Explore The Scientific Connotation Of Kuqin “Good Clearing Lung Heat” Based On Intestinal Flora

Objective: Taking Scutellaria Baicalensis as the research object,based on the great difference in the clinical action direction of two traditional commercial specifications of Kuqin(KQ)and Ziqin(ZQ),we used modern efficacy evaluation methods to evaluate the difference in the therapeutic effect of two traditional commercial specifications of Scutellaria Baicalensis,and to verify the “drug targeting” of KQ on lung diseases.Combined with the research of metabolomics and intestinal flora,the modern scientific connotation of the traditional targeted drug of KQ “clearing the lung heat” is explained,which provides modern scientific basis for the classic theory of ancient Chinese medical books.Methods: 1.High performance liquid chromatography(HPLC)was used to evaluate the quality of the extracts of ZQ and KQ.2.Male C57BL/6 mice were divided into normal group(NC group),lipopolysaccharide(LPS)-induced acute lung injury group(ALI group),dexamethasone treatment group(DEX group),ZQ treatment group(ZQ group),and Kuqin treatment group(KQ group).The mice in each group were treated with normal saline,low dexamethasone injection,ZQ extract and KQ extract for 7 days,and then intratracheally instillation of lipopolysaccharide(LPS)was used to establish the Acute lung injury(ALI)mouse model.The therapeutic effects of KQ and ZQ extract were evaluated.3.The basic morphological differences were evaluated by lung dry/wet weight,organ index,and H&E staining.The levels of inflammatory factors in bronchoalveolar lavage fluid(BALF)were measured by Enzyme linked immunosorbent assay(ELISA).4.UPLC-Q-TOF-MS non-target metabolomics method was used to determine the differential metabolites in mouse plasma.5.16 S r RNA sequencing and gas chromatography-mass spectrometry were used to analyze the changes in the structure of the microbiota and the level of Short-chain fatty acid(SCFAs)in feces.6.To verify the therapeutic effect of the key strain Akkermansia muciniphila(AKK)on ALI mice by eliminating endogenous microbes in mice with mixed Antibiotic(ABX)treatment.Real-time PCR and immunofluorescence staining were used to verify the expression level of Indoleamine2,3-dioxygenase 1(IDO1).Results: 1.The difference of curative effect between ZQ and KQ: compared with the normal group,ALI mice had severe pulmonary edema and decreased immune function,and the levels of inflammatory factors in the body were also significantly increased(p<0.01),and the levels of anti-inflammatory factors were significantly decreased(p<0.01).Compared with ZQ,KQ can better improve ALI induced pulmonary edema,balance immunity and reduce inflammatory factor storm in mice.2.Plasma metabonomics study: there were 13 metabolites involved in the KQ intervention group,which mainly played a role in regulating linoleic acid metabolism and tryptophan metabolism.Compared with the ALI group,KQ intervention could significantly reduce the activity of IDO1(Kyn/Trp)(p<0.01),but there was no significant difference between ZQ group and ALI group;3.The study of intestinal flora: Compared with the normal group,the abundance of intestinal flora in ALI mice was significantly decreased(p<0.05),and the ratio of Firmicutes to Bacteroidetes was down-regulated(p<0.05),the content of short-chain fatty acids was significantly reduced(p<0.05).After KQ treatment,the richness of intestinal flora in ALI mice was increased,the relative content ratio of Firmicutes to Bacteroidetes and the content of short-chain fatty acids were significantly increased(p<0.05).The relative abundance of beneficial bacteria AKK was significantly increased(p<0.05).4.Functional verification of key strains: two forms of AKK(live bacteria group and inactivated group)could improve pulmonary edema,organ damage,and systemic inflammation in mice(p<0.05).The efficacy of the live bacteria group was better than that of the inactivated group(p<0.05).Flow cytometry analysis showed that the accumulation of CD8+T lymphocytes in the two forms of AKK groups was significantly increased(p<0.05),and CD4+T lymphocytes and CD4+/CD8+ ratio were significantly decreased(p<0.05).Real-time quantitative PCR and immunofluorescence staining showed that the expression activity of IDO1 was significantly up-regulated in ALI mice(p<0.05),and the two forms of AKK could significantly reverse this trend(p<0.05).Conclusions: LPS-induced acute lung injury can destroy intestinal homeostasis to a certain extent.KQ can regulate the tryptophan metabolism pathway by increasing the abundance of beneficial bacteria Akkermansia mucophila in the intestine and inhibiting the expression of the key enzyme of tryptophan metabolism IDO1 in the lung tissue to maintain immune homeostasis and alleviate lung inflammation in mice.