Herbal formula Jiawei Xiaochengqi decoction prevents postoperative abdominal adhesion in a rat model through inhibition of CXCL2-CXCR2 pathway

Postoperative abdominal adhesion (PAA) is the most common complication after abdominal surgeries, which can lead to intestinal obstruction, chronic abdominal pain or female infertility. Jiawei Xiaochengqi decoction (JWXCQ) is a hospital preparation widely used for PAA treatment in Nanfang Hospital of Southern Medical University for more than twenty years.This study aimed to investigate the therapeutic effects and potential mechanism of JWXCQ against PAA and provide beneficial information for its clinical application.The main active components of JWXCQ were identified using ultra high performance liquid chromatography (UHPLC) combined with standard substance comparison. The efficacy and underlying mechanism of JWXCQ were evaluated through in vivo experiments with a postsurgical-induced peritoneal adhesion rat model, and in vitro studies with LPS-stimulated Raw 264.7 macrophages and primary fibroblasts. H&E and Masson staining were performed to assess histopathological changes. The levels of cytokines/proteins-associated with inflammation and degradation of extracellular matrix as well as CXCL2-CXCR2 pathway-related proteins were determined by ELISA, qRT-PCR, western blot assays or immunohistochemistry, respectively. Furthermore, siCXCR2 transfection was used to validate the mechanism of action of JWXCQ.JWXCQ treatment significantly reduced the formation of PAA, inhibited the inflammation and collagen deposition, and facilitated the secretion of MMP9, decreased the levels of IL-1β, IL-6, TIMP1, COL-1, and suppressed the CXCL2-CXCR2 pathway in PAA rats. Furthermore, JWXCQ inhibited its downstream pathways, the JAK2-STAT3 and PI3K-AKT signaling, as indicated by the suppression of the phosphorylation levels of STAT3 and AKT. In vitro cell experiments revealed that JWXCQ reduced IL-1β and IL-6 secretion in Raw 264.7 macrophages and COL-1 in primary fibroblasts. The CXCL2-CXCR2, JAK2-STAT3 and PI3K-AKT pathways were also inhibited after JWXCQ treatment, which were consistent with the in vivo results. More importantly, silence of CXCR2 eliminated the regulatory effects of JWXCQ.JWXCQ could effectively prevent the PAA formation by alleviating inflammation and collagen deposition, which was associated with the inhibition of CXCL2-CXCR2 pathway. This study investigated the relevant pharmacological mechanisms of JWXCQ, providing further evidence for the application of JWXCQ in clinical PAA treatment.