Effect of Synthetic Food Colorings on Immunoglobulin Production by Rat Lymphocytes

The effect of 4 azo dyes and 5 non-azo dyes used for food coloring on immunoglobulin (Ig) production by rat spleen and mesenteric lymph node (MLN) lymphocytes was examined. The amounts of IgG and IgM produced by MLN lymphocytes after 72 hr cultivation were the same as those of control culture in the presence of 10^-1 and 10²μM azo dyes. On the other hand, amaranth inhibited IgE to control level at 10³μM while IgE level was 1.5 times higher than control for new coccine and sunset yellow FCF. With regard to non-azo colorings, sodium Cu-chlorophyllin inhibited IgE production by both lymphocytes at the concentrations between 10⁰ and 10¹μM.Among chlorophyll derivatives, Cu- and Fe-derivatives inhibited IgE production by both lymphocytes.Among Mg-derivatives, chlorophyll-b, having aldehyde group as the constituent, enhanced it by both lymphocytes. These results suggest that minerals and aldehyde in porphyllin ring have an important role in the regulation of IgE production.