Comparison of early treatment with low doses of nilotinib, imatinib and a clinically relevant dose of silymarin in thioacetamide-induced liver fibrosis.

Our previous study has already confirmed a promising anti-fibrotic activity especially for nilotinib; when given at a daily dose of 10 mg/kg during the last 4 weeks of thioacetamide (TAA)-induced liver fibrosis for 12 weeks in rats. Therefore, this study was carried out to compare the prophylactic potential of low dose of nilotinib to that of its predecessor, imatinib, and a clinically relevant dose of the standard hepatoprotective treatment, silymarin, in TAA-intoxication. Male Wistar rats received intraperitoneal injections of TAA (150 mg/kg, twice weekly) for 8 weeks, as well as oral treatments with imatinib (5 mg/kg/day), nilotinib (5 mg/kg/day) and silymarin (50 mg/kg/day) from the first day of TAA-intoxication. At the end of the study, chronic hepatic injury was evaluated by analysis of liver function tests in serum. Hepatic oxidative stress was assessed by measuring malondialdehyde, 4-hydroxynonenal, total nitrate/nitrite and reduced glutathione contents, as well as myeloperoxidase and superoxide dismutase activities. Hepatic fibrosis was evaluated by histopathology and collagen content. Our results suggest that the prophylactic potential of nilotinib (5 mg/kg/day), imatinib (5mg/kg/day) and silymarin (50 mg/kg/day) in TAA-intoxication for 8 weeks is lower than the late treatments of nilotinib (10 mg/kg/day), imatinib (10mg/kg/day) and silymarin (100 mg/kg/day) during the last 4 weeks of TAA-intoxication for 12 weeks in rats. Taken together, this study suggests that nilotinib may have higher anti-fibrotic activity when administered at a significant stage of fibrosis as a result of impairment of its metabolism in the fibrotic livers.