Effectiveness of vitamin E and colchicine in amelioration of paraquat lung injuries using an experimental model.

The major cause of death in paraquat poisoning is a rapidly progressive respiratory failure due to an oxidative insult to the alveolar epithelium with subsequent fulminant obliterating fibrosis. The present study evaluates the effectiveness of vitamin E in combination with colchicine in ameliorating paraquat lung injuries in rats. Vitamin E is a biologic antioxidant interfering with lipid peroxidation, and colchicine reduces collagen synthesis which is significantly augmented in pulmonary fibrosis. Eight normal rats were given a single i.p. dose of paraquat at 15 mg/kg. The treated group included eight animals that received, in addition to i.p. paraquat (15 mg/kg), daily doses of vitamin E (100 mg/kg i.p.) and colchicine (0.1 mg/kg i.p.). All the rats in the paraquat group died within 42 to 96 h, six of them within 60 h, following severe respiratory failure. The treated rats developed a somewhat milder form of respiratory insufficiency, six of them dying within 48 to 72 h. Less severe intra-alveolar hemorrhages were observed in this group. Two rats survived, and these had only mild emphysema on autopsy at 21 days. Our preliminary results suggest that the combination of vitamin E with colchicine may be effective in ameliorating lung injuries caused by paraquat, and warrant further studies.