RESUMO
Postinfectious irritable bowel syndrome (PI-IBS) is a highly prevalent gastrointestinal disorder associated with immune dysregulation and depression- and anxiety-like behaviors. Through traditional medicine, the active ingredient of Paeoniae Radix called paeoniflorin (PF) was previously found to prevent the symptoms of PI-IBS. However, there is limited information on the effects of PF on intestinal function and depression- and anxiety-like symptoms in PI-IBS animal models. Here, we aimed to determine the effects of PF treatment on the symptoms of PI-IBS in a rat model. The PI-IBS rat model was established via early postnatal sibling deprivation (EPSD), trinitrobenzenesulfonic acid (TNBS), and chronic unpredictable mild stress (CUMS) stimulation and then treated with different dosages of PF (10, 20, and 40 mg/kg) and leptin (1 and 10 mg/kg). The fecal water content and body weight were measured to evaluate the intestinal function, while the two-bottle test for sucrose intake, open field test (OFT), and elevated plus maze test (EMT) were performed to assess behavioral changes. The serum leptin levels were also measured using an enzyme-linked immunosorbent assay. Furthermore, the expressions of leptin and its receptor, LepRb, were detected in colonic mucosal tissues through an immunohistochemical assay. The activation of the PI3K/AKT signaling pathway and the expression of brain-derived neurotrophic factor (BDNF) were also detected via western blotting. After the experimental period, the PI-IBS rats presented decreased body weight and increased fecal water content, which coincided with elevated leptin levels and heightened depression- and anxiety-like behaviors (e.g., low sucrose intake, less frequency in the center areas during OFT, and fewer activities in the open arms during EMT). However, the PF treatment ameliorated these observed symptoms. Furthermore, PF not only inhibited leptin/LepRb expression but also reduced the PI3K/AKT phosphorylation and BDNF expression in PI-IBS rats. Notably, cotreatment with leptin (10 mg/kg) reduced the effects of PF (20 mg/kg) on colonic fibrosis, leptin/LepRb expression, and PI3K/AKT activation. Therefore, our findings suggest that leptin is targeted by PF via the leptin/LepRb pathway, consequently ameliorating the symptoms of PI-IBS. Our study also contributes novel insights for elucidating the pharmacological action of PF on gastrointestinal disorders and may be used for the clinical treatment of PI-IBS in the future.
RESUMO
Network pharmacology and liver fibrosis(LF) model in vitro were used to analyze the underly mechanism of anti-liver fibrosis effect that induced by Piperis Longi Fructus and its major active compounds. TCMSP and TCMIP were used to search for the chemical constituents of Piperis Longi Fructus, as well as the oral bioavailability(OB), drug-likeness(DL), intercellular permeability of intestinal epithelial cells(Caco-2) and Drug-likeness grading were set as limiting conditions. The related target genes of Piperis Longi Fructus were queried by TCMSP database, while related targets of LF were screened by GeneCards databases. Interaction network was constructed using Cytoscape 3.7.1. These above data were imported into STRING database for PPI network analysis. Enrichment of gene ontology(GO) and pathway analysis(KEGG) within Bioconductor database were utilized to note functions of related targets of Piperis Longi Fructus. Finally, the core targets and pathways were preliminarily verified by in vitro experiments. The effects of piperlongumine(PL), the major active component of Piperis Longi Fructus, on proliferation of rat liver stellate cells(HSC-T6) and expression of α smooth muscle actin(α-SMA) and collagen â were investigated. The major factors TNF-α of tumor necrosis factor(TNF) pathway and NF-κB p65, IL-6 protein expressions of LF process were examined. A total of 12 active compounds such as PL were obtained by analyzing the bioavailability and drug-like properties, which inferred to 48 targets. The functional enrichment analysis of GO obtained 1 240 GO items, mainly involving in process of biology and molecular function. A total of 99 signaling pathways were enriched in the KEGG pathway enrichment analysis, including TNF signaling pathway, cGMP-PKG signaling pathway, calcium signaling pathways. CCK-8 assay showed that PL inhibited proliferation of HSC-T6 induced by transforming growth factor-ß1(TGF-ß1). Western blot analysis found that treated with PL suppressed the protein expressions of α-SMA, collagen â , TNF-α and p65 in HSC-T6. Enzyme linked immunosorbent assay(ELISA) showed that PL inhibited the expressions of TNF-α and IL-6 in the cluture supertant of HSC-T6 cells. In conclusion, PL could play an anti-liver fibrosis role by regulating TNF/NF-κB signaling pathway. This study provided the mechanism basis of anti-LF effects induced by Piperis Longi Fructus and its major active compounds, which might help for the further study of the mechanism and key targets of Piperis Longi Fructus.