西红花酸对高脂血症家兔LDL氧化易感性及血清Ox-LDL水平的影响

Effects of Crocetin on the Susceptibility of LDL to Oxidation and Serum Level of Ox-LDL in Hyperlipidemic Rabbits

目的:观察西红花酸对高脂血症家兔低密度脂蛋白(LDL)氧化易感性及血清氧化低密度脂蛋白(Ox-LDL)水平的影响,并探讨其可能机制。方法:采用喂饲高脂饲料方法建立家兔高脂血症模型,ELISA法测定血清Ox-LDL水平;分离LDL,体外测定其氧化易感性;测定血清总抗氧化能力(TAC)及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPX)活性。结果:西红花酸能显著降低高脂血症家兔LDL氧化易感性和血清Ox-LDL水平;西红花酸30mg·kg-1能明显降低血清TC,TG,LDL-C水平,而15mg·kg-1对血脂水平无明显影响,高,低剂量组皆可显著提高血清TAC及SOD,GPX活性。结论:西红花酸能明显降低高脂血症家兔LDL氧化易感性及血清Ox-LDL水平,其机制与提高血清SOD,GPX活性、提高血清TAC有关。

Objective： To study the effects of crocetin on the susceptibility of low density lipoprotein （LDL） to oxidation and serum level of oxidized LDL （Ox-LDL） in hyperlipidenfic rabbits and the possible mechanisms involved. Methods： Hyperlipidemic rabbits were established by feeding the animals with a high lipid diet for 4 weeks. Serum level of Ox-LDL was determined by sandwich ELISA. Following isolation of LDL, the susceptibility of LDL to oxidation was evaluated by in vitro assay. Serum levels of lipids, serum total antioxidant capacity （TAC） and the activities of superoxide dismutase （SOD） and glutathione peroxidase （GPX） were also determined. Results： Crocetin of dosages of 30 and 15 mg ·kg^-1 markedly reduced serum level of Ox-LDL and the susceptibility of LDL to oxidation, while serum levels of lipids were reduced only by 30 mg· kg^-1 of crocetin. Both dosages of crocetin significantly enhanced serum TAC and the activities of SOD and GPX. Conclusion： Crocetin significantly reduces serum level of Ox-LDL and the susceptibility of LDL to oxidation in hyperlipidemic rabbits, which might be attributed, at least partly, to the enhancement of serum TAC and the activities of SOD and GPX.