DETERMINAÇÃO DA LIPOPEROXIDAÇÃO E ATIVIDADE DA CATALASE EM FÍGADO E BRÂNQUIAS DE PEIXES COLETADOS NO ARROIO SAPUCAIA, BACIA DO GUAÍBA, RS

O trabalho propõem-se a estudar os efeitos da poluição do Arroio Sapucaia sobre o estresseoxidativo em diferentes tecidos de peixes coletados no arroio. Peixes da espécie Cyphocharax saladensis(birus) foram coletados em dois pontos do Arroio Sapucaia: (a) ponto 1: interior do município de SantaTecla – baixos índices de poluição; (b) ponto 2: desembocadura do rio dos Sinos – altos índices depoluição agrícola e industrial. Foram retirados fígado e brânquias desses animais. Os tecidos foram pesados,homogeneizados e centrifugados para a quantificação de proteínas, substâncias reativas ao ácidotiobarbitúrico (TBA-RS) e atividade da enzima antioxidante catalase (CAT). Os peixes coletados noponto 1 apresentaram maior lipoperoxidação (LP) no fígado e menor LP nas brânquias quando comparadosaos animais coletados no ponto 2, nas diferentes estações do ano. Foi observada uma relaçãoinversa entre a LP e a atividade da CAT no fígado e nas brânquias desses animais. Os resultados sugeremum aumento das defesas antioxidantes nos animais que vivem em ambientes poluídos, porém esta respostaparece ser específica para cada tecido

Combination of trans-resveratrol and E-viniferin induces a hepatoprotective effect in rats with severe acute liver failure via reduction of oxidative stress and MMP-9 expression

Stilbenes are a major grapevine class of phenolic compounds, known for their biological activities, including anti-inflammatory and antioxidant, but never studied in combination. We aimed to evaluate the effect of trans-resveratrol + "-viniferin as an antioxidant mixture and its role in inflammatory development an in vivo model of severe acute liver failure induced with TAA. Trans-resveratrol + trans-"-viniferin (5 mg/kg each) was administered to Wistar rats. Resveratrol + "- viniferin significantly decreased TBARS and SOD activity and restored CAT and GST activities in the treated group. This stilbene combination reduced the expression of TNF , iNOS, and COX-2, and inhibited MMP-9. The combination of resveratrol + "-viniferin had a hepatoprotective effect, reducing DNA damage, exhibiting a protective role on the antioxidant pathway by altering SOD, CAT, and GST activities; by downregulating TNF , COX-2, and iNOS; and upregulating IL-10. Our results suggested that adding viniferin to resveratrol may be more effective in hepatoprotection than resveratrol alone, opening a new perspective on using this stilbene combination in functional dietsinfo:eu-repo/semantics/publishedVersio

Hepatic oxidative stress in an animal model of sleep apnoea: effects of different duration of exposure

Background: Repeated apnoea events cause intermittent hypoxia (IH), which alters the function of various systems and produces free radicals and oxidative stress. Methods: We investigated hepatic oxidative stress in adult mice subjected to intermittent hypoxia, simulating sleep apnoea. Three groups were submitted to 21 days of IH (IH-21), 35 days of IH (IH-35), or 35 days of sham IH. We assessed the oxidative damage to lipids by TBARS and to DNA by comet assay; hepatic tissue inflammation was assessed in HE-stained slides. Antioxidants were gauged by catalase, superoxide dismutase, glutathione peroxidase activity and by total glutathione. Results: After IH-21, no significant change was observed in hepatic oxidative stress. After IH-35, significant oxidative stress, lipid peroxidation, DNA damage and reduction of endogenous antioxidants were detected. Conclusions: In an animal model of sleep apnoea, intermittent hypoxia causes liver damage due to oxidative stress after 35 days, but not after 21 days

Antioxidant effect of N-acetylcysteine on prehepatic portal hypertensive gastropathy in rats

Background. Portal hypertension is a clinical syndrome associated with the development of a hyperdynamic circulation and gastroesophageal varices.Aim. To evaluate the antioxidant effect of N-acetylcysteine on portal hypertensive rats.Material and methods. Portal hypertension was induced by partial portal vein ligation (PPVL). Oxidative damage in the stomach was measured by lipoperoxidation trough thiobarbituric acid reactive substances (TBARS) and antioxidant enzyme activity; we also evaluated nitrates and nitrites level and histology stained by hematoxylin-eosin. We performed evaluation of portal pressure and measurement of vessels diameter. Liver damage was evaluated by measuring hepatic enzymes. The animals were divided in four experimental groups (n = 6): Sham-operated (SO), SO + NAC, Partial portal vein ligation (PPVL) and PPVL + NAC. N-acetylcysteine (10 mg/kg ip) was administered daily for 7 days and started 8 days after surgery.Results. The portal hypertensive group showed an increase in portal pressure, vessels diameter, levels of TBARS and nitrates and nitrites when compared to SO group. These values were accompanied by a decrease in superoxide dismutase (SOD) and glutathione peroxidase (GPx) antioxidant enzyme activity. Histology showed dilated vessels in the gastric mucosa in the PPVL group. NAC was able to decrease portal pressure values, vessels diameter, TBARS and also nitrates and nitrites levels when compared to PPVL group. Furthermore, PPVL+NAC group presented an increase in SOD and GPx activity. N-acetylcysteine attenuated damage in gastric mucosa.Conclusion. Oxidative stress is associated with portal hypertension and that antioxidant NAC is able to minimize damages of PPVL in rats

Glutamine prevents gastric oxidative stress in an animal model of portal hypertension gastropathy(◆)(◆)This work was supported by grants from the Conselho Nacional de Desenvolvimiento Científico e Tecnológico (CNPq), Fundaçáo de Amparo a Pesquisa do Rio Grande do Sul (FAPERGS), and Fundo de Incentivo á Pesquisa e Eventos (FIPE) do Hospital de Clínicas de Porto Alegre (HCPA). CIBEREHD is funded by the Instituto de Salud Carlos III.

Background and rationale. Portal hypertension (PHI) is a clinical syndrome characterized by increases of the blood flow and/or of the vascular resistance in the portal system. A direct consequence of PHI can appearance different lesions on the gastric mucosa and submucosa, cumulatively termed portal hypertensive gastropathy (PHG). Aims. To investigate the effects of glutamine on oxidative stress in an experimental model of PHG induced by partial portal vein ligation (PPVL).Material and methods. Portal pressure, transaminase and alkaline phosphatase activity were quantified. Gastric tissue damage was assessed by histological analysis. Oxidative stress was measured by quantification of cytosolic concentration of thiobarbituric acid reactive substances (TBARS), hydroperoxide-initiated chemiluminescence (QL), and nitric oxide (NO) production. Moreover, activities of the antioxidant enzymes superoxide dismutase (SOD), glutathione pe-roxidase (GPx), and catalase (CAT) were analyzed.Results. Transaminase and alkaline phosphatase activities were not significantly modified by PPVL, indicating absence of liver injury. Histological analysis of gastric sections showed a lost of normal architecture, with edema and vasodilatation. TBARS, QL, and NO production were significantly increased in PPVL animals. A reduction of SOD activity was found. Glutamine administration markedly alleviated histological abnormalities and oxidative stress, normalized SOD activity, and blocked NO overproduction.Conclusions. Our results confirm that the use of molecules with antioxidant capacity can provide protection of the gastric tissue in portal hypertension. Glutamine treatment can be useful to reduce the oxidative damage induced by PHI on gastric tissue

Uso de quercetina a longo prazo em ratos cirróticos The long term use of quercetin in cirrhotic rats

OBJETIVO: Avaliar o uso a longo prazo do flavonóide quercetina em ratos cirróticos por ligadura de ducto biliar comum (LDB). MÉTODOS: Foram utilizados 32 ratos machos Wistar, sendo submetidos à LDB ou simulação, e distribuídos em 4 grupos: 1) controle, 2) cirróticos, 3) cirróticos tratados com quercetina 50mg/kg, intraperitonealmente, desde o segundo dia após o procedimento cirúrgico; e 4) cirróticos tratados após o décimo quarto dia do procedimento cirúrgico. Analisou-se a função hepática por meio de testes bioquímicos (BT e BD) e atividade enzimática (ALT, AST, FA e GGT). Na análise anatomopatológica, utilizou-se a coloração de Hematoxilina & Eosina (H&E) e de Picrosírius para fibrose. A análise estatística para avaliação de sobrevivência foi realizada pelo teste Kaplan-Meier. RESULTADOS: Os resultados de sobrevivência dos oito animais de cada grupo foram: Grupo 1 = 200 dias de sobrevivência; Grupo 2 = 46 dias; Grupo 3 = 71 dias; e o Grupo 4 = 90 dias. Nos animais com ligadura de ducto biliar comum houve aumento das provas de função hepática e enzimáticas que se reduziu hipoteticamente com o tratamento com quercetina. Foram identificadas cirrose, congestão vascular porta e centrolobular na análise histopatológica por H&E e Picrosírius. CONCLUSÃO: O uso da quercetina diminuiu de maneira significante as alterações bioquímicas provocadas pela cirrose, aumentando o tempo de sobrevivência dos animais com cirrose biliar secundária à LDB, como verificado pelo teste de análise de sobrevivência.<br>PURPOSE: The long term use of quercetin flavonoid was evaluated in cirrhotic rats by common biliary duct bondage (LDB). METHODS: 32 male Wistar rats were submitted to LDB or simulation, and distributed in 4 groups: 1) control, 2) cirrhotic, 3) cirrhotic treated with quercetin the second day after the surgical procedure; and 4) cirrhotic treated with quercetin after the fourteenth day of the surgical procedure. The hepatic function was analyzed through biochemical tests (TB and DB) and enzymatic activity (ALT, AST, AP and GGT). In the anatomopatological analysis, Hematoxilin & Eosin (H&E) coloration, and Picrosirius (for fibrosis) were used.The statistical analysis for survival evaluation was accomplished by the Kaplan-Meier test. RESULTS: The results of survival of the eight animals of each group were: Group 1 = 200 days of survival; Group 2 = 46 days; Group 3 = 71 days; and the Group 4 = 90 days. In the animals with bondage of common biliary duct, there was an increase of the hepatic and anzymatic function tests, which was reduced with the treatment with quercetin. Cirrhosis, portal and centrolobular vascular congestion, were identified in the histopatological analysis with H&E and Picrosirius. CONCLUSION: The use of quercetin decreased significantly the biochemical alterations caused by cirrhosis, increasing the time of survival of the animals with secondary biliary cirrhosis due to LDB

Oxidative stress and cell damage in a model of precancerous lesions and advanced hepatocellular carcinoma in rats

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer deaths throughout the world. This study was aimed to analyze oxidative stress and cell damage in a multistage model of liver carcinogenesis induced by diethylnitrosamine (DEN) in rats. Male Wistar rats weighing 145–150 g were divided into three groups: control, precancerous lesions (PL) (which received 100 mg DEN once a week every 6 weeks up to 28 weeks), and advanced HCC (50 mg DEN once/twice per week up to 19 weeks). Lipid peroxidation (TBARS), superoxide dismutase (SOD) activity, and expression of transforming growth factor-1 beta (TGF)-1β, endothelial and inducible nitric oxide syntahese (eNOS, iNOS), NADPH quinone oxireductase (NQO)-1, nuclear factor erythroid 2-related factor (NrF)2, kelch-like ECH-associated protein (Keap)1 and heat shock protein (HSP)70 were measured. TBARS concentration was augmented in the PL and advanced HCC groups. SOD activity, TGF-1β and Nrf2 expression were higher in animals with precancerous lesions. In advanced HCC, expression of NQO1 and iNOS increased while there was a decrease in HPS70 expression. Data obtained provide evidence for the differential activation of proteins involved in oxidative stress and cell damage during progression of carcinogenesis in an animal model of HCC

Uso de quercetina a longo prazo em ratos cirróticos

OBJETIVO: Avaliar o uso a longo prazo do flavonóide quercetina em ratos cirróticos por ligadura de ducto biliar comum (LDB). MÉTODOS: Foram utilizados 32 ratos machos Wistar, sendo submetidos à LDB ou simulação, e distribuídos em 4 grupos: 1) controle, 2) cirróticos, 3) cirróticos tratados com quercetina 50mg/kg, intraperitonealmente, desde o segundo dia após o procedimento cirúrgico; e 4) cirróticos tratados após o décimo quarto dia do procedimento cirúrgico. Analisou-se a função hepática por meio de testes bioquímicos (BT e BD) e atividade enzimática (ALT, AST, FA e GGT). Na análise anatomopatológica, utilizou-se a coloração de Hematoxilina & Eosina (H&E) e de Picrosírius para fibrose. A análise estatística para avaliação de sobrevivência foi realizada pelo teste Kaplan-Meier. RESULTADOS: Os resultados de sobrevivência dos oito animais de cada grupo foram: Grupo 1 = 200 dias de sobrevivência; Grupo 2 = 46 dias; Grupo 3 = 71 dias; e o Grupo 4 = 90 dias. Nos animais com ligadura de ducto biliar comum houve aumento das provas de função hepática e enzimáticas que se reduziu hipoteticamente com o tratamento com quercetina. Foram identificadas cirrose, congestão vascular porta e centrolobular na análise histopatológica por H&E e Picrosírius. CONCLUSÃO: O uso da quercetina diminuiu de maneira significante as alterações bioquímicas provocadas pela cirrose, aumentando o tempo de sobrevivência dos animais com cirrose biliar secundária à LDB, como verificado pelo teste de análise de sobrevivência