Combining Metagenomics, Network Pharmacology and RNA-Seq Strategies to Reveal the Therapeutic Effects and Mechanisms of Qingchang Wenzhong Decoction on Inflammatory Bowel Disease in Mice

Inflammatory bowel disease (IBD) is a chronic and recurrent inflammatory disease that lacks effective treatments. Qingchang Wenzhong Decoction (QCWZD) is a clinically effective herbal prescription that has been proven to attenuate intestinal inflammation in IBD. However, its molecular mechanism of action has not been clearly elucidated. We aimed to probe the mechanism of QCWZD for the treatment of IBD. The dextran sulfate sodium (DSS)-induced mouse model of IBD was used to identify the molecular targets involved in the mechanism of action of QCWZD. Metagenomics sequencing was utilized to analyze the differences in gut microbiota and the functional consequences of these changes. Network pharmacology combined with RNA sequencing (RNA-seq) were employed to predict the molecular targets and mechanism of action of QCWZD, and were validated through in vivo experiments. Our results demonstrated that QCWZD treatment alleviated intestinal inflammation and accelerated intestinal mucosal healing that involved restoration of microbial homeostasis. This hypothesis was supported by the results of bacterial metagenomics sequencing that showed attenuation of gut dysbiosis by QCWZD treatment, especially the depletion of the pathogenic bacterial genus , while increasing the beneficial microorganism that led to altered bacterial gene functions, such as metabolic regulation. Network pharmacology and RNA-seq analyses showed that Th17 cell differentiation plays an important role in QCWZD-based treatment of IBD. This was confirmed by in vivo experiments showing a marked decrease in the percentage of CD3 CD4 IL-17 (Th17) cells. Furthermore, our results also showed that the key factors associated with Th17 cell differentiation (IL-17, NF-κB, TNF-α and IL-6) in the colon were significantly reduced in QCWZD-treated colitis mice. QCWZD exerted beneficial effects in the treatment of IBD by modulating microbial homeostasis while inhibiting Th17 cell differentiation and its associated pathways, providing a novel and promising therapeutic strategy for the treatment of IBD.