The Possible Beneficial Effect of Angiotensin II Receptor Antagonist (Losartan) in Experimental- Hepatic Fibrosis in Albino Rats. Histological, Immunohistochemical and Biochemical Study

Background: Hepatic fibrosis is a histological change caused by liver inflammation and characterized by accumulation of extracellular matrix protein (ECM). Losartan is one class of drugs that inhibit the action of angiotensin II (ANG II) at its receptors. It has been used as antihypertensive in human. Aim of the Work: Was to clarify the beneficial effect of losartan in experimental liver fibrosis by bile duct ligation. Materials and Methods: Forty adult male albino rats were divided into four equal groups; GI (control), GII (shamoperated), GIII (bile duct ligated, BDL) and G VI received losartan at a dose of 5 mg/ kg daily after BDL. After four weeks, blood samples were collected for estimation of serum bilirubin (SB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and serum hyaluronic acid (SHA). Rats were sacrificed and their livers were processed for estimation of hydroxyproline and for histological study. Paraffin sections were stained by H and E, Masson’s trichrome and other sections were stained immunohistochemically for desmin. Results: Revealed elevated liver enzymes, serum and tissue fibrosis markers (hyaluronic acid and hydroxyproline) together with dramatic histological changes in liver sections of G III (BDL). Administration of Losartan after BDL (GVI) showed improvement of biochemical analysis of liver enzymes, fibrosis markers and amelioration of the histological changes of hepatic tissues. Moderate expression of desmin from hepatic stellate cells (HSCs) was also evident. From this study. Conclusion: That losartan has a benifical effect in liver fibrosis induced by BDL. However, further study for its usefulness in human hepatic fibrosis is recommended. Original Article