Libanoridin inhibits the mast cell-mediated allergic inflammatory reaction

Background and aim: Corydalis heterocarpa is a biennial herb in South Korea, with spikes of yellow flowers. It has been used for as a folk medicine to cure travail and spasm. However, studies on this herb and its secondary metabolites have rarely been reported. In the present study, we isolated secondary metabolite libanlibanoridin from Corydalis heterocarpa. We have also examined the effect of libanoridin on the inflammatory cytokines production in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore, A2318 stimulated human mast cell line, HMC-1. PMA plus A23187 significantly increased interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α production compared to media control (P<0.05). Results: We report that treatment with libanlibanoridin can inhibit PMA plus A23187-induced IL-1β, IL-6, IL-8, and TNF-α production in a concentration-dependent manner with IC50 of 0.002, 1.38, 1.48, and 0.36μg/ml, respectively. Maximal inhibition rates of IL-1β, IL-6, IL-8, and TNF-α production by libanlibanoridin were about 117.5%, 86.22%, 86.41%, and 90.74%, respectively. libanoridin inhibits the mRNA expression of IL-1β, IL-6, IL-8, and TNF-α. libanoridin also inhibits the expression of cyclooxygenase-2. Conclusion: These results indicate that libanlibanoridin may be helpful in regulating mast cell-mediated allergic inflammatory response.