Diterpenoid WT-29 isolated from Wedelia exerted anti-inflammatory and anti-allergic activities.

ETHNOPHARMACOLOGICAL RELEVANCE

Wedelia (Sphagneticola trilobata) is a traditional anti-inflammatory herb native to tropical America. It is commonly used to treat some inflammatory related diseases clinically, such as pertussis, pharyngitis, etc. However, its specific anti-inflammatory mechanism is still unclear.

AIM OF THE STUDY

WT-29 (3α-angeloyloxy-9β-hydroxyent-kaura-16-en-19-oic acid) is a main bioactive diterpenoid isolated and purified from Wedelia. This study aims to explore the potential anti-inflammatory and anti-allergic properties of WT-29 on RAW264.7 cells stimulated with LPS and P815 cells induced by C48/80, as well as investigating their underlying molecular mechanisms.

METHODS

The anti-inflammatory mechanism of WT-29 was analyzed and predicted using network pharmacology, and then verified through experiments. The Griess reagent assay was employed to evaluate the impact of WT-29 on the generation of nitric oxide (NO) in RAW264.7 cells induced by LPS, the expression of various inflammatory cytokines and the release of histamine in cells were measured through qRT-PCR and ELISA techniques. The impact of WT-29 on the translocation of the NF-κB p65 protein to the nucleus was assessed through immunofluorescence staining. Western blot technique was utilized to investigate protein expression in inflammation, allergy, and autophagy pathways.

RESULTS

The study found that WT-29 can reduce the secretion of inflammatory factors (NO, iNOS, COX-2, IL-6, IL-1β and TNF-α), inhibit NF-κB activation and MAPK family phosphorylation, and induce autophagy in RAW264.7 cells stimulated with LPS. In addition, it demonstrated that WT-29 could inhibit histamine release and degranulation, as well as inhibit the MAPK family in C48/80-induced P815 cells.

CONCLUSION

WT-29 isolated from Wedelia exerts anti-inflammatory and anti-allergic effects mainly through NF-κB, Nrf2/Keap-1, MAPK pathways and regulating of autophagy, suggesting that it might be a potential anti-inflammatory and anti-allergic agent and could be used as medicine or health benefit product.