Blockade of IL-6 secretion pathway by the sesquiterpenoid atractylenolide III.

Atractylenolide III (1) is the major bioactive component of Atractylodes lancea. The aim of this study was to analyze the effect on the regulation of interleukin (IL)-6 secretion pathway caused by 1. This sesquiterpenoid inhibited the secretion and expression of IL-6 in phorbol 12-myristate 13-acetate- and calcium ionophore A23187-stimulated human mast cells (HMC)-1. In addition, 1 inhibited histamine release in stimulated HMC-1 cells. In stimulated HMC-1 cells, 1 suppressed activation of p38 mitogen-activated protein kinase, C-Jun-N-terminal protein kinase, and nuclear factor-κB. In addition, 1 suppressed the activation of caspase-1 and the expression of receptor interacting protein-2. These results provide new insights that atractylenolide III (1) may control immunological reactions by regulating the cellular functions of IL-6 in mast cells.