Extracts from cereal grains induce apoptosis in colorectal cancer cells

Chinkwo K1,2.,L, Rao S1,2o,L, Santakumar A1,20,L and Blanchard C1,2,L

  1. School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, 2650, New South Wales, Australia.
  2. Australian Research Council (ARC) Industrial Transformation Training Centre (ITTC) for Functional Grains, Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, 2650, NSW.

Several plant extracts have been studied for anticancer properties, however the exact mechanisms how these compounds affect tumour growth is largely unknown. One possible mechanism is apoptosis, which is the body’s natural mechanism to eliminate abnormal cells such as cancer cells. Apoptosis is characterised by morphological changes, which include cell shrinkage, protein fragmentation and DNA degradation followed by rapid engulfment of cell debris by macrophages. This study examines the effect of phenolic extracts from four cereal grains including rice, barley, oats and sorghum to induce apoptosis in cancer cells. Whole grain aqueous extracts were used to induce apoptosis on SW480 colorectal cancer cell lines. Morphological observation and monitoring with other biological assays were conducted to study apoptosis. Extracts from pigmented cereals which include yunlu 29, purple rice, shawaya short black 1, IS11316 sorghum, showed a significant reduction in cancer cell proliferation at p<0.005. The pigmented rice extracts reduced cancer cell viability at a concentration of 500μg/mL, while normal cells were not affected. Further analysis to study the mechanism of action with APOPercentage assay, Muse and Flow cytometry showed positive for apoptosis. The results from Muse flow confirmed the activation of multiple caspases 3 and 7 as possible pathways for the induction of apoptosis. This preliminary findings suggest that, whole grain cereals pigmented rice have a potential to prevent cancer growth. Keywords: Apoptosis; Cytotoxicity; Colorectal cancer; Polyphenols; Antioxidant activity; Cancer therapy.