Enoxaparin does not ameliorate liver fibrosis or portal hypertension in rats with advanced cirrhosis

Background & AimsRecent studies suggest that heparins reduce liver fibrosis and the risk of decompensation of liver disease. Here, we evaluated the effects of enoxaparin in several experimental models of advanced cirrhosis. MethodsCirrhosis was induced in male Sprague-Dawley (SD) rats by: (i) Oral gavage with carbon tetrachloride (CCl4(ORAL)), (ii) Bile duct ligation (BDL) and (iii) CCl4 inhalation (CCl4(INH)). Rats received saline or enoxaparin s.c. (40IU/Kg/d or 180IU/Kg/d) following various protocols. Blood biochemical parameters, liver fibrosis, endothelium- and fibrosis-related genes, portal pressure, splenomegaly, bacterial translocation, systemic inflammation and survival were evaluated. Endothelial dysfunction was assessed by in situ bivascular liver perfusions. ResultsEnoxaparin did not ameliorate liver function, liver fibrosis, profibrogenic gene expression, portal hypertension, splenomegaly, ascites development and infection, serum IL-6 levels or survival in rats with CCl4(ORAL) or BDL-induced cirrhosis. Contrarily, enoxaparin worsened portal pressure in BDL rats and decreased survival in CCl4(ORAL) rats. In CCl4(INH) rats, enoxaparin had no effects on hepatic endothelial dysfunction, except for correcting the hepatic arterial dysfunction when enoxaparin was started with the CCl4 exposure. In these rats, however, enoxaparin increased liver fibrosis and the absolute values of portal venous and sinusoidal resistance. ConclusionsOur results do not support a role of enoxaparin for improving liver fibrosis, portal hypertension or endothelial dysfunction in active disease at advanced stages of cirrhosis. These disease-related factors and the possibility of a limited therapeutic window should be considered in future studies evaluating the use of anticoagulants in cirrhosis.