姜黄素对内毒素诱发的小鼠急性肺损伤的保护作用探讨

Protective effect of curcumin on acute lung injury induced by lipopolysaccharide in mice

目的观察姜黄素对脂多糖(LPS)诱导的小鼠急性肺损伤(ALI)的保护作用,并探讨其机制。方法 60只SPF级BALB/C雄性小鼠,随机分为A^F组,每组各10只。A组腹腔注射生理盐水4 m L/次,1次/d,共注射7d;B组先腹腔注射生理盐水4 m L/次,1次/d,连续注射7 d,第8天腹腔注射LPS 5 mg/kg;C组处理同B组,但在腹腔注射LPS前10~12 h每只小鼠先腹腔注射TLR-4/MD抗体50μg;D、E、F组分别腹腔注射姜黄素200、150、100mg/kg,1次/d,连续注射7 d,第8天腹腔注射1次LPS,剂量5 mg/kg。A组第8天、B^F组腹腔注射LPS后4~6h,于无菌条件下取小鼠肺组织和外周血。采用动态浊度法测血浆LPS水平。取各组小鼠肺组织标本行HE染色,光镜下观察肺组织病理变化。用RT-PCR法检测各组小鼠肺组织标本TLR4 mRNA表达。用Western-blot法检测各组小鼠肺组织标本TLR4蛋白表达。取各组小鼠肺组织标本行免疫组化染色,检测My D88及NF-κB表达。结果与A组相比,B组小鼠血浆LPS增高(P<0.01),肺组织呈ALI表现,且TLR4 mRNA及蛋白表达上调(P均<0.01),My D88及NF-κB表达上调(P均<0.01)。与B组相比,D、E、F组小鼠血浆LPS明显降低(P均<0.01),肺组织病理损伤程度下降,TLR4 mRNA及蛋白表达下调(P均<0.01),My D88及NF-κB表达下调(P均<0.01)。结论姜黄素对LPS诱导的小鼠急性肺损伤有保护作用,其主要机制可能与姜黄素抑制LPS-TLR4激活My D88-NF-κB信号转导通路有关。

Objective To observe the protective effect of curcumin on acute lung injury（ ALI） induced by lipopolysaccharide（ LPS） in mice and to investigate the mechanism. Methods Sixty BALB / C male mice in SPF grade were randomly divided into groups A,B,C,D,E and F,10 mice in each group. Mice in the groups A,B and C were daily injected with 4 m L normal saline intraperitoneally,once a day and for 7 d; after that,on day 8,mice in the group B were administered with 5 mg / kg LPS for once,and each mouse in the group C was injected with 50 μg TLR-4 / MD antibodies 10-12 h before being administered with 5 mg / kg LPS. In the group A,on day 8,the lung tissues and peripheral blood were obtained and in groups B-F,the lung tissues and peripheral blood were obtained 4-6 h after intraperitoneal injection of LPS under the sterile conditions. The peripheral blood plasma was separated to detect the plasma LPS levels. The lung tissue specimen in each group received HE staining,then we observed the pathology changes of the lung tissues. The TLR4 mRNA expression in the lung tissues of each group was detected by RT-PCR,and the TLR4 protein expression in the lung tissues of each group was detected by Western blotting. The specimens of lung tissues received immunohistochemical staining,and then we detected the expression of My D88 and NF-κB. Results Compared with group A,the plasma LPS was increased（ P〈0. 01）,lung tissue showed ALI,and TLR4 mRNA and protein expression,My D88 and NF-κB expression was up-regulated in the group B（ all P〈0. 01）. Compared with group B,the plasma LPS was significantly decreased（ all P〈0. 01）,the pathology damage of lung tissues declined,TLR4 mRNA and protein expression was down-regulated（ all P〈0. 01）,My D88 and NF-κB expression was down-regulated in the groups D,E and F（ all P〈0. 01）. Conclusion Curcumin has a protective effect on ALI induced by LPS in mice. The mechanism may be related to the inhibition of LPS-TLR4 combination and the activation of My D88-Nf-k B signal pathway.