The Role of Colchicine in the Prevention of Bleomycin-Induced Pulmonary Fibrosis in Rats

Background: Lung fibrosis is the most popular and serious sequel of interstitial inflammatory diseases and may lead to respiratory failure in critical cases with a mortality rate of 10% to 20%. Its etiology includes chemicals, infections, radiation, allergens, drugs such as bleomycin (BLM), and as a result of the coronavirus disease 2019 (COVID-19). Aim of the work: The purpose of the present work was to detect the preventive outcome of colchicine on lung fibrosis in rats.Material and methods: 24 male albino rats were subdivided into 4 groups, 6 rats per group; group I (control G), group II (colchicine G), group III (BLM G), and group IV (BLM+colchicine G). The lung fibrosis was done by injection of BLM intraperitoneally (dose;0.5 mgkg 2 times week for 3 weeks). BLM+colchicine group was taken BLM as in group III in addition colchicine was taken daily (dose; 1 mg/kg by oral gavage for 3 weeks). By the study period end (3 weeks), the rats were put under anesthesia and the thoracic wall was opened. The lungs were taken and prepared for H&E, Masson’s trichrome, and immunohistochemical staining. Some specimens were prepared and examined by transmission electron microscope (TEM). Results: The histological changes in the lungs of the BLM group were deformed pulmonary architecture, thickened interstitial walls, alveolar collapse, severe invasion by inflammatory cells, highly significant collagen fibrils deposition, severe positive reaction in the interstitial walls by anti-α-SMA, and degenerated pneumocytes I and II by TEM. The preventive group showed restoration of most of the normal lung architecture and a marked decrease in inflammatory and fibrotic changes. Conclusion: Colchicine can lessen the histopathological and ultrastructural changes in the lungs resulting from BLM.