Chemoprevention of pulmonary carcinogenesis by myo-inositol

This abstract summarizes material presented at the "First International Symposium on Disease Prevention by IP6 and other Rice Components "held in Kyoto, Japan in June, 1998. The presentation deals primarily with studies of chemoprevention of pulmonary carcinogenesis by myo-inositol. This compound is largely formed by the dephosphorylation of inositol hexaphosphate (IP6, phytate) within the gastrointestinal tract in humans and animals. myo-Inositol is one of a relatively few compounds that has an inhibitory effect on carcinogenesis of the lung in experimental animals when administered during the post-initiation period. It prevents pulmonary adenoma formation in A/J mice when fed in the diet subsequent to administrations of benzo[a]pyrene or the tobacco specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) to the mice. A second compound, dexamethasone, also prevents pulmonary neoplasia under the same conditions. Experiments in which both myo-inositol and dexamethasone were administered together in the diet showed an additive inhibitory effect. The significance and utility of the chemopreventive properties of these agents remains to be determined.