EFFECTS OF SYNTHETIC FOOD COLORS ON [H-3] SEROTONIN RELEASE FROM RAT BASOPHILIC LEUKEMIA-CELLS (RBL-2H3)

The authors investigated the applicability of an assay method for imme diate allergic reaction in vitro to determine radioactivity of pre-inc orporated [SH]serotonin from rat basophilic leukemia cells (RBL-2H3) s timulated with biotinylated IgE-avidin complex. Using the newly improv ed assay method, the effects of synthetic food colors on immediate all ergic reaction were determined. The optimum ratio and amount of stimul ator for the cell stimulation was found to be 3 mu g/ml (0.015 mu M) o f biotinylated IgE and 1 mu g/ml (0.015 mu M) of avidin. Seven kinds o f food colors including food red No. 2 (amaranth) and food yellow No. 4 (tartrazine) inhibited about 50% of [H-3] serotonin release atl mM c ompared to that of the cells exposed to the stimulator alone. Food blu e No. 2 (indigo carmine) inhibited 20% of the release at 1 mM, while f ood red No. 106 (acid red) had no effect. Food red No. 3 (erythrosine) , food red No. 104 (phloxine) and food red No. 105 (rose bengale) prom oted [H-3]serotonin release from nonstimulated cells at lower concentr ation and showed strong lethal effect to the cells at higher concentra tion. Thus, it was suggested that food colors might modify immediate a llergic response, and show cytotoxic action when ingested orally with foods.