酵母脂多糖对饲喂高脂肪日粮小鼠脂质代谢，病理变化，氧化状态，生化指标和基因表达的影响

发布时间：2018-07-04 20:55

  本文选题：酵母脂多糖 + 肥胖　； 参考：《南京农业大学》2015年硕士论文

【摘要】：背景肥胖与脂肪组织的增多相关,并且通常伴随着高脂血症、炎症和血栓同时出现。通过营养干预来控制甚至治疗肥胖及其并发症的研究是十分必要的。酵母脂多糖作为食品添加剂对机体的有益作用十分广泛。酵母脂多糖可以通过聚集胆汁酸、降低肠道前部的活动和促进纤维消化来降低机体内的胆固醇水平,因此它作为一种潜在的降胆固醇添加剂而引起广泛关注。目的本试验的目的是研究酵母脂多糖对饲喂高脂肪日粮小鼠的脂质代谢、生化指标、抗氧化活性、病理损伤和基因表达的影响。方法选取60只平均体重为23g的4周龄雌性ICR小鼠,随机分为四组,分别为一个阴性对照组和三个高脂肪日粮组。A组小鼠饲喂正常饮食作为阴性对照组,B组小鼠饲喂高脂肪日粮作为阳性对照组,C组小鼠饲喂高脂肪日粮的同时给予低剂量酵母脂多糖(剂量为250mg/kg,每周经口饲喂三次),D组小鼠饲喂高脂肪日粮的同时给予高剂量酵母脂多糖(剂量为450mg/kg,每周经口饲喂三次)。小鼠在20-24℃,相对湿度为50-70%,12小时光照-12小时黑暗,饲喂正常日粮的条件下饲养一周以适应环境。结果结果显示,给予小鼠高脂肪日粮会导致体重、血清脂、脂肪组织和肝脏脂肪堆积明显增加,而在日粮中添加适量酵母脂多糖可以显著抑制体重增长和脂肪组织堆积,降低摄食量、食物吸收率和肝脏胆固醇水平,同时还可以降低脂肪肝和脂肪变性发生的概率,并且酵母脂多糖的这种作用是剂量依赖的。除此之外,酵母脂多糖还可通过增加抗氧化酶活性(SOD活性和GSH、MDA水平)来降低脂质过氧化水平。为了阐明酵母脂多糖的作用机制,我们测定了肝脏β-氧化基因、胆固醇生成和脂肪生成相关基因的表达量,结果显示酵母脂多糖是通过下调SREBP1、FAS、SCD1基因的mRNA水平来抑制脂肪生成,通过上调PPARα、CPT2基因的mRNA水平提高β-氧化作用。这些研究结果表明,日粮中添加酵母脂多糖可以通过抑制脂肪的消化来显著改善高脂日粮诱导产生的肥胖。结论总之,本研究表明酵母脂多糖可通过β-葡萄糖表现出抗肥胖作用,并可以改善肝细胞抗氧化活性,降低体内甘油三酯水平,增加肝脏脂质代谢(通过下调SREBP1、FAS、SCD1基因的mRNA水平来抑制脂肪生成和上调PPARα、CPT2基因的mRNA水平来提高β-氧化作用,从而提高血清高密度脂蛋白胆固醇的水平,降低低密度脂蛋白胆固醇的水平)。高剂量组表现出更加显著的作用。
[Abstract]:Background Obesity is associated with increased adipose tissue and is usually accompanied by hyperlipidemia inflammation and thrombosis. It is necessary to control and even treat obesity and its complications through nutritional intervention. Yeast lipopolysaccharide is widely used as food additive. Yeast lipopolysaccharide can reduce cholesterol level by aggregating bile acid, reducing the activity of anterior intestinal tract and promoting fiber digestion, so it is a potential cholesterol-lowering additive. Objective to study the effects of yeast lipopolysaccharide on lipid metabolism, biochemical index, antioxidant activity, pathological injury and gene expression in mice fed with high fat diet. Methods 60 female ICR mice with an average weight of 23g were randomly divided into four groups. One negative control group and three high fat diet group. Group A mice were fed normal diet as negative control group. Group B mice were fed high fat diet as positive control group C group mice were fed high fat diet. Low dose yeast lipopolysaccharide (250 mg / kg, three times a week) was given to mice in group D with high fat diet (dose 450 mg / kg, oral three times a week). The mice were fed with normal diet for one week in order to adapt to the environment. The mice were exposed to light for 12 hours at 20-24 鈩，

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