Immunomodulatory effect of Wedelia chinensis and demethylwedelolactone by interfering with various inflammatory mediators

Abstract

Wedelia chinensis is a medicinal herb, traditionally used to treat variety of immunological disorders. The herb and its coumestans, wedelolactone (WL) and demethylwedelolactone (DWL) were demonstrated to possess several biological actions . This work was aimed to evaluate the in vitro immunomodulatory effect of DWL as well as the standardized Wedelia chinensis extract (WCE). In vitro immunomodulatory potential was evaluated by assessing the effects on Compound 48/80 (C 48/80)-induced de-granulation of mast cell and LPS-stimulated production of NO, pro-inflammatory cytokines and the expression of costimulatory molecules in macrophages. RP-HPLC analysis of WCE indicated the abundance of WL (1.96 ± 0.03 %, w/w) and DWL (0.61 ± 0.005 %, w/w). Results of the present investigation showed that WCE and DWL dose dependently inhibited the de-granulation of mast cells induced by C 48/80. Additionally, WCE and DWL were also inhibited the production of NO, pro-inflammatory cytokines such as TNF-α, IL-1β and IL-6 and the expression of costimulatory molecules such as CD40, CD80 and CD86 in LPS-stimulated macrophages. These findings suggest that WCE has modulatory effect on various immune-inflammatory mediators mainly due to the presence of WL along with the lesser amount of DWL. Therefore, this plant as well as its coumestans, WL and DWL can be exploited as alternative new therapeutics for various inflammatory diseases.