2+, Cd2+, Pb2+, As3+, Cu2+ and Zn2+, in order to evaluate the potential of the enzyme as biomarker. The optimum pH of M. charruana AChE was 8.5 and the maximum activity peak occurred at 48 °C, being highly thermostable maintaining 97.8% of its activity after incubation at 60 °C. The Michaelis-Menten constants (km) for the substrates acetylthiocholine and propionylthiocholine were 2.8 ± 1.26 and 4.94 ± 6.9 mmol·L-1, respectively. The Vmax values for the same substrates were 22.6 ± 0.90 and 10.2 ± 4.94 mU·mg-1, respectively. Specific inhibition results suggest an AChE presenting active site with dimensions between those of AChE and butyrylcholinesterase (BChE). The IC20 values related to the effect of the pesticides on the enzyme showed higher inhibitory power of temephos (0.17 µmol·L-1), followed by aldicarb (0.19 µmol·L-1) and diflubenzuron (0.23 µmol·L-1). Metal ions inhibited M. charruana enzyme in the following order: Hg2+ > Pb2+ > Cd2+ > As3+ > Cu2+ > Zn2+. These data suggest that the enzyme showed potential as in vitro biomarker of the exposure to temephos, mercury, zinc and copper.
Assuntos
Acetilcolinesterase/metabolismo , Bivalves/enzimologia , Monitoramento Ambiental , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/genética , Animais , Biomarcadores/metabolismo , Metais Pesados , PraguicidasRESUMO
In this study, we investigated the action of varespladib (VPL) alone or in combination with a coral snake antivenom (CAV) on the local and systemic effects induced by Micrurus corallinus venom in rats. Adult male Wistar rats were exposed to venom (1.5 mg/kg - i.m.) and immediately treated with CAV (antivenom:venom ratio 1:1.5 'v/w' - i.p.), VPL (0.5 mg/kg - i.p.), or both of these treatments. The animals were monitored for 120 min and then anesthetized to collect blood samples used for haematological and serum biochemical analysis; after euthanasia, skeletal muscle, renal and hepatic tissue samples were collected for histopathological analysis. M. corallinus venom caused local oedema without subcutaneous haemorrhage or apparent necrosis formation, although there was accentuated muscle morphological damage; none of the treatments prevented oedema formation but the combination of CAV and VPL reduced venom-induced myonecrosis. Venom caused neuromuscular paralysis and respiratory impairment in approximately 60 min following envenomation; CAV alone did not prevent the neurotoxic action, whereas VPL alone prevented neurotoxic symptoms developing as did the combination of CAV and VPL. Venom induced significant increase of serum CK and AST release, mostly due to local and systemic myotoxicity, which was partially prevented by the combination of CAV and VPL. The release of hepatotoxic serum biomarkers (LDH and ALP) induced by M. corallinus venom was not prevented by CAV and VPL when individually administered; their combination effectively prevented ALP release. The venom-induced nephrotoxicity (increase in serum creatinine concentration) was prevented by all the treatments. VPL alone or in combination with CAV significantly prevented the venom-induced lymphocytosis. In conclusion, VPL shows to be effective at preventing the neurotoxic, nephrotoxic, and inflammatory activities of M. corallinus venom. In addition, VPL acts synergistically with antivenom to prevent a number of systemic effects caused by M. corallinus venom.
Assuntos
Acetatos/farmacologia , Cobras Corais/fisiologia , Venenos Elapídicos/toxicidade , Indóis/farmacologia , Cetoácidos/farmacologia , Inibidores de Fosfolipase A2/farmacologia , Animais , Biomarcadores/sangue , Transtornos da Coagulação Sanguínea/induzido quimicamente , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , L-Lactato Desidrogenase/sangue , Fármacos Neuroprotetores/farmacologia , Fosfolipases A2/genética , Fosfolipases A2/metabolismo , Ratos , Ratos WistarRESUMO
Crotalphine (CRP) is a structural analogue to a peptide that was first identified in the crude venom from the South American rattlesnake Crotalus durissus terrificus. This peptide induces a potent and long-lasting antinociceptive effect that is mediated by the activation of peripheral opioid receptors. The opioid receptor activation regulates a variety of intracellular signaling, including the mitogen-activated protein kinase (MAPK) pathway. Using primary cultures of sensory neurons, it was demonstrated that crotalphine increases the level of activated ERK1/2 and JNK-MAPKs and this increase is dependent on the activation of protein kinase Cζ (PKCζ). However, whether PKCζ-MAPK signaling is critical for crotalphine-induced antinociception is unknown. Here, we biochemically demonstrated that the systemic crotalphine activates ERK1/2 and JNK and decreases the phosphorylation of p38 in the lumbar spinal cord. The in vivo pharmacological inhibition of spinal ERK1/2 and JNK, but not of p38, blocks the antinociceptive effect of crotalphine. Of interest, the administration of a PKCζ pseudosubstrate (PKCζ inhibitor) prevents crotalphine-induced ERK activation in the spinal cord, followed by the abolishment of crotalphine-induced analgesia. Together, our results demonstrate that the PKCζ-ERK signaling pathway is involved in crotalphine-induced analgesia. Our study opens a perspective for the PKCζ-MAPK axis as a target for pain control.
Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Dor/tratamento farmacológico , Peptídeos/farmacologia , Proteína Quinase C/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Comportamento Animal , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/genética , Proteína Quinase C/genética , Ratos , Ratos WistarRESUMO
Epstein-Barr virus (EBV) is an oncovirus ubiquitously distributed and associated with different types of cancer. The reason why only a group of infected people develop cancer is still unknown. EBV-associated cancers represent about 1.8% of all cancer deaths worldwide, with more than 150,000 new cases of cancer being reported annually. Since EBV-associated cancers are described as more aggressive and more resistant to the usual treatment compared to EBV-negative ones, the recent introduction of monoclonal antibodies (mAbs) targeting immune checkpoints (ICs) in the treatment of cancer patients represents a possible therapy for EBV-associated diseases. However, the current mAb therapies available still need improvement, since a group of patients do not respond well to treatment. Therefore, the main objective of this review is to summarize the progress made regarding the contribution of EBV infection to the expression of the IC indoleamine 2,3-dioxygenase (IDO) thus far. This IC has the potential to be used as a target in new immune therapies, such as mAbs. We hope that this work helps the development of future immunotherapies, improving the prognosis of EBV-associated cancer patients.
Assuntos
Anticorpos Monoclonais/farmacologia , Infecções por Vírus Epstein-Barr/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Neoplasias/virologia , Anticorpos Monoclonais/uso terapêutico , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Medicina de PrecisãoRESUMO
1,2,3-Triazole is one of the most flexible chemical scaffolds broadly used in various fields. Here, we report the antileishmanial activity of 1,2,3-triazole derivatives, the ultrastructural alterations induced by their treatment, and the nitric oxide (NO) modulation effect on their efficacy against Leishmania amazonensis in vitro infection. After the screening of eleven compounds, compound 4 exhibited better results against L. amazonensis promastigotes (IC50 = 15.52 ± 3.782 µM) and intracellular amastigotes (IC50 = 4.10 ± 1.136 µM), 50% cytotoxicity concentration at 84.01 ± 3.064 µM against BALB/c peritoneal macrophages, and 20.49-fold selectivity for the parasite over the cells. Compound 4 induced ultrastructural mitochondrial alterations and lipid inclusions in L. amazonensis promastigotes, upregulated tumor necrosis factor α, interleukin (IL)-1ß, IL-6, IL-12, and IL-10 messenger RNA expressions, and enhanced the NO production, verified by nitrite (p = 0.0095) and inducible nitric oxide synthase expression (p = 0.0049) quantification, which played an important role in its activity against intramacrophagic L. amazonensis. In silico prediction in association with antileishmanial activity results showed compound 4 as a hit compound with promising potential for further studies of new leishmaniasis treatment options.
Assuntos
Antiprotozoários/farmacologia , Leishmania/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Óxido Nítrico/metabolismo , Triazóis/farmacologia , Animais , Antiprotozoários/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/parasitologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Triazóis/químicaRESUMO
PURPOSE: Cardiac transition from concentric (C-LVH) to eccentric left ventricle hypertrophy (E-LVH) is a maladaptive response of hypertension. Matrix metalloproteinases (MMPs), in particular MMP-2, may contribute to tissue remodeling by proteolyzing extra- and intracellular proteins. Troponin I and dystrophin are two potential targets of MMP-2 examined in this study and their proteolysis would impair cardiac contractile function. We hypothesized that MMP-2 contributes to the decrease in troponin I and dystrophin in the hypertensive heart and thereby controls the transition from C-LVH to E-LVH and cardiac dysfunction. METHODS: Male Wistar rats were divided into sham or two kidney-1 clip (2K-1C) hypertensive groups and treated with water (vehicle) or doxycycline (MMP inhibitor, 15 mg/kg/day) by gavage from the tenth to the sixteenth week post-surgery. Tail-cuff plethysmography, echocardiography, gelatin zymography, confocal microscopy, western blot, mass spectrometry, in silico protein analysis and immunofluorescence were performed. RESULTS: 6 out of 23 2K-1C rats (26%) had E-LVH followed by reduced ejection fraction. The remaining had C-LVH with preserved cardiac function. Doxycycline prevented the transition from C-LVH to E-LVH. MMP activity is increased in C-LVH and E-LVH hearts which was inhibited by doxycycline. This effect was associated with an increase in troponin I cleavage products and a decline in dystrophin in the left ventricle of E-LVH rats, which was prevented by doxycycline. CONCLUSION: Hypertension causes increased cardiac MMP-2 activity which proteolyzes troponin I and dystrophin, contributing to the transition from C-LVH to E-LVH and cardiac dysfunction.
Assuntos
Doxiciclina/farmacologia , Distrofina/metabolismo , Hipertensão/complicações , Hipertrofia Ventricular Esquerda/etiologia , Metaloproteinase 2 da Matriz/metabolismo , Troponina I/metabolismo , Animais , Antibacterianos/farmacologia , Distrofina/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hipertrofia Ventricular Esquerda/metabolismo , Masculino , Metaloproteinase 2 da Matriz/genética , Inibidores de Metaloproteinases de Matriz/farmacologia , Ratos , Ratos Wistar , Troponina I/genéticaRESUMO
Snakebite envenoming is the cause of an ongoing health crisis in several regions of the world, particularly in tropical and neotropical countries. This scenario creates an urgent necessity for new practical solutions to address the limitations of current therapies. The current study investigated the isolation, phytochemical characterization, and myotoxicity inhibition mechanism of gallic acid (GA), a myotoxin inhibitor obtained from Anacardium humile. The identification and isolation of GA was achieved by employing analytical chromatographic separation, which exhibited a compound with retention time and nuclear magnetic resonance spectra compatible with GA's commercial standard and data from the literature. GA alone was able to inhibit the myotoxic activity induced by the crude venom of Bothrops jararacussu and its two main myotoxins, BthTX-I and BthTX-II. Circular dichroism (CD), fluorescence spectroscopy (FS), dynamic light scattering (DLS), and interaction studies by molecular docking suggested that GA forms a complex with BthTX-I and II. Surface plasmon resonance (SPR) kinetics assays showed that GA has a high affinity for BthTX-I with a KD of 9.146 × 10-7 M. Taken together, the two-state reaction mode of GA binding to BthTX-I, and CD, FS and DLS assays, suggest that GA is able to induce oligomerization and secondary structure changes for BthTX-I and -II. GA and other tannins have been shown to be effective inhibitors of snake venoms' toxic effects, and herein we demonstrated GA's ability to bind to and inhibit a snake venom PLA2, thus proposing a new mechanism of PLA2 inhibition, and presenting more evidence of GA's potential as an antivenom compound.
Assuntos
Anacardium/química , Ácido Gálico/farmacologia , Miotoxicidade/tratamento farmacológico , Inibidores de Fosfolipase A2/farmacologia , Fosfolipases A2/metabolismo , Venenos de Serpentes/enzimologia , Animais , Modelos Animais de Doenças , Ácido Gálico/química , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Miotoxicidade/enzimologia , Miotoxicidade/etiologia , Inibidores de Fosfolipase A2/química , Fosfolipases A2/química , Caules de Planta/química , Proteínas de Répteis/química , Proteínas de Répteis/metabolismo , Ressonância de Plasmônio de SuperfícieRESUMO
Spirulina (Arthrospira maxima) has been recognized as a superfood and nutraceutical by its high nutritional value and the benefits of its consumption; it is an important source of lipids, proteins, vitamins, minerals, and antioxidants. It is known that spirulina has positive effects on the toxicity induced by pharmaceuticals and metals. Heavy metals such as cadmium, frequently used in industrial activities, are continuously detected in water bodies and can generate adverse effects on aquatic organisms even at low concentrations. This study aimed to evaluate the protective effect of spirulina (Arthrospira maxima) against the toxic effects induced by cadmium in the early life stages of Xenopus laevis. Twenty Xenopus laevis embryos were exposed to five different treatments on triplicate, control, cadmium (CdCl2 24.5 µg L-1) and three spirulina mixtures Cd + S 1 (24.5 µg L-1 CdCl2 + 2 mg L-1 spirulina), Cd + S 2 (24.5 µg L-1 CdCl2 + 2 mg L-1 spirulina), Cd + S 3 (24.5 µg L-1 CdCl2 + 10 mg L-1 spirulina); after 96 h of exposure: Malformations, mortality and length were evaluated; also, after 192 h, lipid peroxidation (LPX), superoxide dismutase (SOD) and catalase (CAT) were determined. All spirulina treatments decreased mortality from 34 to 50% and reduced malformations on incidence from 36 to 68%. Treatment Cd + S 3 decreased growth inhibition significantly. Spirulina treatment Cd + S 2 decreased lipidic peroxidation and antioxidant activity; these results suggest that spirulina (Arthrospira maxima) can decrease the mortality, frequency of malformations, the severity of malformations, growth inhibition, and oxidative damage induced by cadmium in Xenopus laevis embryos.