Stewart M S, Cameron G S, Pence B C
Department of Pathology, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
J Invest Dermatol. 1996 May;106(5):1086-9. doi: 10.1111/1523-1747.ep12339344.
Ultraviolet B radiation (UVB) induces oxidative damage in DNA, resulting in the formation of the adduct 8-hydroxydeoxyguanosine. Previous studies from this laboratory have demonstrated a decrease in antioxidant enzyme defenses after UVB radiation in Skh: HR-1 hairless mice, implicating antioxidant status in protection against oxidative damage. The present study was undertaken to examine mechanisms of UVB damage to DNA and modulation by vitamin C, selenite, or Trolox, a water-soluble vitamin E analog. BALB/c MK-2 mouse keratinocytes were exposed to a dose range of UVB from 4 to 750 mJ/cm2. DNA damage in the form of 80 HdG was measured using high-pressure liquid chromatography coupled with electrochemical and UV absorbance detection. Preincubation of the cells for 2 days with 0.4 or 0.8 microgram/ml ascorbic acid, 10 or 20 micrograms/ml Trolox, and 5 or 12.5 microM selenite resulted in a significant decrease in the number of 8-hydroxydeoxyguanosine adducts per 10(5) deoxyguanines induced by 500 mJ/cm2 UVB. The results indicate a potential role for antioxidant nutrients in protection against UVB damage to skin cells.
紫外线B辐射（UVB）会诱导DNA发生氧化损伤，导致加合物8-羟基脱氧鸟苷的形成。本实验室先前的研究表明，在Skh:HR-1无毛小鼠接受UVB辐射后，其抗氧化酶防御能力会下降，这表明抗氧化状态在抵御氧化损伤中具有重要作用。本研究旨在探讨UVB对DNA的损伤机制以及维生素C、亚硒酸盐或水溶性维生素E类似物Trolox对其的调节作用。将BALB/c MK-2小鼠角质形成细胞暴露于4至750 mJ/cm2的UVB剂量范围内。采用高压液相色谱结合电化学和紫外吸收检测法测定8-羟基脱氧鸟苷形式的DNA损伤。用0.4或0.8微克/毫升抗坏血酸、10或20微克/毫升Trolox以及5或12.5微摩尔亚硒酸盐对细胞进行2天预孵育，结果显示，500 mJ/cm2 UVB诱导的每10(5)个脱氧鸟嘌呤中8-羟基脱氧鸟苷加合物的数量显著减少。结果表明，抗氧化营养素在保护皮肤细胞免受UVB损伤方面具有潜在作用。
