大蒜硒多糖对紫外线诱发的晶状体损伤的抑制

Inhibition of Lens Damages lnduced by UV lrradiation by Se-Containing Garlic Polysaccharide

紫外线过量照射是产生白内障的重要原因之一。研究证实，晶状体蛋白质在被波长为２００～４００ｎｍ的光源照射后，蛋白质中的色氨酸不断减少，而光敏产物ＮＦＫ（Ｎ－ｆｏｒｍｙｔｋｙｎｕｒｅｎｉｎｅ）的荧光增强。由于紫外线照射，小分子蛋白质不断交联、聚合，造成高分子蛋白质比例明显增加而使晶状体浑浊，产生白内障。从湖北恩施地区所产的富硒大蒜中经提取、除蛋白及凝胶色谱法（ＳｅｘｈａｄｅｘＧ２５－Ｇ２００）分离纯制得到的大蒜硒多糖能够阻止高分子蛋白质的形成，在予防紫外照射对晶状体的氧化损伤有重要的保护作用。对照实验中发现其抗氧化损伤作用比Ｖｉｔｃ强１００倍。这为研究由紫外线诱发的白内障治疗药物提供了一定的依据。

UV-irradiation is among the important factors that can induce cataract in human eyes. After lens proteins were exposed to UV--irradiation by a high voltage Hg lamp at 200-400 nm of wave-length the tryptophan fluorescence decreased, while the light-sensitive material, N-formyl-kynurenine (NFK) increased. In the process,the proteins kept on crossullnking and polymerizing,and the ratio of high molecular weight protein (HMWP) increased. As a result,the lens became cloudy and cataract was formed. \ Se-containing garic polysaccharide (Se-GPS) was isolated and purified by means of Sephadex chromatography. Experiments indicate that Se-GPS possesses protective effects on lens protein against oxidative damage induced by UV-irradiation and is one hundred times as potent as Vitamin C, which paves the way for the preparation and development of the drugs to treat UV-irradiation-induced cataract.