Non-nutritive phytochemicals may reduce risk of chronic disease via antioxidant activity. It is possible that higher concentrations may act as prooxidants and stimulate apoptosis. To determine whether the aglycone anthocyanins malvidin and peonidin act as antioxidants or prooxidants in vitro, we treated HT-29 cells at varying concentrations. Cells were incubated with 1, 5, 10, 25, or 50 g/mL malvidin or peonidin for two hours at 37C, 5% CO2, 95% air. Cells were then treated with H2O2. The Comet assay determined DNA damage, and apoptosis was assessed using a DNA fragmentation ELISA kit. Peonidin decreased H2O2-induced DNA damage at the lowest tested concentration (p< .05). Compared to positive control malvidin at 50 g/mL significantly increased (p<.05) H2O2 induced DNA damage. Our data suggests that at concentrations of 5-50 g/mL malvidin and peonidin did not decrease H2O2 induced DNA damage, and malvidin at 50 g/mL increased H2O2-induced DNA damage in HT-29 cells.
