Genotoxicity evaluation of ionic liquid 1-octyl-3-methylimidazolium bromide in freshwater planarian Dugesia japonica using RAPD assay.

The randomly amplified polymorphic DNA (RAPD) assay has been used to detect DNA alternation and mutation recently. However, the effectiveness of this method in detecting DNA damage in planarians, a model organism for assessing the toxicity of environmental pollutants is unknown. In the present study, RAPD assay was used to detect the DNA damage in planarians treated by the ionic liquid 1-octyl-3-methylimidazolium bromide ([Cmim]Br) for the first time. Among the 20 test RAPD primers, 13 primers with 60-70% GC content produced unique polymorphic band profiles. A total of 60 bands were observed in the untreated control planarians. In comparison with the control group, the [Cmim]Br-treated groups displayed differences in RAPD patterns in the band intensity, disappearance of normal bands and appearance of new bands. The variation of RAPD profiles showed both concentration- and time-effect relationships. Meanwhile, the genomic template stability (GTS) of treated planarians decreased and exhibited negative correlation to the exposure concentration and time of [Cmim]Br. Our results suggested that [Cmim]Br had genotoxic effects on planarians, and this DNA damage analysis would lay the foundation for further elucidating the toxicity mechanisms of ionic liquids on planarians. Furthermore, RAPD analysis was proved to be a highly sensitive method for the detection of DNA damage induced by environmental pollutants like toxic chemicals on planarians.