Antioxidant properties of Korean black raspberry wines and their apoptotic effects on cancer cells

BACKGROUND: The objective of the study was to determine the antioxidant activities of Korean black raspberry concentrate (KBR: Rubus coreanus Miq.) and Korean black raspberry wine concentrates (KBRW-1 and KBRW-2) using the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. The apoptotic effects of the KBRW concentrates on various cancer cells were also investigated. RESULTS: Both the KBR concentrate and KBRW concentrates showed dose-related antioxidant activities in the DPPH assay. At concentrations of 500 mu g mL(-1) and 1000 mu g mL(-1), the KBIR concentrate antioxidant activities were 59% and 79%, respectively. KBRW-1 and KBRW-2 inhibited radical formation at 500 mu g mL(-1) by 19% and 48%, respectively. The antioxidant activity of KBRW-2 was comparable to various red wines (RW-1, RW-2, RW-3, and RW-4). However, at 1000 mu g mL(-1), the antioxidant activities of KBRW-1 and KBRW-2 were 53% and 83% that of alpha-tocopherol, respectively. Both RW-1 and KBRW-2 showed marked antiproliferative effects on all cancer cell types, with decreases in cell viability greater than 50%. This was co-related with apoptotic characteristics, including chromatin condensation and apoptotic body formation, as determined by cell morphological assessment. Cell cycle analysis showed that treating AGS cells with RW-1 and KBRW-2 resulted in 25% and 30% apoptotic cell accumulation, respectively. KBRW-2 induced the cleavage of poly(ADP-ribose) polymerase (PARP) and the activation of caspase-3 within the AGS cells. Levels of PARP cleavage were increased five- and three-fold by RW-1 and KBRW-2, respectively, and the level of caspase-3 was significantly increased by the treatment with KBRW-2. CONCLUSION: Overall, the results of this study suggest that Korean black raspberry wine displays antioxidant activity comparable to that of imported red wines, and has anticancer effects that may be attributed to induction of the apoptotic pathway. (c) 2009 Society of Chemical Industry