Aim: Isoniazid (INH) and Rifampicin (RIF) are hepatotoxic drugs. Oxidative stress has been reported as one of the mechanisms of INH+RIF induced hepatotoxicity.
Methods: Intragastric administration of INH and RIF (50 mg/kg body weight/day each) for 28 days in Wistar rats is hepatotoxic, indicated by raised transaminases and histology. Carotenoids have antioxidant properties. Therefore, different doses of carotenoids (2.5, 5, 10 and 20 mg/kg body weight/day) were administered to study the hepatoprotective effect against INH+RIF.
Results: The higher doses of carotenoids i.e.10 and 20 mg/kg body weight/day showed partial hepatoprotection indicated by return to normal of liver transaminase level and of liver histology in 33.3% of rats. There was no further protective effect seen by increasing the dose of carotenoids from 10 to 20 mg/kg body weight/day. Lower doses of carotenoids i.e. 2.5 and 5 mg/kg body weight/day were not effective.
Conclusion: Thus, a minimum dose with maximum hepatoprotection (10 mg/kg b.wt/ day) was selected as the optimum dose in the present study. The hepatoprotective nature of carotenoids in INH+RIF treated rats may be attributed to their antioxidative property