Preventive effect of melatonin on bleomycin-induced lung fibrosis in rats

: Oxidative stress has an important role in the pathogenesis of idiopathic pulmonary fibrosis. Melatonin has direct and indirect free radical‐detoxifying activity. The present study investigated whether melatonin treatment attenuates bleomycin‐induced lung fibrosis in rats. A group of rats was given one dose of bleomycin while the control animals were given saline. The first dose of melatonin (4 mg/kg/day) was given 2 days before the bleomycin injection. At day 14, fibrotic changes were evaluated using Aschoft's criteria and lung hydroxyproline content. Bleomycin produced a 2.7‐fold rise in the fibrosis score that was decreased 65% by melatonin (P