香烟侧流烟雾引起的DNA分子氧化损伤

Determination of Oxidative DNA Molecule Damage Caused by Environmental Tobacco Smoke Side Stream

目的通过研究环境烟草烟雾的侧流烟雾(ETSS)对DNA分子的氧化损伤 ,探讨环境烟草烟雾 (ETS)的遗传毒性效应及其分子机制。方法以DNA加合物8_羟基脱氧鸟苷(8_OHdG)作为DNA氧化损伤的生物学标志物 ,用高压液相色谱_电化学检测(HPLC_EC)法对ETSS染毒后的DNA中8_OHdG进行定量检测 ,通过气质联用法(GC_MS)对香烟烟雾进行有机成分分析和原子吸收法(AAS)对其进行无机元素分析 ,并从化学组成成分的角度探讨DNA氧化损伤的分子机理。结果ETSS的颗粒物和挥发性有机物均可在体外直接诱导DNA的氧化损伤 ,并呈现一定的剂量_反应关系。分析表明 :颗粒物和挥发性有机物中分别检出有机污染物123种和84种 ,无机元素7种 ,其中醌类、多酚等化合物具有自氧化作用 ,不需要任何生物活性系统 ,在体外就可产生大量的活性氧自由基 ,并在金属的催化作用下进攻DNA的碱基 ,形成加合物8_OHdG。结论ETSS对DNA具有氧化能力 ,体现了直接的遗传毒性效应 。

Objective The genotoxicty and its molecular mechanism of environmental tobacco smoke (ETS) were discussed through the oxidative DNA damage induced by environmental tobacco side_stream smoke(ETSS). Methods DNA adduct 8_hydroxydeoxyguanosine (8_OHdG) was used as a biomarker of oxidative DNA damage. The level of 8_OHdG in DNA exposed to ETSS was detected by HPLC_EC.On the molecular biological level,the biological oxidative ability of ETSS on DNA molecule was studied.Organic and inorganic components in ETSS were analyzed by GC_MS and AAS respectively. Results Particles and VOCs in ETSS could directly induce oxidative DNA damage and form 8_OHdG.It was found that there were 123 and 84 kinds of organic compounds in particles and volatile organic compounds of tobacco smoke side stream,and 7 kinds of inorganic compounds in ETSS.Some components especially quinones and polyphenols in ETS,could produce free radicals in vitro by the auto_oxidation without any biological activity systems,and with the catalytic reaction of metals,the DNA aduct 8_OHdG was produced. Conclusion It was proved that ETS had biological oxidative ability on DNA and expressed direct genotoxicity.8_OHdG was a fine biomarker of effect of oxidative DNA damage.