Pyxinol derivative suppresses LPS-induced inflammation by targeting the p65-p50 heterodimer

Area of Science:

• Natural Products Chemistry
• Pharmacology
• Immunology

Background:

• Pyxinol derivatives exhibit anti-inflammatory properties via the NF-κB pathway, but their specific molecular targets are unknown.
• Ocotillol-type ginsenosides are natural compounds with potential therapeutic applications.

Purpose of the Study:

• To synthesize novel pyxinol derivatives and identify their precise molecular targets in the NF-κB pathway.
• To evaluate the anti-inflammatory and hepatoprotective effects of the most potent derivative.

Main Methods:

• Synthesis of pyxinol derivatives with aromatic moieties at the C-3 hydroxyl group.
• In vitro screening for inhibition of nitric oxide production and inflammatory cytokine release in RAW264.7 cells.
• In vivo assessment of protection against lipopolysaccharide-induced acute liver injury in septic mice.
• Mechanistic studies including pull-down assays and cellular thermal shift assays to determine p65 interaction.

Main Results:

• Derivative 2m displayed significant anti-inflammatory activity with low cytotoxicity.
• 2m suppressed key inflammatory cytokines (IL-1β, TNF-α) and mediators (iNOS, COX-2).
• 2m protected against LPS-induced acute liver injury in vivo.
• Mechanistically, 2m directly inhibited the DNA-binding of phosphorylated NF-κB p65 without affecting its phosphorylation or translocation.

Conclusions:

• Derivative 2m targets the classical NF-κB pathway by directly interacting with p65, blocking its DNA-binding activity.
• This novel mechanism offers a new therapeutic approach for inflammatory conditions.
• The study identifies a specific molecular target for pyxinol-based anti-inflammatory agents.