Evaluation of the Anti-Allergic Effect of Natural Medicines on Mast Cell by Using Two-Dimensional Surface Plasmon Resonance Observation

Demand for novel drug screening methods which are characterized by simple, rapid and low cost is increasing now. In this study, the simple and rapid evaluation of the anti-allergic effect of natural medicines on the degranulation of a model mast cell (RBL-2H3 cells) was successfully achieved by two-dimensional surface plasmon resonance (2D-SPR) measurement. The each cell response was observed by SPR imaging upon model antigen, Albumin from bovine serum, 2, 4-Dintrophenylated (DNP-BSA) stimulation after anti-DNP IgE sensitization on RBL-2H3 cells. Here glycyrrhizic acid (GA) and isoliquiritigenin (ISL) were examined as degranulation inhibitors. After the pretreatment with 30 µmol/L GA or 50 µmol/L ISL, the reflection intensity increase at cell regions upon DNP-BSA stimulation was completely suppressed. In addition, it was shown that the suppression of reflection intensity increase at cell regions in the 2D-SPR observation upon DNP-BSA stimulation was dependent on the GA and ISL concentration in pretreatment as well as β-hexosaminidase assay. These results demonstrated that the suppression effect of GA and ISL on the degranulation of RBL-2H3 cells could be evaluated by 2D-SPR observation at cell regions in quick and simple manner. Our study further suggested that 2D-SPR observation of mast cell response might be applicable to screen anti-allergic components of natural products and useful to discuss its inhibitory effect in the intracellular signaling pathway of mast cell upon antigen stimulation