Effect of Natural Food Colorings on Immunoglobulin Production in Vitro by Rat Spleen Lymphocytes

Abstract

Water-soluble (cacao pigment, cochineal pigment, corn pigment, betanin, carthamus yellow, and monascus pigment) and water-insoluble (gardenia yellow, laccaic acid, bixin, and curcumin) natural colorings inhibited IgE production by rat spleen lymphocytes at 10 and 1μM, respectively. Although many of those colorings only inhibited the production of IgG and IgM at high concentrations, the water-insoluble colorings enhanced IgM production even at 1μM. These results suggest that natural colorings have immunoglobulin production-regulating activity.