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 b y MLN lymphocytes after 72 hr cultivation were the same as those of co ntrol culture in the presence of 10(-1) and 10(2) mu M azo dyes. On th e other hand, amaranth inhibited IgE to control level at 10(3) mu M wh ile IgE level was 1.5 times higher than control for new coccine and su nset yellow FCF. With regard to non-ate colorings, sodium Cu-chlorophy llin inhibited IgE production by both lymphocytes at the concentration s between 10(0) and 10(1) mu M. 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 regulati on of IgE production.