Lansiumamide B and SB-204900 isolated from Clausena lansium inhibit histamine and TNF-α release from RBL-2H3 cells

Aims and objective Mast cells play a central role in allergic and chronic inflammation. Extracts from Clausena lansium (Lour.) Skeels (Rutaceae) possess many pharmacological effects including anti-inflammatory, anti-oxidant, anti-cancer, and anti-trichomonal activities. In addition, the leaves and fruit are used in Chinese folk medicine. We have isolated and identified four known cinnamamides from this plant: lansiumamide C, lansamide I, lansiumamide B, and SB-204900. However, the biological activities of these compounds are not yet understood. The purpose of this paper is to clarify the pharmacological effects of these compounds on mast cells. Methods We measured inflammatory molecules in A23187-stimulated rat basophilic leukemia cells (RBL-2H3) treated with these compounds using HPLC, ELISA, and immunoblotting methods. In addition, some signaling molecules were investigated by immunoblotting. Results Lansamide I, lansiumamide B, and SB-204900 significantly decreased histamine release. Furthermore, lansiumamide B- and SB-204900-treated cells also reduced the protein and/or mRNA levels of TNF-α. SB-204900 markedly suppressed the phosphorylation of p38 MAPK. Conclusion Our findings suggest that lansiumamide B and SB-204900 attenuate mast-cell-induced inflammation.