A comprehensive study of anthocyanin-containing extracts from selected blackberry cultivars: Extraction methods, stability, anticancer properties and mechanisms

The purpose of these studies was to investigate and compare the composition, stability, antioxidant and anticancer properties and mechanisms of anthocyanin-containing blackberry extracts (ACEs) from selected cultivars and using different extraction methods. ACEs were analyzed for total anthocyanin and phenolics content, polymeric color, and total antioxidant capacity (TAC). The influence of water content in the extraction system was evaluated. A 90-day stability study of the extract and a 48-h stability study of the extract in biologically relevant buffers were completed. The cytotoxic effects of ACEs on HT-29, MCF-7, and HL-60 cells were determined. H2O2 production in culture medium was measured and intracellular ROS levels were quantified. As compared to powder-derived ACEs, puree-derived ACEs contained similar amounts of anthocyanins, but greater levels of phenolics, increased TAC, significantly enhanced production of H2O2, and significantly enhanced cytotoxicity in all cell lines. Catalase could not protect cells from ACE-induced cell death. Cyanidin 3-glucoside exerted anticancer effect by acting synergistically or additively with other active components in the extracts. These data suggest that anthocyanins and non-anthocyanin phenolics in ACEs act synergistically or additively in producing anticancer effects. These studies also provide essential information for the development of fruit-derived ACEs as potential Botanical Drug Products.