Antioxidant properties of colchicine in acute carbon tetrachloride induced rat liver injury and its role in the resolution of established cirrhosis

Antioxidant and antifibrotic properties of colchicine were investigated in the carbon tetrachloride (CCl4) rat model. (1) The protective effect of colchicine pretreatment on CCl4 induced oxidant stress was examined in rats subsequently receiving a single lethal dose of CCl4. Urinary 8-isoprostane, kidney and liver malondialdehyde and kidney glutathione levels increased following CCl4 treatment, but only the rise in kidney malondialdehyde was significantly inhibited by colchicine pretreatment. Serum total antioxidant levels were significantly higher in the colchicine pretreatment group. (2) The long term effects of colchicine treatment on CCl4 induced liver damage were investigated using liver histology and biochemical markers (hydroxyproline and type III procollagen peptide). Go-administration of colchicine with sub-lethal doses of CCl4 over 10 weeks did not prevent progression to cirrhosis. However, rats made cirrhotic with repeated CCl4 challenge and subsequently treated with colchicine for 12 months, all showed histological regression of cirrhosis. (3) The antioxidant effect of colchicine in vitro was evident only at very high concentrations compared to other plasma antioxidants. In summary, colchicine has only weak antioxidant properties, but does afford some protection against oxidative stress; more importantly, long term treatment with this drug may be of value in producing regression of established cirrhosis. (C) 2000 Elsevier Science B.V. All rights reserved.