BACKGROUND: This study investigated the effectiveness of pirfenidone compared with antioxidants, in the prevention of pulmonary fibrosis and increasing the survival in acutely paraquat poisoned rats. METHODS: Five groups of ten rats were included in this study. Three groups were poisoned with intraperitoneal injection of 15 mg/kg paraquat. Among these poisoned groups, one group was treated with vitamin C (500 mg/kg, intraperitoneal), vitamin E (200 mg/kg, intraperitoneal) and N-acetylcysteine (250 mg/kg, intravenous); two others were treated with either normal saline or pirfenidone (200 mg/kg, intravenous); two groups were not poisoned and received normal saline or pirfenidone (200 mg/kg, intravenous). All injections except paraquat were repeated in four consecutive days. On the 15th day of study a semi-quantitative determination of lung fibrosis was done using Ashcroft staging criteria on the lung sections. RESULTS: Pirfenidone decreased paraquat induced lung fibrosis (p < 0.001) while antioxidants did not decrease the lung fibrosis (p = 0.413). Life expectancy decreased in paraquat + normal saline (11 days, 95% CI 7.94-14.05) and paraquat + antioxidant (11 days, 95% CI 7.77-14.23) groups. The increase in the survival of rats in paraquat/pirfenidone group was insignificant (13.4 days, 95% CI 11.13-15.67). CONCLUSION: This study showed that pirfenidone is able to decrease pulmonary fibrosis following paraquat poisoning in a rat model.
BACKGROUND: This study investigated the effectiveness of pirfenidone compared with antioxidants, in the prevention of pulmonary fibrosis and increasing the survival in acutely paraquat poisoned rats. METHODS: Five groups of ten rats were included in this study. Three groups were poisoned with intraperitoneal injection of 15 mg/kg paraquat. Among these poisoned groups, one group was treated with vitamin C (500 mg/kg, intraperitoneal), vitamin E (200 mg/kg, intraperitoneal) and N-acetylcysteine (250 mg/kg, intravenous); two others were treated with either normal saline or pirfenidone (200 mg/kg, intravenous); two groups were not poisoned and received normal saline or pirfenidone (200 mg/kg, intravenous). All injections except paraquat were repeated in four consecutive days. On the 15th day of study a semi-quantitative determination of lung fibrosis was done using Ashcroft staging criteria on the lung sections. RESULTS:Pirfenidone decreased paraquat induced lung fibrosis (p < 0.001) while antioxidants did not decrease the lung fibrosis (p = 0.413). Life expectancy decreased in paraquat + normal saline (11 days, 95% CI 7.94-14.05) and paraquat + antioxidant (11 days, 95% CI 7.77-14.23) groups. The increase in the survival of rats in paraquat/pirfenidone group was insignificant (13.4 days, 95% CI 11.13-15.67). CONCLUSION: This study showed that pirfenidone is able to decrease pulmonary fibrosis following paraquatpoisoning in a rat model.