TY - JOUR

T1 - Modification of the umu-assay (ISO 13829) accounting for cytotoxicity in genotoxicity assessment: A preliminary study

AU - Toolaram, Anju Priya

AU - Gutiérrez, Iris Raquel

AU - Ahlf, Wolfgang

PY - 2012/9/18

Y1 - 2012/9/18

N2 - In this study, the umu-assay (ISO 13829) was modified by addition of the resazurin-reduction assay to assess the cytotoxic potential of toxins. The aim was to develop a test system that was capable of examining both genotoxicity and cytotoxicity on the basis of the metabolic health of the cells so as to provide a better assessment of the negative influence of toxic effects on the evaluation of genotoxicity. The test was established and validated with mitomycin C (MMC), 1,3-dinitropyrene (1,3-DNP), 4-nitroquinoline-1-oxide (4-NQO) and chloramphenicol (CHL) as toxins with known responses in the umu-assay. The results indicate that the modified umu-assay was able to reveal genotoxic responses towards MMC, 1,3-DNP and 4-NQO up to 1 μg/ml. Further, the assay was able to determine the cytotoxicity of CHL, MMC and 4-NQO. Hence, the modified umu-assay was proven to be a sensitive test for determining the cytotoxicity and genotoxicity of toxins, with results that were comparable with literature data. Moreover, the modified umu-assay showed that cytotoxic concentrations that cause >50% inhibition of dehydrogenase activity (DHA) can result in unreliable computation of genotoxicity.

AB - In this study, the umu-assay (ISO 13829) was modified by addition of the resazurin-reduction assay to assess the cytotoxic potential of toxins. The aim was to develop a test system that was capable of examining both genotoxicity and cytotoxicity on the basis of the metabolic health of the cells so as to provide a better assessment of the negative influence of toxic effects on the evaluation of genotoxicity. The test was established and validated with mitomycin C (MMC), 1,3-dinitropyrene (1,3-DNP), 4-nitroquinoline-1-oxide (4-NQO) and chloramphenicol (CHL) as toxins with known responses in the umu-assay. The results indicate that the modified umu-assay was able to reveal genotoxic responses towards MMC, 1,3-DNP and 4-NQO up to 1 μg/ml. Further, the assay was able to determine the cytotoxicity of CHL, MMC and 4-NQO. Hence, the modified umu-assay was proven to be a sensitive test for determining the cytotoxicity and genotoxicity of toxins, with results that were comparable with literature data. Moreover, the modified umu-assay showed that cytotoxic concentrations that cause >50% inhibition of dehydrogenase activity (DHA) can result in unreliable computation of genotoxicity.

KW - Chemistry

KW - umu-Assay

KW - Cytotoxicity

KW - Genotoxicity

KW - Resazurin-reduction assay

KW - Sustainability Science

UR - http://www.scopus.com/inward/record.url?scp=84863779946&partnerID=8YFLogxK

U2 - 10.1016/j.mrgentox.2012.05.010

DO - 10.1016/j.mrgentox.2012.05.010

M3 - Journal articles

C2 - 22659122

VL - 747

SP - 190

EP - 196

JO - Mutation Research - Genetic Toxicology and Environmental Mutagenesis

JF - Mutation Research - Genetic Toxicology and Environmental Mutagenesis

SN - 1383-5718

IS - 2

ER -