Protective Effect of Tunisian Flaxseed Oil against Bleomycin-Induced Pulmonary Fibrosis in Rats

The aims of this study are to investigate the preventive effect of flaxseed oil (FO) on bleomycin (BLM)-induced pulmonary fibrosis (PF). Thirty adult male Wistar rats (180-220 g) were randomly divided into three groups. The control group (G₁) received no treatment, the group (G₂) received only intratracheally BLM, and the group (G₃) received FO (2 mL/kg body weight) once a day for 60 days + BLM (4 mg/kg body weight "bw"). Our results demonstrated that FO protected against BLM-induced PF, by increasing proline, fructose, glucose, glyceride, choline, lactate, and malate metabolites in bronchoalveolar lavage fluid (Balf) which are involved in anti-inflammatory reactions. Also, FO-treatment reduced the score of fibrosis and the inflammatory index and revealed a decrease in tumor growth factor beta (TGFβ) density in alveoli, inflammatory infiltrate and fibrocytes, comparatively to the BLM group. As well, our data demonstrated that acute BLM-induced fibrosis was accompanied by an oxidative stress in lung tissue as assessed by an increase of lipid peroxidation as well as antioxidant enzyme activities depletion such as superoxide dismutase (SOD) and catalase (CAT). The FO treatment reversed all disturbances of BLM-induced oxidative stress parameters, and increased fatty acids levels promoting anti-inflammatory reactions especially in erythrocytes (linoleic, α-linolenic, docosapentaenoic acids).