Department of Agricultural Chemistry, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo, Japan.
Alpha Food Co. Ltd., Shimane, Japan.
J Nutr. 2021 Sep 4;151(9):2705-2713. doi: 10.1093/jn/nxab188.
White rice and its unrefined form, brown rice, contain numerous compounds that are beneficial to human health. However, the starch content of rice can contribute to obesity, a main risk factor for nonalcoholic fatty liver disease (NAFLD).
We investigated the effect of rice consumption on NAFLD and its underlying molecular mechanism.
We randomly divided 7-week-old male obese Zucker (fa/fa) rats, an animal model of NAFLD, into 3 groups (n = 10 each) fed 1 of 3 diets for 10 weeks: a control diet (Cont; AIN-93G diet; 53% cornstarch), a white rice diet (WR; AIN-93G diet with cornstarch replaced with white rice powder), or a brown rice diet (BR; AIN-93G diet with cornstarch replaced with brown rice powder). Liver fat accumulation and gene expression related to lipid and vitamin A metabolisms, including retinoic acid (RA) signaling, were analyzed.
Hepatic lipid values were significantly decreased in the BR group compared with the Cont group, by 0.4-fold (P < 0.05). The expression of genes related to hepatic fatty acid oxidation, such as carnitine palmitoyltransferase 2, was approximately 2.1-fold higher in the BR group than the Cont group (P < 0.05). The expression of peroxisomal acyl-coenzyme A oxidase 1 and acyl-CoA dehydrogenase medium chain was also significantly increased, by 1.6-fold, in the BR group compared with the Cont group (P < 0.05). The expression of VLDL-secretion-related genes, such as microsomal triglyceride transfer protein, was also significantly higher in the BR group (2.4-fold; P < 0.05). Furthermore, aldehyde dehydrogenase 1 family member A1, an RA synthase gene, was 2-fold higher in the BR group than the Cont group (P < 0.05).
Brown rice prevented development of NAFLD in obese Zucker (fa/fa) rats. The beneficial effects of pregelatinized rice on NAFLD could be manifested as increased fatty acid oxidation and VLDL secretion, which are regulated by RA signaling.
白米及其未精制形式糙米含有许多对人体健康有益的化合物。然而，大米中的淀粉含量可能导致肥胖，而肥胖是非酒精性脂肪性肝病（NAFLD）的主要危险因素之一。
我们研究了大米摄入对 NAFLD 的影响及其潜在的分子机制。
我们将 7 周龄雄性肥胖 Zucker（fa/fa）大鼠（NAFLD 的动物模型）随机分为 3 组（每组 10 只），喂养 10 周的 3 种饮食之一：对照饮食（Cont；AIN-93G 饮食；53%玉米淀粉）、白米饮食（WR；用白米粉替代 AIN-93G 饮食中的玉米淀粉）或糙米饮食（BR；用糙米粉替代 AIN-93G 饮食中的玉米淀粉）。分析肝脂肪堆积和与脂质及维生素 A 代谢相关的基因表达，包括视黄酸（RA）信号。
与 Cont 组相比，BR 组的肝脂质值显著降低，降低了 0.4 倍（P < 0.05）。BR 组与 Cont 组相比，与肝脂肪酸氧化相关的基因表达增加了约 2.1 倍，如肉碱棕榈酰基转移酶 2（P < 0.05）。过氧化物酶体酰基辅酶 A 氧化酶 1 和酰基辅酶 A 脱氢酶中链的表达也显著增加，BR 组比 Cont 组增加了 1.6 倍（P < 0.05）。BR 组与 Cont 组相比，与 VLDL 分泌相关的基因如微粒体甘油三酯转移蛋白的表达也显著升高（2.4 倍；P < 0.05）。此外，RA 合酶基因醛脱氢酶 1 家族成员 A1 在 BR 组的表达是 Cont 组的 2 倍（P < 0.05）。
糙米可预防肥胖 Zucker（fa/fa）大鼠发生 NAFLD。预糊化米对 NAFLD 的有益作用可能表现为增加脂肪酸氧化和 VLDL 分泌，这受 RA 信号调节。
