Combined Therapy of Lung and Intestine in Treatment of Lung Diseases： A Review / 中国实验方剂学杂志

The theoretical origin of the combined therapy of lung and intestine can be traced back to the Inner Canon of Huangdi （《黄帝内经》）， which explains the physiological and pathological interaction between the lung and the large intestine. In recent years， researchers have investigated the scientific essence of the "lung-intestine axis" theory from many aspects， which enriches the relevant theoretical basis， and applied it to the treatment of COVID-19， acute lung injury， and other lung diseases. The close relation between lung and intestine in many aspects embodies the holistic conception of traditional Chinese medicine and explains the holistic theory of interrelation between organs， which correlate to each other physiologically and pathologically. Intestinal microecological disorders can affect lung immune function and cause respiratory diseases， and respiratory diseases are usually accompanied by gastrointestinal symptoms. Lung diseases can be prevented and treated by regulating intestinal flora. According to histoembryology， the epithelial tissue of the lung and intestine comes from primitive foregut. In immunology， both lung and intestine contain mucosa-associated lymphoid tissue， and the pathological changes of the respiratory tract are also closely related to intestinal microorganisms. The tissue origin of lung and large intestine， the correlation of mucosal immunity， and the synchronization of ecological changes provide a scientific basis for the combined therapy of lung and intestine. Therefore， this paper summarizes the theoretical origin， modern research mechanism， and clinical application of combined therapy of lung and intestine， in order to provide a new direction for its application in clinical and scientific research.

Effect of Combined Therapy of Lung and Intestine on VIP and p38 MAPK Signaling Pathways in Bronchial Asthma Mice / 中国实验方剂学杂志

ObjectiveTo observe the therapeutic effects of the combined therapy of lung and intestine， a common treatment for pulmonary diseases in traditional Chinese medicine （TCM）， on bronchial asthma mice， and further detect the changes of vasoactive intestinal peptide （VIP） and p38 mitogen-activated protein kinase （p38 MAPK） signaling pathway-related proteins which are closely related to the pathogenesis of asthma， in order to elucidate the mechanism of the combined therapy of lung and intestine in the treatment of bronchial asthma. MethodA total of 60 Kunming mice were randomly divided into normal group， model group， dexamethasone group （0.5 mg·kg-1·d-1）， TCM group （2.73 g·kg-1·d-1）， and lung-intestine treatment group （6.825 g·kg-1·d-1）， 12 mice in each group. All mice except the normal group were sensitized by ovalbumin to induce bronchial asthma. After 30 days of intragastric administration， serum and lung tissue samples were obtained. The content of VIP， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α） in the serum of mice in each group was detected by enzyme-linked immunosorbent assay （ELISA）. The mRNA levels of TNF-α， IL-6， and p38 MAPK in lung tissues of mice were detected by real-time quantitative polymerase chain reaction （Real-time PCR）， and the protein levels of TNF-α， IL-6， p38 MAPK， and phosphorylated p38 MAPK （p-p38 MAPK） in lung tissues of mice were assayed by Western blot （WB）. ResultCompared with the normal group， the model group showed decreased content of serum VIP （P<0.05）， increased content of TNF-α and IL-6 （P<0.05）， up-regulated mRNA levels of TNF-α， IL-6， and p38 MAPK， and elevated protein levels of TNF-α， IL-6， and p-p38 MAPK/p38 MAPK in lung tissues （P<0.05）. Compared with the model group， the treatment groups exhibited increased content of serum VIP， TNF-α， and IL-6 （P<0.05）， down-regulated mRNA levels of TNF-α， IL-6， and p38 MAPK， and lower protein levels of TNF-α， IL-6， and p-p38 MAPK/p38 MAPK in lung tissues （P<0.05）. As compared with the lung-intestine treatment group， the serum TNF-α and IL-6 levels in the dexamethasone group were increased （P<0.05）， and the mRNA and protein levels of TNF-α and IL-6 in lung tissues were down-regulated （P<0.05）， while the levels of p38 MAPK， VIP mRNA， and p-p38 MAPK/p38 MAPK protein in lung tissues were up-regulated （P<0.05）. The serum VIP， TNF-α， and IL-6 levels in the TCM group were decreased （P<0.05）， and the mRNA levels of TNF-α， IL-6， p38 MAPK and protein levels of TNF-α， IL-6， p-p38 MAPK/p38 MAPK in lung tissues were up-regulated （P<0.05）， while the level of VIP mRNA in lung tissues was down-regulated （P<0.05）. ConclusionThrough increasing endogenous VIP and inhibiting the excessive activation of p38 MAPK signaling pathway， the combined therapy of lung and intestine can reduce the release of inflammatory factors， inhibit pulmonary inflammation response， and treat bronchial asthma.

Mechanism of Combined Therapy of Lung and Intestine in Alleviating Pulmonary Edema in Treatment of Acute Lung Injury Based on VIP/cAMP/PKA/AQPs Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the mechanism of the combined therapy of lung and intestine （Mahuangtang + Da Chengqitang） in alleviating pulmonary edema in rats with acute lung injury （ALI） induced by lipopolysaccharide （LPS）. MethodWistar rats were randomly divided into blank group， model group， low-， medium-， and high-dose groups with combined therapy of lung and intestine， and positive control group. LPS （10 mg·kg-1） was given （ip） to induce ALI in rats. After modeling， the blank group was given normal saline （25 mL·kg-1）， the combined therapy of lung and intestine treatment groups were given （ig） low- （5 g·kg-1）， medium- （7.5 g·kg-1）， and high-dose （10 g·kg-1） Mahuangtang and Da Chengqitang， and the positive control group was given dexamethasone （5 mg·kg-1）. Medications were administered 0， 8， and 16 h after LPS injection for 3 times. Then lung tissue and serum were collected after administration. The lung tissues were stained with haematoxylin-eosin （HE）， and the pulmonary edema score was evaluated. The dry/wet （D/W） weight ratio of lung tissues in each group was measured， and the content of serum vasoactive intestinal peptide （VIP） in rats was detected by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the protein levels of aquaporin-1 （AQP1）， AQP5， VIP， cyclic adenosine monophosphate （cAMP）， phosphorylated protein kinase A （p-PKA）， and PKA in lung tissues of rats in each group. The level of VIP mRNA in lung tissues of rats was detected by real-time quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the blank group， the model group exhibited obvious lung injury， increased edema score， decreased D/W ratio （P<0.01）， declined AQP1， AQP5， cAMP， and p-PKA/PKA in lung tissues （P<0.05， P<0.01）， elevated VIP content （P<0.01）， and up-regulated levels of VIP protein and mRNA in lung tissues （P<0.05， P<0.01）. Compared with the model group， combined therapy of lung and intestine treatment groups showed alleviated lung injury， increased D/W ratio （P<0.01）， elevated AQP1， AQP5， VIP， cAMP， and p-PKA/PKA in lung tissues （P<0.05， P<0.01）， and up-regulated VIP levels in lung tissues （P<0.05， P<0.01）. ConclusionThe combined therapy of lung and intestine can alleviate ALI-induced lung tissue edema， and the mechanism may be related to the activation of the VIP/cAMP/PKA signaling pathway， which further promotes the expression of AQP1 and AQP5 and enhances the water metabolism of lung tissue.

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.