余甘子对动脉粥样硬化家兔血浆总抗氧化能力及丙二醛和内皮素1水平的影响

背景余甘子含有丰富的维生素C、有机酸及矿物质.现代研究表明,余甘子还含有防癌、抗衰老等功效.近年来,对余甘子功能因子的研究及其相应功能食品的开发越来越引起重视.其降脂作用及其体外抗氧化作用已得到证实,但尚缺乏足够的基础研究支持.目的探讨余甘子提高高脂血症家兔机体抗氧化能力及保护血管内皮功能作用及其机制.设计以实验动物为研究对象的随机对照的实验研究.单位一所大学医院的动脉硬化实验室.材料健康新西兰家兔24只,雄性,体质量(2.2±0.5)kg.方法实验于2001-09/2002-05在北京市安贞医院动脉硬化实验室完成.将24只新西兰雄性白兔随机分为对照组、余甘子粉组(4 g/kg·d)和高胆固醇血症模型组,每组8只,余甘子和高胆固醇组实验期间均饲以高胆固醇饮食.采用酶法测定血清脂质含量;化学法测定血浆总抗氧化能力和丙二醛含量;放免法测定血浆内皮素-1含量;地高辛标记探针,组织原位杂交检测主动脉内膜内皮素mRNA表达;图象分析法测定主动脉内膜粥样硬化斑块面积,和内膜面积与中膜面积比值.主要观察指标主要结局为家兔血脂水平,血清丙二醛浓度,及动脉斑块面积比较.次要结局为血浆内皮素-1的变化.结果实验8周后余甘子果粉组与高脂组相比,①血清总胆固醇(total cholesterol,TC)、三酰甘油(triglyceride,TG)、低密度脂蛋白胆固醇(Low density lipoprotein cholesterol,LDL-C)水平显著下降分别为(11.70±1.73),(14.32±2.22)mmol/L,P<0.05;(0.740±0.107),(1.450±0.220)mmol/L,P<0.01],血清高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)增高(1.652±0.155),(1.179±0.142)mmol/L,P<0.01].②血浆丙二醛显著降低(3.88±0.51),(6.29±1.43)mmol/L, P<0.01]而总抗氧化能力显著增高(10.771±1.818),(7.350±1.158)mmol/L,P<0.05].③光镜下斑块面积、内膜面积与中膜面积比值明显降低(39.46±6.53),(50 69±12.36)mmol/L,P<0.05;(0.62±0.32),(1.38±0.38)mmol/L,P<0.01].④血浆内皮素-1显著降低;主动脉内膜内皮素-1基因杂交阳性颗粒比高脂组明显减少.结论余甘子可能通过调整家兔脂质代谢、提高抗氧化能力减少脂质过氧化、保护内皮功能抑制动脉内膜内皮素-1基因表达而起到防止兔实验性粥样斑块的形成的作用.

Effect of emblic leafflower fruit on total antioxidation and levels of malondialdehyde as well as endothelin in plasma in rabbits with atherosclerosis

BACKGROUND: Emblic leafflower fruit contains rich vitamin C, organic acid and mineral substance. It is indicated in modern research that emblic leaafflower fruit acts on preventing from cancer and anti-aging too. In recent years, more and more concerns have been paid to the researches on functional factor of emblic leafflower fruit and the development of the relevant functional food. It has been verified that emblic leafflower fruit acts on reducing lipid and anti-oxidation in vitro, but there are still lacks of enough basic researches to support it.OBJECTIVE: To probe into mechanism of emblid leafflower fruit on anti-oxidation and protection of vascular endothelial function in rabbits with hyperlipemia.DESIGN: Randomized controlled experimental study based on the experimental animals.SETTING: Atherosclerosis(As) experimental room in a university hospital.MATERIALS: Totally 24 normal NewZealand male rabbits, mass weighted (2.2±0.5) kg.METHODS: The experiment was performed in As Experimental Room of Beijing Anzhen Hospital from September 2001 to May 2002. Totally 24 New Zealand male rabbits were randomized into the control, the power of emblid leafflower fruit group(powder group)(4 g/kg day) and hypercholesterolemia model group (model group), 8 rabbits in each group. In both power and model groups, the rabbits were fed with hypercholesterol food. Oxidase method was applied to assay the content of serum lipid, chemical method to assay the plasma total anti-oxidation and the content of malondialdehyde (MDA), radio-immune method to assay the content of plasma endothelin-1 (ET-1), digoxin labeled probe and tissue hybridism in situ to assay the expression of endothelin mRNA of aortic tunica intima, and image analyzer to assay the area of aortic intimal atherosclerosis plaque and the ratio between the area of tunica intima and the area of tunica media.MAIN OUTCOME MEASURES: The primary outcomes included blood lipid level, serum MDA concentration and the comparison of artery plaque areas. The secondary outcomes included the changes in plasma ET-1.RESULTS: By the comparison between the powder group and model group in triglyceride(TG) and low density lipoprotein cholesterol(LDL-C) were significantly reduced (11.70 ± 1.73), (14.32 ±2.22) mmol/L, P<0.05; (0.740 ± 0.107), (1.450 ± 0.220) mmol/L, P <0.01 successively]and thehigh density lipoprotein cholesterol(HDL-C) was increased MDA was significantly decreased (3.88 ± 0.51 ), (6. 29 ± 1.43 ) mmol / L,P < 0.01 ] and the total anti-oxidation significantly increased (10. 771der photo-microscope that the plaque area and the ratio between intima area and media area were remarkably decreased (39.46±6.53), (50.69± 12.36)mmol/L, P < 0.05; (0. 62 ±0. 32), (1.38 ±0.38) mmol/L, Pgranules of aortic intima ET-1 gene were rem~kably decreased compared with the model group.CONCLUSION: Emblic leafflower fruit prevents from the formation of experimental atheromatous plaque in rabbits probably by regulating rabbit lipid metabolism, improving anti-oxidation to reduce lipid peroxidation and protecting endothelial function to inhibit the expression of artery intima ET-1 gene.