Abstract

Pirfenidone (PFD), one acceptable medication for treating idiopathic pulmonary fbrosis (IPF), is not well tolerated by patients at full doses. Hence, employing of some approaches such as combination therapy may be applicable for increasing therapeutic efcacy of PFD. Losartan (LOS), an angiotensin II receptor antagonist, could be a suitable candidate for combination therapy because of its stabilizing efect on the pulmonary function of IPF patients. Therefore, this study aimed to investigate the efects of LOS in combination with PFD on bleomycin (BLM)-induced lung fbrosis in rats. BLM-exposed rats were treated with LOS alone or in combination with PFD. The edema, pathological changes, level of transforming growth factor-β (TGF-β1), collagen content, and oxidative stress parameters were assessed in the lung tissues. Following BLM exposure, the infammatory response, collagen levels, and antioxidant markers in rat lung tissues were signifcantly improved by PFD, and these efects were improved by combination with LOS. The fndings of this in vivo study suggest that the combined administration of PFD and LOS may provide more potent protection against IPF than single therapy through boosting its anti-infammatory, anti-fbrotic, and anti-oxidant efects. These results hold promise in developing a more efective therapeutic strategy for treating of lung fbrosis.