Effects of curcumin on changes of Egr-1mRNA, IL-1β and TNF-α in paraquat-induced acute lung injury in rats

Abstract

Objective To observe the changes of early growth response factor-1 mRNA (Egr-1 mRNA),interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in rat with paraquat (PQ)-induced acute lung injury,and the potential protective effect of curcumin on this injury.Methods Adult male Sprague-Dauley (SD) rats were randomly (random number) divided into control,PQ-poisoning and curcumin-intervention groups.At 3 h,6 h,24 h,3 d,7 d after treatment,each group respectively further divided into 5 subgroups.Rats in PQ-poisoning group were intraperitoneally (IP) administered with PQ 15 mg/kg,and rats in cureumin-intervention group were administered with PQ 15 mg/kg IP at 15 min after curcumin 200 mg/kg IP.Rats in control group were given normal saline (NS) 1 mL IP instead.The expression of Egr-1 mRNA in lungs tissue were measured with Fluorescence real-time quantitative PCR device.The levels of IL-1β and TNF-α in bronchoalveolar lavage fluid (BALF) were measured with enzyme-hnked immunosorbent assay (ELISA).Pathological changes in lung were observed under light microscope.Experimental data were treated with single-factor analysis of variance and compared between groups with Bonferroni method.Results Compared with the control group,Egr-1 mRNA expression in lungs tissue and TNF-α level in BALF in PQ-poisoning group and curcumin-intervention group,IL-1β level in BALF in PQ-poisoning group increased significantly at 6 h,24 h,3 d,7 d after PQ exposure (P ＜ 0.05 or P ＜ 0.01),and IL-1β level in BALF increased significantly at 24 h after PQ exposure in curcuminintervention group (P ＜ 0.05).Compared with the PQ-poisoning group,Egr-1 mRNA expression in lungs tissue,TNF-α and IL-1 β level in BALF decreased significantly at 24 h,3 d,7 d after PQ exposure in curcumin-intervention group (P ＜ 0.05 or P ＜ 0.01).Pathological changes of lung tissue were more serious in PQ-poisoning group than those in curcumin-intervention group.Conclusions The up-regulated expression of Egr-1 mRNA increased releasing ofIL-1β and TNF-α,and initiating inflammation may be one of the mechanism of PQ-induced acute lung injury in rats.Curcumin may have beneficial protective effects on lung in this above described pathway of signaling. Key words: Paraquat ; Early growth response factor-1 mRNA ; Interleukin-1β ; Tumor necrosis factor-α; Lung injury; Curcumin; Poison; Rat