TY - JOUR
T1 - Melatonin protects the liver and erythrocytes against oxidative stress in cirrhotic rats
AU - Da Rosa, Darlan Pase
AU - Bona, Silvia
AU - Simonetto, Douglas
AU - Zettler, Claudio
AU - Marroni, Cláudio Augusto
AU - Marroni, Norma Possa
PY - 2010/1/1
Y1 - 2010/1/1
N2 - Context - Cirrhosis is a progressive chronic hepatopathy which constitutes an irreversible stage of liver dysfunction. Objectives - To evaluate the oxidative stress in the blood of cirrhotic rats treated with the antioxidant melatonin. Methods - Cirrhosis was induced through inhalation of carbon tetrachloride. Liver integrity was evaluated by measuring serum enzymes, oxidative damage measured by lipoperoxidation, and antioxidant enzyme activity in erythrocytes. Lipoperoxidation, total nitrates, collagen, and histology by picrosirius staining were evaluated in the livers of these animals (n = 15), which were divided in three groups: control, carbon tetrachloride, and carbon tetrachloride + melatonin. Melatonin (20 mg/kg) was administered intraperitoneal from week 10 of carbon tetrachloride inhalation. In order to shorten the cirrhosis induction time, phenobarbital (0.3 g/L) was added to the animals' drinking water. Results - A significant impairment in the liver integrity of melatonin-treated animals as compared to cirrhotic animals was observed. In rat erythrocytes and liver, lipoperoxidation was significantly increased in the cirrhotic rats as compared to controls, as measured through thiobarbituric acid reactive substances, and significantly decreased in melatonin-treated animals as compared to cirrhotic ones. In blood, a decrease in superoxide dismutase and glutathione peroxidase enzymes was detected in the cirrhotic group as compared to the control group, with increased superoxide dismutase activity when melatonin was administered. A reduction in the levels of total nitrates was detected in the hepatic tissue of the animals in the carbon tetrachloride group as compared to the control group and an increase of these levels in the carbon tetrachloride + melatonin group. As for hepatic collagen, we found a significant increase in the carbon tetrachloride group as compared to the controls and a regression of these values in the treated group. In histology, the rats in the carbon tetrachloride group showed fibrosis and formation of fibrotic nodules, characterizing liver cirrhosis; there was reduction of nodules and fibrosis in the melatonin treated group. Conclusion - The data allow us to suggest that the observed oxidative stress is related to the damages caused by carbon tetrachloride and that the use of melatonin can minimize these damages.
AB - Context - Cirrhosis is a progressive chronic hepatopathy which constitutes an irreversible stage of liver dysfunction. Objectives - To evaluate the oxidative stress in the blood of cirrhotic rats treated with the antioxidant melatonin. Methods - Cirrhosis was induced through inhalation of carbon tetrachloride. Liver integrity was evaluated by measuring serum enzymes, oxidative damage measured by lipoperoxidation, and antioxidant enzyme activity in erythrocytes. Lipoperoxidation, total nitrates, collagen, and histology by picrosirius staining were evaluated in the livers of these animals (n = 15), which were divided in three groups: control, carbon tetrachloride, and carbon tetrachloride + melatonin. Melatonin (20 mg/kg) was administered intraperitoneal from week 10 of carbon tetrachloride inhalation. In order to shorten the cirrhosis induction time, phenobarbital (0.3 g/L) was added to the animals' drinking water. Results - A significant impairment in the liver integrity of melatonin-treated animals as compared to cirrhotic animals was observed. In rat erythrocytes and liver, lipoperoxidation was significantly increased in the cirrhotic rats as compared to controls, as measured through thiobarbituric acid reactive substances, and significantly decreased in melatonin-treated animals as compared to cirrhotic ones. In blood, a decrease in superoxide dismutase and glutathione peroxidase enzymes was detected in the cirrhotic group as compared to the control group, with increased superoxide dismutase activity when melatonin was administered. A reduction in the levels of total nitrates was detected in the hepatic tissue of the animals in the carbon tetrachloride group as compared to the control group and an increase of these levels in the carbon tetrachloride + melatonin group. As for hepatic collagen, we found a significant increase in the carbon tetrachloride group as compared to the controls and a regression of these values in the treated group. In histology, the rats in the carbon tetrachloride group showed fibrosis and formation of fibrotic nodules, characterizing liver cirrhosis; there was reduction of nodules and fibrosis in the melatonin treated group. Conclusion - The data allow us to suggest that the observed oxidative stress is related to the damages caused by carbon tetrachloride and that the use of melatonin can minimize these damages.
KW - Carbon tetrachloride
KW - Erythrocytes
KW - Liver cirrhosis, experimental
KW - Melatonin
KW - Oxidative stress
KW - Rats
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U2 - 10.1590/S0004-28032010000100013
DO - 10.1590/S0004-28032010000100013
M3 - Article
C2 - 20520979
AN - SCOPUS:77953182657
SN - 0004-2803
VL - 47
SP - 72
EP - 78
JO - Arquivos de Gastroenterologia
JF - Arquivos de Gastroenterologia
IS - 1
ER -