Correlation of 32 P-postlabelling-detection of DNA adducts in mouse skin in vivo with the polycyclic aromatic compound content and mutagenicity in Salmonella typhimurium of a range of oil products

Abstract

The in vivo genotoxic activities in mouse skin of the dimethyl sulphoxide (DMSO) extracts of a range of oil products [residual aromatic extract; untreated heavy paraffinic distillate aromatic extract; mildly refined light naphthenic base oil; bitumen (vacuum residue); high viscosity index base oil obtained by catalytic hydrogenation] were evaluated by 32P-postlabelling DNA analysis. The results of quantitative 32P-postlabelling analyses of epidermal DNA from mice treated with the DMSO extracts showed linear relationships with the total polycyclic aromatic compound (PAC) contents, determined by the Institute of Petroleum method IP 346 and also the 3-6 ring PAC contents, measured by on-line liquid-liquid extraction using flow injection analysis. The 32P-postlabelling data also showed a linear relationship with the mutagenicity indices of these oil products determined in S. typhimurium TA98 using the modified Ames Salmonella microsome test. The in vivo genotoxicity of the DMSO extracts from the oil products was low, judged by 32P-postlabelling analysis of DNA adducts measured in epidermal DNA of treated mouse skin, and ranging from 2 to 723 attomole/microg DNA per mg oil product. The in vivo 32P-postlabelling data from this study are consistent with these materials expressing low genotoxicity in mouse skin in vivo. The DMSO extraction procedure coupled with 32P-postlabelling DNA analysis is useful for ranking the relative genotoxic potency in vivo of a wide range of oil products. In general the trend observed is similar to rankings based on physicochemical measurements of total PAC contents or 3 6 ring PAC contents of the oil products.

Genotoxicity of complex PAH mixtures recovered from contaminated lake sediments as assessed by three different methods

“…The absence of an increase in genotoxic response for E1 as the dose increased (Table III) would be consistent with the presence of cytotoxic or inhibitory compounds. Previous studies showed both increasing levels of mutagenicity with increasing BP concentrations Booth et al, 1998], and decreasing levels of mutagenicity with increasing BP concentrations [Donnelly et al, 1993]. It is likely that bioassay-directed fractionation would have reduced or eliminated the cytotoxicity of sample E1, and may have allowed this sample to express a higher level of genotoxicity.…”

“…Randerath et al [1996] recently reviewed the literature pertinent to the analysis of adducts from complex mixtures. In a recent quantitative study, Booth et al [1998] reported linear correlation of DNA adducts in mouse skin in vivo with polycyclic aromatic compound content and bacterial mutagenicity in a range of petroleum products. A tier of biological tests, when coupled with chemical analysis, may help define situations where the standard risk estimation provides accurate results, as well as those situations where standard methodology is inappropriate.…”

Scientific Opinion on Mineral Oil Hydrocarbons in Food

“…BaP may be inhibited by less active MOAH) (Brooks et al, 1995;Booth et al, 1998;Mackerer et al, 2003). Hence, it is not possible to sum up the activity of a number of single fractions.…”

32 P-postlabeling of DNA adducts arising from complex mixtures: HPLC versus TLC separation applied to adducts from petroleum products

“…Examples are the modified Ames test, measurements of 3-to 7-ring PAC content, and different methods for analyzing DNA adducts (Roy et al 1988;Blackburn et al 1996;Booth et al 1998). Methods for analysis of DNA adducts include immunoassays, fluorescence and phosphorescence spectroscopy, mass spectrometry, and postlabeling .…”