Perez-Ternero Cristina, Claro Carmen, Parrado Juan, Herrera Maria Dolores, Alvarez de Sotomayor Maria
Department of Pharmacology, School of Pharmacy, University of Seville, Seville, Spain.
Department of Pharmacology, School of Pharmacy, University of Seville, Seville, Spain.
Nutrition. 2017 May;37:22-29. doi: 10.1016/j.nut.2016.12.005. Epub 2016 Dec 22.
Rice bran is a by-product of rice milling and is rich in bioactive molecules such as γ-oryzanol, phytosterols, and tocotrienols. The rice bran enzymatic extract (RBEE) previously showed vessel remodeling prevention and lipid-lowering, antioxidant, anti-inflammatory, and antiapoptotic activities. The aim of this study was to identify RBEE hypolipidemic mechanisms and to study the effects of RBEE on the progression of atherosclerosis disease and linked vascular dysfunction and liver steatosis in apolipoprotein E-knockout (ApoE-/-) mice fed low- or high-fat (LFD, HFD, respectively) and cholesterol diets.
ApoE-/- mice were fed LFD (13% kcal) or HFD (42% kcal) supplemented or not supplemented with 1 or 5% RBEE (w/w) for 23 wk. Then, serum, aorta, liver, and feces were collected and flash frozen for further analysis.
RBEE supplementation of HFD improved serum values by augmenting high-density lipoprotein cholesterol and preventing total cholesterol and aspartate aminotransferase increase. 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity was attenuated (1 and 5% RBEE) and cholesterol excretion increased (5% RBEE). Diet supplementation with 5% RBEE reduced plaque development regardless of the diet. In HFD-fed mice, both doses of RBEE reduced lipid deposition and macrophage infiltration in the aortic sinus and downregulated intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression. None of these effects was observed in mice fed LFD. Liver steatosis was reduced by RBEE supplementation of LFD (1% RBEE) and HFD (1 and 5% RBEE) and nuclear peroxisome proliferator-activated receptor-α expression upregulated in the HDF 5% RBEE group.
Regular consumption of RBEE-supplemented HFD reduced plaque development and liver steatosis by decreasing inflammation and hyperlipidemia through an HMG-CoA reductase activity and lipid excretion-related mechanism.
米糠是稻米加工的副产品，富含γ-谷维素、植物甾醇和生育三烯酚等生物活性分子。米糠酶提取物（RBEE）先前已显示出预防血管重塑以及降脂、抗氧化、抗炎和抗凋亡活性。本研究的目的是确定RBEE的降血脂机制，并研究RBEE对喂食低脂或高脂（分别为LFD、HFD）及胆固醇饮食的载脂蛋白E基因敲除（ApoE-/-）小鼠动脉粥样硬化疾病进展以及相关血管功能障碍和肝脏脂肪变性的影响。
给ApoE-/-小鼠喂食添加或不添加1%或5%（w/w）RBEE的LFD（13%千卡）或HFD（42%千卡），持续23周。然后，收集血清、主动脉、肝脏和粪便并速冻以备进一步分析。
在HFD中添加RBEE可通过增加高密度脂蛋白胆固醇并防止总胆固醇和天冬氨酸转氨酶升高来改善血清值。3-羟基-3-甲基戊二酰辅酶A（HMG-CoA）还原酶活性减弱（1%和5% RBEE），胆固醇排泄增加（5% RBEE）。无论饮食如何，添加5% RBEE的饮食均可减少斑块形成。在喂食HFD的小鼠中，两种剂量的RBEE均可减少主动脉窦中的脂质沉积和巨噬细胞浸润，并下调细胞间黏附分子-1和血管细胞黏附分子-1的表达。在喂食LFD的小鼠中未观察到这些作用。通过在LFD（1% RBEE）和HFD（1%和5% RBEE）中添加RBEE可减轻肝脏脂肪变性，并且在HDF 5% RBEE组中核过氧化物酶体增殖物激活受体-α表达上调。
经常食用添加RBEE的HFD可通过HMG-CoA还原酶活性和脂质排泄相关机制减少炎症和高脂血症，从而减少斑块形成和肝脏脂肪变性。
