Aerosolized Administration of N-Acetylcysteine Attenuates Lung Fibrosis Induced by Bleomycin in Mice

Abstract

Reactive oxygen species (ROS) play an important role in the pathogenesis of pulmonary fibrosis. We previously demonstrated that N-acetylcysteine (NAC), an antioxidant, inhibited adhesion molecule expression and cytokine production in lung cells. When NAC is inhaled into the alveolar space, it is expected to directly interact with inflammatory cells and to elevate glutathione levels in the epithelial lining fluids. We therefore examined whether inhaled NAC inhibits lung fibrosis induced by bleomycin (BLM). Male ICR mice were given a single intravenous injection of BLM (150 mg/ kg). Thirty milliliters of NAC (70 mg/ml) or saline were inhaled twice a day for 28 d using an ultrasonic nebulizer. In the inflammatory phase (Day 7), NAC administration attenuated the cellular infiltration in both bronchoalveolar lavage fluid (BALF) and alveolar tissues. At Day 28, the fibrotic changes estimated by Aschroft's criteria and hydroxyproline content in the NAC inhalation group were significantly decreased compared with the BLM-only group (p < 0.05). CXC chemokines, macrophage inflammatory protein-2 (MIP-2), cytokine-induced neutrophil chemoattractant (KC), and CC chemokines, macrophage inflammatory protein-1alpha (MIP-1alpha), in BALF were mostly elevated on Day 7 in the BLM-only group; however, these elevations were significantly repressed by NAC inhalation (p < 0.05). Lipid hydroperoxide (LPO) was also quantified in BALF. LPO was markedly increased on Day 3 in the BLM-only group, and this increase was significantly decreased by NAC inhalation (p < 0.05). These results revealed that aerosolized NAC ameliorated acute pulmonary inflammation induced by BLM injection via the repression of chemokines and LPO production, resulting in the attenuation of subsequent lung fibrosis. These findings are limited to the BLM-induced lung fibrosis animal model. However, NAC inhalation will be expected to be a potential therapy for patients with other interstitial pneumonias because ROS are involved in the pathogenesis of lung injury in most interstitial pneumonia.

α‐melanocyte–stimulating hormone suppresses bleomycin‐induced collagen synthesis and reduces tissue fibrosis in a mouse model of scleroderma: Melanocortin peptides as a novel treatment strategy for scleroderma?

“…Increased ROS production has also been detected in lung phagocytes and type II alveolar epithelial cells in BLM-induced lung fibrosis in the rat (36). N-acetylcysteine administered intraperitoneally or as an aerosol attenuated BLMinduced lung fibrosis in rats and mice (37,38).…”

Long-Term Administration of a Small Molecular Weight Catalytic Metalloporphyrin Antioxidant AEOL 10150 Protects Lungs From Radiation-Induced Injury

“…Inflammatory cells are a known source of ROS [43,44]. They also release inflammatory and fibrogenic cytokines [45].…”

The bleomycin animal model: A useful tool to investigate treatment options for idiopathic pulmonary fibrosis?

“…J. Wang, Giri, Hyde, Nakashima, & Javadi, 1990), Taurin (Blaisdell & Giri, 1995;Gurujeyalakshmi, Hollinger, & Giri, 1998;Gurujeyalakshmi, Iyer, Hollinger, & Giri, 1996;Gurujeyalakshmi, Wang, & Giri, 2000;Q. J. Wang, Giri, Hyde, & Nakashima, 1989), N-Acetylcysteine (Cortijo et al, 2001;Hagiwara, Ishii, & Kitamura, 2000;Mata et al, 2003;Serrano-Mollar et al, 2003;Shahzeidi, Sarnstrand, Jeffery, McAnulty, & Laurent, 1991;Yildirim et al, 2005), Vitamin E (Kilinc et al, 1993), Curcumin (Punithavathi, Venkatesan, & Babu, 2000), Aminoguanidine (X. L. Chen, Huang, Li, Wang, & Wang, 2001; X. L. Chen, Li, Zhou, Ai, & Huang, 2003;de Rezende, Martinez, Capelozzi, Simoes, & Beppu, 2000;Giri, Biring, Nguyen, Wang, & Hyde, 2002;Hu, Xu, & Li, 1999;Yildirim et al, 2004), Melatonin (Arslan, Zerin, Vural, & Coskun, 2002;Genovese, Di Paola et al, 2005;Yildirim et al, 2006), Bilirubin (H. D. , CAPE = caffeic acid phenethyl ester , Erdosteine (Boyaci et al, 2006;Sogut et al, 2004;Yildirim et al, 2005;Yildirim et al, 2004) etc. ), Angiotensin converting enzyme inhibitors (Captopril (R. Wang, Ibarra-Sunga, Verlinski, Pick, & Uhal, 2000), Ramipril (Marshall et al, 2004) etc.…”