Notoginsenoside R1 attenuates experimental inflammatory bowel disease via pregnane X receptor activation.

Abstract

Notoginsenoside R1 (R1) is the main bioactive component in Panax notoginseng, an old herb medicine widely used in Asian countries in the treatment of microcirculatory diseases. However, little is known about the effect of R1 on inflammatory bowel disease (IBD). The present study demonstrated that R1 alleviated the severity of dextran sulfate sodium-induced colitis in mice by decreasing the activity of myeloperoxidase, the production of cytokines, the expression of proinflammatory genes, and the phosphorylation of IκB kinase, IκBα, and p65 in the colon. Further studies indicated that R1 dose-dependently activated human/mouse pregnane X receptor (PXR), a known target for decreasing inflammation in IBD, and upregulated the expression of genes involved in xenobiotic metabolism in colorectal cells and the colon. Ligand pocket-filling mutant (S247W/C284W or S247W/C284W/S208W) of the human PXR abrogated the effect of R1 on PXR activation. Time-resolved fluorescence resonance energy transfer PXR competitive binding assay confirmed R1 (ligand) binding affinity. In addition, PXR overexpression inhibited nuclear factor-κB (NF-κB)-luciferase activity, which was potentiated by R1 treatment. PXR knockdown by small interfering RNA demonstrated the necessity of PXR in R1-induced upregulation of the expression of xenobiotic-metabolizing enzymes and downregulation of NF-κB activity. Finally, the anti-inflammatory effect of R1 was confirmed in trinitrobenzene sulfonic acid-induced colitis in mice. These findings suggest that R1 attenuates experimental IBD possibly via the activation of intestinal PXR signaling.

• Authors: Jingjing Zhang, Lili Ding, Baocan Wang, Gaiyan Ren, Aning Sun, Chao Deng, Xiaohui Wei, Sridhar Mani, Zhengtao Wang, Wei Dou
• Journal: The Journal of pharmacology and experimental therapeutics (J Pharmacol Exp Ther) Vol. 352 Issue 2 Pg. 315-24 (Feb 2015) ISSN: 1521-0103 [Electronic] United States
• PMID: 25472953 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 by The American Society for Pharmacology and Experimental Therapeutics.

Chemical References

• Anti-Inflammatory Agents
• Ginsenosides
• Interleukin-6
• NF-kappa B
• Pregnane X Receptor
• Receptors, Steroid
• Tumor Necrosis Factor-alpha
• Peroxidase
• notoginsenoside R1

Topics

• Animals
• Anti-Inflammatory Agents (administration & dosage, pharmacology, therapeutic use)
• Colon (drug effects, immunology, metabolism, pathology)
• Disease Models, Animal
• Female
• Gene Expression (drug effects)
• Ginsenosides (administration & dosage, pharmacology, therapeutic use)
• HT29 Cells
• Humans
• Inflammatory Bowel Diseases (drug therapy, immunology, metabolism, pathology)
• Interleukin-6 (metabolism)
• Mice, Inbred C57BL
• NF-kappa B (genetics, metabolism)
• Peroxidase (metabolism)
• Pregnane X Receptor
• Receptors, Steroid (metabolism)
• Signal Transduction
• Tumor Necrosis Factor-alpha (metabolism)