Effects of anthocyanins and other phenolics of boysenberry and blackcurrant as inhibitors of oxidative stress and damage to cellular DNA in SH-SY5Y and HL-60 cells

There is growing interest both from consumers and researchers in the role that berries play in human health. The objective of this study was to investigate whether anthocyanins and other phenolics present in boysenberries and blackcurrants are effective in protecting cells against the oxidative damage induced by hydrogen peroxide (H2O2). The concentrations of polyphenols used were within the human physiological range. The data showed that SH-SY5Y human neuroblastoma cells were protected against H2O2-induced toxicity by the anthocyanins and phenolic fractions. The concurrent addition of either fractions of these berries with H2O2 significantly inhibited the increase in intracellular reactive oxygen species (ROS) production. Pre-incubation of cells with the same concentrations had no effect on the ROS level-a result that may be due to the metabolic conversion to inactive compounds. Anthocyanins and phenolic fractions of blackcurrant were better at protecting DNA of HL-60 human promyelocytic cells from damage than similar fractions from boysenberry. The phenolic extract of blackcurrant demonstrated the highest protective effect against H2O2-induced neurotoxicity, oxidative stress and DNA damage and may be a good candidate for inclusion into a processed functional food. (c) 2006 Society of Chemical Industry.