Objective: to investigate whether pirfenidone (PFD) presents the antifibrotic effect in silicosis of rats.
Methods: SD rats were randomly divided into five groups: the non-treat group, the normal saline group, the normal saline + PFD group, the SiO2 group, the SiO2 + PFD group. Rats except in the non-treat group were intratracheally instilled with SiO2 (25 mg/ml) or normal saline. The rats in normal saline + PFD group and the SiO2 + PFD group were given PFD (50 mg/kg) orally the next day after instillation and throughout the study. Rats were respectively sacrificed 7, 21, 42 days after instillation. The pathology changes were evaluated by Haematoxylin-eosin (HE), Van Gieson and Foot staining, and the hydroxyproline (HYP) content of pulmonary tissue was determined.
Results: compared with the SiO2 group, PFD could relieve the fibrotic changes in the lungs of rats. The fibrotic degree in silicotic lesions of lungs was lower in the SiO2 + PFD group than that of SiO2 group. The HYP content in the lungs of the SiO2 + PFD group [(0.75 ± 0.12) mg/g] was significantly lower than that of the SiO2 group [(1.19 ± 0.17) mg/g] at 42 days after instillation (P < 0.05).
Conclusion: these data support that PFD has an antifibrotic effect against SiO2 induced lung fibrosis in rats, Which appears to be changing collagen accumulation and inhibiting pulmonary fibrosis.