ROS-modulating anticancer effects of gastrointestinally digested Ribes nigrum L. fruit extract in human colon cancer cells

Reactive oxygen species (ROS) and antioxidants play a crucial role in dose-dependent promotion and suppression of colorectal tumourigenesis. In this study, ROS-modulating anticancer effects were analysed in colon cancer HT-29 cells exposed to the blackcurrant (BC) extract digested in an artificial gastrointestinal tract. The obtained results indicate that the colon-available fraction of gastrointestinal-digested BC extract dose-dependently inhibited the growth of colon cancer cells by inducing a G(0)/G(1) phase cell cycle arrest and targeting cells to a caspase 3-mediated apoptosis pathway. The extract significantly suppressed cell invasion by down-regulation of matrix metalloproteinase MMP-2 and MMP-9 expression. The anticancer effect of the BC extract was related to the dose-dependent modulation of intracellular ROS accumulation. Given the bioavailability of BC polyphenols to the colon and their multi-directional anticancer activity, BC fruit may be proposed as a natural therapeutic agent and functional food ingredient to support prevention and treatment of colorectal cancer.