*2.4. Human Peripheral Blood Basophilic Leukemia Cells (KU812 Cells) Culture and Degranulation Assay*

The basophil histamine release test was carried out according to the method of Wang et al. [15]. KU812 cells were cultured in RPMI-1640 medium with 20% fetal bovine serum (FBS) and 105 U/L penicillin/streptomycin for 24 h. A total of 5 × 105 cells was in each well. The culture condition was 37 ◦C with CO2 (5%). The cells were then activated with human anti-OVM IgE serum for 24 h, and followed by, stimulated by 50 μg/well of samples for 4 h. Cells treated with PBS buffer were served as the negative control. The release of β-hex, TNF-γ, histamine and IL-6 were analyzed by ELISA kits, following the manufacturer's instructions [16,17].
