Protective Effect of Eucalyptus globulus Extracts Against Bleomycin-Induced Pulmonary Fibrosis in Rats

Pulmonary fibrosis (PF) is a fibrous interstitial pneumonia that causes damage to the lung tissue and thus alters all respiratory functions. In this study, we aim to investigate the therapeutic effects of fresh leaves of Eucalyptus globulus extracts on bleomycin (BLM)-induced (PF). Twenty-four rats were divided into four groups. The control group received no treatment, the BLM group received only intratracheally BLM (2 mg/kg), the essential water of Eucalyptus globulus (EWEG) group underwent administration of BLM followed by E. globulus hydrosol (2000 mg/kg), and the essential oil of Eucalyptus globulus (EOCG) group received BLM followed by E. globulus essential oil (10 mg/kg). Gas chromatography–mass spectrometry analysis showed that the main compounds of EOEG and EWEG are eucalyptol and spathulenol. Obtained results showed that BLM-induced PF caused a large accumulation of lymphocytes and monocytes in lung bronchoalveolar lavage fluid, a high fibrosis score, and an inflammatory index coupled to an oxidative stress state assessed by an increase in lipid peroxidation and depletion of the activities of antioxidant enzymes: superoxide dismutase and catalase. Otherwise, the treatment with EWEG and EOEG reversed the deleterious effects of reactive oxygen species and the inflammation raised by BLM. E. globulus extracts could improve BLM-induced PF, thus suggesting that the latter could serve as a potential therapeutic approach for PF.