Fábio Cangeri Di Naso

Exogenous Superoxide Dismutase: Action on Liver Oxidative Stress in Animals with Streptozotocin-Induced Diabetes

Aim. To investigate the effects of exogenous antioxidant copper zinc superoxide dismutase (Cu/Zn SOD) on oxidative stress in the experimental model of diabetes mellitus (DM). Methods. Twenty eight male Wistar rats divided in four groups were used: control (CO), controls treated with SOD (CO + SOD), diabetics (DM), and diabetics treated with SOD (DM + SOD). SOD (orgotein, 13 mg/Kg body weight was administered. DM was induced by a single streptozotocin injection (i.p., 70 mg/kg), and 60 days later, we evaluated liver oxidative stress. Results. Liver lipoperoxidation was increased in the DM group and significantly decreased in the DM + SOD group. Nitrite and nitrate measures were reduced in the DM and increased in the DM + SOD group, while iNOS expression in the DM group was 32% greater than in the CO and 53% greater in the DM + SOD group than in the DM group (P < .01). P65 expression was 37% higher in the DM (P < .05), and there was no significant difference between the DM and DM + SOD groups. Conclusion. SOD treatment reduced liver oxidative stress in diabetic animals, even though it did not change NFκB. SOD also increased NO, probably by the increased dismutation of the superoxide radical. The iNOS expression increase, which became even more evident after SOD administration.

Obesity depresses the anti‐inflammatory HSP70 pathway, contributing to NAFLD progression

To evaluate whether reduced activity of the anti‐inflammatory HSP70 pathway correlates with nonalcoholic fatty liver disease (NAFLD) progression and with markers of oxidative stress because obesity activates inflammatory JNKs, whereas HSP70 exerts the opposite effect.

Quercetin Treatment Ameliorates Systemic Oxidative Stress in Cirrhotic Rats

Our aim was to investigate whether the antioxidant quercetin protects against liver injury and ameliorates the systemic oxidative stress in rats with common bile duct ligation. Secondary biliary cirrhosis was induced through 28 days of bile duct obstruction. Animals received quercetin (Q) after 14 days of obstruction. Groups of control (CO) and cirrhotic (CBDL) animals received a daily 50 mg/kg body weight i.p. injection of quercetin (CO + Q; CBDL + Q) or vehicle (CO; CBDL). Quercetin corrected the reduction in superoxide dismutase (SOD), catalase CAT, and glutathione peroxidase GPx activities and prevented the increase of thiobarbituric acid reactive substances (TBARS), aminotransferases, and alkaline phosphatase in cirrhotic animals. Quercetin administration also corrected the reduced total nitrate concentration in the liver and prevented liver fibrosis and necrosis. These effects suggest that quercetin might be a useful agent to preserve liver function and prevent systemic oxidative stress.

Effect of Antioxidant Treatment on Fibrogenesis in Rats with Carbon Tetrachloride-Induced Cirrhosis

Aim. This study aimed to assess the antioxidant activity of quercetin (Q) in an experimental model of cirrhosis induced by CCl4 inhalation. Materials and Methods. We used 25 male Wistar rats (250 g) that were divided into 3 groups: control (CO), CCl4, and CCl4 + Q. The rats were subjected to CCl4 inhalation (2x/week) for 16 weeks, and they received phenobarbital in their drinking water at a dose of 0.3 g/dL as a P450 enzyme inducer. Q (50 mg/Kg) was initiated intraperitoneally at 10 weeks of inhalation and lasted until the end of the experiment. Statistical analysis was by ANOVA Student Newman-Keuls (mean ± SEM), and differences were considered statistically significant when P < 0.05. Results. After treatment with quercetin, we observed an improvement in liver complications, decreased fibrosis, as analyzed by picrosirius for the quantification of collagen, and decreased levels of matrix metalloproteinase 2 (MMP-2) compared with the CCl4 group. It also reduced oxidative stress, as confirmed by the decrease of substances reacting to thiobarbituric acid (TBARS), the increased activity of antioxidant enzymes, and the reduced glutathione ratio and glutathione disulfide (GSH/GSSG). Conclusion. We suggest that the use of quercetin might be promising as an antioxidant therapy in liver fibrosis.

Effect of Agaricus blazei Murill on the Pulmonary Tissue of Animals with Streptozotocin-Induced Diabetes

The present study was designed to evaluate the oxidative stress as well as the therapeutic effect of Agaricus blazei Muril (A. Blazei) in rats with streptozotocin-induced diabetes. We used 25 Wistar rats, and DM was induced by injecting streptozotocin (70 mg/Kg i.p.). Agaricus blazei Muril was administered daily starting 40 days after disease onset. A. Blazei was tested as an aqueous extract for its phytochemical composition, and its antioxidant activity in vitro was also evaluated. Lipoperoxidation (LPO), and superoxide dismutase (SOD), catalase, and glutathione peroxidase activities were measured in the pulmonary tissue, as well as the presence of inducible nitric oxide synthase (iNOS), through immunohistochemistry. An anatomopathologic study was also performed. Phytochemical screening of A. Blazei detected the presence of alkaloids and saponins. The extract exhibited a significant antioxidant activity in the DPPH-scavenging and the hipoxanthine/xanthine oxidase assays. Pulmonary LPO increased in diabetic animals (0.43 ± 0.09; P < .001) as compared to the control group (0.18 ± 0.02), followed by a reduction in the A. Blazei-treated group (0.33 ± 0.04; P < .05). iNOS was found increased in the lung in diabetic rats and reduced in the A. Blazei-treated group. The pulmonary tissue in diabetic rats showed oxidative alterations related to the streptozotocin treatment. The A. Blazei treatment effectively reduced the oxidative stress and contributed to tissue recovery.

Aminoguanidine reduces oxidative stress and structural lung changes in experimental diabetes mellitus

We evaluated the effect of aminoguanidine on pulmonary oxidative stress and lung structure in an experimental model of diabetes mellitus. Thiobarbituric acid reactive substances (TBARS), histology and arterial blood gases were evaluated in animals with diabetes mellitus (DM group), animals with diabetes mellitus treated with aminoguanidine (DM+AG group), and controls. The TBARS levels were significantly higher in the DM group than in the control and DM+AG groups (2.90 ± 1.12 vs. 1.62 ± 0.28 and 1.68 ± 0.04 nmol/mg protein, respectively), as was PaCO2 when compared with that of the control group (49.2 ± 1.65 vs. 38.12 ± 4.85 mmHg), and PaO2 was significantly higher in the control group (104.5 ± 6.3 vs. 16.30 ± 69.48 and 97.05 ± 14.02 mmHg, respectively). In this experimental model of diabetes mellitus, aminoguanidine reduced oxidative stress, structural tissue alterations, and gas exchange.

Treatment with aqueous extract from Croton cajucara Benth reduces hepatic oxidative stress in streptozotocin-diabetic rats.

Croton cajucara Benth is a plant found in Amazonia, Brazil and the bark and leaf infusion of this plant have been popularly used to treat diabetes and hepatic disorders. The present study was designed to evaluate the oxidative stress as well as the therapeutic effect of Croton cajucara Benth (1.5 mL of the C. cajucara extract i.g.) in rats with streptozotocin-induced diabetes. Croton cajucara Benth was tested as an aqueous extract for its phytochemical composition, and its antioxidant activity in vitro was also evaluated. Lipid peroxidation and superoxide dismutase, catalase, and glutathione reductase activities were measured in the hepatic tissue, as well as the presence activation of p65 (NF-κB), through western blot. Phytochemical screening of Croton cajucara Benth detected the presence of flavonoids, coumarins and alkaloids. The extract exhibited a significant antioxidant activity in the DPPH-scavenging and the hypoxanthine/xanthine oxidase assays. Liver lipid peroxidation increased in diabetic animals followed by a reduction in the Croton-cajucara-Benth-treated group. There was activation of p65 nuclear expression in the diabetic animals, which was attenuated in the animals receiving the Croton cajucara Benth aqueous extract. The liver tissue in diabetic rats showed oxidative alterations related to the streptozotocin treatment. In conclusion the Croton cajucara Benth aqueus extract treatment effectively reduced the oxidative stress and contributed to tissue recovery.

Hepatic nitrosative stress in experimental diabetes

AIM The effects of the inhibition of nitrosative stress by aminoguanidine in an experimental model of diabetes mellitus (DM) were investigated. METHODS Twenty-one male Wistar rats were divided into three groups: control (CO), diabetic (DM), and diabetic treated with aminoguanidine (DM+AG). Aminoguanidine (aminoguanidine hemisulfate salt, Sigma Chemical Co., St. Louis, MO, USA) was used at a dose of 50 mg/kg (i.p.) during the last 30 days of the experiment. The expression levels of liver lipoperoxidation (TBARS - nmol/mg protein), inducible oxide nitric synthase (iNOS), nitrotyrosine and the NFκB nuclear transcription factor p65 were examined using western blot analysis. RESULTS The DM group demonstrated an increase in lipoperoxidation and in the expression of iNOS, nitrotyrosine and p65. Aminoguanidine reduced hepatic lipid peroxidation and protein expression levels of iNOS, nitrotyrosine and p65. CONCLUSION Aminoguanidine treatment reduces liver oxidative and nitrosative stress in diabetic animals. In addition, aminoguanidine reduced the expression of p65 in the liver.

Correlações entre variáveis respiratórias e funcionais na insuficiência cardíaca

Background: Respiratory alterations can impact on the functional performance of patients with heart failure. Aim: To correlate maximum inspiratory muscular force and lung function variables with functional capacity in heart failure patients. Methods: A transversal study January-July 2007 with 42 chronic heart disease patients (28 males) with no prior pulmonary illness. The patients were in New York Heart Association Functional Class I, II and III. The variables used were maximum inspiratory pressure, forced vital capacity and forced expiratory volume in the first second. Respiratory variables measured were distance covered in the six-minute walk test, NYHA functional class and the physical functioning domain of the Short Form-36 Quality of Life Questionnaire. Results: Maximum inspiratory pressure correlated with the six-minute walk test (r = 0.543 and p < 0.001), functional capacity (r = -0.566 and p < 0.001) and the physical functioning domain score of the Short Form-36 (r = 0.459 and p = 0.002). The same was true of forced vital capacity and the six-minute walk test (r = 0.501 and p = 0.001), functional capacity (r = -0.477 and p = 0.001) and Short Form-36 (r = 0.314 and p = 0.043) variables. Forced expiratory volume correlated with the distance covered in the six-minute walk test (r = 0.514 and p < 0.001) and functional capacity (r = -0.383 and p = 0.012). Conclusion: Lung function and inspiratory muscular force respiratory variables correlated with functional variables in patients with heart failure. Rev Port Pneumol 2009; XV (5): 875-890

A classe da NYHA tem relação com a condição funcional e qualidade de vida na insuficiência cardíaca

A insuficiencia cardiaca (IC) e uma sindrome que se apresenta com crescente prevalencia, podendo limitar o individuo quanto a capacidade fisico-funcional, condicao pulmonar e qualidade de vida. Este estudo tem como objetivo verificar as limitacoes pulmonares e fisicas, bem como a qualidade de vida dos pacientes e compara-las com as classes funcionais da New York Heart Association (NYHA). Estudo transversal, com amostra de 66 pacientes (45 homens). Foram aplicados uma ficha de avaliacao padronizada e o questionario de qualidade de vida Short Form-36 (SF-36). Foram realizados espirometria, manovacuometria e o teste da caminhada de seis minutos (TC6M). Os pacientes (classe I: 24 individuos, classe II: 27 e classe III: 15) possuiam uma media de idade de 57,95±10,96 anos e representaram uma amostra com caracteristicas antropometricas homogeneas. Para a condicao pulmonar, observou-se diferenca estatistica quanto a Capacidade Vital Forcada (CVF), Pico de Fluxo Expiratorio e Pressao Expiratoria Maxima (Pemax). Na distância do TC6M houve diferenca entre classe I e III e entre II e III (classe I: 439,27±58,85 m, classe II: 370,96±74,41 m e classe III: 268,96±83,88 m), com p<0,001. Para o SF-36, houve decrescimo da qualidade de vida conforme o agravo das classes funcionais. Pacientes com IC apresentam diminuicao da condicao pulmonar, capacidade fisico-funcional e qualidade de vida relacionada ao aumento da classe funcional da NYHA.