Objective To explore the toxicity of single or combined exposure to formaldehyde and ethylbenzene on DNA damage in brain cells of mice and to analyze the type of joint toxic effect.
Methods Based on a 4& #215;4 factorial experiment design, single cell gel electrophoresis (SCGE) technique was used to investigate DNA damage in mice brain cells exposed to formaldehyde (0, 0.2, 2.0, and 20.0 mg/kg), ethylbenzene (0, 50, 250, and 500 mg/kg), and both.
Results Compared with the control group, the comet cells ratio, the percentage of tail DNA, and the Olive tail moment in all exposure groups increased significantly (P<0.05). The comet cells ratio showed a significant upward tendency with increasing chemicals' doses, and was significantly elevated in the group treated with high-dose mixture compared with the other exposure groups (P<0.05). The percentage of tail DNA and the Olive tail moment were also increased as the dose of ethylbenzene or formaldehyde increased, but not in the group treated with high dose of formaldehyde. An interaction between toxic effects of formaldehyde and ethylbenzene was identified (P<0.05).
Conclusion Formaldehyde and ethlybenzene could cause DNA damage in mice brain cells and the joint exposure show severer effect than either single exposure. The joint toxic effect on DNA damage appears to be synergistic.
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