Ginsenosides Regulate PXR/NF-κB Signaling and Attenuate Dextran Sulfate Sodium-Induced Colitis

Area of Science:

• Pharmacology
• Molecular Biology
• Immunology

Background:

• Pregnane X receptor (PXR) activation has anti-inflammatory properties by inhibiting nuclear factor-κB (NF-κB).
• Overactivation of PXR can disrupt the homeostasis of key enzymes and transporters.
• Understanding how natural compounds modulate PXR/NF-κB signaling is crucial for therapeutic development.

Purpose of the Study:

• To investigate the effects of ginsenosides on PXR/NF-κB signaling in inflammatory conditions.
• To elucidate the mechanisms by which ginsenosides regulate PXR and NF-κB.
• To evaluate the therapeutic potential of ginsenosides in experimental inflammatory bowel disease.

Main Methods:

• In vitro studies using LS174T cells stimulated with tumor necrosis factor-α.
• In vivo studies using a dextran sulfate sodium-induced experimental colitis model.
• Assessment of PXR/NF-κB interaction, nuclear translocation of NF-κB p65, and PXR target gene expression.

Main Results:

• Ginsenosides inhibited NF-κB activation and restored PXR target gene expression in inflamed cells.
• Ginsenosides repressed NF-κB activation in a PXR-dependent manner without acting as PXR agonists.
• Ginsenosides enhanced the physical association between PXR and NF-κB p65, reducing p65 nuclear translocation.
• Ginsenoside Rb1 and compound K (CK) were identified as key bioactive compounds.
• Ginsenosides attenuated experimental colitis, correlating with restored PXR/NF-κB signaling.

Conclusions:

• Ginsenosides exert anti-inflammatory effects by targeting the PXR/NF-κB interaction.
• This modulation occurs without disrupting normal PXR function, suggesting a safe therapeutic window.
• Ginsenoside Rb1 and CK show promise as lead compounds for developing new drugs for inflammatory bowel disease targeting the PXR/NF-κB pathway.