Department of Biological Science, Ajou University, Suwon, Republic of Korea.
Mol Nutr Food Res. 2013 Mar;57(3):390-400. doi: 10.1002/mnfr.201200515. Epub 2012 Dec 23.
Feeding a diet supplemented with 10% (w/w) black and brown rice brans inhibited growth of transplanted tumors in mice.
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.
喂食添加 10%（w/w）黑米和糙米糠的饮食抑制了小鼠移植肿瘤的生长。
来自 Oryza sativa LK1-3-6-12-1 和 Chuchung 品种的黑米和糙米糠各含有 21 种通过 GC/MS 鉴定的化合物。用添加米糠的饮食喂养两周的小鼠通过皮内接种 CT-26 小鼠癌细胞，并再喂食相同的饮食两周。黑糠和棕糠喂养组的肿瘤质量分别降低了 35%和 19%。肿瘤抑制与脾自然杀伤（NK）细胞的细胞溶解活性增加有关；腹腔巨噬细胞中一氧化氮产生和吞噬作用部分恢复；巨噬细胞释放的肿瘤坏死因子-α、IL-1β 和 IL-6 增加；白细胞浸润肿瘤增加；肿瘤内血管生成减少。肿瘤细胞的 ELISA 证实 COX-2 和 5-LOX 的表达减少。COX-2 和 5-LOX 的表达减少下调了血管内皮生长因子并抑制了肿瘤内的新血管生成。
诱导 NK 活性和巨噬细胞以及抑制血管生成似乎有助于肿瘤消退。
