Introduction and Aim of the Work: Idiopathic pulmonary fibrosis is a disease of unknown etiology that causes fibrosis in lung parenchyma with progressive irreversible nature with no appropriate therapy, so this study worked to evaluate the therapeutic effect of pirfenidone on a rat model of bleomycin-induced pulmonary fibrosis.
Materails and Methods: Thirty adult male albino rats were used in this study; classified into 5 groups: group I (control group), group II (prifenidone group), group III (model group), group IV (recovery group) and group V (treated group). Lung specimens were taken from rats of group IA and group III on the 14th day of the experiments while specimens from the rest of the groups were taken on the 28th day of the experiment. The specimens were subjected to biochemical analysis for malondialdehyde and glutathione as well as histological study using H & E, Masson's trichrome, toluidine blue stain for semithin sections and immunohistochemical stain for αSMA. The area percent of collagen and αSMA immunopositive cells were measured and statistically analysed using image analyser.
Results: Groups III and IV showed deposition of collagen in the thickened interalveolar septa and infiltration of interstitial tissue by inflammatory cells causing narrowing or even collapse of the intervening alveoli. There was a significant increase in the mean area percent of collagen and αSMA immunopositive cells with significant decrease in GSH and a significant increase in MDA as compared to control. Meanwhile group V showed restoring of normal lung architecture. There was a significant decrease in the mean area percent of collagen and αSMA immunopositive cells, significant increase in GSH and a significant decrease in MDA as compared to groups III and IV.
Conclusion: Pirfenidone was effective as antifibrotic agent with significant reduction of fibrosis and oxidative stress in rat model of lung fibrosis.