IMMUNOLOGICAL ASPECTS OF THE COMMON FOOD COLORANTS, AMARANTH AND TARTRAZINE

We describe a sensitive and reproducible microassay model using human peripheral blood lymphocytes (PBL) for discrimination between the cyto toxic and immunosuppressive effects of food colorants such as amaranth and tartrazine. The cytotoxic effects of a wide range of concentratio ns of these substances were studied on human PBL by the colorimetric i n vitro cytotoxicity assays, neutral red uptake (NR) and thiaizolyl bl ue tetrazolium bromide (MTT). The immunotoxic properties of these 2 su bstances were determined by a [H-3]thymidine DNA incorporation assay o n phytohemagglutinin stimulated or non-stimulated lymphocytes, as well as by a Cr-51 release Natural Killer assays. The results showed clear immunosuppressive effects from the 2 substances tested, although the concentrations chosen for this study proved to be non-cytotoxic by NR and MTT cytotoxic endpoints.