Evaluation of 8-hydroxydeoxyguanosine in human oral cells: The importance of tobacco smoke and urban environment

The DNA adduct 8-hydroxydeoxyguanosine (8-OHdG) has been widely used as a s ensitive biomarker for oxidative damage. To investigate the role of environ mental factors on oxidative DNA damage formation the level of 8-OHdG was de termined in oral cells from 109 healthy volunteers by an immunohistochemica l method. A statistically significantly higher content of 8-OHdG was detect ed in oral cells from smokers (111+/-55, n=38) compared with non smokers (7 8+/-48, n=71), (p<0.01). Moreover; subjects living in an urban area showed a higher level of oxidative damage with respect to those living in a countr yside-suburban ar ea (99+/-53, n=58 vs. 78+/-51, n=51), (p=0.03). No signif icant association was detected between 8-OHdG in oral cells and other varia bles such as passive smoke, oral infections, alcohol or vitamin intake and grilled food consumption. This work suggests that tobacco smoke and environ mental exposure to pollutants lead to a measurable increase of oxidative da mage in oral cells and confirms that the immunoperoxidase method is an appr opriate approach for epidemiological analyses.