Antagonistic effect of bilirulin on acute lung injury induced by LPS in rats

AIM: To investigate the effect of bilirubin on acute lung injury (ALI) and the mechanism. METHODS: 30 male Wistar rats were divided into normal group, ALI group and bilirubin treatment group. Lung specimens were examined by histopathological technique. Lung index (LI) and lung permeability index (LPI) were measured. Moreover, white blood cell (WBC) count, neutrophil percentage (PMN%) and the content of protein (Pr) in the bronchoalveolar lavage fluid (BALF), as well as the contents of superoxide dismutase (SOD), malonaldehyde (MDA) and glutathione peroxidase (GSH-Px) in the lung homogenate were determined. RESULTS: (1) In ALI group: LI, WBC count, PMN%, Pr and LPI increased significantly compared with normal group (P<0.01). In bilirubin treatment group, all the values determined decreased compared with ALI group (P<0.01; P<0.05). No notable discrepancy between bilirubin treatment group and normal group (P>0.05) was observed. (2) In ALI group, the content of MDA was significantly higher (P<0.01), but the contents of SOD and GSH-Px were significantly lower than those in normal group (P<0.01). In bilirubin treatment group, the content of MDA decreased significantly (P<0.01) but the contents of SOD and GSH-Px increased significantly (P<0.01; P<0.05) compared with ALI group. No notable discrepancy between bilirubin treatment group and normal group was observed (P>0.05). CONCLUSION: Bilirubin relieves ALI induced by LPS in rats via antioxidation.