The Effect of Aspirin on Pulmonary Fibrotic Lesions and Oxidative Stress Induced by Bleomycin in Pulmonary Tissue of Rat

Abstract

Background: Idiopathic pulmonary fibrosis is a chronic and inflammatory disease of lung which lead to formation of collagen in its tissue. Due to the inflammatory nature of fibrosis, this study aimed to evaluate the effectiveness of different doses of aspirin on bleomycin-induced pulmonary fibrosis. Methods: The current study were done on male adult Wistar rats whom were randomly divided into groups with 6 animals in each. Sham group, control group, bleomycin groups which respectively received 15 units/kg bleomycin intraperitoneally (IP) or 5 units/kg bleomycin by intratracheal instillation, and aspirin groups which respectively received 50, 100, or 150 mg/kg aspirin by gavage concomitant with the intraperitoneal bleomycin. The treatment of animals lasted 28 days; and then the lung tissue was removed for histological examination and measurement of hydroxyproline and malondialdehyde levels. Findings: The same as intratracheal instillation of bleomycin, its intraperitoneal injection caused a significant increase in hydroxyproline and malondialdehyde levels in rat lung tissue (P < 0.001). Administration of aspirin for 28 consecutive days significantly reduced the levels of hydroxyproline and malondialdehyde in bleomycin-induced pulmonary fibrotic rats (P < 0.001). In addition, it caused a significant improvement in histological factors indicating inflammation and fibrosis. There was no significant difference in fibrotic and inflammatory indexes between the studied doses of aspirin. Conclusion: Intraperitoneal injection of bleomycin caused pulmonary fibrosis in rat's pulmonary tissue the same as when bleomycin instilled intratracheally. Aspirin remarkably improved bleomycin-induced pulmonary fibrosis and oxidative stress. There was no difference in the effectiveness of the studied doses of aspirin. The exact involving mechanisms of aspirin and its effect in other doses need to be more investigated. © 2021 Isfahan University of Medical Sciences(IUMS). All rights reserved.