Effect of curcumin on heme oxygenase-1 expression in the lung of rats treated with LPS

AIM: To study the regulatory effect of curcumin on expression of heme oxygenase-1 (HO-1) in the lung of rat treated with LPS. METHODS: Eighteen rats were divided into three groups injected with different agents via lingua vein: control group (animals received equivalent saline), LPS group (animals received a bolus dose of LPS 5 mg·0.5 mL-1·kg-1) and LPS+curcumin group (animals received AP-1 inhibitor curcumin 20 mg·0.5 mL-1·kg-1 20 min before the injection of LPS 5 mg·0.5 mL-1·kg-1). The expression of HO-1 mRNA and protein in the lung were examined 7 h after LPS administration by reverse transcribed polymerase chain reaction (RT-PCR) and Western blotting, respectively. Carboxyhemoglobin (HbCO) formation within pulmonary tissue was measured to represent CO content. RESULTS: The results showed that HO-1 mRNA and protein expression as well as CO content in the lung of rats in LPS group were significantly higher than those in control group (P<0.01), while the parameters mentioned above in LPS+curcumin group were markedly lower than that in LPS group. CONCLUSION: The increased HO-1 expression in the lung of rat induced by LPS may be regulated by activating AP-1.