This study investigated the synergistic efficacy of keto-carotenoid astaxanthin (AST, from shrimp) plus hydrocarbon (β-carotene, BC) and hydroxyl (lutein, L) carotenoids (from greens) on molecular events in MCF-7 cells. MCF-7 cells were treated with either of carotenoid (20 μM, AST or BC or L) separately or the mixture of them (an equimolar concentration of carotenoids mixture, CM) or saponified carotenoid extract from shrimp (SSCE) for 48 h and analyzed cellular uptake, cytotoxicity, and apoptosis. The IC50 and combination-index values of AST co-treatment with a lower concentration of BC and L (5 μM) exhibited enhanced cytotoxicity and oxidative stress as compared with individual carotenoids or SSCE. Further, higher cellular uptake/accumulation of AST along with BC and L found to synergistically induce apoptosis through modulation of cyclin D1, p53, Bax and Bcl-2 expressions by arresting cell cycle at G0/G1 phase. Further, CM or SSCE treatments are unlikely to affect proliferation of normal breast epithelial cells (MCF-10A). The results of selective killing of MCF-7 cells demonstrated a greater insight on the synergistic effect of shrimp AST plus BC and L. It is concluded that consumption of shrimp along with green leafy vegetables helps in combating cancer chemoprevention.
Keywords: Cytotoxicity; Lutein; MCF-7 cells proliferation; Shrimp astaxanthin; Synergism; β-Carotene.
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