Metabolism food mutagens

METABOLIC ACTIVATION AND FORMATION OF DNA ADDUCTS BY FOOD MUTAGENS AND CARCINOGENS... 

De France, B. F. Carter, M. H. Josephy, R D. Comparative metabolism and mutagenicity of azo and hydrazone dyes in the Ames test. Food Chem. Toxicol. 1986, 24, 165-169. 

Our experiments on the mutagenicity of these materials revealed that a water extract of the crumbs did not give a positive Ames test. On the other hand the ethanol extract after distillation produced reverted colonies in the range of the positive control (2-AF) with the most sensitive strains, but only without metabolic activation. The Maillard products responsible for mutations seemed to be metabolized in the living organism. In view of our experiments and the present international evaluation on heat-processed foods, the crumbs present no more detrimental risk to human health than other heat-processed foods, when consumed. 

In this volume, we have focused on how xenobiotics are metabolized in higher animals and how this metabolism is mediated by the nutritional status of the target animal. Emphasis has been placed on the toxic, mutagenic, carcinogenic and potentially mutagenic or carcinogenic compounds. The topic is a natural follow-up and expansion of Xenobiotics in Foods and Feeds (ACS Symposium Series No. 234, Finley and Schwass, Eds.) in which sources of xenobiotics were identified and discussed at length. The authors in this volume discuss how and why these xenobiotics are toxic and how nutritional intervention can mediate some of the toxicities. 

In 1985 it was published [1] that stevioside was completely safe but that metabolically activated steviol was mutagenic in a "Forward Mutation Test". Steviol had to be applied together with the microsomal fraction of liver of animals treated with carcinogenic compounds (polychlorinated biphenyl or phenobarbital plus 5,6-benzoflavone). This publication has led to a confusing discussion between advocates and opponents of the use of Stevia or stevioside. To unravel the problem we must consider the opinion of authoritative international organisations such as OECD (Organisation for Economic Co-Operation and Development) and ICH (International Council of Harmonisation). To accept new substances as food three different mutagenesis tests are accepted and required by the OECD as well as by the ICH. These can be seen in Table 1. 

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