RESUMO
BACKGROUND: Acetaminophen (APAP) is a commonly used analgesic and antipyretic. When administered in high doses, APAP is a clinical problem in the US and Europe, often resulting in severe liver injury and potentially acute liver failure. Studies have demonstrated that antioxidants and anti-inflammatory agents effectively protect against the acute hepatotoxicity induced by APAP overdose. METHODS: The present study attempted to investigate the protective effect of B. trimera against APAP-induced hepatic damage in rats. The liver-function markers ALT and AST, biomarkers of oxidative stress, antioxidant parameters, and histopathological changes were examined. RESULTS: The pretreatment with B. trimera attenuated serum activities of ALT and AST that were enhanced by administration of APAP. Furthermore, pretreatment with the extract decreases the activity of the enzyme SOD and increases the activity of catalase and the concentration of total glutathione. Histopathological analysis confirmed the alleviation of liver damage and reduced lesions caused by APAP. CONCLUSIONS: The hepatoprotective action of B. trimera extract may rely on its effect on reducing the oxidative stress caused by APAP-induced hepatic damage in a rat model. General Significance. These results make the extract of B. trimera a potential candidate drug capable of protecting the liver against damage caused by APAP overdose.
Assuntos
Baccharis , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Fitoterapia , Acetaminofen/toxicidade , Alanina Transaminase/sangue , Analgésicos não Narcóticos/toxicidade , Animais , Antioxidantes/metabolismo , Antipiréticos/toxicidade , Aspartato Aminotransferases/sangue , Baccharis/química , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Modelos Animais de Doenças , Células Hep G2 , Humanos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Endogâmicos F344RESUMO
Annatto has been identified as carotenoids that have antioxidative effects. It is well known that one of the key elements in the development of diabetic complications is oxidative stress. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen species and reactive nitrogen species as part of the body's defense mechanisms to destroy invading pathogens. Reactive oxygen species/reactive nitrogen species are excessively produced by active peripheral neutrophils, and may damage essential cellular components, which in turn can cause vascular complications in diabetes. The present study was undertaken to evaluate the possible protective effects of annatto on the reactive oxygen species and nitric oxide (NO) inhibition in neutrophils from alloxan-induced diabetic rats. Adult female rats were divided into six groups based on receiving either a standard diet with or without supplementation of annatto extract or beta carotene. All animals were sacrificed 30 days after treatment and the neutrophils were isolated using two gradients of different densities. The reactive oxygen species and NO were quantified by a chemiluminescence and spectrophotometric assays, respectively. Our results show that neutrophils from diabetic animals produce significantly more reactive oxygen species and NO than their respective controls and that supplementation with beta carotene and annatto is able to modulate the production of these species. Annatto extract may have therapeutic potential for modulation of the balance reactive oxygen species/NO induced by diabetes.
RESUMO
Annatto (Bixa orellana L.) contains a mixture of orange-yellowish pigments due to the presence of various carotenoids that have antioxidant effect. The immune system is especially vulnerable to oxidative damage because many immune cells, such as neutrophils, produce reactive oxygen and nitrogen species (ROS and RNS) as part of the body's defence mechanisms to destroy invading pathogens. It is well known that the function of neutrophils is altered in diabetes; one of the major functional changes in neutrophils in diabetes is the increased generation of extracellular superoxide via the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system. The purpose of this study is to evaluate the production of ROS and nitric oxide (NO) as well as the expression of NADPH oxidase subunits, inducible nitric oxide (iNOS), superoxide dismutase (SOD) and catalase (CAT) in neutrophils from diabetic rats treated with annatto extract and ß-carotene. Forty-eight female Fisher rats were distributed into six groups according to the treatment received. All animals were sacrificed 7 days after treatment, and the neutrophils were isolated using two gradients of different densities. The ROS and NO were quantified by a chemiluminescence and spectrophotometric assays, respectively. Analyses of gene expression were performed using quantitative real time polymerase chain reaction (qRT-PCR). The results show that treatment with annatto extract and ß-carotene was able to decrease ROS production and the mRNA levels of p22(phox) and p47(phox) and increase the mRNA levels of SOD and CAT in neutrophils from diabetic rats. These data suggest that annatto extract and ß-carotene exerts antioxidant effect via inhibition of expression of the NADPH oxidase subunits and increase expression/activity of antioxidant enzymes.
Assuntos
Carotenoides/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Sequestradores de Radicais Livres/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Extratos Vegetais/farmacologia , beta Caroteno/farmacologia , Aloxano , Animais , Bixaceae , Catalase/biossíntese , Catalase/genética , Células Cultivadas/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/imunologia , Avaliação Pré-Clínica de Medicamentos , Feminino , Hepatócitos/efeitos dos fármacos , NADPH Oxidases/biossíntese , NADPH Oxidases/genética , Neutrófilos/enzimologia , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Ratos Endogâmicos F344 , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Superóxido Dismutase/biossíntese , Superóxido Dismutase/genéticaRESUMO
The aim of this study was to investigate the possible effects of captopril as a promoter in modulating the oxidant-antioxidant balance in rats with type 1 diabetes, and the influence of protein kinase C (PKC) pathways in the production of reactive oxygen species (ROS) induced by bradykinin in type 1 diabetic rats. This study evaluated the redox status in both the cardiac tissue and at the cellular level (neutrophils). Two concentrations of captopril were utilized: (i) 5 mg·(kg body mass)(-1), which was considered a therapeutic dose; and (ii) 10 mg·(kg body mass)(-1). Body mass, plasma glucose, and serum insulin were evaluated. To investigate the redox status of the cardiac tissue, we analyzed lipid peroxidation, concentration of carbonylated protein, catalase activity, and the concentration of glutathione. For a more accurate assessment of the possible antioxidant effect of captopril, we also analyzed ROS in neutrophils (in vivo), and ROS production induced by bradykinin and the influence of the PKC pathway in this production (in vitro). Our data show that the hearts of diabetic animals have increased oxidative damage, exemplified by the increased concentration of carbonylated protein and thiobarbituric acid reactive substances (TBARS). However, animals treated with captopril at both concentrations showed lower concentrations of carbonylated protein compared with untreated diabetic animals. We found an increase of catalase activity in the heart of diabetic rats, which was reversed by captopril treatment at both of the dosages tested. Our data showed that captopril was able to reduce ROS production in the neutrophils of diabetic rats at a dose of 10 mg captopril·(kg body mass)(-1). However, the antioxidant effect of captopril is independent of bradykinin. Diabetes induces oxidative stress, and these results suggest that captopril has an antioxidant effect and can modulate the production of ROS in circulating neutrophils.
Assuntos
Antioxidantes/farmacologia , Bradicinina/metabolismo , Captopril/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Proteína Quinase C/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Antioxidantes/uso terapêutico , Glicemia/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Captopril/uso terapêutico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Insulina/sangue , Miocárdio/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos Endogâmicos F344 , Transdução de SinaisRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Baccharis trimera (Less.) (Asteraceae) is a native plant of Brazil. Also known as "carqueja", it has been popularly used to treat liver diseases, diabetes, as well as digestive disorders. Other studies have described the hepatoprotective, antioxidant and anti-inflammatory activities of the species. AIM OF THE STUDY: The aim of the present study was to investigate the antioxidant properties of Baccharis trimera in the neutrophils of Fisher rats in both in vitro and in vivo experimental models. MATERIAL AND METHODS: In the in vitro assay, the neutrophils of male rats were isolated and incubated with Baccharis trimera extract at concentrations of 0.5, 5.0 and 50.0 microg/mL. In the in vivo assay, male rats were first treated with crude extract 600 mg/kg body weight of Baccharis trimera or with 50 mg/kg body weight of quercetin (reference substance) and then treated with 835 mg/kg of acetaminophen (APAP) after 24 h. RESULTS: The hydroethanolic extract of Baccharis trimera reduced the release of reactive oxygen species in the neutrophils in both the in vitro and in vivo experimental models. Therefore confirming its antioxidant effect. CONCLUSION: The results of this study confirm the antioxidant effect of Baccharis trimera.