RESUMO
AIMS: Hypobaric hypoxia (HH), linked to oxidative stress, impairs cardiac function. We synthesized a novel nitronyl nitroxide radical, an HPN derivative (HEPN) and investigated the protective effects of HEPN and HPN against HH-induced heart injury in mice and the underlying mechanisms of action. MAIN METHODS: Mice were administered with HPN (200â¯mg/kg) or HEPN (200â¯mg/kg) 30â¯min before exposed to HH. The cardiac function was measured. Serum AST, CK, LDH and cTnI were estimated. Heart tissue oxidase activity, SOD, CAT, GSH-Px, ROS and MDA were estimated. ATP content, Na+/K+-ATPase and Ca2+/Mg2+-ATPase activity was measured. The expression of HIF-1, VEGF, Nrf2, HO-1, Bax, Bcl-2, Caspase-3 was estimated. KEY FINDINGS: Results showed that pretreatment with HEPN or HPN led to a dramatic decrease in the activity of biochemical markers AST, CK, LDH and cTnI in murine serum. They increased the activity of SOD, CAT and GSH-Px and reduced the level of ROS and MDA in the hearts of mice. HEPN and HPN could increase the expression of Nrf2 and OH-1. They could maintain the ATPase activity. The Bax and Caspase-3 expression as well as the ratio of Bax/Bcl-2 were significantly downregulated and the Bcl-2 expression was upregulated by HPN or HEPN compared to the HH group. They may attenuate the HH-induced oxidant stress via free radical scavenging activity. SIGNIFICANCE: The present study showed that the nitronyl nitroxide radical HEPN and HPN may be potential therapeutic agents for treatment of HH-induced cardiac dysfunction.
Assuntos
Antioxidantes/farmacologia , Cardiotônicos/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , Hipóxia/tratamento farmacológico , Óxidos de Nitrogênio/farmacologia , Animais , Antioxidantes/síntese química , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/genética , ATPase de Ca(2+) e Mg(2+)/genética , ATPase de Ca(2+) e Mg(2+)/metabolismo , Cardiotônicos/síntese química , Caseína Quinases/sangue , Caseína Quinases/genética , Caspase 3/genética , Caspase 3/metabolismo , Catalase/sangue , Catalase/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa Peroxidase/sangue , Glutationa Peroxidase/genética , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/fisiopatologia , Testes de Função Cardíaca , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Hipóxia/complicações , Hipóxia/genética , Hipóxia/fisiopatologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , L-Lactato Desidrogenase/sangue , L-Lactato Desidrogenase/genética , Masculino , Malondialdeído/antagonistas & inibidores , Malondialdeído/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Óxidos de Nitrogênio/síntese química , Estresse Oxidativo/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/sangue , Superóxido Dismutase/genética , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Baicalin belongs to glucuronic acid glycosides and after hydrolysis baicalein and glucuronic acid come into being. It has such effects as clearing heat and removing toxicity, anti-inflammation, choleresis, bringing high blood pressure down, diuresis, anti-allergic reaction and so on. In this study, we investigated whether baicalin ameliorates isoproterenol-induced acute myocardial infarction and its mechanism. Rat model of acute myocardial infarction was induced by isoproterenol. Casein kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH), cardiac troponin T (cTnT) and infarct size measurement were used to measure the protective effect of baicalin on isoproterenol-induced acute myocardial infarction. iNOS protein expression in rat was analyzed using western blot analysis. Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), malondialdehyde (MDA) and superoxide dismutase (SOD) and caspase-3 activation levels were explored using commercial ELISA kits. In the acute myocardial infarction experiment, baicalin effectively ameliorates the level of CK, CK-MB, LDH and cTnT, reduced infarct size in acute myocardial infarction rat model. Meanwhile, treatment with baicalin effectively decreased the iNOS protein expression, inflammatory factors and oxidative stresses in a rat model of acute myocardial infarction. However, baicalin emerged that anti-apoptosis activity and suppressed the activation of caspase-3 in a rat model of acute myocardial infarction. The data suggest that the protective effect of baicalin ameliorates isoproterenol-induced acute myocardial infarction through iNOS, inflammation and oxidative stress in rat.