Study On The Genotoxicity And The Oxidative Damage Of Formaldehyde

Formaldehyde, a kind of popular indoor air pollutant, and it is a global environmental pollutant. Now the research of the toxicity of formaldehyde is a hot and difficult spot in the field of hygienical because of its characteristics of extensive sources, high level of pollution, long-term duration and widely toxicity. The effects of FA on human health include eyes and upper respiratory irritancy, neurotoxicity, reproductive toxicity, allery and immunological effects, oxidative damage, genotoxicity and cancer, et al. The research is oriented on genotoxicity and oxidative damage of FA, and studies its molecular mechanism, which is of great significance for a full understanding of the genetic toxicity of FA, and provides a certain experimental data for the study of the genetic toxicity of FA and oxidative damage, and also provides scientific basis to further evaluate the quality of indoor air. Research is objected on rat liver cell to study genetic toxicity of FA by means of detecting contents of 8-OHdG (8-hydroxy-2'-deoxyguanosine) to explore the genetic toxicity, and study its oxidative damage effect by means of detecting contents of MDA. Experimental results are as follows:1. FA induced genetic toxicity effectIn order to explore the quantitative detection method that can reflect the degree of visceral cell DNA oxidative damage induced by exogenous compound exposures, we tried to use 8-OHdG as a molecular biomarker. In this study formaldehyde (FA) was used as a model exogenous compound. Rat liver cell suspension was applied in this in vitro exposure experiments as testing material. The liver cells of rat were exposed to different concentrations of FA (0,5,15,45μmol/L) for 1h, and then the contents of 8-OHdG was measured. Research results showed that the contents of 8-OHdG increaed gradually with the increase of formaldehyde concentration (F=59.55, p<0.01).At high FA level (45μmol/L) the 8-OHdG contents were extremely significant different when compared with the control group, at the middle FA level (15μmol/L) their differences were significant (p<0.01), and at the low level (5μmol/L) there was no significant difference (p>0.05). The conclusion is that 8-OHdG can be used not only for blood and urine sample testing, but also as a good biomarker of visceral cell DNA oxidative damage, as it was explored in this study.2. FA induced oxidative damage effectUsing rat liver cell suspension as research material, determination MDA content of liver cells. The effect of oxidative damage induced by FA on mouse liver cells was detected. The results showed:With the increased concentration of FA exposure, MDA content of liver cells in mice also increased(F=75.82, p<0.01), and compared with the control group, the MDA content of liver cells in mice increased one by one, and this increase has significant difference in concentration of 15μmol/L (p<0.05). At high FA level (45μmol/L) the 8-OHdG contents were extremely significant different when compared with the control group (p<0.01). It was caused by the high concentration of FA rat cell membrane serious injury.