Cytotoxicity Evaluation of the First Ten MEIC Chemicals: Acute Lethal Toxicity in Man Predicted by Cytotoxicity in Five Cellular Assays and by Oral LD50 Tests in Rodents

1989 ◽  
Vol 17 (2) ◽  
pp. 83-100
Author(s):  
Björn Ekwall ◽  
Inger Bondesson ◽  
José V. Castell ◽  
Maria José Gómez-Lechón ◽  
Sven Hellberg ◽  
...  
Keyword(s):  
In Vitro Cytotoxicity ◽  
In Vitro Tests ◽  
Human Toxicity ◽  
Blood Concentrations ◽  
Cell Systems ◽  
Cellular Assays ◽  
Preliminary Validation ◽  
Partial Least Squares Model ◽  
Lethal Dosage

The MEIC (multicentre evaluation of in vitro cytotoxicity) programme is a five-year programme to validate in vitro tests for general toxicity, and is organised by the Scandinavian Society for Cell Toxicology. Interested laboratories are invited, on an international basis, to test 50 published reference chemicals in their respective assays. Submitted results will then be evaluated yearly by the MEIC Committee for their relevance to various types of human toxicity, including an evaluation for the same chemicals of the prediction by animal tests of human toxicity. To establish the validation methods, a preliminary validation cycle is being performed in 1989/90 with submitted results for the first ten MEIC chemicals. The present paper is the very first step of this preliminary validation process. The prediction of human toxicity by five cytotoxicity assays (altogether 14 different cell systems/endpoints) has been evaluated, and also compared with the predictive value of rodent LD50 tests. Mouse LD50 prediction of human lethal dosage for these substances was good, while rat LD50 prediction was less satisfactory. The collective predictions by all 14 cell systems/endpoints of human toxicity in the form of a multivariate PLS (partial least squares) model of human acute lethal blood concentrations, as well as the corresponding prediction by a HeLa cell assay, were comparable to the efficiency of mouse LD50 prediction of human lethal dosage. When combined with simple toxicokinetic data (absorption of chemicals in the intestine and distribution volumes), the PLS model and the HeLa assay were able to predict human lethal dosage of the ten chemicals as accurately as the mouse LD50 value. The small number of chemicals studied to date means that general conclusions cannot be drawn from these results. Further validation of more chemicals with the in vitro methods is essential and promises to be worthwhile.

Analogy Models for Prediction of Human Toxicity

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 103-116
Author(s):  
Sven Hellberg ◽  
Lennart Eriksson ◽  
Jörgen Jonsson ◽  
Fredrik Lindgren ◽  
Michael Sjöström ◽  
...  
Keyword(s):  
Human Subjects ◽  
Toxicity Testing ◽  
In Vitro Cytotoxicity ◽  
Alternative Methods ◽  
Laboratory Animals ◽  
In Vitro Tests ◽  
Human Toxicity ◽  
Efficient Data ◽  
Basal Cytotoxicity

Estimating the toxicity to humans of chemicals by testing on human subjects is not considered to be ethically acceptable, and toxicity testing on laboratory animals is also questionable. Therefore, there is a need for alternative methods that will give estimates of various aspects of human toxicity. Batteries of in vitro tests, together with physicochemical and toxicokinetic data, analysed by efficient data analytical methods, may enable analogy models to be constructed that can predict human toxicity. It may be possible to model non-specific toxicity relating to lipophilicity, or basal cytotoxicity, for a series of diverse compounds with large variation in chemical structure and physicochemical properties. However, local models for a series of similar compounds are generally expected to be more accurate, as well as being capable of modelling more-specific interactions. Analogy models for the prediction of human toxicity are discussed and exemplified with physicochemical and cytotoxicity data from the first ten chemicals in the multicenter evaluation of in vitro cytotoxicity (MEIC) project.

An Animal Protection Sponsor's View of MEIC

1997 ◽  
Vol 25 (3) ◽  
pp. 343-345
Author(s):  
Ethel Thurston
Keyword(s):  
Gold Standard ◽  
Animal Cell ◽  
Scientific Evidence ◽  
In Vitro Cytotoxicity ◽  
In Vitro Tests ◽  
Blood Concentrations ◽  
Animal Protection ◽  
Animal Tests ◽  
Lethal Blood

The Multicenter Evaluation of In Vitro Cytotoxicity programme is most important to animal protection, since it has validated 64 in vitro tests using advanced human data for 50 chemicals as the “gold standard”. Therefore, it has been able to compare animal cell tests, human cell tests and whole-animal tests fairly with unbiased scientific evidence. Added bonuses have included the identification and development of missing in vitro information (“missing tests”), publication of time-related lethal blood concentrations for all 50 chemicals, and some preliminary plans to resolve the 50,000 untested (or poorly tested) chemicals in the chemical mountain.

MEIC Evaluation of Acute Systemic Toxicity

1998 ◽  
Vol 26 (2_suppl) ◽  
pp. 571-616 ◽  
Author(s):  
Björn Ekwall ◽  
Cecilia Clemedson ◽  
Balcarras Crafoord ◽  
Barbro Ekwall ◽  
Sara Hallander ◽  
...  
Keyword(s):  
In Vitro Cytotoxicity ◽  
Systemic Toxicity ◽  
Peak Time ◽  
Volume Distribution ◽  
Human Toxicity ◽  
Toxicity Data ◽  
Blood Concentrations ◽  
Target Organs ◽  
Lethal Blood

The Multicenter Evaluation of In Vitro Cytotoxicity (MEIC) programme was set up to evaluate the relevance for acute human systemic toxicity of in vitro cytotoxicity tests. At the end of the programme in the summer of 1996, 29 laboratories had tested all 50 reference chemicals in 61 cytotoxicity assays. As a necessary prerequisite to the forthcoming evaluation papers of this series, this paper presents the animal and human toxicity data of the programme. This database contains tabulated handbook data for the 50 chemicals, on: a) oral rat and mouse LD50 values; b) acute oral lethal doses in humans; c) clinically measured acute lethal serum concentrations in humans; d) acute lethal blood concentrations in humans measured postmortem; e) peaks from curves of an approximate 50% lethal blood/serum concentration over time after ingestion (LC50 curves), derived from a compilation of human acute poisoning case reports; f) human kinetics of single doses, including absorption, peak time, distribution/elimination curve, plasma half-life, distribution volume, distribution to organs (notably brain), and blood protein binding; and g) qualitative human acute toxicity data, including lethal symptoms, main causes of death, average time to death, target organs, presence of histopathological injury in target organs, presence of toxic metabolites, and known or hypothetical mechanisms for the lethal toxicity. The rationales for selection of the human toxicity data are also noted. The methods used to compile the in vivo toxicity data are described, including a presentation of a new method of constructing LC50 curves. Finally, the merits and shortcomings of the various human toxicity data for evaluation purposes are discussed.

The Development and Evaluation of In Vitro Tests by the FRAME Alternatives Laboratory

1995 ◽  
Vol 23 (1) ◽  
pp. 75-90
Author(s):  
Richard H. Clothier ◽  
Karen A. Atkinson ◽  
Michael J. Garle ◽  
Rachel K. Ward ◽  
Angela Willshaw
Keyword(s):  
Research Programme ◽  
Neutral Red ◽  
In Vitro Cytotoxicity ◽  
In Vitro Tests ◽  
Dermal Toxicity ◽  
Mechanisms Of Toxicity ◽  
The Us ◽  
Detergent Association ◽  
Assay Methods

This review outlines the work which has been conducted in the FRAME Alternatives Laboratory during the first ten years of the FRAME Research Programme. A number of in vitro tests, including the kenacid blue, neutral red release and fluorescein leakage assay methods, have been evaluated and have subsequently been included in validation schemes organised by the US Soap and Detergent Association, the US Cosmetic, Toiletry and Fragrance Association, the European Commission and the European Cosmetic, Toiletry and Perfumery Association, as well as in the Scandinavian multicentre evaluation of in vitro cytotoxicity testing scheme. More recently, research has been undertaken in the areas of phototoxicity, immunotoxicity, dermal toxicity and intercellular communication, in addition to investigations into fundamental mechanisms of toxicity.

MEIC Evaluation of Acute Systemic Toxicity

1998 ◽  
Vol 26 (2_suppl) ◽  
pp. 617-658 ◽  
Author(s):  
Björn Ekwall ◽  
Frank A. Barile ◽  
Argelia Castano ◽  
Cecilia Clemedson ◽  
Richard H. Clothier ◽  
...  
Keyword(s):  
Cell Line ◽  
Blood Brain Barrier ◽  
Human Cell ◽  
Human Cell Line ◽  
Brain Barrier ◽  
Human Toxicity ◽  
Blood Concentrations ◽  
Blood Brain ◽  
Ic50 Values

The Multicenter Evaluation of In Vitro Cytotoxicity (MEIC) programme was set up to evaluate the relevance for human acute toxicity of in vitro cytotoxicity tests. At the end of the project in 1996, 29 laboratories had tested all 50 reference chemicals in 61 cytotoxicity assays. Five previous articles have presented the in vitro data and the human database to be used in the evaluation. This article presents three important parts of the final evaluation: a) a comparison of rat and mouse oral LD50 with human acute lethal doses for all 50 chemicals; b) a display of the correlations between IC50 (concentration causing 50% inhibition) values from all 61 assays and three independent sets of human acute lethal blood concentrations, i.e. clinical lethal concentrations, forensic lethal concentrations, and peak concentrations; and c) a series of comparisons between average IC50 values from ten human cell line 24-hour assays and human lethal blood concentrations. In the latter comparisons, results from correlations were linked with known human toxicity data for the chemicals, to provide an understanding of correlative results. This correlative/mechanistic approach had the double purpose of assessing the relevance of the in vitro cytotoxicities, and of testing a series of hypotheses connected with the basal cytotoxicity concept. The results of the studies were as follows. Rat LD50 predictions of human lethal dosage were only relatively good (R2 = 0.61), while mouse LD50s gave a somewhat better prediction (R2 = 0.65). Comparisons performed between IC50 values from the 61 assays and the human lethal peak concentrations demonstrated that human ceil line tests gave the best average results (R2 = 0.64), while mammalian and fish cell tests correlated less well (R2 = 0.52–0.58), followed by non-fish ecotoxicological tests (R2 = 0.36). Most of the 61 assays underpredicted human toxicity for digoxin, malathion, carbon tetrachloride and atropine sulphate. In the correlative/mechanistic study, the 50 chemicals were first separated into three groups: A = fast-acting chemicals with a restricted passage across the blood–brain barrier; B = slow-acting chemicals with a restricted passage across the blood–brain barrier; and C = chemicals which cross the blood–brain barrier freely, while inducing a non-specific excitation/depression of the central nervous system (CNS). The IC50 values for chemicals in group C were divided by a factor of ten to compensate for a hypothetical extra vulnerability of the CNS to cytotoxicity. Finally, the average human cell line IC50 values (24-hour IC50 for groups A and C, and after 48-hour for group B) were compared with relevant human lethal blood concentrations (peak concentrations for groups A and C, and 48-hour concentrations for group B). As a result, in vitro toxicity and in vivo toxicity correlated very well for all groups (R2 = 0.98, 0.82 and 0.85, respectively). No clear overprediction of human toxicity was made by the human cell tests. The human cell line tests underpredicted human toxicity for only four of the 50 chemicals. These outlier chemicals were digoxin, malathion, nicotine and atropine sulphate, all of which have a lethal action in man through interaction with specific target sites not usually found in cell lines. Potassium cyanide has a cellular human lethal action which cannot be measured by standard anaerobic cell lines. The good prediction of the human lethal whole-blood concentration of this chemical was not conclusive, i.e. was probably a “false good correlation”. Another two chemicals in group C resulted in “false good correlations”, i.e. paracetamol and paraquat. The comparisons thus indicated that human cell line cytotoxicities are relevant for the human acute lethal action for 43 of the 50 chemicals. The results strongly support the basal cytotoxicity concept, and further point to the non-specific CNS depression being the obligatory reaction of humans to cytotoxic concentrations of chemicals, provided that the chemicals are able to pass the blood–brain barrier.

In Vitro Cytotoxicity Testing: 24-hour and 72-hour Studies with Cultured Lung Cells

1993 ◽  
Vol 21 (2) ◽  
pp. 167-172
Author(s):  
Desirée Hopkinson ◽  
Rae Bourne ◽  
Frank A. Barile
Keyword(s):  
Cultured Cells ◽  
Linear Regression Analysis ◽  
Biological Significance ◽  
Culture Method ◽  
In Vitro Cytotoxicity ◽  
Lung Epithelial Cells ◽  
Blood Concentrations ◽  
Lung Epithelial ◽  
Ic50 Values

This study was designed to evaluate the potential of an in vitro cell culture method for its ability to determine cytotoxicity and to compare the cytotoxic concentrations with established LD50 values for the same chemicals. Rat lung epithelial cells (L2) were incubated in the absence or presence of increasing concentrations of the test chemical for 24 hours, and the inhibition of incorporation of radio-labelled amino acids into newly synthesised proteins was used as a marker for toxicity. In addition, cultured cells were exposed to the test chemicals for 72 hours, and cell proliferation experiments were performed as parallel measures of toxicity. Inhibitory concentrations were extrapolated from concentration-effect curves after linear regression analysis. The biological significance of the results of testing 20 chemicals shows that the experimental IC50 values are as accurate as predictors of human toxicity as are equivalent toxic blood concentrations derived from rodent LD50s. Results obtained from 72-hour growth studies reveal a greater sensitivity to cytotoxicity than from the 24-hour protein synthesis experiments. Statistically, however, the differences between the two protocols are inconclusive. It is anticipated that these procedures, together with a related battery of tests, may supplement or replace animal protocols currently used for human risk assessment.

MEIC Evaluation of Acute Systemic Toxicity

1996 ◽  
Vol 24 (1_part_1) ◽  
pp. 251-272 ◽  
Author(s):  
Cecilia Clemedson ◽  
Elisabeth McFarlane-Abdulla ◽  
Marianne Andersson ◽  
Frank A. Barile ◽  
Mabel C. Calleja ◽  
...  
Keyword(s):  
Full Range ◽  
Primary Cultures ◽  
In Vitro Cytotoxicity ◽  
Systemic Toxicity ◽  
Toxicity Tests ◽  
In Vitro Toxicity ◽  
Blood Concentrations ◽  
Differentiated Cells ◽  
Basal Cytotoxicity

The multicentre evaluation of in vitro cytotoxicity (MEIC) study is a programme designed to evaluate the relevance of in vitro toxicity tests for predicting human toxicity, and is organised by the Scandinavian Society for Cell Toxicology. The project started in 1989 and is scheduled to be finished by June 1996. MEIC is a voluntary effort by international laboratories to test the same 50 reference chemicals in their own in vitro toxicity systems. At present, 31 laboratories have submitted results for the first 30 reference chemicals from a total of 68 in vitro cytotoxicity tests. In the definitive evaluation of the MEIC programme, these in vitro results will be compared with human lethal blood concentrations and other relevant acute systemic toxicity data, and the results will be published as a series of articles. This paper, which is the first article in this series, describes and analyses the methodologies used in the 68 tests. The origins and purities of the test chemicals, the biological systems and the toxicity endpoints are also discussed. Since MEIC is not centrally directed, the selection of tests was entirely dependent on the preferences of the individual laboratories. Thus, the collection of tests is not representative of the full range of existing in vitro toxicity tests. In our study, basal cytotoxicity tests and ecotoxicological tests are prevalent, while tests for toxicity to primary cultures of differentiated cells, measured by organotypic toxicity endpoints, are clearly under-represented.

Use of the PFGE Assay for Studies of DNA Breakage Induced by Toxic Chemicals

2003 ◽  
Vol 31 (3) ◽  
pp. 283-288
Author(s):  
Eva Markova ◽  
Cecilia Clemedson ◽  
Ada Kolman
Keyword(s):  
Human Fibroblasts ◽  
In Vitro Cytotoxicity ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Blood Concentrations ◽  
Strand Breaks ◽  
Cell Monolayers ◽  
Ic50 Values ◽  
Lethal Blood

The relevance of the pulsed field gel electrophoresis (PFGE) assay for the estimation of the DNA damaging effects of chemicals was studied. Four chemicals were randomly chosen from the list of 50 Multicentre Evaluation of In Vitro Cytotoxicity (MEIC) reference chemicals with known human acute systemic toxicity: acetylsalicylic acid, paracetamol, ethylene glycol and sodium chloride. Human fibroblasts (VH-10) were used as a model system. For the estimation of cytotoxic effect, cell monolayers were treated with chemicals for 24 hours. Cloning efficiency (colony-forming ability) at different concentrations of the test chemicals was estimated, and the 50% inhibitory concentration (IC50) was determined. The IC50 values obtained demonstrated a correlation with human lethal blood concentrations. The induction of DNA double-strand breaks, measured by PFGE as the fraction of activity released, was detected after treatment with paracetamol. However, the other three chemicals tested mainly induced DNA degradation.

MEIC—A new international multicenter project to evaluate the relevance to human toxicity of in vitro cytotoxicity tests

1989 ◽  
Vol 5 (3) ◽  
pp. 331-347 ◽  
Author(s):  
Inger Bondesson ◽  
Björn Ekwall ◽  
Sven Hellberg ◽  
Lennart Romert ◽  
Kjell Stenberg ◽  
...  
Keyword(s):  
In Vitro Cytotoxicity ◽  
Human Toxicity ◽  
International Multicenter

scholarly journals In vitro Cytotoxicity Studies of Industrially Used Common Nanomaterials on L929 and 3T3 Fibroblast Cells

2020 ◽  
Vol 1 (5) ◽  
pp. 192-200
Author(s):  
Madhulika Srikanth ◽  
Waseem S Khan ◽  
Ramazan Asmatulu ◽  
Heath E Misak ◽  
Shang-You Yang ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Cell Types ◽  
In Vitro Cytotoxicity ◽  
In Vitro Tests ◽  
Fibroblast Cells ◽  
In Vivo Experiments ◽  
Cytotoxicity Studies ◽  
Biomedical Electronics

The unique structures and properties of nanomaterials have attracted many engineers and scientists to these resources for different applications, including biomedical, electronics, manufacturing, transportation, energy, and defense. The increasing applications of nanomaterials have also caused some concern among the scientific community about their safety and cytotoxicity. To successfully use nanomaterials in different fields, their interaction with mammalian cells in vitro must be addressed before in vivo experiments can be carried out successfully. In this study, the cytotoxicity values of commonly known nanomaterials, such as 100-ply Carbon Nanotube (CNT) wires, graphene, CNTs, nanoclay, and fullerene, were investigated through in vitro tests on human L929 and mice 3T3 fibroblast cells and compared with each other. The effects of cytotoxicity on both cell types were similar in many ways, but not closely identical due to structural and morphological differences. Compared to mice fibroblast cells, human fibroblast cells have a larger surface area; therefore, the viability values of L929 cells at different dilutions and time durations vary over a larger range. Pristine 100-ply CNT wires were found to be the least cytotoxic, with an average viability of 86.9%, whereas materials with high aspect ratio (e.g., CNTs and graphene) had higher cytotoxicity values due to their potential to pierce through cell membranes.

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