1
|
Barrett H, Sun J, Chen Y, Yang D, Verreault J, Houde M, Wania F, Peng H. Emerging investigator series: nontargeted screening of aryl hydrocarbon receptor agonists in endangered beluga whales from the St. Lawrence Estuary: beyond legacy contaminants. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024. [PMID: 38904418 DOI: 10.1039/d4em00243a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The elevated concentrations of organohalogen contaminants in the endangered St. Lawrence Estuary (SLE) belugas have prompted the hypothesis that aryl hydrocarbon receptor (AhR) activity may be a contributor towards their potential adverse effects. While indirect associations between AhR and contaminant levels have been reported in SLE beluga tissues, AhR activity was never directly measured. Using bioassays and nontargeted analysis, this study contrasted AhR activity and agonist profiles between pooled tissue extracts of endangered SLE and non-threatened Arctic belugas. Tissue extracts of SLE belugas exhibited significantly higher overall AhR activity than that of Arctic belugas, with a 2000s SLE beluga liver extract exerting significantly higher activity than blubber extracts of SLE and Arctic belugas from the same time period. Contrary to our expectations, well-known AhR agonists detected by nontargeted analysis, including polychlorinated biphenyls (PCBs), were only minor contributors to the observed AhR activity. Instead, Tox21 suspect screening identified more polar chemicals, such as dyes and natural indoles, as potential contributors. Notably, the natural product bromoindole was selectively detected in SLE beluga liver at high abundance and was further confirmed as an AhR agonist. These findings highlighted the significance of the AhR-mediated toxicity pathway in belugas and underscored the importance of novel AhR agonists, particularly polar compounds, in its induction.
Collapse
Affiliation(s)
- Holly Barrett
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
| | - Jianxian Sun
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
| | - Yuhao Chen
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada
| | - Diwen Yang
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
| | - Jonathan Verreault
- Centre de Recherche en Toxicologie de L'environnement (TOXEN), Département des Sciences Biologiques, Université du Québec à Montréal, Succursale Centre-ville, P.O. Box 8888, Montreal, QC H3C 3P8, Canada
| | - Magali Houde
- Environment and Climate Change Canada, 105 McGill Street, Montreal, QC H2Y 2E7, Canada
| | - Frank Wania
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada
| | - Hui Peng
- Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
- School of the Environment, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
2
|
Reiter EB, Escher BI, Rojo-Nieto E, Nolte H, Siebert U, Jahnke A. Characterizing the marine mammal exposome by iceberg modeling, linking chemical analysis and in vitro bioassays. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:1802-1816. [PMID: 37132588 PMCID: PMC10647987 DOI: 10.1039/d3em00033h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 04/02/2023] [Indexed: 05/04/2023]
Abstract
The present study complements work on mixture effects measured with in vitro bioassays of passive equilibrium sampling extracts using the silicone polydimethylsiloxane (PDMS) in organs from marine mammals with chemical profiling. Blubber, liver, kidney and brain tissues of harbor porpoise (Phocoena phocoena), harbor seal (Phoca vitulina), ringed seal (Phoca hispida) and orca (Orcinus orca) from the North and Baltic Seas were investigated. We analyzed 117 chemicals including legacy and emerging contaminants using gas chromatography-high resolution mass spectrometry and quantified 70 of those chemicals in at least one sample. No systematic differences between the organs were found. Only for single compounds a clear distribution pattern was observed. For example, 4,4'-dichlorodiphenyltrichloroethane, enzacamene and etofenprox were mainly detected in blubber, whereas tonalide and the hexachlorocyclohexanes were more often found in liver. Furthermore, we compared the chemical profiling with the bioanalytical results using an iceberg mixture model, evaluating how much of the biological effect could be explained by the analyzed chemicals. The mixture effect predicted from the quantified chemical concentrations explained 0.014-83% of the aryl hydrocarbon receptor activating effect (AhR-CALUX), but less than 0.13% for the activation of the oxidative stress response (AREc32) and peroxisome-proliferator activated receptor (PPARγ). The quantified chemicals also explained between 0.044-45% of the cytotoxic effect measured with the AhR-CALUX. The largest fraction of the observed effect was explained for the orca, which was the individuum with the highest chemical burden. This study underlines that chemical analysis and bioassays are complementary to comprehensively characterize the mixture exposome of marine mammals.
Collapse
Affiliation(s)
- Eva B Reiter
- Department of Ecological Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
| | - Beate I Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany
- Environmental Toxicology, Department of Geosciences, Eberhard Karls University Tübingen, Schnarrenbergstr. 94-96, 72076, Tübingen, Germany
| | - Elisa Rojo-Nieto
- Department of Ecological Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
| | - Hannah Nolte
- Department of Ecological Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
- Institute for Environmental Research, RWTH Aachen University, Aachen, 52074, Germany
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstr. 6, 25761, Büsum, Germany
| | - Annika Jahnke
- Department of Ecological Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318, Leipzig, Germany.
- Institute for Environmental Research, RWTH Aachen University, Aachen, 52074, Germany
| |
Collapse
|
3
|
Escher BI, Binnington MJ, König M, Lei YD, Wania F. Mixture effect assessment applying in vitro bioassays to in-tissue silicone extracts of traditional foods prepared from beluga whale blubber. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:1759-1770. [PMID: 37254953 DOI: 10.1039/d3em00076a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We complement an earlier study on the nutrient and environmental contaminant levels in Arctic beluga whale traditional foods by mixture effect assessment using in vitro bioassays. Mixtures were extracted by in-tissue sampling of raw blubber and several traditional food preparations including Muktuk and Uqsuq using silicone (polydimethylsiloxane, PDMS) as sampler. PDMS extracts persistent and degradable neutral organic chemicals of a wide range of hydrophobicity with defined lipid-PDMS partition ratios. The solvent extracts of PDMS were dosed in various reporter gene assays based on human cell lines. Cytotoxicity was consistent across all cell lines and was a good indicator of overall chemical burden. No hormone-like effects on the estrogen receptor, the progesterone receptor and the glucocorticoid receptor were observed but a few samples activated the androgen receptor, albeit with low potency. The peroxisome-proliferator activated receptor (PPARγ) was the most sensitive endpoint followed by activation of oxidative stress response and activation of the arylhydrocarbon (AhR) receptor. The detected pollutants only explained a small fraction of the experimental mixture effects, indicating additional bioactive pollutants. The effect levels of the extracted mixtures were higher than those observed in blubber extracts of dugongs living off the shore of Australia. Roasting over an open fire or food preparation near a smokehouse led to increased PAH levels that were reflected in increased oxidative stress response and activation of the AhR. So far in vitro assays have only been used to quantify persistent dioxin-like chemicals in food and feed but this pilot study demonstrates a much broader potential for food safety evaluations complementing chemical analytical monitoring.
Collapse
Affiliation(s)
- Beate I Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
- Environmental Toxicology, Department of Geosciences, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Matthew J Binnington
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
| | - Maria König
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
| | - Ying D Lei
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
| | - Frank Wania
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada.
| |
Collapse
|
4
|
Schaap I, Buedenbender L, Johann S, Hollert H, Dogruer G. Impact of chemical pollution on threatened marine mammals: A systematic review. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132203. [PMID: 37567134 DOI: 10.1016/j.jhazmat.2023.132203] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/20/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023]
Abstract
Marine mammals, due to their long life span, key position in the food web, and large lipid deposits, often face significant health risks from accumulating contaminants. This systematic review examines published literature on pollutant-induced adverse health effects in the International Union for Conservation of Nature (IUCN) red-listed marine mammal species. Thereby, identifying gaps in literature across different extinction risk categories, spatial distribution and climatic zones of studied habitats, commonly used methodologies, researched pollutants, and mechanisms from cellular to population levels. Our findings reveal a lower availability of exposure-effect data for higher extinction risk species (critically endangered 16%, endangered 15%, vulnerable 66%), highlighting the need for more research. For many threatened species in the Southern Hemisphere pollutant-effect relationships are not established. Non-destructively sampled tissues, like blood or skin, are commonly measured for exposure assessment. The most studied pollutants are POPs (31%), metals (30%), and pesticides (17%). Research on mixture toxicity is scarce while pollution-effect studies primarily focus on molecular and cellular levels. Bridging the gap between molecular data and higher-level effects is crucial, with computational approaches offering a high potential through in vitro to in vivo extrapolation using (toxico-)kinetic modelling. This could aid in population-level risk assessment for threatened marine mammals.
Collapse
Affiliation(s)
- Iris Schaap
- Farm Technology, Department of Plant Sciences, Wageningen University, 6708PB Wageningen, the Netherlands.
| | - Larissa Buedenbender
- Centro Interdisciplinar de Química e Bioloxía (CICA), Facultade de Ciencias, Universidade da Coruña, 15071 A Coruña, Spain
| | - Sarah Johann
- Department Evolutionary Ecology & Environmental Toxicology, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Henner Hollert
- Department Evolutionary Ecology & Environmental Toxicology, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; Department Environmental Media Related Ecotoxicology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Auf dem Aberg 1, 57392 Schmallenberg, Germany; LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Senckenberganlage 25, 60325 Frankfurt am Main, Germany
| | - Gulsah Dogruer
- Wageningen Marine Research, Wageningen Research, 1976CP IJmuiden, the Netherlands
| |
Collapse
|
5
|
Inesta-Vaquera F, Miyashita L, Grigg J, Henderson CJ, Wolf CR. Defining the in vivo mechanism of air pollutant toxicity using murine stress response biomarkers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 888:164211. [PMID: 37196967 DOI: 10.1016/j.scitotenv.2023.164211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 05/19/2023]
Abstract
Air pollution can cause a wide range of serious human diseases. For the informed instigation of interventions which prevent these outcomes there is an urgent need to develop robust in vivo biomarkers which provide insights into mechanisms of toxicity and relate pollutants to specific adverse outcomes. We exemplify for a first time the application of in vivo stress response reporters in establishing mechanisms of air pollution toxicity and the application of this knowledge in epidemiological studies. We first demonstrated the utility of reporter mice to understand toxicity mechanisms of air pollutants using diesel exhaust particles compounds. We observed that nitro-PAHs induced Hmox1 and CYP1a1 reporters in a time- and dose-dependent, cell- and tissue-specific manner. Using in vivo genetic and pharmacological approaches we confirmed that the NRF2 pathway mediated this Hmox1-reporter induction stress reporter activity. We then correlated the activation of stress-reporter models (oxidative stress/inflammation, DNA damage and Ah receptor -AhR- activity) with responses in primary human nasal cells exposed to chemicals present in particulate matter (PM; PM2.5-SRM2975, PM10-SRM1648b) or fresh roadside PM10. To exemplify their use in clinical studies, Pneumococcal adhesion was assessed in exposed primary human nasal epithelial cells (HPNEpC). The combined use of HPNEpC and in vivo reporters demonstrated that London roadside PM10 particles induced pneumococcal infection in HPNEpC mediated by oxidative stress responses. The combined use of in vivo reporter models with human data thus provides a robust approach to define the relationship between air pollutant exposure and health risks. Moreover, these models can be used in epidemiological studies to hazard ranking environmental pollutants by considering the complexity of mechanisms of toxicity. These data will facilitate the relationship between toxic potential and the level of pollutant exposure in populations to be established and potentially extremely valuable tools for intervention studies for disease prevention.
Collapse
Affiliation(s)
- Francisco Inesta-Vaquera
- Division of Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee DD1 9SY, UK
| | | | | | - Colin J Henderson
- Division of Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee DD1 9SY, UK
| | - C Roland Wolf
- Division of Systems Medicine, School of Medicine, University of Dundee, Jacqui Wood Cancer Centre, Ninewells Hospital, Dundee DD1 9SY, UK.
| |
Collapse
|
6
|
Ye L, Ding X, Liu C, Ruan F, Zhong H, Lv R, Yu Y, He C, Zuo Z, Huang J. The hepatoprotective effects of Herbt Tea Essences on phenanthrene-induced liver damage in mice. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 256:114899. [PMID: 37060801 DOI: 10.1016/j.ecoenv.2023.114899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 02/09/2023] [Accepted: 04/09/2023] [Indexed: 06/19/2023]
Abstract
Phenanthrene (Phe), one of the most frequently occurring pollutants in nature, can cause substantial damage to the human liver. Herbt Tea Essences (HTE), a kind of black tea extract with strong anti-inflammatory activity, can protect humans against disease. Currently, whether HTE can protect the liver from Phe-induced hepatotoxicity remains unclear. Herein, we explore the protective effects of HTE against Phe-induced hepatotoxicity. Our results showed that Phe exposure could significantly induce liver damage and increase serum hepatic enzyme levels in mice. HTE could prevent liver damage and recover the expression levels of inflammatory factors. Furthermore, we found that HTE suppressed the excessive activation of the nuclear transcription factor kappa-B and transforming growth factor-β/SMAD signaling pathways to alleviate Phe-induced liver inflammation and fibrosis. Overall, our data showed that HTE treatment could be a new preventive means for Phe-induced liver disease.
Collapse
Affiliation(s)
- Lingxiao Ye
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaoyan Ding
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China
| | - Changqian Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China
| | - Fengkai Ruan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China
| | - Hongbin Zhong
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China
| | - Rongfu Lv
- Xiamen Herbt Biotechnology Company Limited, Xiamen, Fujian 361005, China
| | - Yi Yu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China
| | - Chengyong He
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhenghong Zuo
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China.
| | - Jiyi Huang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Nephrology, Fujian Clinical Research Center for Chronic Glomerular Disease, The Fifth Hospital of Xiamen, Xiang'an Branch of the First Affiliated Hospital, Xiamen University, Xiamen, Fujian 361102, China.
| |
Collapse
|
7
|
Rojo-Nieto E, Jahnke A. Chemometers: an integrative tool for chemical assessment in multimedia environments. Chem Commun (Camb) 2023; 59:3193-3205. [PMID: 36826793 PMCID: PMC10013656 DOI: 10.1039/d2cc06882f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/08/2023] [Indexed: 02/25/2023]
Abstract
We propose novel chemometers - passive equilibrium samplers of, e.g., silicone - as an integrative tool for the assessment of hydrophobic organic compounds in multimedia environments. The traditional way of assessing levels of organic pollutants across different environmental compartments is to compare the chemical concentration normalized to the major sorptive phase in two or more media. These sorptive phases for hydrophobic organic compounds differ between compartments, e.g., lipids in biota and organic carbon in sediments. Hence, comparability across media can suffer due to differences in sorptive capacities, but also extraction protocols and bioavailability. Chemometers overcome these drawbacks; they are a common, universal and well-defined polymer reference phase for sampling of a large range of nonpolar organic pollutants in different matrices like biota, sediment and water. When bringing the chemometer into direct contact with the sample, the chemicals partition between the sample and the polymer until thermodynamic equilibrium partitioning is established. At equilibrium, the chemical concentrations in the chemometers can be determined and directly compared between media, e.g., between organisms of different trophic levels or inhabiting different areas, between organs within an organism or between biotic and abiotic compartments, amongst others. Chemometers hence allow expressing the data on a common basis, as the equilibrium partitioning concentrations in the polymer, circumventing normalizations. The approach is based on chemical activity rather than total concentrations, and as such, gives a measure of the "effective concentration" of a compound or a mixture. Furthermore, chemical activity is the main driver for partitioning, biouptake and toxicity. As an additional benefit, the extracts of the chemometers only require limited cleanup efforts, avoiding introduction of a bias between chemicals of different persistence, and can be submitted to both chemical analysis and/or bioanalytical profiling.
Collapse
Affiliation(s)
- Elisa Rojo-Nieto
- Helmholtz Centre for Environmental Research - UFZ, Department of Ecological Chemistry, Permoserstr. 15, 04318 Leipzig, Germany.
| | - Annika Jahnke
- Helmholtz Centre for Environmental Research - UFZ, Department of Ecological Chemistry, Permoserstr. 15, 04318 Leipzig, Germany.
- Institute for Environmental Research, RWTH Aachen University, 52074 Aachen, Germany
| |
Collapse
|
8
|
In Vitro Evaluation of the Cytotoxic Potential of Environmental Contaminant Mixtures Present in Water for Human Use. ADSORPT SCI TECHNOL 2022. [DOI: 10.1155/2022/3102007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Chemicals from Pharmaceuticals and Personal Care Products (PPCPs) have become much more prevalent in the environment in recent years. The effects of these substances on human health and the environment are frequently debatable because they typically have poorly understood mechanisms of toxic action. For this reason, we set out to evaluate a binary mixture consisting of butylhydroxyanisole (BHA) and propylparaben (PPB), two approved additives that have been found in the environment and have a range of health-related effects. Based on our prior research, we chose an experimental model called Vero cells, kidney fibroblasts from the African green monkey (Chlorocebus aethiops), with high sensitivity in toxicology studies and ideal characteristics for the analysis of chemical compounds’ mechanisms of action. The experimental design includes a battery of tests using many complimentary biochemical and morphological biomarkers, the usefulness of which we have previously established. The outcomes demonstrated that the mixtures of BHA and PPB cause significant functional alterations brought on by osmotic imbalance, which are connected to irregularities in cell cycle progression, increases in ploidy, which included cell cycle imbalances as well as increases in proliferation. On the other hand, we have been able to show that the quantitative estimate of the anticipated cellular responses generally does not adjust precisely to the observed effect through the analysis of the prediction of the combined effect using mathematical models. However, once the individual compounds’ respective mechanisms of action have been established, the toxicity caused by the mixtures can be qualitatively predicted.
Collapse
|