Diosmin ameliorative effects on oxidative stress and fibrosis in paraquat-induced lung injury in mice.

Paraquat (PQ) induces pulmonary fibrosis, a progressive lung disorder resulting in severe respiratory failure and death. Increased oxidative stress, inflammatory reactions, and multiple fibrotic lesions are major features of PQ-induced lung injury. Diosmin (Dio) is a safe drug that is available for clinical use for vascular disorders. Dio exhibits antioxidant, anti-inflammatory, and antifibrotic activities. Accordingly, the aim of this study was to evaluate the protective effect of diosmin on PQ-induced lung injury in mice and the underlying mechanisms involved. Lung injury was induced by PQ (30 mg/kg, intraperitoneally) in NMRI albino mice and Dio (50 and 100 mg/kg, gavage) was administrated 3 days before PQ and continued for 10 or 24 days. After euthanizing the mice, the biochemical and histopathological markers of lung tissue were determined. PQ significantly increased oxidative stress, inflammatory, and fibrotic markers. PQ increased the level of malonedaldehyde (MDA) and hydroxyproline (HYP) and decreased the level of glutathione (GSH) and catalase activity in the lung. Dio (50 and 100 mg/kg) significantly increased GSH levels and catalase activity and decreased HYP content and MDA levels. In addition, Dio reduced histopathological injuries in hematoxylin and eosin-stained and Masson's trichrome-stained sections. These findings suggest that Dio has protective effects against PQ-induced lung injury, which may be due to its antioxidant, anti-inflammatory, and antifibrotic effects.