天然产物化学英文版---副本汇总.doc

科技英语与文献检索翻译作业Effect of Oryzanol and Ferulic Acid on the Glucose Metabolism of Mice Fed with a High-Fat DietMyoung Jin Son, Catherine W. Rico, Seok Hyun Nam, and Mi Young KangAbstract: The effects of oryzanol and ferulic acid on the glucose metabolism of high-fat-fed mice were investigated. Male C57BL/6N mice were randomly divided into 4 groups: NC group fed with normal control diet; HF group fed with high-fat (17%) diet; HF-O group fed with high-fat diet supplemented with 0.5% oryzanol; and HF-FA group fed with high-fat diet supplemented with 0.5% ferulic acid. All animals were allowed free access to the experimental diets and water for 7 wk. At the end of the experimental period, the HF-O and HF-FA groups exhibited significantly lower blood glucose level and glucose-6-phosphatase (G6pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities, and higher glycogen and insulin concentrations and glucokinase (GK) activity compared with NC and HF groups. The results of this study illustrate that both oryzanol and ferulic acid could reduce the risk of high-fat diet-induced hyperglycemia via regulation of insulin secretion and hepatic glucose-regulating enzyme activities.Keywords: diabetes, ferulic acid, high-fat-fed mice, hypoglycemic effect, oryzanolIntroductionChronic consumption of a high-fat diet has been associated with the development of obesity and type 2 diabetes mellitus (Hill and others 1992; Bray and others 2004). Scientific studies have shown that excessive intake of dietary fat results in increased body weight and poor glucose regulation (Alsaif and Duwaihy2004; Petro and others 2004; Messier and others 2007). Diabetes is characterized by hyperglycemia that results in the generation of free radicals leading to oxidative stress (West 2000). Due to changes in lifestyle patterns, particularly poor eating habit and sedentary lifestyle, the incidence of diabetes has rapidly increased in epidemic proportions. Around 171 million cases of diabetes worldwide were reported in 2001 and it was projected that by 2030, 366 million people will have diabetes (Wild and others 2004). With this increasing global prevalence of diabetes, the need for therapeutic measures against the disease has become stronger and more urgent. A wide range of oral medicines are currently being used for treating diabetes. However, various adverse effects and high rates of secondary failures have been associated with the available antidiabetic medicines (Inzucchi 2002). Thus, finding natural drugs with hypoglycemic activity has now become the focus of scientists and researchers. At present, there is a considerable public and scientific interest in utilizing phytochemicals for the treatment and prevention of various diseases. Naturally occurring phenolic compounds, such as oryzanol and ferulic acid, are known to have strong antioxidant activities (Wang and others 2002; Srinivasan and others 2007). Oryzanol is a mixture of ferulic acid (4-hydroxy-3-methoxycinnamic acid) esters with phytosterols (Lerma-Garcia and others 2009) and primarily extracted from rice bran. Ferulic acid is commonly found in fruits and vegetables, including banana, broccoli, rice bran, and citrus fruits (Zhao and Moghadasian 2008). Both oryzanol and ferulic acid possess several physiological proper ties, such as reduction of serum cholesterol levels (Wilson and others 2007), inhibition of tumor promotion (Yasukawa and others 1998), and protective action against liver injury (Choti-markorn and Ushio 2008). Oxidative stress is regarded as the key factor in the development of diabetes and its associated health disorders. The high-fat diet fed C 57BL/6 mouse model has long been used by researchers in investigating the pathophysiology of impaired glucose tolerance and type 2 diabetes and for the development of new treatments (Surwit and others 1988; Surwit and other s 1991; Schreyer and others 1998; Winzell and Ahren 2004). Since diabetes is a free radical mediated disease, the strong antioxidant activity of oryzanol and ferulic acid may be useful in preventing the development of diabetic hyperglycemia under a high-fat diet. There are limited reports on the physiological functions of these phenolic compounds in relation to glucose metabolism in animal models. Thus, this study was conducted to investigate the effects of dietary feeding of oryzanol and ferulic acid on the glucose metabolism in high-fat-fed C57BL/6 mice.1. Materials and Methods1.1 Animals and dietsTwenty-four male C57BL/6N mice of 4 wk of age, weighing 12 g, were obtained from Orient Inc. (Seoul, Korea). They were individually housed in stainless steel cages in a room maintained at 25C with 50% relative humidity and 12/12 h light/dark cycle and fed with a pelletized chow diet for 2 wk after arrival. The mice were then randomly divided into 4 dietary groups (n = 6). The 1st and 2nd groups were fed with a normal and high-fat (17%, w/w) diets, respectively, while the other 2 groups were fed with high-fat diet supplemented with either 0.5% oryzanol or 0.5% ferulic acid (98% pure, Tsuno, Osaka, Japan). The composition of the experimental diet (Table 1) was based on the AIN-76 semisynthetic diet. The mice were fed for 7 wk and allowed free access to food and water during the experimental period. The body weight gain was measured weekly. At the end of the experimental period, the mice were anaesthetized with 60-L Ketamine-HCl following a 12 h fast and sacrificed. Blood samples were collected and centrifuged at 1000 g for 15 min at 4C to obtain the plasma. The livers were removed, rinsed with physiological saline, and stored at 70C until analysis. The current study protocol was approved by the Ethics Committee of Kyungpook Natl. Univ. for anima studies.1.2 Measurement of blood glucose levelThe blood glucose level in mice was measured using Accu-Chek Active Blood Glucose Test Strips (Roche Diagnostics GmbH, Germany). Blood samples were drawn from the tail vein of the mice before and after 3 and 7 wk of feeding the animals with experimental diets. 1.3 Determination of glycogen and insulin levelsThe glycogen concentration in liver was determined using the method described by Seifter and others (1950)。 Fresh liver (100 mg) was mixed with 30% KOH and heated at 100C for 30 min. The mixture was then added with 1.5 mL ethanol (95%) and kept over night at 4C. The pellet was mixed with 4 mL distilled water. A 500 L of the mixture was added with 0.2% anthrone (in 95% H2SO4) and the absorbance of the sample solution was measured at 620 nm. The results were calculated on the basis of a standard calibration curve of glucose. The insulin content was measured using enzyme-linked immunosorbent assay (ELISA) kits (TMB Mouse Insulin ELISA kit, Sibayagi, Japan).1.4 Measurement of hepatic glucose-regulating enzyme activitiesThe hepatic enzyme source was prepared according to the method developed by Hulcher and Oleson (1973). The glucokinase (GK) activity was determined based from the method of Davidson and Arion (1987) with slight modification. A 0.98 mL of the reaction mixture containing 50 mM Hepes-NaOH(pH 7.4), 100 mM KCl, 7.5 m M MgCl2, 2.5 mM dithioerythritol, 10 mg/mL albumin, 10 mM glucose, 4 units of glucose-6-phosphate ( G6pase) dehydrogenase, 50 mM NAD+, and 10 L cytosol was preincubated at 37C for 10 min. The reaction was initiated with the addition of 10 L of 5 mM ATP and the mixture was incubated at 37C for 10 min. The G6pase activity was measured using the method described by Alegre and others (1988). The reaction mixture contained 765 L of 131.58 mM Hepes-NaOH (pH 6.5), 100 L of 18 mM EDTA ( pH 6.5), 100 L of 265 mM G6pase, 10 L of 0.2 M NADP+, 0.6 IU/mL mutarotase, and 0.6 IU/mL glucose dehydrogenase. the mixture was added with 5 L microsome and incubated at 37C for 4 min. The change in absorbance at 340 nm was measured. The phosphoenolpyruvate carboxykinase (PEPCK) activity was determined based from the method developed by Bentle and Lardy (1976). The reaction mixture consisted of 72.92 mM sodium Hepes (pH 7.0), 10 mM dithiothreitol, 500 mM NaHCO3, 10 mM MnCl2, 25 mM NADH, 100 mM IDP, 200 mM PEP, 7.2 unit of malic dehydrogenase, and 10L cytosol. The enzyme activity was determined based from the decrease in the absorbance of the mixture at 350 nm at 25C.在25C 350nm。1.5 Statistical analysisAll data are presented as the mean SE. The data were evaluated by 1-way ANOVA using a Statistical Package for Social Sciences software program (SPSS Inc., Chicago, Ill., U.S.A.) and the differences between the means we reassessed using Duncans multiple range test. Statistical significance was considered at P 98%的纯,参会者,大阪,日本)。实验饮食的组成(表1)是基于ain - 76半合成的饮食。7周的老鼠,允许自由获取食物和水在实验期间。每周身体体重测量。在实验周期结束后,小鼠麻醉与60-L Ketamine-HCl 12 h后快速和牺牲。血液样本收集和离心机在1000 g15分钟4C获得等离子体。肝脏被移除,用生理盐水冲洗,并存储在70C直到分析。当前的研究协议是变异性庆北的经伦理委员会批准。大学生命研究。1.2测量血糖水平小鼠的血糖水平是衡量使用Accu-Chek活跃的血糖测试条(德国罗氏诊断GmbH)。血液样本取自小鼠尾静脉的前后3和7周的饮食喂养的动物实验。1.3测定糖原和胰岛素水平肝脏的糖原含量是决定使用Seifter描述的方法和其他人(1950)。新鲜肝脏(100毫克)与30% KOH和混合加热30分钟的100C。然后添加1.5毫升乙醇混合物(95%)和保持在晚上4C。颗粒与4毫升蒸馏水混合。500L混合物添加0.2%蒽酮硫酸(95%)和样品溶液的吸光度测量在620海里。计算结果的基础上,一个标准的校准曲线的葡萄糖。胰岛素含量测定采用酶联免疫吸附试验(ELISA)试剂盒(三甲小鼠胰岛素酶联免疫试剂盒,Sibayagi,日本)。1.4测量肝glucose-regulating酶的活动肝酶源制备根据方法由Hulcher和奥尔森(1973)。葡糖激酶(门将)活动确定方法的基础戴维森和Arion(1987)与轻微的修改。0.98毫升的反应混合物50 mM Hepes-NaOH(pH值7.4),100毫米氯化钾,MgCl2 7.5米,2.5毫米dithioerythritol,10毫克/毫升白蛋白,10毫米葡萄糖,4单位glucose-6-phosphate(G6pase)脱氢酶,NAD + 50毫米,和10L细胞溶质在37 preincubatedC 10分钟。反应开始的10L 5毫米ATP和混合物在37孵化C 10分钟。G6pase活动被全部用描述的方法测量等人(1988)。131.58毫米的反应混合物含有765L Hepes-NaOH(pH值6.5),100L 18毫米EDTA(pH值6.5),100L 265毫米G6pase 10L辅酶ii + 0.2米,0.6国际单位/毫升mutarotase,0.6国际单位/毫升葡萄糖脱氢酶。混合添加5L微粒体和孵化37C 4分钟。在340纳米测量吸光度的变化。磷酸烯醇丙酮酸的carboxykinase(PEPCK)活动是基于确定的方法由Bentle和拉迪(1976)。72.92毫米钠的反应混合物由玫瑰(pH值7.0),10毫米二硫苏糖醇,500毫米NaHCO3,10毫米MnCl2,25毫米NADH IDP 100毫米,200毫米PEP,7.2单位的苹果酸脱氢酶,和10l胞质。基于酶活性测定的吸光度下降的混合物在350 nm 25C。在25C 350海里。1.5统计分析所有数据提出了均值SE。方法进行评估的数据方差分析使用社会科学统计软件包软件程序(SPSS Inc .)、芝加哥、生病。、美国)和之间的差异意味着我们重新使用邓肯的多个测试范围。统计显著性被认为是在P 0.05。2结果2.1身体体重增加没有显著差异之前在动物体重组与实验饮食喂养的老鼠(表2)。老鼠是恒定的日常食物摄取(3 g / d)在整个研究。实验周期的结束,然而,显著增加在动物喂食高脂肪的饮食(高频组)相对于控制的老鼠(NC组)。当老鼠与高脂肪饮食补充谷维素(HF-O组)或阿魏酸(HF-FA组)也显示更高的体重增加与NC组相比,他们的身体体重明显低于高频组。HF-O和HF-FA团体之间,后者表现出较低的最终体重。2.2血糖水平之前最初的小鼠的血糖水平与实验饮食喂养各组之间没有显著差异(图1)然而,高脂肪喂养导致显著增加3周后小鼠的血糖水平。数控组还显示葡萄糖含量的增加类似于高频老鼠。最后工作,HF-O HF-FA老鼠表现出大幅降低葡萄糖水平较高频和对照组。2.3糖原和胰岛素水平糖原和胰岛素浓度远远高于HF-O和HF-FA老鼠比控制和高频的(表3)。2.4肝glucose-regulating酶的活动肝GK酶活性明显高于在白鼠谷