SOS chromotest results in a broader context: Empirical relationships between genotoxic potency, mutagenic potency, and carcinogenic potency

White, Paul A.; Rasmussen, Joseph B.

doi:10.1002/(sici)1098-2280(1996)27:4<270::aid-em4>3.0.co;2-h

Cited by 31 publications

(8 citation statements)

References 183 publications

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“…Grabow et al [35] measured the Ames/Salmonella mutagenicity of dichloromethane extracts of suspended particulates from the Vaal River (Republic of South Africa). Although neither of these studies used the SOS Chromotest, the empirical models developed by White and Rasmussen [36] can be used to predict the Salmonella mutagenicity of the SPM samples examined in this study. The geometric mean potency of SPM extracts examined here (in IF units per equivalent L) is equivalent to approximately 14 Salmonella TA98 revertants/L (no S9).…”

Section: Resultsmentioning

confidence: 99%

Genotoxic Substances in the St. Lawrence System. I: Industrial Genotoxins Sorbed to Particulate Matter in the St. Lawrence, St. Maurice, and Saguenay Rivers, Canada

White¹,

Rasmussen²,

Blaise³

1998

Environ Toxicol Chem

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Abstract-Previous investigations of organic genotoxins in industrial effluents discharged into the St. Lawrence River system (Quebec, Canada) indicated that a substantial fraction of the genotoxicity is adsorbed to suspended particulate matter. This study used the SOS Chromotest to investigate the presence, potency, and behavior of particle-bound genotoxins in the downstream ecosystem. The results indicate that although extracts of both suspended and sedimented particulate matter are genotoxic, suspended particulate matter samples are more potent in the absence of S9 activation, with the reverse being true for bottom sediments. The results confirmed a positive relationship between the genotoxicity of bottom sediment extracts and sediment organic matter content. A similar relationship between organic matter content and total polycyclic aromatic hydrocarbon (PAH) concentration indicates that putative genotoxins have physicochemical properties similar to the PAH class of contaminants. Conversion of PAH values to benzo[a]pyrene equivalents indicates that measured PAHs only account for a small fraction (ϳ10%) of the observed SOS Chromotest response. Sites that receive discharges from foundries, aluminum refineries, and petroleum refineries yielded several of the most genotoxic samples. Further analyses revealed that the genotoxicity of suspended and sedimented particulate matter extracts is empirically related to the genotoxicity of industrial discharges. Comparisons of total genotoxicity levels in suspended particulates and bottom sediments suggest that direct-acting substances adsorbed to suspended matter are rapidly degraded and/or converted to more stable progenotoxins upon deposition. Further research is required to test this hypothesis and investigate effects on indigenous biota.

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Section: Resultsmentioning

confidence: 99%

Genotoxic Substances in the St. Lawrence System. I: Industrial Genotoxins Sorbed to Particulate Matter in the St. Lawrence, St. Maurice, and Saguenay Rivers, Canada

White¹,

Rasmussen²,

Blaise³

1998

Environ Toxicol Chem

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“…Second, the suppression of SOS repair in E. coli comprises a possible mechanism of antimutagenicity and protective effects of common vegetables . In addition to this, the SOS Chromotest is a validated genotoxicity assay that compared to other methods allows greater throughput screening .…”

Section: Discussionmentioning

confidence: 99%

Antigenotoxic Effect Against Ultraviolet Radiation‐induced DNA Damage of the Essential Oils from Lippia Species

Ruiz

Campo

Stashenko

et al. 2017

Photochem & Photobiology

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The antigenotoxicity against ultraviolet radiation (UV)-induced DNA damage of essential oils (EO) from Lippia species was studied using SOS Chromotest. Based on the minimum concentration that significantly inhibits genotoxicity, the genoprotective potential of EO from highest to lowest was Lippia graveolens, thymol-RC ≈ Lippia origanoides, carvacrol-RC ≈ L. origanoides, thymol-RC > Lippia alba, citral-RC ≈ Lippia citriodora, citral-RC ≈ Lippia micromera, thymol-RC > L. alba, myrcenone-RC. EO from L. alba, carvone/limonene-RC, L. origanoides, α-phellandrene-RC and L. dulcis, trans-β-caryophyllene-RC did not reduce the UV genotoxicity at any of the doses tested. A gas chromatography with flame ionization detection analysis (GC-FID) was conducted to evaluate the solubility of the major EO constituents under our experimental conditions. GC-FID analysis showed that, at least partially, major EO constituents were water-soluble and therefore, they were related with the antigenotoxicity detected for EO. Constituents such as p-cymene, geraniol, carvacrol, thymol, citral and 1,8-cineole showed antigenotoxicity. The antioxidant activity of EO constituents was also determined using the oxygen radical antioxidant capacity (ORAC) assay. The results showed that the antigenotoxicity of the EO constituents was unconnected with their antioxidant activity. The antigenotoxicity to different constituent binary mixtures suggests that synergistic effects can occur in some of the studied EO.

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“…However, the high degree of standardization and substantial volume of data already available from these assays (39,47) will no doubt make sure that they will be around, along with the Ames test, for many years to come. The strength of our particular construct lies in the use of GFP as a reporter, which has been applied while retaining high sensitivity, and should therefore enable us to perform a variety of in situ studies.…”

Section: Discussionmentioning

confidence: 99%

Construction of a ColD cda Promoter-Based SOS-Green Fluorescent Protein Whole-Cell Biosensor with Higher Sensitivity toward Genotoxic Compounds than Constructs Based on recA , umuDC , or sulA Promoters

Norman

Hansen

Sørensen

2005

Appl Environ Microbiol

100

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Four different green fluorescent protein (GFP)-based whole-cell biosensors were created based on the DNA damage inducible SOS response of Escherichia coli in order to evaluate the sensitivity of individual SOS promoters toward genotoxic substances. Treatment with the known carcinogen N-methyl-N-nitro-N-nitrosoguanidine (MNNG) revealed that the promoter for the ColD plasmid-borne cda gene had responses 12, 5, and 3 times greater than the recA, sulA, and umuDC promoters, respectively, and also considerably higher sensitivity. Furthermore, we showed that when the SOS-GFP construct was introduced into an E. coli host deficient in the tolC gene, the minimal detection limits toward mitomycin C, MNNG, nalidixic acid, and formaldehyde were lowered to 9.1 nM, 0.16 M, 1.1 M, and 141 M, respectively, which were two to six times lower than those in the wild-type strain. This study thus presents a new SOS-GFP whole-cell biosensor which is not only able to detect minute levels of genotoxins but, due to its use of the green fluorescent protein, also a reporter system which should be applicable in high-throughput screening assays as well as a wide variety of in situ detection studies.As a result of modern life, we are in daily contact with an ever increasing myriad of substances. This has necessitated the ability to screen large numbers of samples for harmful properties like carcinogenicity. Short-term bacteriological mutagenicity assays have shown great consistency with traditional rodent bioassays and are popular due to the relative ease with which multiple substances can be screened, with only modest requirements for laboratory equipment and space.In addition to the classic Ames test (2), used as a standard mutagenicity assay since the 1970s, many assays based on the Escherichia coli DNA repair SOS response have been developed. This has been done in order to provide even cheaper and faster alternatives and to accommodate high-throughput screening (13,33,35,36). SOS-based genotoxicity assays function via simple SOS promoter/reporter gene fusions, introduced into strains of E. coli or Salmonella enterica serovar Typhimurium. SOS induction is thereby an indicator of a genotoxic presence (measured by a subsequent increase in reporter gene levels).SOS genes are controlled by a single repressor, LexA, and are derepressed when cells undergo DNA damage, due to the accumulation of single-stranded DNA-RecA complexes which act as coproteases in a LexA self-cleaving mechanism (22,28,29). Expression of a given SOS gene depends on the specific LexA-binding properties of its promoter. These properties are determined by the presence of LexA-binding sequences (SOS boxes), which share a great deal of homology but are distinct from gene to gene (14,27). The response of an SOS-based genotoxicity assay is therefore greatly influenced by the employed promoter. The preferred promoters have typically been the recA, umuDC, and sulA promoters, as was the case with the rec-lac test (32), the umu test, and the SOS chromotest, respectively. A relatively...

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SOS chromotest results in a broader context: Empirical relationships between genotoxic potency, mutagenic potency, and carcinogenic potency

Cited by 31 publications

References 183 publications

Genotoxic Substances in the St. Lawrence System. I: Industrial Genotoxins Sorbed to Particulate Matter in the St. Lawrence, St. Maurice, and Saguenay Rivers, Canada

Genotoxic Substances in the St. Lawrence System. I: Industrial Genotoxins Sorbed to Particulate Matter in the St. Lawrence, St. Maurice, and Saguenay Rivers, Canada

Antigenotoxic Effect Against Ultraviolet Radiation‐induced DNA Damage of the Essential Oils from Lippia Species

Construction of a ColD cda Promoter-Based SOS-Green Fluorescent Protein Whole-Cell Biosensor with Higher Sensitivity toward Genotoxic Compounds than Constructs Based on recA , umuDC , or sulA Promoters

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