The natural anti-inflammatory sesquiterpene lactone achillolide A reduces atopic dermatitis in a murine model

Plant-derived substances have been shown to affect potential targets in inflammatory diseases. We have previously purified from the desert plant Achillea fragrantissima, a sesquiterpene lactone named achillolide A, and demonstrated its anti-inflammatory activities in cultured brain macrophages named microglial cells. In the present study, we further investigated achillolide A in alleviating atopic dermatitis, a chronic and recurring inflammatory skin disease. We investigated achillolide A for its in vivo anti-inflammatory activity using the oxazolone model of atopic dermatitis in mice, in which oxazolone induces ear swelling. Our results show that mice treated with achillolide A showed a significant decrease in the oxazolone-induced ear swelling. Since macrophages are inflammatory cells that play a pivotal role in the pathogenesis of atopic dermatitis, the anti-inflammatory effects of achillolide A were also studied in spleen cells. We demonstrated that achillolide A reduced the levels of LPS-induced inflammatory cytokines IL-2, IL-6, TNFα, IFNγ and IL-12 that were secreted from cultured splenocytes. These data suggest that achillolide A should be considered for further research in treating atopic dermatitis.