烹调油烟雾诱导核酸氧化损伤及其标志物8-羟基脱氧鸟苷的形成机制

目的 了解烹调油烟雾的遗传毒性效应。方法 以核酸加合物8-羟基脱氧鸟苷(8-OHdG)作为DNA氧化损伤的生物学标志物,用高效液相色谱-电化学检测法(HPLC-EC)对烹调油烟雾染毒的小牛胸腺DNA及Wistar大鼠气管灌注染毒的肺组织DNA中8-OHdG进行定量检测,通过气质联用法(GC-MS)进行有机成分和原子吸收法(AAS)进行无机元素分析,并从混合污染物化学组成成分的角度推断了烹调油烟雾造成DNA氧化损伤的分子机理。结果体外试验表明烹调油烟雾的各组分,包括油烟冷凝物、残留油、油烟颗粒物、油烟挥发性有机物均能能诱导DNA氧化产生8-OHdG,产生量的顺序为残留油>冷凝物>油烟颗粒物>油烟挥发性有机物。体内实验结果表明油烟冷凝物可诱导大鼠肺组织DNA的氧化且具有剂量一反应关系和时间一效应关系。结论烹调油烟雾具有明确的遗传毒性,可诱导核酸氧化产生加合物8-OHdG,其机制可能是烹调油混合污染物中存在痕量金属离子如Fe2+、Cu2+等,介导Fenton反应生成羟自由基,直接进攻DNA造成氧化损伤。

Oxidative Damage of DNA and Formation of Its Biomarker 8-Hydroxydeoxyguanosine Induced by Heated Cooking Oil Vapors

Objective To discuss the genotoxicity of heated cooking oil. Methods DNA adduct 8-hydroxydeoxyguanosine (8-OHdG) was used as a biomarker of oxidative DNA damage, the levels of 8-OHdG in DNA of calf thymus exposed to heated cooking oil vapors (HCOVs) and lung tissue of Wistar rats exposed to HCOVs by intratracheal injection in vitro and in vivo were determined using HPLC-EC. Organic and inorganic components in HCOVs were analyzed by GC-MS and AAS respectively. In addition, the molecular mechanism of oxidative DNA damage induced by HCOVs were probed on the basis of chemical composition and components. Results The components of heated cooking oil, such as the condensed matter, rudimental oil, particle matters and vapors, could induce oxidative DNA damage and form 8-OHdG in vitro. The condensed matter, rudimental oil, particle matters and vapors were arranged in the order of induced concentrations of 8-OHdG. The condensed matter could induce oxidative DNA damage to form 8-OHdG in vivo, and had the dose-response and time-effect relationship. Conclusions The products of heated cooking oil could induce oxidative DNA damage to form 8-OHdG and showed the significant genotoxicity. The possible mechanism was some trace metals such as Fe and Cu existing in the pollutants mediated Fenton reaction to produce the radical OH ,which attacked the DNA to form 8-OHdG directly.