These authors equally contributed to this work.
Antitumor effects of dietary black and brown rice brans in tumor-bearing mice: Relationship to composition
Article first published online: 23 DEC 2012
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Molecular Nutrition & Food Research
Volume 57, Issue 3, pages 390–400, March 2013
How to Cite
Choi, S. P., Kim, S. P., Nam, S. H. and Friedman, M. (2013), Antitumor effects of dietary black and brown rice brans in tumor-bearing mice: Relationship to composition. Mol. Nutr. Food Res., 57: 390–400. doi: 10.1002/mnfr.201200515
- Issue published online: 12 MAR 2013
- Article first published online: 23 DEC 2012
- Manuscript Accepted: 5 NOV 2012
- Manuscript Revised: 30 OCT 2012
- Manuscript Received: 2 AUG 2012
- Black rice bran;
- Brown rice bran;
- Antitumor effects
Feeding a diet supplemented with 10% (w/w) black and brown rice brans inhibited growth of transplanted tumors in mice.
Methods and results
Black and brown rice brans from Oryza sativa LK1–3-6–12-1 and Chuchung cultivars each contained 21 compounds characterized by GC/MS. Mice fed diets with added rice brans for 2 weeks were intracutaneously inoculated with CT-26 mouse cancer cells and fed the same diet for two additional weeks. Tumor mass was 35 and 19% lower in the black and brown bran-fed groups, respectively. Tumor inhibition was associated with increases in cytolytic activity of splenic natural killer (NK) cells; partial restoration of nitric oxide production and phagocytosis in peritoneal macrophages; increases in released tumor necrosis factor-α, IL-1β, and IL-6 from macrophages; increases in infiltration of leukocyte into the tumor; and reduction in angiogenesis inside the tumor. Proangiogenic biomarkers vascular endothelial growth factor, cyclooxygenase-2 (COX-2), and 5-lipoxygenase (5-LOX) were also reduced in mRNA and protein expression. ELISA of tumor cells confirmed reduced expression of COX-2 and 5-LOX. Reduced COX-2 and 5-LOX expression downregulated vascular endothelial growth factor and inhibited neoangiogenesis inside the tumors.
Induction of NK activity and macrophages and inhibition of angiogenesis seem to contribute to tumor regression.