possible protective effects of melatonin and estrogen against carbon tetrachloride-induced liver cirrhosis

ABSTRACT

Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrotic scar tissue. Melatonin is a hormone found in all living creatures from algae to human. Estrogens are a group of steroid compounds named for their importance in estrus cycle and function as a primary female sex hormone. This work aimed at studying possible protective action of each of melatonin and estrogen on liver cirrhosis induced by CCl[4]. To this end, 50 healthy male Sprague Dawley rats were divided into 5 groups [n=10 each] [i] normal control group, [ii] CCl[4] [0.4ml/100g, i.p., twice a week for 12 weeks, [iii] melatonin [0.2mg/100g, i.p., daily dose for 21 days], estrogen [0.1mg/100g, i.p., twice a week for 12 weeks], [iv] CCl[4+] melatonin and [v]CCl[4+]estrogen-treated groups. Twenty four hours later, blood samples were collected for determination of prothrombin time, alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], albumin, total protein, total bilirubin and relative liver weight. Histopathological examination of rats' livers was also performed. Results showed that CCl[4] administration induced significant increase in prothrombin time, ALT, AST, ALP, total bilirubin, relative liver weight and significant decrease levels of serum albumin and total protein. Co-administration of melatonin with CCl[4] significantly increased level of serum albumin and total protein and reduced level of serum ALT, AST, ALP, total bilirubin, prothrombin time and relative liver weight compared to CCl[4]-treated group. Histopathological examination of liver tissue showed that melatonin co-administration decrease the cellular changes induced by CCl[4] alone. Meanwhile, co-administration of estrogen with CCl[4] significantly reduced relative liver weight. Moreover, evaluation of liver tissue showed that estrogen co-administration slightly decrease the cellular changes induced by CCl[4]. These data suggested that melatonin and estrogen induce some protection against liver cirrhosis induced by CCl[4]