维生素E补充对外周血细胞活性的影响及机制研究

目的观察不同剂量维生素E(VE)补充对大鼠外周血淋巴细胞增殖活性和抗DNA氧化损伤能力以及红细胞膜流动性的影响。方法将48只Wistar大鼠随机分为对照组和VE1、VE2及VE3三个VE补充组,各组VE摄入量分别为每天7.5、50、200和750IUkgbw,实验期为8周。实验结束后无痛处死动物并留取全血,分别测定血浆VE和MDA含量,分析红细胞膜GSHPx活性、红细胞膜流动性、淋巴细胞转化率及DNA氧化损伤。结果3个干预组血浆VE水平较对照组明显升高(P<0.05);50IUkgbw·dVE(VE1)组血浆MDA含量为(2.29±0.55)nmolml,显著低于其它三组(P<0.05),红细胞膜GSHPx活性为(367.17±129.86)Umgprot,明显高于其它三组(P<0.05);与对照、VE2、VE3组相比,VE1组淋巴细胞转化率分别提高了261.86%、199.23%、412.97%(P<0.05),10μmolLH2O2诱导的DNA氧化损伤程度显著降低(P<0.05);VE1组红细胞膜P、η值明显低于其它三组(P<0.05),即该组膜流动性显著提高。结论本实验揭示VE能明显改善红细胞膜流动性、提高淋巴细胞DNA抗氧化能力及增殖活性的有效补充剂量为50IUkgbw·d;补充剂量过大时未观察到类似作用,甚至显示细胞功能下降。

Study on influence of different dosage of vitamin E on peripheral blood cell activities in rats

OBJECTIVE: To investigate the influences of vitamin E (VE) at different dosage on peripheral blood lymphocyte (PBL) proliferation and anti-DNA oxidative damage activities and erythrocyte membrane fluidity. METHODS: 48 Wistar rats were randomly divided into four groups including control group, VE1, VE2, and VE3 groups supplemented with 7.5, 50, 200, 750 IU/kg bw x d VE, respectively. The trial lasted 8 weeks and the blood samples were collected at the end of the trial. The level of plasma VE was analyzed by fluorescent spectrometry. Plasma MDA and membrane GSH-Px were analyzed by kits. The blood erythrocyte membrane fluidity was detected by fluorescence polarization method, lymphocyte transformation rate by MTT method and DNA oxidative damage by comet assay. RESULTS: The results showed that plasma VE levels significantly increased in VE1, VE2, and VE3 groups. Plasma MDA and erythocyte membrane GSH-Px activity in the rats in 50 IU/kg bw x d (VE1) group were (2.29 +/- 0.55) nmol/ml and (367.17 +/- 129.86) U/mg prot, respectively. P (fluorescence polarization) and eta(microviscosity), which were inversely related with membrane fluidity, in VE1 group were significantly lower. Lymphocyte transformation rate was significantly increased by 261.86%, 199.23% and 412.97% and H2O2 induced DNA damage significantly decreased compared with the control, VE2, and VE3 groups. CONCLUSION: It is indicated that an effective intake of VE for enhancing erythrocyte membrane fluidity, lymphocyte proliferation and DNA stability was 50 IU/kg bw x d, while too excessive intake of VE could not be found to be beneficial.