Background: bleomycin-induced lung toxicity and oxidative damage by decreasing the deactivating enzyme, genetic vulnerability, and released cytokinesof inflammation. Melatonin has a free radical detoxifying effect, coenzyme Q10 has a strong antioxidant effect. Aim of the study: this study aimed toevaluate the possible protective role of melatonin and coenzyme Q10 inbleomycin-induced lung injury in Albino rats. Material and Methods: forty male Albino rats were categorized into five groups; group I (control group), group II (bleomycin group): rats were given a single dose of bleomycin intra-tracheal for inducing lung injury, group III (melatonin group): rats were given melatonin for three weeks after intratracheal installation of bleomycin, group IV (coenzymeQ10 group): rats were given coenzymeQ10 for three weeks after intratracheal installation of bleomycin and group V (combined melatonin and Co Q10 group): rats were given a combination of melatonin and coenzyme Q10for three weeks after induction of bleomycin lung toxicity. Lung tissues were prepared for biochemical, histological and immunohistochemical studies. Results: bleomycin produced a significant increase in the level of malondialdehyde and a significant reduction in glutathione peroxidase activity in lung tissues with loss of normal histological lung architecture, significant elevation in main area percent of collagen fibers deposition and caspase-3 immuno positive expression. In group III melatonin enhanced a significant improvement in the biochemical changes, moderate prevention of histopathological changes in lung tissue with a significant reduction in main area percent of collagen fibers deposition and caspase-3 immuno positive expression. While, in group IV co enzyme Q10 enhanced non significant improvement in the biochemical changes, mild prevention of histopathological changes and non-significant reduction in main area percent of collagen fibers deposition and caspase-3 immuno positive expression. Using a combination of both drugs in group V enhanced a significant improvement in the biochemical changes and almost preservation of normal histological architecture of the lung tissue.Conclusion: administration of both melatonin and coenzyme Q10 produced almost a complete recovery of bleomycin induced lung injury. |