Blocking angiotensin pathway induces anti-fibrotic effects in a mouse model of schistosomiasis by decreasing egg burden and granulomatous reaction

Abstract

Background: Schistosoma mansoni infection is associated with hepatic fibrosis and portal hypertension. Previous studies reported that blocking some components of rennin angiotensin system can ameliorate the liver pathology induced by S. mansoni infection. Aim: The present study investigated the potential effect of losartan, an angiotensin II receptor antagonist, and enalapril, an angiotensin-converting enzyme inhibitor, on hepatic fibrosis caused by S. mansoni in a murine model. Materials and Methods: S. mansoni-infected mice were treated at week 5 after infection with losartan, enalapril, or their combination. A group of infected mice was treated with the reference drug praziquantel (PZQ) as controls. Parasitological and histological parameters were investigated. Results: Our results showed that when compared with enalapril, treatment with losartan alone caused a considerable decrease in liver index (28.92% versus 25.09%), spleen index (47.19% versus 37.08%), worm burden (38.7% versus 24.8%), hepatic tissue egg load (62.7% versus 54%), granuloma size (40.4% versus 29.4%) and fibrosis (48.7% versus 29.4%). The combination of losartan and enalapril did not produce a more pronounced effect than those of losartan. Conclusion: Our results suggest the promising effect of enalapril and losartan in amelioration of hepatic pathology but further studies to determine their effects in combination with other antischistosomal agents such as praziquantel are recommended.