Campsiandra laurifolia reduces oxidative stress and Iiflammation in rats with ulcerative colitis

Ulcerative colitis (UC) affects the mucosa and submucosa of the large intestine. One of the mechanisms involved in its etiology is oxidative stress (OS), directly involved in the inflammatory process characteristic of UC. The Campsiandra laurifolia, known as acapurana, was described as possessing antioxidant properties. We used 24 male Wistar rats, divided into control (CO), control + acapurana (CO + A), colitis (CL), and colitis + acapurana (CL + A) groups. This study performed histological analysis, measuring anal sphincter pressure (ASP) and lipoperoxidation (LPO). The activity of the antioxidant enzyme superoxide dismutase (SOD) and glutathione (GSH) levels were evaluated. The expression of the nuclear factor kappa B (NFkB) and inducible nitric oxide synthase (iNOS) was analyzed by immunohistochemistry. The statistical analysis used was the one-way analysis of variance (ANOVA), followed by the Student-Newman-Keuls test; values were expressed as mean ± standard error, and the significance level was p < 0.05. In the animals of the CL group, we observed the destruction of the crypts and the presence of mucosal ulcers, edema, and submucosal inflammatory infiltrate, as well as increased damage to the intestinal mucosa, reduced ASP, increased LPO and SOD activity, reduced GSH levels, and increased expression of NFkB and iNOS. The administration of C. laurifolia in the CL + A group was shown to cause regeneration of crypts, reduction of inflammatory infiltrate, reduction of damage to the intestinal mucosa, increase in ASP, and reduction in LPO with the restoration of SOD activity and GSH levels. The immunohistochemistry of NFkB and iNOS was significantly reduced. Therefore, the C. laurifolia aqueous extract appears to exert an antioxidant and anti-inflammatory effect in rats with AA-induced colitis. (AU)

Melatonin Attenuates Inflammation, Oxidative Stress, and DNA Damage in Mice with Nonalcoholic Steatohepatitis Induced by a Methionine- and Choline-Deficient Diet.

Nonalcoholic steatohepatitis (NASH) is a disease with a high incidence worldwide, but its diagnosis and treatment are poorly managed. In this study, NASH pathophysiology and DNA damage biomarkers were investigated in mice with NASH treated and untreated with melatonin (MLT). C57BL/6 mice were fed a methionine- and choline-deficient (MCD) diet for 4 weeks to develop NASH. Melatonin was administered at 20 mg/kg during the last 2 weeks. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured, and hepatic tissue was dissected for histological analysis, evaluation of lipoperoxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as nuclear factor-erythroid 2 (Nrf2), tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS), and transforming growth factor beta (TGF-ß) expression by immunohistochemistry. DNA damage was evaluated using Comet assay, while a micronucleus test in bone marrow was performed to assess the genomic instability associated with the disease. Melatonin decreased AST and ALT, liver inflammatory processes, balloonization, and fibrosis in mice with NASH, decreasing TNF-α, iNOS, and TGF-ß, as well as oxidative stress, shown by reducing lipoperoxidation and intensifying Nrf2 expression. The SOD and GPx activities were increased, while CAT was decreased by treatment with MLT. Although the micronucleus frequency was not increased in mice with NASH, a protective effect on DNA was observed with MLT treatment in blood and liver tissues using Comet assay. As conclusions, MLT slows down the progression of NASH, reducing hepatic oxidative stress and inflammatory processes, inhibiting DNA damage via anti-inflammatory and antioxidant actions.

Photobiomodulation intervention improves oxidative, inflammatory, and morphological parameters of skeletal muscle in cirrhotic Wistar rats.

Photobiomodulation (PBM) might be an intervention method to mitigate sarcopenia in cirrhotic patients. Given the lack of research on this issue, the goal of this study was to evaluate possible beneficial effects of PBM on the structural and functional properties of skeletal muscle from cirrhotic rats. Cirrhosis was induced by secondary bile duct ligation (BDL). Wistar rats were randomized into four groups: sham-operated control (Sham), Sham + PBM, BDL, and BDL + PBM. After cirrhosis induction, a dose of PBM (1 J; 100mW; 10 s; 880 nm; 6 × per week) was applied to each quadriceps, from the 15th to the 45th day after surgery. The locomotor ability was performed using an open-field task. The muscle structure was analyzed using histological methods. Cell damage was also evaluated assessing oxidative stress and DNA damage markers, and IL-1ß pro-inflammatory interleukin by immunohistochemical analysis. An increase in the number of crossings was observed in the BDL + PBM group in relation to BDL. The BDL group showed muscle atrophy and increased IL-1ß in relation to Sham, while in the BDL + PBM group, the fiber muscle was restructured and there was a decrease of IL-1 ß. TBARS increased in the liver and muscle tissues in the BDL group and decreased it in the BDL + PBM group. SOD increased while CAT decreased in the BDL + PBM group in relation to the BDL group. No genotoxic or mutagenic effect was observed for PBM treatment. PBM improved the locomotion and the morphology of the muscle fibers, decreasing oxidative stress and inflammation, without causing DNA damage in cirrhotic rats.

Sarcopenia, oxidative stress and inflammatory process in muscle of cirrhotic rats - Action of melatonin and physical exercise.

Sarcopenia is one of the most common features of cirrhosis, contributing to morbidity and mortality in this population. We aimed to evaluate the effect of melatonin (MLT) and exercise (EX) on the quadriceps muscle in rats with biliary cirrhosis induced by bile duct ligation (BDL). We used 48 males (mean weight = 300 g), divided into eight groups. A 20 mg/Kg MLT dose was administered via i.p. (1 x daily), and the EX, the animals were set to swim in couples for 10 min each day. Upon completion, blood, liver, and quadriceps samples were taken for analysis. In the liver enzymes analysis and comet assay results, a reduction was observed in the groups treated with MLT with/or EX comparing to the BDL group. In the evaluation of substances that react to thiobarbituric acid (TBARS), nitric oxide levels (NO), and tumor necrosis factor-alpha levels (TNF-α), there was a significant increase in the BDL group and a reduction in the treated groups. In the activity of the superoxide dismutase enzyme (SOD) and interleukin-10 levels (IL-10) concentrations, there was a significant increase in the treated groups of the BDL group. Histological analysis revealed muscle hypotrophy in the BDL group in comparison with the control group (CO) and increased muscle mass in the treated groups. There was an increase in weight gain and phase angle in the groups treated with MLT with/or EX comparing to the BDL group. We suggest that treatments may contribute to the reduction of muscle changes in cirrhotic patients.

Melatonin effects on pulmonary tissue in the experimental model of Hepatopulmonary Syndrome.

OBJECTIVE: To evaluate the pulmonary alterations of animals with Hepatopulmonary Syndrome (HPS) submitted to Biliary Duct Ligature (BDL), as well as the antioxidant effect of Melatonin (MEL). METHODS: Sixteen male Wistar rats, divided into four Sham groups: BDL group, Sham + MEL group and BDL + MEL. The pulmonary and hepatic histology, lipoperoxidation and antioxidant activity of lung tissue, alveolar-arterial O2 difference and lung / body weight ratio (%) were evaluated. RESULTS: When comparing the groups, could be observed an increase of vasodilation and pulmonary fibrosis in the BDL group and the reduction of this in relation to the BDL + MEL group. It was also observed significant changes in the activity of catalase, ApCO2, ApO2 in the LBD group when compared to the other groups. CONCLUSION: The use of MEL has been shown to be effective in reducing vasodilation, fibrosis levels and oxidative stress as well as gas exchange in an experimental HPS model.

Anti-inflammatory and antioxidant effect of melatonin on recovery from muscular trauma induced in rats.

In recent decades, the number of people who practice sports has grown exponentially, increasing the number of muscular injuries. Trauma injury occurs when the muscle is exposed to a sudden compression force. Melatonin (MLT) has often been cited in the literature as a potent antioxidant and anti-inflammatory agent. This study was designed to evaluate MLT action on muscle tissue in Wistar rats in an experimental model of muscle trauma. Twenty-eight Wistar rats were used, divided into four groups: CO (Control), CO + MLT (Control + Melatonin), T (Trauma) and T + MLT (Trauma + Melatonin). MLT (20 mg/kg) was administered (ip) daily at dusk until day 7. The trauma occurred on day 1, 2 h before the first MLT application. On day 8, muscle tissue was collected for histological analysis (HE), immunohistochemistry (TNF-α and NFκB), evaluation of oxidative stress through analysis of lipoperoxidation by TBARS and activity of SOD and GPx enzymes, and analysis of nitrites and nitrates. In the evaluation of TBARS and SOD, we observed a significant increase in the T group and a significant decrease in the T + MLT group. In the evaluation of GPx, there was a significant increase in the T group and a significant decrease in the T + MLT group. The histological analysis of muscle tissue revealed structural changes of muscle fibers and inflammatory infiltrate in the T group but a decrease in this damage in the T + MLT group. In the immunohistochemical evaluation, increased expression of TNFα and NFκB proteins in the T group was observed and a significant decrease of this expression in the T + MLT group. MLT was shown to attenuate oxidative damage and to diminish the expression of inflammatory proteins and tissue damage in this experimental model.

Melatonin effects on pulmonary tissue in the experimental model of Hepatopulmonary Syndrome / Efeitos da melatonina sobre o tecido pulmonar no modelo experimental de Síndrome Hepatopulmonar

ABSTRACT Objective: To evaluate the pulmonary alterations of animals with Hepatopulmonary Syndrome (HPS) submitted to Biliary Duct Ligature (BDL), as well as the antioxidant effect of Melatonin (MEL). Methods: Sixteen male Wistar rats, divided into four Sham groups: BDL group, Sham + MEL group and BDL + MEL. The pulmonary and hepatic histology, lipoperoxidation and antioxidant activity of lung tissue, alveolar-arterial O2 difference and lung / body weight ratio (%) were evaluated. Results: When comparing the groups, could be observed an increase of vasodilation and pulmonary fibrosis in the BDL group and the reduction of this in relation to the BDL + MEL group. It was also observed significant changes in the activity of catalase, ApCO2, ApO2 in the LBD group when compared to the other groups. Conclusion: The use of MEL has been shown to be effective in reducing vasodilation, fibrosis levels and oxidative stress as well as gas exchange in an experimental HPS model.

RESUMO Objetivo: Avaliar as alterações pulmonares de animais com Síndrome Hepatopulmonar (SHP), submetidos à ligadura de ducto biliar (LDB), bem como o efeito antioxidante da Melatonina (MEL). Métodos: Dezesseis ratos machos da espécie Wistar, divididos em quatro grupos: Sham, Grupo LDB, Grupo Sham + MEL e LDB + MEL. Foram avaliadas a histologia pulmonar e hepática, a lipoperoxidação e atividade antioxidante do tecido pulmonar, diferença álveolo-arterial de O2 e relação peso pulmonar/peso corporal (%). Resultados: Quando comparados os grupos, observamos um aumento da vasodilatação e fibrose pulmonar no grupo LDB e a redução deste em relação ao grupo LDB+MEL. Observamos ainda alterações significativas na atividade da catalase, PaCO2, PaO2 no grupo LBD quando comparado aos demais grupos. Conclusões: A utilização da MEL demonstrou-se eficaz na redução da vasodilatação, níveis de fibrose e estresse oxidativo assim como na troca gasosa em modelo experimental de SHP.

Effect of glutamine on liver injuries induced by intestinal ischemia-reperfusion in rats

INTRODUCTION: Intestinal ischemia-reperfusion (I/R) injury may cause cell and tissue damage, reaching also other organs such as the liver. Because of the involvement of free radicals in I/R injury, treatment options with antioxidants have been studied and tested. OBJECTIVE: To evaluate the effect of glutamine (Gln) in the liver of animals with intestinal I/R injury. METHODS: We used 20 male Wistar rats divided into four groups: sham-operated (SO); glutamine + sham-operated (G+SO); intestinal ischemia-reperfusion (I/R); glutamine + intestinal ischemia-reperfusion (G+I/R). The superior mesenteric artery was clamped for 30 minutes and reperfused for 15 minutes. Gln (25 mg/kg/day) diluted in 1 ml of saline was administered intraperitoneally on the two days before I/R induction. RESULTS: Levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP), lipid peroxidation (LPO) and expressions of interleukin-6 (IL-6) and nuclear factor kappa B (NF-kB) showed a significant reduction in the G+I/R group as compared with the I/R group. The activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and the levels of glutathione (GSH) showed an increase in the G+I/R group as compared with the I/R group. CONCLUSION: Pretreatment with Gln reduced oxidative, tissue damage and showed a decrease expression of inflammatory mediators.

Action of vitamin e on experimental severe acute liver failure / Composição corporal de pacientes com doença de Crohn e colite ulcerativa

ABSTRACT BACKGROUND Severe Acute Liver Failure (ALF) is a life-threatening clinical syndrome characterized by hepatocyte necrosis, loss of hepatic architecture, and impairment of liver functions. One of the main causes of ALF is hepatotoxicity from chemical agents, which damage hepatocytes and result in increase of reactive oxygen species. The vitamin E isoform is the one with the strongest biological antioxidant activity. OBJECTIVE To evaluate the antioxidant effect of vitamin E in this ALF model. METHODS We used 56 rats (mean weight of 300 g) divided into eight groups, four groups assessed at 24 hours and 4 assessed at 48 hours after induction: control group (CO); Vitamin E (Vit. E); Thioacetamide (TAA) and Thioacetamide + Vitamina E (TAA+Vit.E). Rats were submitted to injections of thioacetamide (400 mg/kg i.p.) at baseline and 8 hours later. Vitamin E (100 mg/kg ip) was administered 30 minutes after the second dose of thioacetamide. The 48-hour group rats received two additional doses of vitamin E (24h and 36h). At 24h or 48 hours after the administration of the first dose of TAA, rats were weighed and anesthetized and their blood sampled for evaluation of liver integrity through enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Liver tissue was sampled for assessment of lipid peroxidation (LPO) by the technique TBARS, antioxidant enzymes SOD, CAT, GPx and GST activity, levels of the NO 2 /NO 3 and histology by H&E in two times. The results were expressed as mean ± standard deviation and statistically analyzed by ANOVA followed by Student-Newman-Keuls, with P <0.05 considered as significant. RESULTS After treatment with vitamin E, we observed a reduction in liver enzymes AST (U/L) (101.32±19.45 in 24 hours and 97.85±29.65 in 48 hours) related to the TAA group (469.56± 0.69 in 24 hours and 598.23±55.45 in 48 hours) and ALT (U/L) (76.59±8.56 in 24 hours and 68.47±6.49 in 48 hours) compared to the TAA group (312.21±10.23 in 24 hours and 359.15±17.58 in 48 hours). There was a reduction of LPO (nmol/mg Prot) in the TAA+Vit.E group (0.77±0.07 in 24 hours and 0.95±0.08 in 48 hours) compared to the TAA group (1.50±0.07 in 24 hours e 1.65±0.16 in 48 hours). SOD decreased in the TAA+Vit.E group (49.48±9.47 in 24 hours and 62.45±18, 47 in 48 hours), related to the TAA group (98.46±15.48 in 24 hours and 154.13±21.46 in 48 hours), as well as GST (nmol/min/mg Prot) in the TAA+Vit.E group (350.57±36.93 in 24 hours and 453.29±13.84 in 48 hours) compared to the TAA group (561.57±64.56 in 24 hours and 673.43±38.13 in 48 hours). There was an increase in CAT (pmol/min/mg Prot) in the TAA+Vit.E group (3.40±0.44 in 24 hours and 3.0±0.35 in 48 hours) compared to the TAA group (1.65±0.21 in 24 hours and 1.86±0.42 in 48 hours). The GPx (nmol/min/mg Prot) increased in 24 hours in the TAA+Vit.E group (1.01±0.16) compared to the TAA group (0.41±0.04) and decreased in 48 hours (1.19±0.17) compared to the TAA group (1.76±0.21). There was a reduction in NO2/NO3 (mmol/L) levels in the TAA+Vit.E group (31.47±4.26 in 24 hours and 38.93±5.20 in 48 hours) compared to the TAA group (49.37±5.12 in 24 hours and 53.53±5.97 in 48 hours). The histopathological evaluation showed a decrease in liver injury (necrosis and inflammation) in both studied times. CONCLUSION These results suggest that vitamin E was able to protect the liver from lesions caused by thioacetamide.

RESUMO CONTEXTO A Insuficiência Hepática Aguda Grave (IHAG) é uma síndrome clínica potencialmente fatal, na qual ocorre necrose dos hepatócitos, perda da arquitetura hepática e deterioração de suas funções. Dentre as principais causas da IHAG está a hepatotoxicidade decorrente de agentes químicos, que lesam os hepatócitos e acarretam aumento das espécies reativas de oxigênio. A vitamina E tem alta atividade antioxidante biológica e é amplamente distribuída nos tecidos. OBJETIVO Avaliar o efeito antioxidante da Vitamina E no modelo de IHAG. MÉTODOS Foram utilizados 56 ratos, com peso médio de 300 g, divididos em oito grupos, quatro grupos avaliados em 24 horas e quatro em 48 horas após a indução: grupo controle (CO); Vitamina E (Vit.E); Tioacetamida (TAA) e Tioacetamida + Vitamina E (TAA+Vit.E). Os ratos foram submetidos a injeções de tioacetamida, na dose de 400 mg/Kg de peso i.p., no início do experimento e, posteriormente, após 8 horas. A vit E (100 mg//Kg i.p.) foi administrada 30 minutos após a segunda dose de tioacetamida. Os animais do tempo 48 horas receberam mais duas doses de vit. E (24h e 36h). Transcorridas 24 ou 48 horas após a administração da primeira dose de TAA, os animais foram pesados, anestesiados e o sangue retirado para a avaliação da integridade hepática através das enzimas Aspartatoaminotransferase (AST) e Alanina aminotransferase (ALT). O tecido hepático foi retirado para avaliação da lipoperoxidação através da técnica de TBARS, atividade das enzimas antioxidantes SOD, CAT, GPx, e GST, avaliação de NO 2 /NO 3 e avaliação histológica pela coloração de hematoxilina e eosina nos dois tempos. Os resultados foram expressos como média ± erro padrão e a análise estatística utilizada foi ANOVA, seguido de teste de Student-Newman-Keuls, considerado significativo P <0,05. RESULTADOS Após o tratamento com a vit. E, observamos uma redução nas enzimas de integridade hepática AST (U/L) (101,32±19,45 em 24h e 97,85±29,65 em 48h) relacionado ao grupo TAA (469,56±20,69 em 24h e 598,23±55,45 em 48h) e ALT (U/L) (76,59±8,56 em 24h e 68,47±6,49 em 48h) comparado ao grupo TAA (312,21±10,23 em 24h e 359,15±17,58 em 48h). Houve uma redução da LPO (nmol/mg Prot), no grupo TAA+Vit.E (0,77±0,07 em 24h e 0,95±0,08 em 48h) comparado ao grupo TAA (1,50±0,07 em 24h e 1,65±0,16 em 48h). A SOD (USOD/min/mg Prot) diminuiu no grupo TAA+Vit.E (49,48±9,47 em 24h e 62,45±18,47 em 48h) relacionado ao grupo TAA (98,46±15,48 em 24h e 154,13±21,46 em 48h), assim como a GST (nmol/min/mg Prot) no grupo TAA+Vit.E (350,57±36,93 em 24h e 453,29±13,84 em 48h) comparado ao grupo TAA (561,57±64,56 em 24h e 673,43±38,13 em 48h). Houve aumento da CAT (pmol/min/mg Prot) no grupo TAA+Vit.E (3,40±0,44 em 24h e 3,01±0,35 em 48h) em relação ao grupo TAA (1,65±0,21 em 24h e 1,86±0,42 em 48h). A GPx (nmol/min/mg Prot) aumentou em 24h no grupo TAA+Vit.E (1,01±0,16) comparado ao grupo TAA (0,41±0,04) e diminuiu em 48h (1,19±0,17) em relação ao grupo TAA (1,76±0,21). Verificou-se redução nos níveis de NO 2 /NO 3 (mmol/L) no grupo TAA+Vit.E (31,47±4,26 em 24h e 38,93±5,20 em 48h) em relação ao grupo TAA (49,37±5,12 em 24h e 53,53±5,97 em 48h). A avaliação histopatológica mostrou diminuição da lesão hepática (necrose e inflamação) em ambas os tempos estudados. CONCLUSÃO Estes resultados sugerem que a vitamina E foi capaz de proteger o fígado de lesões causadas por tioacetamida.

Protective effect of glutamine on the main and adjacent organs damaged by ischemia-reperfusion in rats.

Intestinal ischemia and reperfusion (I/R) causes cellular and tissue damage to the intestine and remote organs such as the liver. Increased production of ROS and nitric oxide and dysregulation of cytoprotective enzymes may be involved in intestinal I/R. The aim was to evaluate the protective effects of glutamine on the intestine and liver of rats with intestinal I/R injury. Twenty male Wistar rats (300 g) were divided into four groups: sham-operated (SO), glutamine + SO (G + SO), I/R, and glutamine + I/R (G + I/R). Occlusion of the SMA for 30 min was followed by 15-min reperfusion. Glutamine (25 mg/kg/day) was administered once daily 24 and 48 h before I/R induction. Blood and tissue of were collected for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, histopathological analysis, immunohistochemistry of IL-1ß and TNF-α, thiobarbituric acid reactive substance (TBARS) and nitric oxide, Nrf2/keap1, superoxide dismutase (SOD), NADPH quinone oxidoreductase1 (NQO1), inducible nitric oxide synthase (iNOS), heat shock protein (HSP70), glucose-regulated protein 78 (GRP78), and activating transcription factor 6 (ATF-6) by western blot. Statistic analysis by ANOVA-Student-Newman-Keuls test (mean ± SE) significantly was p < 0.05. Tissue damage, AST, ALT, IL-1ß, TNF-α, TBARS, NO, Keap1, iNOS, GRP78, and ATF-6 expression were significantly lower in the G + I/R group as compared to the I/R group. Expression of Nrf2, SOD, NQO1, and HSP70, was significantly higher in the G + I/R group as compared to I/R group. Pre-treatment with glutamine provided protection against oxidative damage in the intestine and liver in an experimental model of intestinal I/R.

ACTION OF VITAMIN E ON EXPERIMENTAL SEVERE ACUTE LIVER FAILURE.

BACKGROUND: Severe Acute Liver Failure (ALF) is a life-threatening clinical syndrome characterized by hepatocyte necrosis, loss of hepatic architecture, and impairment of liver functions. One of the main causes of ALF is hepatotoxicity from chemical agents, which damage hepatocytes and result in increase of reactive oxygen species. The vitamin E isoform is the one with the strongest biological antioxidant activity. OBJECTIVE: To evaluate the antioxidant effect of vitamin E in this ALF model. METHODS: We used 56 rats (mean weight of 300 g) divided into eight groups, four groups assessed at 24 hours and 4 assessed at 48 hours after induction: control group (CO); Vitamin E (Vit. E); Thioacetamide (TAA) and Thioacetamide + Vitamina E (TAA+Vit.E). Rats were submitted to injections of thioacetamide (400 mg/kg i.p.) at baseline and 8 hours later. Vitamin E (100 mg/kg ip) was administered 30 minutes after the second dose of thioacetamide. The 48-hour group rats received two additional doses of vitamin E (24h and 36h). At 24h or 48 hours after the administration of the first dose of TAA, rats were weighed and anesthetized and their blood sampled for evaluation of liver integrity through enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Liver tissue was sampled for assessment of lipid peroxidation (LPO) by the technique TBARS, antioxidant enzymes SOD, CAT, GPx and GST activity, levels of the NO 2 /NO 3 and histology by H&E in two times. The results were expressed as mean ± standard deviation and statistically analyzed by ANOVA followed by Student-Newman-Keuls, with P <0.05 considered as significant. RESULTS: After treatment with vitamin E, we observed a reduction in liver enzymes AST (U/L) (101.32±19.45 in 24 hours and 97.85±29.65 in 48 hours) related to the TAA group (469.56± 0.69 in 24 hours and 598.23±55.45 in 48 hours) and ALT (U/L) (76.59±8.56 in 24 hours and 68.47±6.49 in 48 hours) compared to the TAA group (312.21±10.23 in 24 hours and 359.15±17.58 in 48 hours). There was a reduction of LPO (nmol/mg Prot) in the TAA+Vit.E group (0.77±0.07 in 24 hours and 0.95±0.08 in 48 hours) compared to the TAA group (1.50±0.07 in 24 hours e 1.65±0.16 in 48 hours). SOD decreased in the TAA+Vit.E group (49.48±9.47 in 24 hours and 62.45±18, 47 in 48 hours), related to the TAA group (98.46±15.48 in 24 hours and 154.13±21.46 in 48 hours), as well as GST (nmol/min/mg Prot) in the TAA+Vit.E group (350.57±36.93 in 24 hours and 453.29±13.84 in 48 hours) compared to the TAA group (561.57±64.56 in 24 hours and 673.43±38.13 in 48 hours). There was an increase in CAT (pmol/min/mg Prot) in the TAA+Vit.E group (3.40±0.44 in 24 hours and 3.0±0.35 in 48 hours) compared to the TAA group (1.65±0.21 in 24 hours and 1.86±0.42 in 48 hours). The GPx (nmol/min/mg Prot) increased in 24 hours in the TAA+Vit.E group (1.01±0.16) compared to the TAA group (0.41±0.04) and decreased in 48 hours (1.19±0.17) compared to the TAA group (1.76±0.21). There was a reduction in NO2/NO3 (mmol/L) levels in the TAA+Vit.E group (31.47±4.26 in 24 hours and 38.93±5.20 in 48 hours) compared to the TAA group (49.37±5.12 in 24 hours and 53.53±5.97 in 48 hours). The histopathological evaluation showed a decrease in liver injury (necrosis and inflammation) in both studied times. CONCLUSION: These results suggest that vitamin E was able to protect the liver from lesions caused by thioacetamide.

Inflammatory bowel and oxidative stress changes in an experimental model of portal hypertension: action of N-acetylcysteine / Alterações intestinais inflamatórias e de estresse oxidativo em modelo experimental de hipertensão portal: ação da N-acetilcisteína

Introduction: Portal hypertension (PH) is characterized by vasodilatation in the portal system and the bowel is one of the severely affected organs. N-acetylcysteine (NAC) is a molecule with important properties and widely used in clinical practice. Objective: To evaluate NAC action in the bowel of animals submitted to the animal model of partial portal vein ligation (PPVL). Methods: 18 male Wistar rats were divided into three experimental groups (n = 6): sham-operated (SO), PPVL, and PPVL + NAC. On the 8th day after surgery, N-acetylcysteine (10 mg/kg, ip) was administered daily for 7 days. On the 15th day the animals' bowel was collected for oxidative stress analysis, immunohistochemistry and Western blot. We evaluated the expression of NF-KB and TNF-α by immunohistochemistry and of iNOS by Western blot. Lipid peroxidation was assessed by TBARS technique, and the activities of antioxidant enzymes superoxide dismutase (SOD) and glutation peroxidase (GPx) were checked. Results: We observed an increased expression of NF-KB and TNF-α in PPVL group, and an increased iNOS expression assessed by Western blot. NAC reduced the expression of all proteins evaluated. We also observed an increase in oxidative stress in the bowel of mice PPVL group compared to controls (SO), and NAC was effective in reducing these values in PPVL + NAC group. Also, a reduction in the activity of SOD and GPx enzymes was observed in the diseased group, and NAC was able to restore the activity of the enzymes assessed. Conclusion: We suggest the anti-inflammatory and antioxidant action of NAC in the bowel of animals submitted to PPVL model.

Introdução: A Hipertensão Portal (HP) é caracterizada por uma vasodilatação no sistema portal, e o intestino é um dos órgãos gravemente acometidos. A N-acetilcisteína (NAC) é uma molécula com importantes propriedades, amplamente utilizada na clínica. Objetivo: Avaliar a ação da NAC no intestino de animais submetidos ao modelo animal de ligadura parcial da veia porta (LPVP). Métodos: Foram utilizados 18 ratos machos Wistar divididos em três grupos experimentais (n = 6): Sham-operated (SO), LPVP, LPVP + NAC. No 8° dia após a cirurgia, a N-acetilcisteína (10 mg/kg,ip) foi administrada diariamente durante 7 dias. No 15° dia foi coletado o intestino dos animais para análises de estresse oxidativo, imunohistoquímica e Western blot. Nós avaliamos a expressão do NF-kb e TNF-α; por imunohistoquímica e da iNOS por Western blot. A lipoperoxidação foi avaliada pela técnica de TBARS, e as atividades das enzimas antioxidantes Superóxido Dismutase (SOD) e GlutationaPeroxidase (GPx) foram verificadas. Resultados: Observamos um aumento da expressão do NF-kb e TNF-α;; no grupo LPVP, e aumento na expressão da iNOS avaliada por Western blot. A NAC reduziu a expressão de todas as proteínas avaliadas. Observamos um aumento do estresse oxidativo no intestino dos ratos do grupo LPVP com relação aos controles (SO), sendo a NAC eficaz na redução desses valores no grupo LPVP + NAC. Ainda, uma redução na atividade das enzimas SOD e GPx no grupo doente, sendo a NAC capaz de restaurar a atividade das enzimas avaliadas. Conclusão: Sugerimos a ação anti-inflamatória e antioxidante da NAC no intestino de animais submetidos ao modelo LPVP.

Antioxidant and anti-inflammatory action of melatonin in an experimental model of secondary biliary cirrhosis induced by bile duct ligation.

AIM: To evaluate the effects of melatonin (Mel) on oxidative stress in an experimental model of bile duct ligation (BDL). METHODS: Male Wistar rats (n = 32, weight ± 300 g) were allocated across four groups: CO (sham BDL), BDL (BDL surgery), CO + Mel (sham BDL and Mel administration) and BDL + Mel (BDL surgery and Mel administration). Mel was administered intraperitoneally for 2 wk, starting on postoperative day 15, at a dose of 20 mg/kg. RESULTS: Mel was effective at the different standards, reestablishing normal liver enzyme levels, reducing the hepatosomatic and splenosomatic indices, restoring lipoperoxidation and antioxidant enzyme concentrations, reducing fibrosis and inflammation, and thereby reducing liver tissue injury in the treated animals. CONCLUSION: The results of this study suggest a protective effect of Mel when administered to rats with secondary biliary cirrhosis induced by BDL.

Antioxidant effect of mesalazine in the experimental colitis model induced by acetic acid / Efeito antioxidante da mesalazina no modelo de colite experimental induzida por ácido acético

Abstract Introduction Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the gastrointestinal tract, without specific cause or pathogen. Objective The effect of mesalazine in a colitis model induced by acetic acid (AA) was evaluated. Methods We used 40 Wistar rats, ±350 g, divided into 4 groups: control (CO); control + mesalazine (CO + M); colitis (CL) and colitis + M (CL + M) at 24 and 48 h of treatment. The animals received the substances by an intracolonic enema of AA 4% and treatment with mesalazine PO 20 mg/kg after colitis induction. Results Mesalazine reduced tissue damage in the gut, normalized sphincter anal pressure levels and decreased lipid peroxidation, metabolites of nitric oxide and iNOS and NF-kB expression in the treated groups in both treatment time points (24 and 48 h), as well as the activity of antioxidant enzymes. Conclusion Mesalazine was effective in reducing tissue damage and oxidative and inflammatory damage, restored antioxidant capacity and increased anal sphincter pressure levels, possibly due to its antioxidant effect.

Resumo Introdução A doença inflamatória intestinal (DII) caracteriza-se por uma inflamação crônica do trato gastrointestinal sem uma causa ou patógeno específico. Objetivo Foi avaliado o efeito da mesalazina no modelo de colite induzida por ácido acético (AA). Material e métodos Foram utilizados 40 ratos wistar, ±350 gramas, divididos em 4 grupos: Controle (CO); Controle + Mesalasina (CO + M); Colite (CL) e Colite + M (CL + M) nos tempos de 24 e 48 horas de tratamento. Os animais foram submetidos à administração intracolônica por enema com solução de AA a 4% e tratamento com mesalazina na dose oral de 20 mg/kg após a indução da colite. Resultados A mesalazina reduziu as lesões teciduais no intestino, normalizou os níveis de pressão anal esfincteriana, reduziu a lipoperoxidação, metabólitos do óxido nítrico e expressão da iNOS e do NF-kB nos grupos tratados em ambos os tempos de tratamento (24 e 48 horas), bem como a atividade das enzimas antioxidantes. Conclusão A mesalazina demonstrou eficácia na redução das lesões teciduais, danos oxidativos e inflamatórios, restabeleceu a capacidade antioxidante e aumentou os níveis de pressão anal esfincteriana, possivelmente pelo seu efeito antioxidante.

Effect of lecithin on oxidative stress in an experimental model of rats colitis induced by acetic acid / Efeito da lecitina sobre o estresse oxidativo no modelo experimental de colite induzida por ácido acético em ratos

Ulcerative colitis (UC) is an inflammatory disease that affects the bowels. Reactive oxygen species (ROS) are involved in the progress of UC. Objective: Evaluate the antioxidant effect of lecithin in an experimental model of acute UC induced by administration of acetic acid (AA) in rats. Methods: Lecithin (0.5 mL/kg/day) administered orally 2 days before and after induction of colitis with 4% AA in a volume of 4 mL. Twenty-five male Wistar rats were divided in 5 groups: control (CO); control + lecithin (CO + LE); colitis (CL); colitis + lecithin (CL + LE); lecithin + colitis (LE + CL). Anal sphincter pressure, LPO (TBARS), and antioxidant activity of enzymes superoxide dismutase (SOD) and catalase (CAT) were measured, and a histological analysis with H&E was performed. Results and discussion: Anal sphincter pressure was significantly smaller in the CO group, lecithin treatment increased it in pre- and post-treated groups. LPO and SOD activity were increased in the CO group and decreased in the lecithin-treated groups. CAT activity was increased in CO group and decreased in lecithin groups. The histological analysis showed damage to the bowels with destruction of crypts, edema, and inflammatory infiltrate. Use of lecithin preserved the crypts and decreased the edema. Conclusion: Ulcerative colitis increased lipid peroxidation, and the use of lecithin was effective reducing damage to the bowels in the model of experimental colitis.

A retocolite ulcerativa (RCUI) é uma doença intestinal inflamatória. Espécies reativas de oxigênio (ERO) estão envolvidas no progresso da RCUI. Objetivo: Avaliar o efeito antioxidante de lecitina em modelo experimental de RCUI induzida pela administração de ácido acético (AA) em ratos. Métodos: A Lecitina (0,5 mL/kg/dia) foi administrada por via oral 2 dias antes e após a indução de colite com AA. Vinte e cinco ratos Wistar machos foram divididos em 5 grupos: controle (CO); controle + lecitina (CO + LE); colite (CL); colite + lecitina (CL + LE); lecitina + colite (LE + CL). Foram avaliadas: pressão do esfíncter anal, lipoperoxidação (LPO), atividade antioxidante das enzimas superóxido dismutase (SOD) e catalase (CAT), e foi realizada uma análise histológica com H&E. Resultados e discussão: A pressão do esfíncter anal foi significativamente menor no grupo CL, o tratamento com lecitina aumentou a pressão nos grupos pré e pós tratados. A LPO e atividade da SOD aumentaram no grupo CL e diminuíram nos grupos tratados com lecitina. A atividade da CAT foi aumentada no grupo CL e diminuiu nos grupos com lecitina. A análise histológica mostrou danos ao intestino com destruição das criptas, edema e infiltrado inflamatório. O uso de lecitina proporcionou uma preservação das criptas e diminuição do edema. Conclusão: A RCUI aumenta a LPO, a utilização de lecitina foi eficaz na redução dos danos ao intestino induzido por AA no modelo de colite experimental.

Effect of glutamine on oxidative stress and inflammation in a rat model of fulminant hepatic failure / Efecto de la glutamina en el estrés oxidativo y la inflamación en un modelo de rata con insuficiencia hepática fulminante

Introduction: Fulminant hepatic failure (FHF) is a rare clinical syndrome, characterized by sudden and severe liver dysfunction. Thioacetamide (TAA) is a hepatotoxin whose administration can induce centrilobular necrosis in liver cells and increase the formation of reactive oxygen species and lipid peroxidation in rats. Glutamine is a precursor for glutathione synthesis. Objective: The objective of the study to assess the antioxidant effects of glutamine in a rat model of TAA-induced FHF. Methods: Male Wistar rats were divided into four groups according to treatment and time of assessment: control, glutamine (25 mg/kg), thioacetamide (400 mg/kg) and thioacetamide plus glutamine. Animals were assessed after 24, 36 and 48 hours. Blood samples were collected for the analysis of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), total bilirubin (TB) and creatinine (CRE) levels, and liver samples were used to evaluate lipid peroxidation, acid-reactive thiobarbituric substances (TBARS), antioxidant enzyme activity superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione S-transferase (GST). Nuclear factor kB (NF-kB), tumor necrosis factors (TNF-a) and nitric oxide synthase inducible (iNOS) levels were assessed by histology and immunohistochemistry. Results: TAA caused alterations in biochemical and histological parameters, and increased markers of the inflammatory process. TBARS levels and the activity of SOD and GST were significantly lower in the glutamine group as compared to the TAA group. CAT activity was elevated in animals treated with glutamine as compared to the TAA groups. GPx activity was also lower in the glutamine-treated groups than in TAA-treated animals at 36 and 48 hours. Tissue damage and NF-kB, TNF-a and iNOS expression were significantly lower in animals treated with glutamine. Conclusion: Glutamine has shown to have protective effects against liver damage in a rat model of TAA-induced FHF (AU)

Introducción: la insuficiencia hepática fulminante (IHF) es un síndrome clínico poco frecuente, que se caracteriza por una disfunción hepática severa y repentina. La tioacetamida (TAA) es una hepatotoxina cuya administración puede inducir necrosis centrolobulillar en las células hepáticas y aumentar la formación de especies reactivas de oxígeno y la peroxidación lipídica en ratas. La glutamina es un precursor para la síntesis de glutatión. Objetivo: el objetivo del estudio es evaluar los efectos antioxidantes de la glutamina en un modelo de rata de IHF inducida por TAA. Métodos: ratas macho Wistar se dividieron en cuatro grupos de acuerdo con el tratamiento y el tiempo de evaluación: control, glutamina (25 mg/kg), tioacetamida (400 mg/kg) y tioacetamida más glutamina. Los animales se evaluaron después de 24, 36 y 48 horas. Se recogieron muestras de sangre para el análisis de los niveles de aspartato aminotransferasa (AST), alanina aminotransferasa (ALT), fosfatasa alcalina (AP), bilirrubina total (TB) y creatinina (CRE), y muestras de hígado para evaluar la peroxidación lipídica, las sustancias reactivas al ácido tiobarbitúrico (TBARS), la actividad de las enzimas antioxidantes superóxido dismutasa (SOD), glutatión peroxidasa (GPx), catalasa (CAT) y glutatión S-transferasa (GST). Además se midieron mediante inmunohistoquímica el factor nuclear kappa N (NF-κB), el fator de necrosis tumoral (TNF-α) y la óxido nítrico sintasa inducible (iNOS). Resultados: la TAA causó alteraciones en los parámetros bioquímicos e histológicos, y el aumento de los marcadores del proceso inflamatorio. Los niveles de TBARS y la actividad de SOD y GST fueron significativamente inferiores en los grupos de glutamina en comparación con TAA. La actividad de CAT se incrementó en los animales tratados con glutamina en comparación con la TAA. La actividad GPx también fue menor a las 36 y 48 h en los animales tratados com glutamina. El daño tisular y la expresión de NF-κB, TNF-α e iNOS fueron significativamente inferiores en los animales tratados con glutamina. Conclusión: la glutamina ha demostrado tener efectos protectores contra el daño hepático en un modelo de IHF inducida por TAA en la rata (AU)

N-acetylcysteine modulates angiogenesis and vasodilation in stomach such as DNA damage in blood of portal hypertensive rats.

AIM: To evaluate the antioxidant effect of N-acetylcysteine (NAC) on the stomach of rats with portal hypertension. METHODS: Twenty-four male Wistar rats weighing ± 250 g were divided into four experimental groups (n = 6 each): Sham-operated (SO), SO + NAC, partial portal vein ligation (PPVL), and PPVL + NAC. Treatment with NAC in a dose of 10 mg/kg (i.p.) diluted in 0.6 mL of saline solution was administered daily for 7 d starting 8 d after the surgery. Animals from the PPVL and SO group received saline solution (0.6 mL) for the same period of time as the PPVL + NAC and SO + NAC group. On the 15(th) day the animals were anesthetized and we evaluated portal pressure by cannulating mesenteric artery. After, we removed the stomach for further analysis. We performed immunohistochemical analysis for endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and nitrotirosine (NTT) proteins in stomach. We also evaluated eNOS and VEGF by Western blot analysis and assessed DNA damage in blood samples by the comet assay. RESULTS: The portal hypertension group exhibited increases in portal pressure when compared to SO group (29.8 ± 1.8 vs 12.0 ± 0.3 mmHg) (P < 0.001). The same was observed when we compared the eNOS (56.8 ± 3.7 vs 13.46 ± 2.8 pixels) (P < 0.001), VEGF (34.9 ± 4.7 vs 17.46 ± 2.6 pixels) (P < 0.05), and NTT (39.01 ± 4.0 vs 12.77 ± 2.3 pixels) (P < 0.05) expression by immunohistochemistry of the PPVL animals with the SO group. The expression of eNOS (0.39 ± 0.03 vs 0.25 ± 0.03 a.µ) (P < 0.01) and VEGF (0.38 ± 0.04 vs 0.26 ± 0.04 a.µ) (P < 0.01) were also evaluated by Western blot analysis, and we observed an increase of both proteins on PPVL animals. We also evaluated the DNA damage by comet assay, and observed an increase on damage index and damage frequency on those animals. NAC decreased portal pressure values in PPVL + NAC animals (16.46 ± 2 vs 29.8 ± 1.8 mmHg) (P < 0.001) when compared to PPVL. The expression of eNOS (14.60 ± 4.1 vs 56.8 ± 3.7 pixels) (P < 0.001), VEGF (19.53 ± 3.2 vs 34.9 ± 4.7 pixels) (P < 0.05) and NTT (21.84 ± 0.7 vs 39.01 ± 4.0 pixels) (P < 0.05) evaluated by immunohistochemistry were also reduced in PPVL + NAC animals. Also, when evaluated by Western blot eNOS expression (0.32 ± 0.03 vs 0.39 ± 0.03 a.µ) (P < 0.05) and VEGF expression (0.31 ± 0.09 vs 0.38 ± 0.04 a.µ) (P < 0.01). Furthermore, NAC modulated DNA damage in PPVL + NAC animals. CONCLUSION: In view of these results, we believe NAC is able to protect the stomach from the alterations induced by the PPVL procedure.

Effects of quercetin on polychlorinated biphenyls-induced liver injury in rats / Efecto de la quercetina sobre la lesión hepática inducida por bifenilos policlorados en ratas

Introduction: Polychlorinated biphenyls (PCBs), used as pesticides in agriculture, can lead to irreversible injuries in living organisms, particularly in liver. Oxidative stress has been implicated in the liver pathogenesis induced by different molecules, including PCBs. It has been demonstrated that quercetin, an antioxidant flavonoid found in the diet, exhibits a potent antioxidant effect in different liver pathologies. Objective: To evaluate oxidative stress caused by PCBs in liver and the antioxidant activity of quercetin. Methodology: We used male Wistar rats (n = 36), divided in 4 groups: control, quercetin (50 mg/kg/day), PCBs (0.4 ml/kg/day), and rats treated with both PCBs and quercetin. On day 25 blood was collected to assess liver integrity (enzymes AST, ALT and ALP), and liver samples to measure oxidative stress (TBARS), activity of antioxidant enzymes (SOD, CAT, GPx) and DNA damage (micronucleus assay), and histological damage. Results: TBARS concentration and SOD activity were significantly higher in PCBs animals as compared to the PCB group receiving quercetin. CAT and GPx decreased in PCBs and increased when quercetin was added. The histological analysis showed damage to hepatocytes in PCBs, but quercetin was able to afford protection against such damage. The micronucleus test showed there was an increase in the production of microclenucleus compared to control, and quercetin was able to reduce this effect. Conclusion: Contamination with PCBs led to increased lipid peroxidation and DNA damage, and the use of antioxidant quercetin was effective in reducing PCBs-induced liver injury (AU)

Introducción: los bifenilospoliclonados (PCBs) son pesticidas ampliamente usados en agricultura que pueden inducir daños irreversibles particularmente en el hígado. El estrés oxidativo ha sido implicado en diversas patogénesis hepáticas, incluidas las relacionadas conPCBs. La quercetina, un flavonoide de la dieta, ha demostrado tener un potente efecto antioxidante en diversos modelos de patología hepática. Objetivo: Evaluar el estrés oxidativo hepático inducido por PCBs y la actividad antioxidante de la quercetina. Metodología: Se usaron ratas macho de raza Wistar (n = 36), divididas en cuatro grupos: control, quercetina (50 mg/kg/día), PCBs (0,4 ml/kg/día) y ratas tratadas tanto con PCBs como con quercetina. Transcurridos 25 días de tratamiento se recogieron muestras de sangre, para evaluar la integridad hepática (AST, ALT y ALP), y de tejido para cuantificar el estrés oxidativo (TBARS), actividad antioxidante (SOD, CAT, GPx), daño al DNA (ensayo de micronúcleos) y daño histológico. Resultados: la concentración de TBARS y la actividad SOD fueron significativamente mayores en los animales que recibieron PCBs que en los que recibían quercetina. La actividad de CAT y GPx se redujo con los PCBs y se incrementó al administrar quercetina. Los análisis histológicos y de micronúcleos mostraron daño hepático y al DNA respectivamente inducido por PCBs que eran revertidos con el tratamiento con quercetina. Conclusion: La contaminación con PCBs induce un incremento en la peroxidación lipídica, modificación en la actividad de enzimas antioxidantes, daño histológico y al DNA en el hígado, siendo el antioxidante quercetina es capaz de reducir dichos cambios (AU)