Effects of pirfenidone, vitamin E, and pirfenidone–vitamin E combination in paraquat-induced pulmonary fibrosis

Paraquat-induced pulmonary fibrosis is a progressive and fatal interstitial lung disease, a condition for that, there is no effective treatment and its prognosis is appalling. Since multiple coactivated pathways are involved, targeting these pathways using combination regimens is plausible for successful therapy. So, the aim of the present study was to evaluate the therapeutic efficacy of pirfenidone–vitamin E combination therapy in (paraquat) PQ-induced lung fibrosis model. After the development of PQ-induced lung fibrosis, pirfenidone, vitamin E, pirfenidone plus vitamin E, and water (as a vehicle) were orally administered for 14 consecutive days (From day 14 to day 28). The comparison of efficacies was performed by evaluating histopathology changes, hydroxyproline content, and oxidative stress. Either pirfenidone or vitamin E solely could recover the pathological changes of paraquat, decreased lipid peroxidation, and restored the antioxidant enzymes towards normal values. Hydroxyproline content was significantly reduced by both pirfenidone and vitamin E administration. Concurrent treatment with pirfenidone and vitamin E intensified all of these therapeutics effects indicating more potent antifibrotic and anti-inflammatory impacts. Therefore, pirfenidone plus vitamin E offers potential as a combination therapy for the treatment of paraquat-induced pulmonary fibrosis.