RESUMO
PURPOSE: To determine the antioxidant and anti-inflammatory effects of alfa lipoic acid (ALA) on the liver injury induced by methotrexate (MTX) in rats. METHODS: Thirty two rats were randomly assigned into four equal groups; control, ALA, MTX and MTX with ALA groups. Liver injury was performed with a single dose of MTX (20 mg/kg) to groups 3 and 4. The ALA was administered intraperitonealy for five days in groups 2 and 4. The other rats received saline injection. At the sixth day the rats decapitated, blood and liver tissue samples were removed for TNF-α, IL-1ß, malondialdehyde, glutathione, myeloperoxidase and sodium potassium-adenosine triphosphatase levels measurement and histological examination. RESULTS: MTX administration caused a significant decrease in tissue GSH, and tissue Na+, K+ ATPase activity and which was accompanied with significant increases in tissue MDA and MPO activity. Moreover the pro-inflammatory cytokines (TNF-α, IL- ß) were significantly increased in the MTX group. On the other hand, ALA treatment reversed all these biochemical indices as well as histopathological alterations induced by MTX. CONCLUSION: Alfa lipoic acid ameliorates methotrexate induced oxidative damage of liver in rats with its anti-inflammatory and antioxidant effects.
Assuntos
Antimetabólitos Antineoplásicos/toxicidade , Antioxidantes/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Metotrexato/toxicidade , Ácido Tióctico/uso terapêutico , Animais , Anti-Inflamatórios/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/patologia , Ensaio de Imunoadsorção Enzimática , Feminino , Glutationa/análise , Interleucina-1beta/sangue , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Malondialdeído/análise , Necrose/patologia , Peroxidase/análise , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Resultado do Tratamento , Fator de Necrose Tumoral alfa/sangueRESUMO
OBJECTIVE: Obstructive sleep apnea syndrome is characterized by repetitive obstruction of the upper airways, and it is a risk factor for cardiovascular diseases. There have been several studies demonstrating low levels of nitric oxide in patients with obstructive sleep apnea syndrome compared with healthy controls. In this study, we hypothesized that reduced nitric oxide levels would result in high arginase activity. Arginase reacts with L-arginine and produces urea and L-ornithine, whereas L-arginine is a substrate for nitric oxide synthase, which produces nitric oxide. METHODS: The study group consisted of 51 obstructive sleep apnea syndrome patients (M/F: 43/8; mean age 49±10 years of age) and 15 healthy control subjects (M/F: 13/3; mean age 46±14 years of age). Obstructive sleep apnea syndrome patients were divided into two subgroups based on the presence or absence of cardiovascular disease. Nitric oxide levels and arginase activity were measured via an enzyme-linked immunosorbent assay of serum samples. RESULTS: Serum nitric oxide levels in the control subjects were higher than in the obstructive sleep apnea patients with and without cardiovascular diseases (p<0.05). Arginase activity was significantly higher (p<0.01) in obstructive sleep apnea syndrome patients without cardiovascular diseases compared with the control group. Obstructive sleep apnea syndrome patients with cardiovascular diseases had higher arginase activity than the controls (p<0.001) and the obstructive sleep apnea syndrome patients without cardiovascular diseases (p<0.05). CONCLUSION: Low nitric oxide levels are associated with high arginase activity. The mechanism of nitric oxide depletion in sleep apnea patients suggests that increased arginase activity might reduce the substrate availability of nitric oxide synthase and thus could reduce nitric oxide levels.