ABSTRACT
ObjectiveTo investigate the effect of Bufeitang on intestinal flora of rats with lung Qi-deficiency syndrome of chronic obstructive pulmonary disease（COPD）， and to explore the mechanism of traditional Chinese medicine in regulating intestinal flora and thus restoring the balance of lung-gut axis. MethodA total of 84 rats were randomly divided into 7 groups， including blank group， model group， fecal bacterial transplantation（FMT） group， dexamethasone group and low， medium and high dose groups of Bufeitang， 12 rats in each group. Except for the blank group， cigarette and sawdust fumigation combined with intratracheal instillation of lipopolysaccharide（LPS） were used to establish the COPD rat model with lung Qi-deficiency syndrome in all other groups. The low， medium and high dose groups of Bufeitang were intragastric administrated with Bufeitang（3.645， 7.29， 14.58 g·kg-1）， the FMT group was given fecal bacteria liquid enema（10 mL·kg-1）， dexamethasone group was given dexamethasone acetate tablet suspension by gavage（0.135 mg·kg-1）， the blank group and model group were given equal amount of distilled water. Fresh feces were collected after 28 d of continuous intervention for 16S rRNA gene sequencing. Lung and colon tissues were stained with hematoxylin-eosin（HE） for pathomorphological observation， and enzyme-linked immunosorbent assay （ELISA） was performed to detect the contents of tumor necrosis factor-α（TNF-α） and interleukin-8（IL-8） in lung tissues. ResultCompared with the blank group， the model group showed severe abnormal lung tissue structure with alveolar atrophy and collapse accompanied by severe inflammatory cell infiltration. Compared with the model group， the extent of injury was significantly improved， and inflammatory cell infiltration was reduced with basically normal alveolar structure in the high dose group of Bufeitang. Compared with the blank group， the model group had severely abnormal colonic tissue structure， the epithelial cells in the mucosal layer were eroded and shed， the number of inflammatory cells increased， the submucosal layer was edematous and the gap was enlarged. Compared with the model group， the extent of damage was significantly improved in the medium and high dose groups of Bufeitang， the epithelial cells in the mucosal layer were neatly and closely arranged， with only a small amount of inflammatory cell infiltration and no significant degeneration. Compared with the blank group， the TNF-α and IL-8 levels of lung tissue in the model group were significantly increased（P<0.01）. Compared with the model group， the TNF-α and IL-8 levels of lung tissues in the low， medium and high dose groups of Bufeitang were significantly decreased（P<0.01）. Bufeitang significantly modulated the number of bacteria species as well as alpha and beta diversity of model rats， corrected the return of intestinal flora to normal abundance and diversity， and positively regulated 4 differential phyla（such as Firmicutes， Proteobacteria） and 13 differential genera（such as Turicibacter， Lactobacillus， Anaerobiospirillum， Intestinimonas） in COPD model rats with lung Qi-deficiency syndrome， and down-regulated 2 carbohydrate metabolic pathway functions， including the pentose phosphate pathway（non-oxidative branch） Ⅰ and the Calvin-Benson-Bassham cycle. ConclusionBufeitang can modulate the abundance and diversity of intestinal flora species， affect the function of metabolic pathways， repair the structure of lung and colon tissues， regulate the level of inflammatory factors， and thus improve COPD with lung Qi-deficiency syndrome. The mechanism may be related to its regulation of inflammation-related intestinal flora to restore the balance of lung-gut axis in COPD with lung Qi-deficiency syndrome.
ABSTRACT
ObjectiveTo investigate the mechanism of Gegen Qinliantang（GQT） on the intestinal flora of antibiotic-associated diarrhea（AAD） by 16S rRNA sequencing and network pharmacology. MethodSixty SD rats were randomly divided into six groups（n=10）， including blank group， model group， GQT high-， medium- and low-dose groups（10.08， 5.04， 2.52 g·kg-1） as well as Lizhu Changle group（0.15 g·kg-1）， except for the blank group， each group was given clindamycin（250 mg·kg-1） by gavage once a day for 7 consecutive days. After successful modeling， the blank group and the model group were given equal volumes of normal saline by gavage. The other groups were given corresponding doses of drugs by gavage for 14 days. Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform（TCMSP） was used to screen the active components and targets of GQT， GeneCards， Online Mendelian Inheritance in Man（OMIM） database， Pharmacogenetics and Pharmacogenomics Knowledge Base（PharmGKB）， DrugBank and DisGeNET were used to search for AAD disease targets. The drug-disease common targets were obtained by R software. STRING was applied to analyze the target protein-protein interaction， and Kyoto Encyclopedia of Genes and Genomes（KEGG） pathway enrichment analysis was performed. Then hematoxylin-eosin（HE） staining was used to observe the pathological changes of the colon， and 16S rRNA sequencing of AAD colon content flora structure further verified the results of network pharmacology. ResultThrough network pharmacology， it was found that 238 active components were screened from GQT and acted on 276 component targets， among which quercetin， puerarin， wogonin and apigenin were the main core components of GQT， 1 097 AAD disease targets and 127 drug-disease intersection targets. The protein-protein interaction network mainly included core targets such as protein kinase B1（Akt1）， interleukin（IL）-6 and IL-1β， which were mainly enriched in the IL-17 signaling pathway. It was verified through animal experiments that compared with the blank group， the colon structure of the model group was seriously abnormal， the intestinal epithelial columnar cells were damaged， the goblet cells were reduced， and a large number of inflammatory cells were infiltrated. Compared with the model group， the colon structure of the GQT high-dose group improved， but there were still abnormalities， the colon structure of GQT medium- and low- dose groups and Lizhu Changle group improved significantly and reached the normal level. GQT could improve the structural diversity of AAD intestinal flora. At the phylum level， the abundance of Firmicutes was increased and the abundance of Bacteroidetes was decreased. At the genus level， the abundance of Lactobacillus was increased， and the abundances of Prevotella and Bacteroides were decreased. Among them， Lactococcus could be used as a biomarker for AAD treatment with GQT， and the prediction of functional metabolism of intestinal flora revealed that GQT could promote acetate and lactate metabolic pathways in the intestine. ConclusionGQT may activate IL-17 signaling pathway by acting on the targets of Akt1 and IL-6 through key components such as quercetin and wogonin， and improve the abundance of Lactococcus in the intestinal tract as well as acetate and lactate metabolic pathways， so as to play a role in repairing the intestinal barrier for the treatment of AAD.