Ceratonia siliqua pod extract ameliorates Schistosoma mansoni-induced liver fibrosis and oxidative stress

Background: Schistosomiasis is a prevalent parasitic disease found predominantly in tropical and sub-tropical areas of the developing world, with the second highest socioeconomic and public health burden despite strenuous control efforts. In the present study, we aimed to investigate the ameliorative effects of Ceratonia siliqua pod extract (CPE) on liver fibrosis and oxidative stress in mice infected with Schistosoma mansoni. Methods: The schistosomal hepatopathologic mouse model was established by tail immersion with schistosomal cercaria. The extract was given daily for 10 days beginning 42 days post-infection. Liver samples were obtained from mice sacrificed 9 weeks after infection. Liver histopathological changes were observed with hematoxylin-eosin and Masson trichrome staining. Results: Typical schistosomal hepatopathologic changes were induced in the untreated mice. However, the oral administration of CPE was effective in reducing worm number and the egg load in the liver. This treatment also decreased granuloma size and collagen deposition by inhibiting tissue inhibitor of metalloproteinases-2 (TIMP-2) expression. Schistosomal infection induced oxidative stress by increasing lipid peroxidation (LPO) and nitrite/nitrate (nitric oxide; NO) production along with concomitant decreases in glutathione (GSH) and various antioxidant enzymes, including superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. However, treatment of mice with CPE at 300 or 600 mg/kg inhibited LPO and NO production, increased GSH content, and restored the activities of the antioxidant enzymes compared with untreated infected mice. Furthermore, treatment with CPE inhibited apoptosis, as indicated by the reduced Bax expression in hepatic tissue. Conclusion: These data indicated that extracts from Ceratonia siliqua pods may play an important role in combating schistosomal hepatopathology and may inhibit granuloma formation and liver fibrosis through down-regulation of TIMP-2 expression.