Effects of ALBE on cell viability and antigen-induced β-hexosaminidase in RBL-2H3 cells. (A) The cells were treated with various concentration of ALBE for 24 h. Cell viability was assessed using XTT assay. Absorbance was measure data at 450 nm and 650 nm. (B) The cells were sensitized by overnight incubation with 1 μg/ml of DNP-specific IgE in medium. This DNP-IgE-sensitized RBL-2H3 cells were pre-incubated with various concentration of ALBE for 30 min and then incubated with antigen (DNP-BSA) for 15 min in order to measure the release of β-hexosaminidase. Each bar shows the means ± SEM of four independent experiments. ##P < 0.01: significantly different from control group **P < 0.01, *P < 0.05: significantly different from DNP-BSA alone. KF; ketotifen fumarate.