叶黄素对铁过载大鼠氧化应激水平影响的实验研究

目的:铁是人体必需的微量元素之一,但机体内铁负荷过多可诱导氧化应激,造成细胞和组织损伤。本研究通过建立铁过载大鼠模型,探讨不同剂量叶黄素对其氧化应激水平的影响。方法:60只SD雄性大鼠随机分为5组,每组12只。正常对照组大鼠饲喂基础饲料(铁含量50 mg/kg),其他大鼠均饲喂高铁饲料(铁含量1 000 mg/kg),建立铁过载模型大鼠,同时随机分为高铁负荷组、高铁+叶黄素低剂量组(10 mg/kg·bw)、高铁+叶黄素中剂量组(20 mg/kg·bw)、高铁+叶黄素高剂量组(40 mg/kg·bw)。持续喂养6w后,测定血清铁蛋白、血清铁、肝组织铁及血清和肝匀浆中总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、丙二醛(MDA)等含量。结果:与正常对照组比较,高铁负荷组大鼠血清铁及血清铁蛋白含量均升高28%(P值均0.05),肝组织铁含量升高23%(P0.01)。与高铁负荷组大鼠比较,添加叶黄素低剂量、中剂量和高剂量的高铁负荷组大鼠血清铁、血清铁蛋白及肝组织铁含量均显著降低(P值均0.05),与正常对照组水平无显著差异(P值均0.05)。氧化应激水平分析显示,高铁负荷组大鼠血清GSH-Px活力和肝匀浆GSH-Px活力比正常对照组分别降低了12%和20%(P值均0.05)。中剂量叶黄素组大鼠血清GSH-Px及CAT活力比高铁负荷组分别提高了12%、32%(P值均0.05);高剂量叶黄素组肝匀浆GSH-Px活力比高铁负荷组大鼠提高了23%(P0.05)。与正常对照组比较,高铁负荷和高铁+低剂量叶黄素组肝匀浆T-SOD活力分别降低了20%和17%(P值均0.05)。而高剂量叶黄素组大鼠肝匀浆T-SOD活力与高铁负荷和高铁+低剂量叶黄素组大鼠相比分别提高了22%和19%(P值均0.05)。高铁负荷组大鼠肝匀浆CAT活力比正常组降低了19%(P0.05),比中剂量叶黄素组下降了22%(P0.05)。结论:铁负荷过载可降低机体多种抗氧化酶的活性,增加机体氧化应激水平;补充叶黄素可有效地减少高铁负荷损伤,提高抗氧化能力,较高剂量补充的效果可能更明显。

Protective Effects of Lutein on Oxidative Stress in Iron Overloaded Rats

Objective] Iron is one of the essential trace elements,but excessive iron deposited in the tissues may rise free radicals that eventually damage cells and interfere normal organ function.The aim of the study is to investigate the protective effects of lutein on oxidative stress in iron overloaded rats.Method] Totally 60 SD rats were randomly divided into the 5 groups with 12 rats in each group including control （standard rat chow,including Fe 50 mg/kg）,iron model （high iron diet,including Fe 1000 mg/kg）,iron model ＋ lutein 10,20,40mg/kg · bw intragastrical administration.Animals were killed after 6 weeks.Serum and liver iron concentration,serum ferritin,total superoxide dismutase （T-SOD）,glutathione peroxidase （GSH-Px）,catalase （CAT）,malonaldehyde （MDA） were detected.Result] Compared with control group,both serum ferritin and serum iron were elevated 28％ （P ＜ 0.05） and liver iron concentration increased by 23％ （P ＜0.01） in the iron model group.Compared with the iron model group,serum ferritin,serum and liver iron concentration were decreased significantly （P ＜ 0.05） and had no differences with control group （P ＞0.05） in the iron model ＋ lutein groups.Oxidative stress analysis showed the serum and liver GSH-Px activity in the iron model group were 12％ and 20％ lower than the control group respectively （P ＜0.05）.The serum GSH-Px and CAT activity in the iron model ＋ lutein 20mg/kg bw group increased by 12％ and 32％ （P ＜0.05） respectively compared with the iron model group,and the serum GSH-Px in the iron model ＋ lutein 40mg/kg · bw group was 23％ （P ＜ 0.05） higher than the iron model group.The liver T-SOD activity in the iron model and iron model ＋ lutein 10mg/kg · bw groups reduced by 20％ and 17％ （P ＜0.05） compared with the control group,and were 22％ and 19％ （P ＜0.05） lower than the iron model ＋ lutein 40mg/kg · bw group respectively.The liver CAT activity in the iron model was 19％ and 22％ （P ＜0.05） lower than the control and iron model ＋ lutein 20mg/kg · bw groups respectively.Conclusion] Iron overload could reduce the activity of antioxidant enzymes and increase oxidative stress.Lutein supplementation might effectively reduce the iron-induced oxidative damage,enhance the antioxidant properties,and the effects of high dose supplementation might be more obvious.