[Effects of melatonin on anti-oxidative function of lung injury induced by lipopolysaccharide in rats and ICAM-1 expression].

ABSTRACT

AIM: To investigate the protective effect of melatonin (MT) on lung tissues during acute lung injury (ALI) in rats and its possible mechanism. METHODS: All rats were randomly divided into four groups control group, lipopolysaccharide (LPS) group, dexamethasone (DEX) and MT treatment group. Myeloperoxidase (MPO) activity, superoxide dismutase (SOD) activity and malonaldehyde (MDA) content of lung tissues were detected at 3, 6 and 12 h after intratracheal instillation in each group. In addition, the expression of intercellular adhesion molecule-1 (ICAM-1) were observed through immunohistochemistry staining in lung tissues. RESULTS: Compared with control group, SOD activity decreased significantly in LPS group (P < 0.01), but MPO activity,MDA content and the expression of ICAM-1 increased obviously (P < 0.01). The administration of MT and DEX mitigated above changes significantly (P < 0.05 or P < 0.01). CONCLUSION: MT possessed protective effect on lung tissues during ALI through scavenging free radicals and inhibiting the expression of ICAM-1 probably.