The effect of five artificial sweeteners on Caco-2, HT-29 and HEK-293 cells

Context: Artificial sweeteners (AS) have been associated with tumor development (including colon cancer) in both animals and humans although evidence has been conflicting. Objectives: Additional research was thus conducted by studying the effects of 5 AS on the morphology, cell proliferation and DNA in cells by utilizing Caco-2, HT-29 (colon) and HEK-293 (kidney) cell lines. Materials and methods: Cells were exposed to sodium cyclamate, sodium saccharin, sucralose and acesulfame-K (0-50 mM) and aspartame (0-35 mM) over 24, 48 and 72 hours. Morphological changes were presented photographically and % cell viability was determined by using the MTT cell viability assay. Possible DNA damage (comet assay) induced by the AS (0.1, 1 and 10 mM, treated for 24, 48 and 72 hours) was studied. The appearance of comets was scored from no damage to severe damage (0-4). Results: Cells became flatter and less well defined at higher AS concentrations (410 mM). At concentrations 410 mM, decreased cell viability was noted with both increasing concentration and increasing incubation time for all cell lines tested. In general, HEK-293 cells seemed to be less affected then the colon cancer cells. Sucralose and sodium saccharin seemed to elicit the greatest degree of DNA fragmentation of all the sweeteners tested in all the cell lines used. Discussion: Morphological cell alterations, cell viability and DNA fragmentation seemed to be more in the colon cancer cells. Conclusions: Further studies have to be performed to clarify mechanisms involved causing these alterations in mammalian cells.