Protective effect of carnosol on lung injury induced by intestinal ischemia/reperfusion

Carnosol is a phenolic diterpene that has potent antioxidant and anti-inflammatory activities. The purpose of this study was to investigate the preconditioning effects of carnosol on lung injury induced by intestinal ischemia/reperfusion (II/R). Rats were divided into control, II/R, and carnosol groups. The II/R model was established by clamping the superior mesenteric artery for 1 h and reperfusion at 2, 4, and 6 h after ischemia. The carnosol group received 3 mg/kg carnosol intraperitoneally 1 h before the operation. The rats were then euthanized, and blood and lung specimens were obtained for analysis. The II/R induced lung injury, characterized by histological changes and significant increasing of bronchoalveolar lavage fluid protein. The activity of lung tissue superoxide was weakened, the tissue myeloperoxidase activity and serum interleukin-6 level increased significantly in II/R groups. A strong positive expression of lung intercellular adhesion molecule-1 (ICAM-1) and nuclear factor kappa B (NF-kappa B) were observed. Pretreatment with carnosol markedly reduced lung injury by increasing the tissue superoxide activity and decreasing the myeloperoxidase activity and interleukin-6 level, which was parallel to the decreased expression of ICAM-1 and NF-kappa B. Carnosol was able to ablate lung injury induced by II/R, partly attributed to the inhibition of NF-kappa B activation.