1 This study examines the activity of the antioxidant N-acetylcysteine on bleomycin-induced pulmonary fibrosis in rats with emphasis on the early inflammatory phase. 2 Rats receiving N-acetylcysteine (300 mg kg À1 day À1 , intraperitoneal) had less augmented lung wet weight, and lower levels of proteins, lactate dehydrogenase, neutrophil and macrophage counts in bronchoalveolar lavage fluid and lung myeloperoxidase activity with a betterment of histological score at 3 days postbleomycin. 3 A diminished lung GSH/GSSG ratio and augmented lipid hydroperoxides were observed 3 days postbleomycin. These changes were attenuated by N-acetylcysteine. Alveolar macrophages from bleomycin-exposed rats released augmented amounts of superoxide anion and nitric oxide. NAcetylcysteine did not modify superoxide anion generation but reduced the increased production of nitric oxide. 4 N-Acetylcysteine suppressed the bleomycin-induced increased activation of lung NF-kB (shift assay and immunohistochemistry), and decreased the augmented levels of the early inflammatory cytokines, tumour necrosis factor-a, interleukin-b, interleukin-6 and macrophage inflammatory protein-2 observed in bronchoalveolar lavage fluid at 1 and 3 days postbleomycin exposure. 5 At 15 days postbleomycin, N-acetylcysteine decreased collagen deposition in bleomycin-exposed rats (hydroxyproline content: 63517669 and 46267288 mg per lung in drug vehicle-and Nacetylcysteine-treated rats, respectively; Po0.05). Semiquantitative histological assessment at this stage showed less collagen deposition in N-acetylcysteine-treated rats compared to those receiving bleomycin alone. 6 These results indicate that N-acetylcysteine reduces the primary inflammatory events, thus preventing cellular damage and the subsequent development of pulmonary fibrosis in the bleomycin rat model.

Oral N-acetylcysteine attenuates the rat pulmonary inflammatory response to antigen. S. Blesa, J. Cortijo, M. Mata, A. Serrano, D. Closa, F. Santangelo, J.M. Estrela, J. Suchankova, E.J. Morcillo. #ERS Journals Ltd 2003. ABSTRACT: Oxidative stress is involved in the pathophysiology of inflammatory airway diseases including asthma; therefore, antioxidants might be of clinical benefit in asthma treatment. In the present study, the effects of N-acetylcysteine on sensitised brown Norway rats were examined.N-Acetylcysteine (3 mmol?kg body weight -1 administered orally) was given daily for 1 week before challenge and various antigen-induced pulmonary responses were studied.Antigen exposure increased lipid peroxidation in bronchoalveolar lavage fluid (BALF) and oxidised glutathione levels in lung tissue 2 h after challenge. Lung nuclear transcription factor-kB-binding activity was increased 2 h after challenge, and BALF tumour necrosis factor-a and inducible nitric oxide synthase expression in lungs peaked 4 h after challenge. Expression of intercellular adhesion molecule-1 and mucin MUC5AC was also increased 4 h after challenge. These changes in oxidant status, transcription factor activation, and inflammatory cytokine and gene expression were reduced by N-acetylcysteine. This thiol did not affect the immediate bronchospasm reaction to antigen in anaesthetised rats but inhibited airways hyperresponsiveness to 5-hydroxytryptamine and the augmented eosinophil numbers in BALF, which appear 24 h after exposure of conscious rats to antigen aerosol, and abolished antigen-induced extravasation of Evans blue into BALF.These results indicate that oral N-acetylcysteine exerts an antioxidant protective effect and attenuates pulmonary inflammation in experimental asthma.

Obesity has grown worldwide over the last few decades. In its different degrees, obesity is accompanied by many clinical and biochemical alterations reflecting the pathological condition of various body tissues. Among the mechanisms underlying the pathogenesis of obesity and associated complications, oxidative stress (OS) may be playing an important role. In the present study, we have characterized at systemic level the degree of OS status in a group of morbid obese patients (BMI>40 kg/m2) at basal sate and its modulation during one year after bariatric surgery using the laparoscopic sleeve gastrectomy (LSG) technique. As compared with normal weight subjects matched in age, peripheral blood mononuclear cells (PBMc) of obese patients present a significant reduction of the antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) as well as a significant increase of the oxidized/reduced glutathione ratio (GSSG/GSH) in these cells. Lipid peroxidation is significantly increased in the patient group as shown by the increased levels of malondialdehyde (MDA) in PBMc and the amount of F2-Isoprostanes (F2-IsoPs) released in urine. In addition, the DNA damage product 8-oxo-7,8-2′-deoxyguanosine (8-oxo-dG) was also observed to be increased in serum and urine of morbid obese patients as compared with the control group. After LSG, an improvement of their ponderal and metabolic profile was accompanied by a progressive recovery of antioxidant enzyme activities and the decline of oxidative byproducts both in PBMc and biological fluids. The observed changes of urinary 8-oxo-dG levels correlate positively with its serum concentration, the lipid peroxidation products MDA and F2-IsoPs, triglycerides, glucose, insulin, HOMA index and body weight and negatively with the percentage of weight and BMI loss and antioxidant activities. We conclude that the analysis of urinary 8-oxo-dG could be validated as a useful marker for the monitoring of ponderal and metabolic status of morbid obese patients.