N‐diethylnitrosamine (DEN), a well‐known carcinogen, not only induces excessive reactive oxygen species but also suppresses DNA methylation. This study investigated the effect of fermented rice bran (FRB) treatment on DEN‐induced oxidative stress through DNA methylation and telomere length analysis. To evaluate the potential protective role of FRB in oxidative stress, two different doses of FRB, DEN, and their combination were administered to mice that were preadapted or not to FRB. Glutathione‐S‐transferase P1 (GSTP1) methylation levels significantly decreased at 2 and 24 hr after FRB and DEN co‐administration in mice with and without pre‐adaptation. Moreover, GSTP1 mRNA was upregulated under DEN‐induced oxidative stress. Furthermore, changes in long interspersed nuclear element‐1 methylation were observed from the viewpoint of genomic instability. In addition, FRB preadapted mice displayed a lower telomere length ratio than the non‐adapted mice, suggesting that FRB adaptation offers advantages over the non‐adapted conditions in terms of inflammation suppression.

中文翻译：

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发酵的米糠对DEN诱导的小鼠氧化应激的影响：GSTP1，LINE-1甲基化和端粒长度比。

N-二乙基亚硝胺（DEN）是一种著名的致癌物，不仅会诱导过量的活性氧，而且会抑制DNA甲基化。本研究通过DNA甲基化和端粒长度分析研究了发酵的米糠（FRB）处理对DEN诱导的氧化应激的影响。为了评估FRB在氧化应激中的潜在保护作用，将两种不同剂量的FRB，DEN及其组合用于预先适应或不适应FRB的小鼠。在有和没有预先适应的小鼠中，FRB和DEN并用后2小时和24小时，谷胱甘肽S转移酶P1（GSTP1）甲基化水平显着降低。此外，GSTP1在DEN诱导的氧化应激下，mRNA上调。此外，从基因组不稳定性的角度观察到长时间散布的核元素-1甲基化的变化。另外，FRB预先适应的小鼠显示出比未适应小鼠低的端粒长度比，这表明就炎症抑制而言，FRB适应比非适应性小鼠具有优势。