Evidence from in Vitro Murine Immunologic Assays That Some Phenolic Food Additives May Function as Antipromoters by Lowering Intracellular Cyclic GMP Levels

Butylated hydroxyanisole was previously shown to suppress murine in vitro immune responses by inhibiting guanylate cyclase function resulting in decreased levels of cyclic GMP. Like butylated hydroxyanisole, butylated hydroxytoluene, methyl paraben, and gallic acid suppress in vitro immune responses, the suppression being reversible by adding exogenous dibutyryl cyclic GMP or Ca2+. Since there is a correlation between the strength of tumor promoters and their ability to cause intracellular increases in cyclic GMP, the data suggest that (i) some phenolic food additives may protect from carcinogens by acting as antipromoters in that they lower cyclic GMP levels and (ii) the in vitro immune response may be a useful system in which to study promoter-antipromoter interactions.