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

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.

Mechanism of lung and intestine combination therapy in treatment of acute lung injury by inhibiting inflammatory response based on NF-κB/NLRP3 signaling pathway and alveolar macrophage activation / 中国中药杂志

Lung and intestine combination therapy(LICT) is effective in the treatment of acute lung injury(ALI). In this study, the combination of Mahuang Decoction and Dachengqi Decoction(hereinafter referred to as the combination), a manifestation of LICT, was employed to explore the effect of nuclear factor kappaB(NF-κB)/nucleotide binding oligomerization domain-like receptors-3(NLRP3) pathway and alveolar macrophage activation on the lung inflammation in rats with ALI, for the purpose of elucidating the mechanism of LICT in treating ALI. After the modeling of ALI with limpolysaccharide(LPS, ip), rats were respectively given(ig) the combination at 10, 7.5, and 5 g·kg~(-1)(high-dose, medium-dose, and low-dose LICT groups, separately), once every 8 h for 3 times. Haematoxylin-eosin(HE) staining was used to observe the histopathological changes of lung tissue, followed by the scoring of inflammation. Immunohistochemistry was applied to detect alveolar macrophage activation, enzyme-linked immunosorbent assay(ELISA) was applied to detect the serum content of tumor necrosis factor-α(TNF-α) and interleukin-18(IL-18), Western blot was applied to detect the protein expression of phosphorylated-nuclear factor kappaB p65(p-NF-κB p65), nuclear factor kappaB p65(NF-κB p65), phosphorylated-inhibitor kappaB alpha(p-IκBα), inhibitor kappaB alpha(IκBα), and NLRP3 in lung tissue, and quantitative reverse transcription-PCR(qRT-PCR) was applied to detect the mRNA expression of TNF-α, IL-18, NLRP3, and NF-κB p65 in lung tissue. The results showed that LICT groups demonstrated lung injury relief, decrease in inflammation score, alleviation of alveolar macrophage activation, significant decline in serum content of inflammatory factors TNF-α and IL-18, and decrease of the protein expression of p-NF-κB p65/NF-κB p65, p-IκBα/IκBα, and NLRP3, and mRNA expression of TNF-α, IL-18, NLRP3, and NF-κB p65 in lung tissue. In summary, LICT has definite therapeutic effect on ALI. The mechanism is that it inhibits alveolar macrophage activation by suppressing NF-κB/NLRP3 signaling pathway, thereby reducing the activation and release of inflammatory factors and finally inhibiting inflammation.