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An evidence base to support the one concentration approach in fish bioconcentration studies for plant protection products and general chemicals
Abstracts / Toxicology Letters 238S (2015) S56–S383
reduce cell viability significantly. However, the expression of TUJ1 was significantly reduced by 400 nM of MeHg. In high-contents screening (HCS) methods, we identified the toxic effects including alteration of mitochondrial membrane potential, accumulation of intra-cellular calcium by low dose of MeHg, CPX/BPAA. In neurite outgrowth analysis, neurite length, neurite intensity, branch point count, branch point distance from cell body showed a tendency to decrease by low dose of MeHg. In this study, we successfully applied advanced in vitro test methods as new strategies to assess developmental neurotoxicity (DNT) of low dose of MeHg, CPX/BPAA. These in vitro DNT test methods are applicable to high-throughput screening and provide a simple, predictive stem cell-based method for DNT testing. http://dx.doi.org/10.1016/j.toxlet.2015.08.919
P14-007 Assessment of the Tobacco Heating System 2.2, a candidate Modified Risk Tobacco Product, on human organotypic nasal and bronchial epithelial tissue culture using systems toxicology approach C. Mathis ∗ , A. Iskandar, S. Johne, S. Majeed, D. Grandolfo, D. Kuehn, C. Merg, A. Elamin, E. Guedj, R. Dulize, D. Peric, K. Trivedi, A. Benyagoub, Y. Xiang, F. Martin, P. Leroy, S. Frentzel, N. Ivanov, M. Peitsch, J. Hoeng Philip Morris International, Research & Development, Neuchatel, Switzerland The development of new tobacco product that could reduce cigarette smoke related health impact is ongoing and require careful safety assessment strategy. In line with the 21st century toxicology paradigm and with the use of human in vitro organotypic models as an alternative to animal testing approach, the impact of the aerosol generated by Philip Morris’s candidate Modified Risk Tobacco Product (MRTP), named Tobacco Heating System 2.2 (THS2.2), was assessed on both human nasal and bronchial epithelial tissue culture exposed for 28 min at the air–liquid interface. In parallel, exposure with air (sham control) or with mainstream smoke from combustible cigarette (CS) (at doses where nicotine level within the smoke are matching those of THS2.2 aerosol) was performed. Various endpoints (cytotoxicity, cilia beating frequency, CYP1A1/1B1 enzyme activity, inflammatory markers release, morphological and transcriptomic changes) were collected at different times following exposure (4, 24, 48 and 72 h) to identify and compare the dose- and time-dependent effect of each exposure conditions. By using systems toxicology-based risk assessment approaches combining computable biological network models and gene expression changes, we compared the molecular perturbations resulting from both combustible product and candidate MRTP exposure conditions. While significant effect was quantified over different post-exposure time points in the networks representing cell death, inflammation, proliferation and cellular stress after CS exposure, the impact of THS2.2 exposure (at similar dose) was closer to sham controls and mostly limited at the earliest time point (4 h). The results of all the additional endpoints measured during this study support a reduced impact of THS2.2 exposure on both nasal and bronchial epithelial tissue culture compared to conventional CS. http://dx.doi.org/10.1016/j.toxlet.2015.08.920
S323
P14-008 An evidence base to support the one concentration approach in fish bioconcentration studies for plant protection products and general chemicals N. Burden 1,∗ , S. Creton 1 , L. Weltje 2 , S.K. Maynard 3 , H. Hobson 3 , J.R. Wheeler 4 1
NC3Rs, London, United Kingdom BASF SE, Limbergerhof, Germany 3 Syngenta, Bracknell, United Kingdom 4 Dow AgroSciences, Abingdon, United Kingdom 2
Fish bioconcentration studies are conducted to address various regulatory requirements. These tests result in the generation of a bioconcentration factor (BCF), which is used to determine whether substances are bioaccumulative and/or need further consideration regarding accumulation in the food chain and for secondary poisoning assessments. Bioconcentration tests are resource and animal intensive, often requiring more than 100 fish per study. Replacing, reducing or refining the use of fish for BCF testing would therefore have multiple benefits, including improved efficiency, reduced costs and supporting animal welfare considerations. Since its revision in 2012, the OECD Test Guideline 305 ‘Bioaccumulation in fish’ includes the option to use one exposure concentration rather than two, providing there is scientific justification. However, two concentrations may still be required for some regulatory purposes. To determine whether the one concentration approach could be justified for plant protection product (PPP) actives and general chemicals, BCF values resulting from low and high exposure concentrations were compared (55 PPP actives and 236 general chemicals). There was no statistically significant difference in the BCF values from low and high exposure concentrations for either substance type. This suggests that the testing of one exposure concentration is sufficient to reliably estimate the BCF value. The relationship between the low and high exposure concentration BCF values was particularly strong for BCFs ≥ 1000 L/kg, which is beneficial as only chemicals with relatively high BCFs (e.g. >2000 L/kg, for the EU ‘B’ criterion) may require regulatory action. This analysis provides a data-driven rationale for using the one test concentration approach for PPP actives and general chemicals, and where applied would decrease the numbers of fish used by one third. http://dx.doi.org/10.1016/j.toxlet.2015.08.921
P14-009 Beauvericin exposure induces cell cycle arrest, cell death and mitochondrial membrane potential disruption in CHO-K1 Cells M. Beatriz ∗ , J.-G. Ana, G. Font, M.-J. Ruiz Leal ∗ University of Valencia, Preventive Medicine, Oxicology, Burjassot-Valencia, Spain Beauvericin (BEA) is a secondary metabolite of Fusarium fungus and Beauveria bassiana. It has been demonstrated that BEA produced cytotoxicity in several cell lines. BEA is an ionophore, forming a complex with essential cations (Ca2+ , Na+ , K+ ), that increases ion permeability in biological membranes, which may affect the ionic homeostasis. The aim of this study was to determine in CHO-K1 the effect of BEA (0.1, 1 and 5 M) in mitochondrial membrane potential (m) after 24 h of exposure by rhodamine 123 method; as well as to study cell cycle disruption and apoptosis/necrosis induc-
reduce cell viability significantly. However, the expression of TUJ1 was significantly reduced by 400 nM of MeHg. In high-contents screening (HCS) methods, we identified the toxic effects including alteration of mitochondrial membrane potential, accumulation of intra-cellular calcium by low dose of MeHg, CPX/BPAA. In neurite outgrowth analysis, neurite length, neurite intensity, branch point count, branch point distance from cell body showed a tendency to decrease by low dose of MeHg. In this study, we successfully applied advanced in vitro test methods as new strategies to assess developmental neurotoxicity (DNT) of low dose of MeHg, CPX/BPAA. These in vitro DNT test methods are applicable to high-throughput screening and provide a simple, predictive stem cell-based method for DNT testing. http://dx.doi.org/10.1016/j.toxlet.2015.08.919
P14-007 Assessment of the Tobacco Heating System 2.2, a candidate Modified Risk Tobacco Product, on human organotypic nasal and bronchial epithelial tissue culture using systems toxicology approach C. Mathis ∗ , A. Iskandar, S. Johne, S. Majeed, D. Grandolfo, D. Kuehn, C. Merg, A. Elamin, E. Guedj, R. Dulize, D. Peric, K. Trivedi, A. Benyagoub, Y. Xiang, F. Martin, P. Leroy, S. Frentzel, N. Ivanov, M. Peitsch, J. Hoeng Philip Morris International, Research & Development, Neuchatel, Switzerland The development of new tobacco product that could reduce cigarette smoke related health impact is ongoing and require careful safety assessment strategy. In line with the 21st century toxicology paradigm and with the use of human in vitro organotypic models as an alternative to animal testing approach, the impact of the aerosol generated by Philip Morris’s candidate Modified Risk Tobacco Product (MRTP), named Tobacco Heating System 2.2 (THS2.2), was assessed on both human nasal and bronchial epithelial tissue culture exposed for 28 min at the air–liquid interface. In parallel, exposure with air (sham control) or with mainstream smoke from combustible cigarette (CS) (at doses where nicotine level within the smoke are matching those of THS2.2 aerosol) was performed. Various endpoints (cytotoxicity, cilia beating frequency, CYP1A1/1B1 enzyme activity, inflammatory markers release, morphological and transcriptomic changes) were collected at different times following exposure (4, 24, 48 and 72 h) to identify and compare the dose- and time-dependent effect of each exposure conditions. By using systems toxicology-based risk assessment approaches combining computable biological network models and gene expression changes, we compared the molecular perturbations resulting from both combustible product and candidate MRTP exposure conditions. While significant effect was quantified over different post-exposure time points in the networks representing cell death, inflammation, proliferation and cellular stress after CS exposure, the impact of THS2.2 exposure (at similar dose) was closer to sham controls and mostly limited at the earliest time point (4 h). The results of all the additional endpoints measured during this study support a reduced impact of THS2.2 exposure on both nasal and bronchial epithelial tissue culture compared to conventional CS. http://dx.doi.org/10.1016/j.toxlet.2015.08.920
S323
P14-008 An evidence base to support the one concentration approach in fish bioconcentration studies for plant protection products and general chemicals N. Burden 1,∗ , S. Creton 1 , L. Weltje 2 , S.K. Maynard 3 , H. Hobson 3 , J.R. Wheeler 4 1
NC3Rs, London, United Kingdom BASF SE, Limbergerhof, Germany 3 Syngenta, Bracknell, United Kingdom 4 Dow AgroSciences, Abingdon, United Kingdom 2
Fish bioconcentration studies are conducted to address various regulatory requirements. These tests result in the generation of a bioconcentration factor (BCF), which is used to determine whether substances are bioaccumulative and/or need further consideration regarding accumulation in the food chain and for secondary poisoning assessments. Bioconcentration tests are resource and animal intensive, often requiring more than 100 fish per study. Replacing, reducing or refining the use of fish for BCF testing would therefore have multiple benefits, including improved efficiency, reduced costs and supporting animal welfare considerations. Since its revision in 2012, the OECD Test Guideline 305 ‘Bioaccumulation in fish’ includes the option to use one exposure concentration rather than two, providing there is scientific justification. However, two concentrations may still be required for some regulatory purposes. To determine whether the one concentration approach could be justified for plant protection product (PPP) actives and general chemicals, BCF values resulting from low and high exposure concentrations were compared (55 PPP actives and 236 general chemicals). There was no statistically significant difference in the BCF values from low and high exposure concentrations for either substance type. This suggests that the testing of one exposure concentration is sufficient to reliably estimate the BCF value. The relationship between the low and high exposure concentration BCF values was particularly strong for BCFs ≥ 1000 L/kg, which is beneficial as only chemicals with relatively high BCFs (e.g. >2000 L/kg, for the EU ‘B’ criterion) may require regulatory action. This analysis provides a data-driven rationale for using the one test concentration approach for PPP actives and general chemicals, and where applied would decrease the numbers of fish used by one third. http://dx.doi.org/10.1016/j.toxlet.2015.08.921
P14-009 Beauvericin exposure induces cell cycle arrest, cell death and mitochondrial membrane potential disruption in CHO-K1 Cells M. Beatriz ∗ , J.-G. Ana, G. Font, M.-J. Ruiz Leal ∗ University of Valencia, Preventive Medicine, Oxicology, Burjassot-Valencia, Spain Beauvericin (BEA) is a secondary metabolite of Fusarium fungus and Beauveria bassiana. It has been demonstrated that BEA produced cytotoxicity in several cell lines. BEA is an ionophore, forming a complex with essential cations (Ca2+ , Na+ , K+ ), that increases ion permeability in biological membranes, which may affect the ionic homeostasis. The aim of this study was to determine in CHO-K1 the effect of BEA (0.1, 1 and 5 M) in mitochondrial membrane potential (m) after 24 h of exposure by rhodamine 123 method; as well as to study cell cycle disruption and apoptosis/necrosis induc-