Yoshimura Mika, Kashiba Misato, Oka Jun, Sugisawa Ayako, Umegaki Keizo
Department of Food Science Research for Health, The National Institute of Health and Nutrition, Toyama, Tokyo, Japan.
Free Radic Res. 2002 Jan;36(1):107-12. doi: 10.1080/10715760210166.
We examined the effects of dietary vitamin E (VE) on oxidative damage to DNA and lipids in the liver a few days after total body irradiation (TBI). ODS rats, which lack vitamin C synthesis, were fed either a low VE diet (4.3 mg VE/kg) or a basal VE diet (75.6 mg VE/kg) for 5 weeks while vitamin C was supplied in the drinking water. The VE level in the liver of the low VE group was lower and the levels of lipid peroxides were higher compared to those of the basal VE group: the relative levels in the two groups were 1:30 for VE, 18:1 for 4-hydroxynonenal (HNE), and 10:1 for hexanal (HA). The level of 8-hydroxydeoxyguanosine (8OHdG), a marker of oxidative DNA damage, did not differ between the low VE and the basal VE groups. When the rats received TBI at the dose of 3 Gy and were killed on day 6, the levels of HNE, HA and 8OHdG increased by 2.2-, 2-, and 1.5-times, respectively, in the low VE group, but TBI did not cause such increases in the basal VE group. Changes in antioxidative enzymes (glutathione peroxidase, catalase, and Cu/Zn-SOD) in the liver could not explain the different responses of the two diet groups to TBI-induced oxidative damage. The concentrations of vitamin C and glutathione in the liver did not differ between the two groups. These results suggest that dietary VE can prevent the oxidative damage to DNA and lipids in the liver which appear a few days after TBI at dose of 3 Gy.
我们研究了全身照射（TBI）后数天，膳食维生素E（VE）对肝脏中DNA和脂质氧化损伤的影响。缺乏维生素C合成能力的ODS大鼠，在饮用含维生素C的水的同时，分别给予低VE饮食（4.3 mg VE/kg）或基础VE饮食（75.6 mg VE/kg）5周。与基础VE组相比，低VE组肝脏中的VE水平较低，脂质过氧化物水平较高：两组的相对水平分别为，VE为1:30、4-羟基壬烯醛（HNE）为18:1、己醛（HA）为10:1。氧化DNA损伤的标志物8-羟基脱氧鸟苷（8OHdG）水平在低VE组和基础VE组之间没有差异。当大鼠接受3 Gy剂量的TBI并在第6天处死时，低VE组中HNE、HA和8OHdG的水平分别增加了2.2倍、2倍和1.5倍，但TBI在基础VE组中并未引起此类增加。肝脏中抗氧化酶（谷胱甘肽过氧化物酶、过氧化氢酶和铜/锌超氧化物歧化酶）的变化无法解释两个饮食组对TBI诱导的氧化损伤的不同反应。两组肝脏中维生素C和谷胱甘肽的浓度没有差异。这些结果表明，膳食VE可以预防3 Gy剂量TBI后数天出现的肝脏中DNA和脂质的氧化损伤。
