Withanolides against TLR4-Activated Innate Inflammatory Signalling Pathways: A Comparative Computational and...

Area of Science:

• Immunology
• Pharmacology
• Phytochemistry

Background:

• Innate inflammation, driven by pathogen-associated molecular patterns and lipopolysaccharide (LPS), significantly contributes to disease and mortality.
• Toll-like receptor 4 (TLR4) activation by LPS triggers mitogen-activated protein kinases (MAPKs) and NF-κB signaling pathways, crucial in inflammatory responses.
• Withania somnifera, a medicinal herb, possesses known anti-inflammatory properties, making its active compounds potential therapeutic agents.

Purpose of the Study:

• To evaluate the anti-inflammatory potential of Withania somnifera extracts and isolated withanolides against LPS-induced inflammation in macrophages.
• To identify specific withanolides and extracts that effectively modulate key inflammatory signaling pathways.

Main Methods:

• In silico molecular docking analysis to predict the binding efficacy of withanolides against inflammatory targets.
• In vitro experiments using LPS-induced bone marrow-derived macrophages to assess the effects of withanolides and extracts on inflammatory markers.
• Analysis of signaling pathways, including MAPKs and NF-κB, affected by the treatments.

Main Results:

• Molecular docking identified withaferin A, withanone, and withanolide A as potent inhibitors of inflammatory targets.
• Withaferin A and withanone significantly suppressed the expression of pro-inflammatory cytokines in LPS-stimulated macrophages.
• Withaferin A demonstrated comprehensive regulation of both MAPK and NF-κB pathways, while Withania extracts rich in withaferin A also exhibited significant anti-inflammatory effects.

Conclusions:

• Withaferin A is the most effective withanolide in suppressing activated inflammatory pathways.
• Withania somnifera extracts with high withaferin A content, particularly from in vitro propagated leaves and field-grown roots, are promising candidates for treating innate inflammation.
• Withaferin A and these specific extracts represent potential therapeutic agents for managing inflammatory conditions.