Cytoprotective effects of anthocyanins and other phenolic fractions of Boysenberry and blackcurrant on dopamine and amyloid [beta]-induced oxidative stress in transfected COS-7 cells

There is growing interest both from consumers and researchers in the role that berries play in human health. In the experiments reported here, we assessed the ability of anthocyanins and phenolic fractions of Boysenberry and blackcurrant to ameliorate the deleterious effect of the amyloid β25– 35 (100 μmol L−1, 24 h) and dopamine (1 mmol L−1, 4 h) on calcium buffering (recovery) of M1 muscarinic receptor-transfected COS-7 cells. Cell viability was also studied. Our results demonstrate that extracts of Boysenberry and blackcurrant showed significant protective effect and restored the calcium buffering ability of cells that had been subjected to oxidative stress induced by dopamine and the amyloid β25– 35. Blackcurrant polyphenolics showed slightly higher protective effect against dopamine, whereas Boysenberry polyphenolics had a higher effect against the amyloid β25– 35. In viability studies, all extracts showed significant protective effects against dopamine and amyloid β25– 35-induced cytotoxicity. Our results provide further evidence for the protective effects of berries against the neurotoxic effect of dopamine and amyloid β25– 35 in brain cells.  2007 Society of Chemical Industry