Cytogenetic response to coffee in Chinese hamster ovary AUXB1 cells and human peripheral lymphocytes

We have investigated the genotoxic effects of three differentbrands and three types of coffee (freshly brewed regular, instantregular and freshly brewed decaffeinated) in two mammalian systems:the Chinese hamster ovary (CHO) AUXB1 cell line and human peripherallymphocytes. Sisterchromatid exchanges (SCEs) and endoreduplicatedcells (ERCs) were used as the endpoints. Coffee was preparedaccording to the manufacturer's suggestions, and after cooling,administered to cultured cells at dilutions ranging up to 11%that of full-strength coffee. Each brand and type of coffeeinduced significant levels of SCEs and ERCs in AUXB1 cells.SCEs, but not ERCs, were induced in human peripheral lymphocytes.Bisulfite, which complexes with carbonyls and reduces theirgenotoxicity, significantly diminished the number of SCEs andERCs found after administration of coffee. Catalase and peroxidase,enzymes that destroy hydrogen peroxide activity, had no significanteffect upon the SCE and ERC frequencies in AUXB1 cultures treatedwith freshly brewed regular coffee. These experiments indicatethat different brands and types of coffee have sufficient genotoxicactivity to increase SCEs and ERCs at levels only a fractionof those normally consumed. 1,2-Dicarbonyls alone and peroxidesalone do not appear to be responsible for the majority of SCEsand ERCs that were observed to be induced by dilute coffee.