Cytotoxicity of alpha-dicarbonyl compounds submitted to in vitro simulated digestion process

alpha-Dicarbonyl compounds (alpha-DCs), such as glyoxal, methylglyoxal and 2,3-butanedione, are highly reactive substances occurring in thermally treated and fermented foods, that may react with amino and sulphydryl groups of side chains of proteins to form Maillard reaction end products, inducing a negative impact on the digestibility and on nutritional value of protein. In recent years the role of food derived alpha-DCs in gastroduodenal tract is under investigation to understand whether excess consumption of such dietary compounds might be a risk for human health. In this study the interactions between a mixture of glyoxal, methylglyoxal and 2,3-butanedione and the digestive enzymes (pepsin and pancreatin) were studied. The results showed that during gastroduodenal digestion alpha-DCs react with digestive enzymes to produce carbonylated proteins. Moreover, undigested and digested alpha-DC cytotoxicity against human cells, as well as their ability to inhibit the function of human enzymes responsible for DNA repair were shown. Copyright 2012 Elsevier Ltd. All rights reserved.