Effect of curcumin on phosphorylation of TAK1 during endotoxin-induced lung injury in rats

Abstract

Objective To evaluate the effect of curcumin on the phosphorylation of transforming growth factor-β-activated kinase 1 (TAK1) during endotoxin-induced lung injury in rats. Methods Eighteen pathogen-free healthy male Sprague-Dawley rats, weighing 180-220 g, were divided into 3 groups (n=6 each) using a random number table: control group (group C), lung injury group (group LI) and curcumin group (group CUR). Lung injury was induced by intra-tracheal instillation of lipopolysaccharide 5 mg/kg in 1 ml of normal saline in LI and CUR groups.Curcumin 200 mg/kg was injected intraperitoneally at 30 min before establishment of the model in group CUR, while the equal volume of dimethyl sulfoxide was given instead in group LI.The rats were sacrificed at 12 h after administration of lipopolysaccharide or normal saline, and lungs were removed for determination of the expression of TAK1 and phosphorylated TAK1 (p-TAK1) in lung tissues.The right upper lobe of the lung was removed for determination of wet/dry weight ratio (W/D ratio). Results Compared with group C, the W/D ratio was significantly increased, and the expression of TAK1 and p-TAK1 was up-regulated in group LI (P<0.05). Compared with group LI, the W/D ratio was significantly decreased, and the expression of TAK1 and p-TAK1 was down-regulated in group CUR (P<0.05). Conclusion The mechanism by which curcumin attenuates endotoxin-induced lung injury is related to inhibition of the phosphorylation of TAK1 in lung tissues of rats. Key words: Curcumin; Endotoxemia; Respiratory distress syndrome, adult; Transforming growth factor beta