糙米通过激活维 A 酸合成增加脂质氧化来抑制肥胖 Zucker(fa/fa)大鼠非酒精性脂肪性肝病的发展。

Brown Rice Inhibits Development of Nonalcoholic Fatty Liver Disease in Obese Zucker (fa/fa) Rats by Increasing Lipid Oxidation Via Activation of Retinoic Acid Synthesis.

机构信息

Department of Agricultural Chemistry, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo, Japan.

Alpha Food Co. Ltd., Shimane, Japan.

出版信息

J Nutr. 2021 Sep 4;151(9):2705-2713. doi: 10.1093/jn/nxab188.

DOI:10.1093/jn/nxab188

PMID:34224565

Abstract

BACKGROUND

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).

OBJECTIVES

We investigated the effect of rice consumption on NAFLD and its underlying molecular mechanism.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

摘要

背景

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。

目的

我们研究了大米摄入对 NAFLD 的影响及其潜在的分子机制。

方法

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。

结果

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）。