Dietary rice bran component γ-oryzanol inhibits tumor growth in tumor-bearing mice

Mol Nutr Food Res. 2012 Jun;56(6):935-44. doi: 10.1002/mnfr.201200057.


Scope: We investigated the effects of rice bran and components on tumor growth in mice.

Methods and results: Mice fed standard diets supplemented with rice bran, γ-oryzanol, Ricetrienol®, ferulic acid, or phytic acid for 2 weeks were inoculated with CT-26 colon cancer cells and fed the same diet for two additional weeks. Tumor mass was significantly lower in the γ-oryzanol and less so in the phytic acid group. Tumor inhibition was associated with the following biomarkers: increases in cytolytic activity of splenic natural killer (NK) cells; partial restoration of nitric oxide production and phagocytosis in peritoneal macrophages increases in released the pro-inflammatory cytokines tumor necrosis factor-α, IL-1β, and IL-6 from macrophages; and reductions in the number of blood vessels inside the tumor. Pro-angiogenic biomarkers vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and 5-lipoxygenase-5 (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. ELISA of tumor cells confirmed reduced expression of COX-2 and 5-LOX up to 30%. Reduced COX-2 and 5-LOX expression downregulated VEGF and inhibited neoangiogenesis inside the tumors.

Conclusion: Induction of NK activity, activation of macrophages, and inhibition of angiogenesis seem to contribute to the inhibitory mechanism of tumor regression by γ-oryzanol.

Publication types

  • Comparative Study

MeSH terms

  • Angiogenesis Inhibitors / adverse effects
  • Angiogenesis Inhibitors / therapeutic use*
  • Animals
  • Antineoplastic Agents, Phytogenic / adverse effects
  • Antineoplastic Agents, Phytogenic / therapeutic use*
  • Colonic Neoplasms / diet therapy*
  • Colonic Neoplasms / immunology
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology
  • Coumaric Acids / adverse effects
  • Coumaric Acids / therapeutic use
  • Cytotoxicity, Immunologic
  • Dietary Supplements*
  • Female
  • Macrophages, Peritoneal / immunology
  • Macrophages, Peritoneal / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Natural Killer T-Cells / immunology
  • Natural Killer T-Cells / metabolism
  • Neoplasm Transplantation
  • Neovascularization, Pathologic / prevention & control
  • Oryza / chemistry*
  • Phenylpropionates / adverse effects
  • Phenylpropionates / therapeutic use
  • Plant Extracts / adverse effects
  • Plant Extracts / therapeutic use*
  • Random Allocation
  • Seeds / chemistry*
  • Specific Pathogen-Free Organisms
  • Spleen / immunology
  • Spleen / pathology
  • Tumor Burden


  • Angiogenesis Inhibitors
  • Antineoplastic Agents, Phytogenic
  • Coumaric Acids
  • Phenylpropionates
  • Plant Extracts
  • cycloartenyl ferulate
  • gamma-oryzanol