Effect of Combined Therapy of Lung and Intestine on NF-κB Inflammatory Pathway and Macrophage Polarization in LPS-induced Acute Lung Injury Rats / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo investigate the effect of combined therapy of lung and intestine （Mahuangtang + Da Chengqitang） on lipopolysaccharide （LPS）-induced acute lung injury （ALI） in rats and its protective mechanism. MethodWistar rats were randomly divided into blank group， model group， low-， medium-， and high-dose groups with combined therapy of lung and intestine ， and dexamethasone group. LPS （10 mg·kg-1） was given （ip） to induce ALI in rats. The general state of rats in each group was observed and recorded. The body temperature of rats in each group was recorded 0-8 h after modeling by means of anal temperature measurement. Serum and lung tissues were collected 24 h after modeling. Serum levels of interleukin-1β （IL-1β）， tumor necrosis factor-α （TNF-α）， interleukin-10 （IL-10）， and arginase-1 （Arg-1） were determined by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the protein levels of nuclear factor kappa B p65 （NF-κB p65）， phosphorylated NF-κB p65 （p-NF-κB p65）， NF-κB inhibitor α （IκBα）， and phosphorylated IκBα （p-IκBα） in lung tissues of rats. The levels of classically activated （M1） macrophage marker CD80 and IL-1β and macrophage markers F4/80 and IL-10 were detected by double immunofluorescence. ResultCompared with the blank group， the model group showed increased body temperature and thermal response index （TRI）， elevated serum levels of pro-inflammatory factor TNF-α and IL-1β and anti-inflammatory factor IL-10 （P<0.01）， up-regulated protein levels of p-NF-κB p65 and p-IκBα in lung tissues （P<0.01）， and increased levels of F4/80， CD80， and IL-1β in lung tissues （P<0.01）. Compared with the model group， the lung-intestine combined treatment groups and the dexamethasone group exhibited decreased body temperature and TRI in rats （P<0.01）， declined serum levels of inflammatory factor TNF-α and IL-1β （P<0.05， P<0.01）， elevated serum levels of anti-inflammatory factor IL-10 and Arg-1 （P<0.05， P<0.01）， down-regulated protein levels of p-NF-κB p65 and p-IκBα in lung tissues （P<0.05， P<0.01）， decreased levels of CD80 and IL-1β， and increased levels of IL-10 in lung tissues （P<0.01）， while the level of F4/80 was not significantly changed. ConclusionThe combined therapy of lung and intestine can obviously alleviate the fever and inflammatory state of ALI rats， and the mechanism may be related to the inhibition of NF-κB inflammatory pathway and the polarization of lung tissue macrophages to anti-inflammatory phenotype.