Cha Jae Hoon, Kim Sun Rim, Kang Hyun Joong, Kim Myung Hwan, Ha Ae Wha, Kim Woo Kyoung
Department of Food Science and Nutrition, Dankook University, 152, Juljeon-ro, Suji-gu, Yonin-si, Gyeonggi 16890, Korea.
Agriculture Science Technology, 300 Nongsaengmyeong-ro, Wansan-gu, Jeonju-si, Jeonbuk 54875, Korea.
Nutr Res Pract. 2016 Oct;10(5):501-506. doi: 10.4162/nrp.2016.10.5.501. Epub 2016 Jul 4.
BACKGROUND/OBJECTIVES: Corn silk (CS) extract contains large amounts of maysin, which is a major flavonoid in CS. However, studies regarding the effect of CS extract on cholesterol metabolism is limited. Therefore, the purpose of this study was to determine the effect of CS extract on cholesterol metabolism in C57BL/6J mouse fed high-fat diets.
MATERIALS/METHODS: Normal-fat group fed 7% fat diet, high-fat (HF) group fed 25% fat diet, and high-fat with corn silk (HFCS) group were orally administered CS extract (100 mg/kg body weight) daily. Serum and hepatic levels of total lipids, triglycerides, and total cholesterol as well as serum free fatty acid, glucose, and insulin levels were determined. The mRNA expression levels of acyl-CoA: cholesterol acyltransferase (ACAT), cholesterol 7-alpha hydroxylase (CYP7A1), farnesoid X receptor (FXR), lecithin cholesterol acyltransferase (LCAT), low-density lipoprotein receptor, 3-hyroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), adiponectin, leptin, and tumor necrosis factor α were determined.
Oral administration of CS extract with HF improved serum glucose and insulin levels as well as attenuated HF-induced fatty liver. CS extracts significantly elevated mRNA expression levels of adipocytokines and reduced mRNA expression levels of HMG-CoA reductase, ACAT, and FXR. The mRNA expression levels of CYP7A1 and LCAT between the HF group and HFCS group were not statistically different.
CS extract supplementation with a high-fat diet improves levels of adipocytokine secretion and glucose homeostasis. CS extract is also effective in decreasing the regulatory pool of hepatic cholesterol, in line with decreased blood and hepatic levels of cholesterol though modulation of mRNA expression levels of HMG-CoA reductase, ACAT, and FXR.
背景/目的：玉米须提取物含有大量的玉米黄素，这是玉米须中的主要黄酮类化合物。然而，关于玉米须提取物对胆固醇代谢影响的研究有限。因此，本研究的目的是确定玉米须提取物对高脂饮食喂养的C57BL/6J小鼠胆固醇代谢的影响。
材料/方法：正常脂肪组喂食7%脂肪饮食，高脂（HF）组喂食25%脂肪饮食，高脂加玉米须（HFCS）组每天口服玉米须提取物（100毫克/千克体重）。测定血清和肝脏中的总脂质、甘油三酯和总胆固醇水平以及血清游离脂肪酸、葡萄糖和胰岛素水平。测定酰基辅酶A：胆固醇酰基转移酶（ACAT）、胆固醇7-α羟化酶（CYP7A1）、法尼醇X受体（FXR）、卵磷脂胆固醇酰基转移酶（LCAT）、低密度脂蛋白受体、3-羟基-3-甲基戊二酰辅酶A还原酶（HMG-CoA还原酶）、脂联素、瘦素和肿瘤坏死因子α的mRNA表达水平。
高脂饮食同时口服玉米须提取物可改善血清葡萄糖和胰岛素水平，并减轻高脂饮食诱导的脂肪肝。玉米须提取物显著提高了脂肪细胞因子的mRNA表达水平，并降低了HMG-CoA还原酶、ACAT和FXR的mRNA表达水平。HF组和HFCS组之间CYP7A1和LCAT的mRNA表达水平无统计学差异。
高脂饮食补充玉米须提取物可改善脂肪细胞因子分泌水平和葡萄糖稳态。玉米须提取物还可有效降低肝脏胆固醇的调节池，这与通过调节HMG-CoA还原酶、ACAT和FXR的mRNA表达水平降低血液和肝脏中的胆固醇水平一致。
