Tajasuwan Laleewan, Kettawan Aikkarach, Rungruang Thanaporn, Wunjuntuk Kansuda, Prombutara Pinidphon, Muangnoi Chawanphat, Kettawan Aurawan Kringkasemsee
Graduate Student in Doctor of Philosophy Program in Nutrition, Faculty of Medicine Ramathibodi Hospital and Institute of Nutrition, Mahidol University, Bangkok 10400, Thailand.
Institute of Nutrition, Mahidol University, Nakhon Pathom 73170, Thailand.
Foods. 2022 Nov 2;11(21):3488. doi: 10.3390/foods11213488.
Defatted rice bran (DRB) is gaining immense popularity worldwide because of its nutritional and functional aspects. Emerging evidence suggests that DRB is a potential source of dietary fiber and phenolic compounds with numerous purported health benefits. However, less is known about its chemoprotective efficacy. In the present study, we determined and examined the nutrient composition of DRB and its chemopreventive effect on azoxymethane and dextran sulphate sodium (AOM/DSS)-induced colitis-associated colorectal cancer (CRC) in rats. The results showed the presence of several bioactive compounds, such as dietary fiber, phytic acid, and phenolic acids, in DRB. In addition, DRB supplementation reduced the progression of CRC symptoms, such as colonic shortening, disease activity index (DAI), and histopathological changes. Interestingly, a significant decrease was observed in total numbers of aberrant crypt foci (ACFs) and tumors with DRB supplementation. Furthermore, DRB supplementation suppressed the expression of pro-inflammatory cytokines (IL-6) and inflammatory mediators (NF-κB and COX-2) through the inactivation of the NF-κB signaling pathway. The administration of DRB revealed a negative effect on cancer cell proliferation by repressing the expression of nuclear β-catenin, cyclin D1, and c-Myc. These findings suggest that DRB supplementation mitigates chronic inflammation and cancer cell proliferation and delays tumorigenesis in rat AOM/DSS-induced colitis-associated CRC. Therefore, the establishment of DRB as a natural dietary food-derived chemopreventive agent has the potential to have a significant impact on cancer prevention in the global population.
脱脂米糠（DRB）因其营养和功能特性而在全球范围内广受欢迎。新出现的证据表明，DRB是膳食纤维和酚类化合物的潜在来源，据称具有多种健康益处。然而，关于其化学预防功效的了解较少。在本研究中，我们测定并研究了DRB的营养成分及其对大鼠由氧化偶氮甲烷和葡聚糖硫酸钠（AOM/DSS）诱导的结肠炎相关结直肠癌（CRC）的化学预防作用。结果显示DRB中存在几种生物活性化合物，如膳食纤维、植酸和酚酸。此外，补充DRB可减轻CRC症状的进展，如结肠缩短、疾病活动指数（DAI）和组织病理学变化。有趣的是，补充DRB后异常隐窝病灶（ACF）和肿瘤的总数显著减少。此外，补充DRB通过使NF-κB信号通路失活，抑制促炎细胞因子（IL-6）和炎症介质（NF-κB和COX-2）的表达。给予DRB通过抑制核β-连环蛋白、细胞周期蛋白D1和c-Myc的表达，对癌细胞增殖产生负面影响。这些发现表明，补充DRB可减轻大鼠AOM/DSS诱导的结肠炎相关CRC中的慢性炎症和癌细胞增殖，并延迟肿瘤发生。因此，将DRB确立为天然膳食来源的化学预防剂可能对全球人群的癌症预防产生重大影响。
