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《中国食品添加剂》2015,(9)
目的:研究黑米对小鼠血脂以及肝脏中胆固醇代谢相关基因及蛋白表达的影响。方法:雄性C57BL/6J小鼠随机分为4组,以玉米淀粉为碳水化合物来源的高脂高胆固醇膳食组为对照,实验组分别在高脂饲料中添加白米(精)和黑米(低剂量C+BL和高剂量C+BH)代替玉米淀粉。测定血清总胆固醇(TC)、甘油三酯(TG)和高密度脂蛋白胆固醇(HDL-C)水平,Real-time PCR(RT-PCR)法检测肝脏中胆固醇代谢调控相关基因HMG-Co A-R、LXR-α、SREBP-2、LDL-R、CYP7A1等的m RNA表达水平,Western blot法检测LDL-R和CYP7A1的蛋白表达水平。结果:白米组血清中TC、TG、HDL-C含量较对照组无统计学差异,但黑米组血清中TC和TG含量较对照组降低,且HDL-C显著升高(P0.05)。RT-PCR结果显示,与高脂组相比,黑米添加组LXR-α、SREBP-2、CYP7A1 m RNA表达水平均上调(P0.05)。与高脂组相比,C+BH组小鼠CYP7A1蛋白表达显著上调(p0.05)。结论:黑米调节机体胆固醇代谢平衡可能是通过升高血清中HDL-C含量,上调肝脏中胆固醇向胆汁酸转化酶CYP7A1的表达。 相似文献
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Mani O Körner M Ontsouka CE Sorensen MT Sejrsen K Bruckmaier RM Albrecht C 《Journal of dairy science》2011,94(3):1265-1276
The ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 play an important role in cellular cholesterol homeostasis, but their function in mammary gland (MG) tissue remains elusive. A bovine MG model that allows repeated MG sampling in identical animals at different functional stages was used to test whether 1) ABCA1 and ABCG1 protein expression and subcellular localization in mammary epithelial cells (MEC) change during the pregnancy-lactation cycle, and 2) these 2 proteins were present in milk fat globules (MFG). Expression and localization in MEC were investigated in bovine MG tissues at the end of lactation, during the dry period (DP), and early lactation using immunohistochemical and immunofluorescence approaches. The presence of ABCA1 and ABCG1 in MFG isolated from fresh milk was determined by immunofluorescence. The ABCA1 protein expression in MEC, expressed as arbitrary units, was higher during the end of lactation (12.2 ± 0.24) and the DP (12.5 ± 0.22) as compared with during early lactation (10.2 ± 0.65). In contrast, no significant change in ABCG1 expression existed between the stages. Throughout the cycle, ABCA1 and ABCG1 were detected in the apical (41.9 ± 24.8 and 49.0 ± 4.96% of cows, respectively), basal (56.2 ± 28.1 and 54.6 ± 7.78% of cows, respectively), or entire cytoplasm (56.8 ± 13.4 and 61.6 ± 14.4% of cows, respectively) of MEC, or showed combined localization. Unlike ABCG1, ABCA1 was absent at the apical aspect of MEC during early lactation. Immunolabeling experiments revealed the presence of ABCA1 and ABCG1 in MFG membranes. Findings suggest a differential, functional stage-dependent role of ABCA1 and ABCG1 in cholesterol homeostasis of the MG epithelium. The presence of ABCA1 and ABCG1 in MFG membranes suggests that these proteins are involved in cholesterol exchange between MEC and alveolar milk. 相似文献
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国产血清胆固醇试剂盒测定蛋黄胆固醇的研究 总被引:2,自引:0,他引:2
以两种国产血清胆固醇酶法试剂盒(Ⅰ、Ⅱ)测定蛋黄胆固醇含量,评价用血清胆固醇试剂盒测定食品胆固醇的可行性。并将此法与国家标准方法(Feng法)进行比较。其结果是:试剂盒Ⅰ在胆固醇409μg/管,粗脂肪8878μg/管范围内线性良好,rⅠ=0.9999,YⅠ=0.00390X+0.0040;试剂盒Ⅱ在胆固醇205μg/管,粗脂肪4439μg/管内线性良好,rⅡ=0.9994,YⅡ=0.00414X-0.0005。批内变异:C·VI=3.286%,C·VⅡ=3.774%,批间变异:C·VⅠ=4.157%,C·VⅡ=4.906%;回收率:Ⅰ为97.6~104.0%,Ⅱ为98.38~104.9%。试剂盒法与国标法相关良好;rⅠ=0.9972,YⅠ=1.049X-2.083;rⅡ=0.9989,YⅡ=0.9984X-0.6266。试剂盒酶法比国标法省略了皂化,再萃取,再抽干和试剂配制的步骤,而且可以避免强酸伤害人体和腐蚀仪器。 相似文献
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A Fourier transformed infrared (FTIR) spectroscopic method is described to estimate cholesterol after a single step extraction instead of the conventional colorimetric method. FTIR spectrum of pure cholesterol was characterized and the region between 2800 and 3200 cm−1 was used for quantitative estimation. Partial least square (PLS) and principal component regression (PCR) analysis were used for quantitative analysis. FTIR spectroscopy with chemometrics could predict the cholesterol content accurate to an r 2 greater than 0.99 and a standard error of prediction (SEP) of less than 0.98. The developed model was successfully applied to predict cholesterol in commercial dairy products and validated with standard method and recovery studies. Results indicate that FTIR spectroscopy can determine the cholesterol content in dairy products in approximately 5 min. 相似文献
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Piperine inhibits ABCA1 degradation and promotes cholesterol efflux from THP‐1‐derived macrophages
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Veronika Palme Susanne Rotter Nicole Schilcher Malsor Cukaj Dongdong Wang Angela Ladurner Elke H. Heiss Herbert Stangl Verena M. Dirsch Atanas G. Atanasov 《Molecular nutrition & food research》2017,61(4)
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《Food chemistry》2002,77(4):457-463
An efficient process for reducing yolk cholesterol by enzymatic treatment was developed in this paper. Extracellular cholesterol oxidase (COD) from a mutant Brevibacterium sp. ODG-007, showed a strong capacity in bioconversion of yolk cholesterol to cholest-4-en-3-one, especially supplemented with NaCl and lipase C, as a yolk granule solubilizer. The bioconversion process was investigated first, to obtain basic information of the process and was further optimized by analysis of parameters, including COD concentration, dilution ratio and incubation time on the cholesterol conversion, employing Response Surface Methodology (RSM) and Central Composite Design (CCD). Under the optimum operational conditions: COD concentration of 5.39 U/g yolk powder, water: solid ratio of 3.54 and incubation time of 13.75 h, up to 85.6% yolk cholesterol was reduced, and the remaining cholestenone, an effective anti obesity medicine in the product, may raise its commercial value. 相似文献
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胆固醇氧化酶的研究进展 总被引:2,自引:0,他引:2
胆固醇氧化酶在食品加工、医疗监测、生物抗虫等方面作用日益受到人们的重视,并且显示出巨大应用潜力,现已成为一大研究热点。笔者综述了产酶的微生物、酶活测定方法及发酵工艺等,并对胆固醇氧化酶的研究进行了展望。 相似文献
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研究黑米对高脂高胆固醇膳食饲喂雌性小鼠血脂水平及小肠胆固醇代谢相关基因调控的影响。将48只雌性C57BL/6J小鼠随机分成高脂对照组和三个实验组(高脂饲料中添加白米和黑米代替玉米淀粉),测定血清中总胆固醇(TC)、甘油三酯(TG)及高密度脂蛋白胆固醇(HDL-C)水平,气相色谱法检测肝脏中胆固醇含量,Real-time PCR法分析调控小肠胆固醇代谢相关基因HMG-Co A-R、MTP、ABCG5/8、ABCA1、NPC1L1等的m RNA表达水平。与高脂组相比,黑米组血清中TC和TG含量较对照组极显著降低,但白米组血清中TC、TG、HDL-C含量较对照组无统计学差异。与高脂组相比,白米组小鼠肝脏中胆固醇含量无显著变化,黑米低剂量组显著降低(P0.05),黑米高剂量组极显著降低(P0.01)。Real-time PCR结果显示,与高脂组相比,黑米添加组ABCG5、ABCA1 m RNA表达水平均显著上调(P0.01),MTP m RNA表达水平均显著下调(P0.05);黑米低剂量组ABCG8 m RNA表达水平显著升高(P0.05),高剂量组上调极显著(P0.01);黑米低剂量组NPC1L1 m RNA表达水平降低(P0.05),高剂量组下调极显著(P0.01);黑米高剂量组HMG-Co A-Rm RNA表达水平显著降低(P0.05)。结果表明,黑米对高脂高胆固醇膳食饲喂小鼠胆固醇代谢平衡的调节,可能是通过增加小肠中胆固醇排泄并抑制固醇的吸收实现的。 相似文献
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为降低胆固醇酯类水解及小肠对胆固醇的吸收,本实验体外模拟人体小肠内环境,研究EGCG和槲皮素对胆固醇酯酶活性及胆固醇胶束溶解度的抑制效果。同时比较了9种功能因子对胆固醇酯酶活性及胆固醇胶束溶解度的抑制效果。结果表明,槲皮素和EGCG均降低了胆固醇胶束溶解度,IC50值分别是2.2、0.08mg/m L,其抑制效果呈浓度依赖性;槲皮素和EGCG对胆固醇酯酶活性的IC50值分别是0.27、1.43mg/m L。槲皮素对胆固醇胶束溶解度的抑制效果小于EGCG,但是对胆固醇酯酶活性的抑制效果大于EGCG。结果初步证明了,槲皮素和EGCG延迟了餐后高胆固醇形成,对高血脂症有一定的预防和治疗作用。 相似文献
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Karuna Meghwal Vivek Sharma Darshan Lal Sumit Arora 《International Journal of Dairy Technology》2013,66(1):98-102
Grain formation is one of the critical attributes affecting consumer acceptability of ghee. It was observed that both control ghee and low‐cholesterol ghee had grains of 0.236 ± 0.006 and 0.250 ± 0.002 mm size after incubation at 29 °C for 24 h, respectively. The maximum grain yield was 63 ± 2.60% and 68 ± 1.15% at 26 °C in control and low‐cholesterol ghee, respectively. Ghee grains in both the cases were stable over a temperature range of 25° to 36 °C. Time taken by both the samples for onset of nucleation was 50 min. The study revealed that cholesterol removal did not affect the crystallisation behaviour. 相似文献
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《Food chemistry》2005,89(3):475-484
Cholesterol oxides, cholesterol, total lipids and fatty acids were determined in the lipid extracts from eight processed turkey meat products (blanquet, frankfurter, ham, meatball, smoked breast, smoked ham and roule). Cholesterol and cholesterol oxides were determined simultaneously by high performance liquid chromatography using a diode array detector at 210 nm and a refractive index detector. Only two cholesterol oxides were identified, 7-ketocholesterol (not detected up to 184 μg/100 g) and β-epoxycholesterol (not detected up to 450 μg/100 g). With the exception of the meatballs, hamburger and frankfurters, all the turkey meat products showed less than 5% fat, and could thus be considered as low fat foods. The cholesterol content varied from 32 to 43 mg/100 g, the ratio of polyunsaturated:saturated fatty acids varied from 1.1 to 1.8 and the ratio of ω6:ω3 from 18 to 28. Trans fatty acids were present in significant amounts in both hamburger and meatball. 相似文献
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Hosomi R Fukunaga K Arai H Kanda S Nishiyama T Yoshida M 《Journal of food science》2011,76(4):H116-H121
Fish protein has been shown to decrease serum cholesterol content by inhibiting absorption of cholesterol and bile acid in laboratory animals, though the mechanism underlying this effect is not yet fully understood. The purpose of this study was to elucidate the mechanism underlying the inhibition of cholesterol and bile acid absorption following fish protein intake. Male Wistar rats were divided into 2 dietary groups of 7 rats each, 1 group receiving a diet consisting of 20% casein and the other receiving a diet consisting of 10% casein and 10% fish protein. Both experimental diets also contained 0.5% cholesterol and 0.1% sodium cholate. After the rats had been on their respective diets for 4 wk, their serum and liver cholesterol contents and fecal cholesterol, bile acid, and nitrogen excretion contents were measured. Fish protein consumption decreased serum and liver cholesterol content and increased fecal cholesterol and bile acid excretion and simultaneously increased fecal nitrogen excretion. In addition, fish protein hydrolyzate prepared by in vitro digestion had lower micellar solubility of cholesterol and higher binding capacity for bile acids compared with casein hydrolyzate. These results suggest that the hypocholesterolemic effect of fish protein is mediated by increased fecal cholesterol and bile acid excretion, which is due to the digestion products of fish protein having reduced micellar solubility of cholesterol and increased bile acid binding capacity. 相似文献
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