piperine and Inflammatory-Bowel-Diseases

The anti-inflammatory effect of piperine has been largely investigated in macrophages, but its activity on epithelial cells in inflammatory settings is unclear. The present study aimed to investigate the effect of piperine on the expression of inflammatory cytokines in lipopolysaccharide (LPS)-stimulated human epithelial-like SW480 and HT-29 cells. Our data showed that although piperine inhibited the proliferation of SW480 and HT-29 cells in a dose-dependent manner, it had low cytotoxicity on these cell lines with 50 % inhibiting concentration (IC50) values greater than 100 μM. As epithelial-like cells, SW480 and HT-29 cells secreted high levels of the chemokine CXCL8 upon LPS stimulation. Importantly, piperine dose-dependently suppressed LPS-induced secretion of CXCL8 and the expression of CXCL8 messenger RNA (mRNA). Although piperine failed to affect the critical inflammatory nuclear factor-κB pathway, it attenuated the c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) signaling. Consistent with previous reports, p38 signaling seemed to play a more pronounced role on the CXCL8 expression than JNK signaling since inhibition of p38, instead of JNK, greatly suppressed LPS-induced CXCL8 expression. Collectively, our results indicated that piperine could attenuate the inflammatory response in epithelial cells via downregulating the MAPK signaling and thus the expression of CXCL8, suggesting its potential application in anti-inflammation therapy.

Topics: Alkaloids; Anti-Inflammatory Agents; Benzodioxoles; Cell Line; Cell Proliferation; Cell Survival; Down-Regulation; Epithelial Cells; HT29 Cells; Humans; Inflammation; Inflammatory Bowel Diseases; Interleukin-8; JNK Mitogen-Activated Protein Kinases; Lipopolysaccharides; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Piperidines; Polyunsaturated Alkamides; RNA, Messenger

Inflammatory bowel disease (IBD) is associated with chronic inflammation of the intestinal tract. Piperine (1-peperoylpiperidine), the primary lipophilic component in black pepper (Piper nigrum) and long pepper (Piper longum), has been reported to be effective for anti-inflammatory. Rencently, several ethnopharmacological purity compounds, such as baicalin and artemisinin, are reported to have potentially therapeutic role in treating IBD. In the present study, the effects of piperine on pregnane X receptor (PXR)-mediated CYP3A expression and its therapeutic role in IBD were investigated.. LS174T cells and C57BL/6J mice were treated by the piperine. Gene expressions were analyzed by real-time PCR, Western blot analysis, transient transfections assay and histological analysis.. Data indicated that treatment of LS174T cells with piperine markedly increased both CYP3A4 and PXR mRNA and protein. Transient transfection experiments indicated that transcriptional activation of the CYP3A4 gene via piperine was PXR-dependent. Data show that pre-administration of piperine decreased clinical hallmarks of colitis in DSS-treated PXR mice as measured by body weight loss and assessment of diarrhea, rectal bleeding, colon length, and histology. Inflammatory mediators (CCR2, ICAM-1, IL-1β, IL-6, IL-10, iNOS, MCP-1, and TNFα) after DSS treatment were significantly decreased in mice pretreated with piperine but corresponding conditions did not occur in mice with down-regulation of PXR by small interfering RNA (siRNA).. Piperine is a potential agonist of PXR and an inducer of PXR, which may induce CYP3A4 gene expression at the mRNA and protein levels. These results establish that piperine may contribute to prevention or reduction of colonic inflammation.

Topics: Alkaloids; Animals; Benzodioxoles; Cell Line; Dextran Sulfate; Hep G2 Cells; Humans; Inflammatory Bowel Diseases; Male; Mice; Mice, Inbred C57BL; Piper nigrum; Piperidines; Polyunsaturated Alkamides; Pregnane X Receptor; Receptors, Steroid