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.

Automation of an in vitro cytotoxicity assay used to estimate starting doses in acute oral systemic toxicity tests

2012 ◽  
Vol 50 (6) ◽  
pp. 2084-2096 ◽  
Author(s):  
Mounir Bouhifd ◽  
Gilles Bories ◽  
Juan Casado ◽  
Sandra Coecke ◽  
Hedvig Norlén ◽  
...  
Keyword(s):  
In Vitro Cytotoxicity ◽  
Systemic Toxicity ◽  
Cytotoxicity Assay ◽  
Toxicity Tests

MEIC Evaluation of Acute Systemic Toxicity

1998 ◽  
Vol 26 (1_suppl) ◽  
pp. 93-129 ◽  
Author(s):  
Cecilia Clemedson ◽  
Frank A. Barile ◽  
Barbro Ekwall ◽  
Maria José Gómez-Lechón ◽  
Tony Hall ◽  
...  
Keyword(s):  
Cell Lines ◽  
Primary Cultures ◽  
Toxicity Testing ◽  
Preceding Paper ◽  
In Vitro Toxicity ◽  
Toxicity Data ◽  
Animal Cells ◽  
Basal Cytotoxicity

Results from tests on the first 30 MEIC reference chemicals in 16 different systems are presented as a prerequisite to the subsequent in vitro/in vivo comparisons of acute toxicity data, i.e. the final MEIC evaluation of all test results of the study. The study is a supplement to the previously published results from 68 methods (including methods 45B and 46B [old numbers]) used to test the same set of chemicals. The strategies and methods of the preceding paper were employed to enable a comparative cytotoxicity analysis of the results from these 68 methods and from the 16 new methods to be made. Principal components analysis (PCA) of 82 assays demonstrated a dominating first component which described as much as 83% of the variance in the toxicity data. This remarkable similarity of all toxicity data was the main finding of the present study, and confirmed the results of the previous study with a less-extensive database. Also, the influence on the general variability of results of several key methodological factors was evaluated by analysis of selected sets of data, including linear regression of the results of pairs of methods, which were similar in all respects except for the factor under analysis. This analysis of the same 82 assays as before also confirmed previous results from the 68 assay database: a) the toxicities of a third of the chemicals increased considerably with exposure time; b) in general, cytotoxicity for human cells was well predicted by cytotoxicity tests with animal cells; c) this prediction was poor for two chemicals, i.e. digoxin and malathion; d) prediction of human cytotoxicity by ecotoxicological tests was only fairly good; e) 25 comparisons of similar assays employing different cell lines showed strikingly similar toxicities (mean R2 = 0.86); f) 22 comparisons of similar pairs of assays employing different primary cultures and cell lines also revealed similar toxicities (mean R2 = 0.79); and g) 15 comparisons of similar assays with different growth/viability endpoint measurements demonstrated strikingly similar toxicities (mean R2 = 0.89). Results b, e, f and g must be the main causes of the general similarity of results, while results a, c and d, together with other factors, could explain the 20% dissimilarity. These findings support the basal cytotoxicity concept and may assist in guiding and refining in vitro toxicity testing in the future.

Can the In Vivo Maximum Tolerated Dose be Predicted Using In Vitro Techniques? A Working Hypothesis

1991 ◽  
Vol 19 (4) ◽  
pp. 393-402
Author(s):  
Ravi Shrivastava ◽  
Gareth W. John ◽  
Ginette Rispat ◽  
Annick Chevalier ◽  
Roy Massingham
Keyword(s):  
Cell Death ◽  
Research Effort ◽  
Maximum Tolerated Dose ◽  
In Vitro Cytotoxicity ◽  
Toxicity Tests ◽  
In Vitro Toxicity ◽  
Working Hypothesis ◽  
Wide Range

All new chemical entities synthesised in our laboratories have routinely been subjected to in vitro toxicity tests. Out of curiosity, we established a working hypothesis in which the in vitro data could be empirically transformed to predict the in vivo four-week standard maximum tolerated dose (MTD) studies in rats and dogs. As a first step to verifying this hypothesis, we report here the findings of an in vitro cytotoxicity study of 25 compounds randomly selected from our files, possessing a wide range of pharmacological activities and for which data from standard four-week MTD studies were available. Single blind in vitro toxicity studies in three carefully selected types of primary and cell line cultures were carried out. In vitro CT50 (concentration inducing 50% cell death) and CT100 (concentration inducing 100% cell death) values were obtained for each of the three cell types and, using empirical assumptions, these results were used to predict the MTD in vivo in the rat and dog. The actual in vivo threshold and toxic doses were obtained from the MTD study reports. The in vivo toxicity values predicted from the in vitro toxicity results with this series of 25 compounds showed a better than 80% correlation with the actual in vivo results obtained in the MTD studies. Whether or not in vitro cytotoxicity predictions are ultimately found to be directly and consistently related to the MTD in vivo for all pharmacological classes of compounds will require many additional studies, but it is hoped that these results will stimulate the necessary research effort required to answer this question.

The Use of Human Lymphocytes for the In Vitro Estimation of Acute Toxicity of Ten Chemicals from the MEIC List

1991 ◽  
Vol 19 (2) ◽  
pp. 187-190
Author(s):  
Mette Tingleff Skaanild ◽  
Jørgen Clausen
Keyword(s):  
Hela Cells ◽  
Cultured Cells ◽  
Human Lymphocytes ◽  
Primary Cultures ◽  
Biological Significance ◽  
In Vitro Cytotoxicity ◽  
In Vitro Toxicity ◽  
Human Hepatoma Cells ◽  
Response Curves

The acute cytotoxicity of ten chemicals included in the MEIC (multicentre evaluation of in vitro cytotoxicity) list has already been estimated in various cell lines, e.g. primary rat hepatocytes, HeLa cells, human hepatoma cells, and 3T3 and mouse fibroma cells. In the present study, primary cultures of human lymphocytes, with or without an S9-mix (microsomes), were used to assay for in vitro toxicity. The cultured cells were initially treated with different concentrations of the respective drugs for 24 hours. Then cellular enzymatic activity was estimated using two assay systems, namely, measurement of cytosolic LDH activity and the mitochondrial (diaphorase) MTT test. Since the biological significance of the assay of LC50 values is dependent upon the slope of the dose-response curves, the results are expressed as LC20, LC50 and LC80 values in μM for the ten drugs. A Spearman rank correlation analysis revealed a significant correlation between the results from the two assays in both cell culture systems (r=1.00 and r=0.99). The LC50 values found in the lymphocyte cultures, both with and without an S9-mix, correlated well with the results previously found using primary cultures of hepatocytes and HeLa cells.

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.

MEIC Evaluation of Acute Systemic Toxicity

1996 ◽  
Vol 24 (1_part_1) ◽  
pp. 273-311 ◽  
Author(s):  
Cecilia Clemedson ◽  
Elisabeth McFarlane-Abdulla ◽  
Marianne Andersson ◽  
Frank A. Barile ◽  
Mabel C. Calleja ◽  
...  
Keyword(s):  
Toxicity Testing ◽  
Cell Types ◽  
In Vitro Toxicity ◽  
Test Systems ◽  
Differentiated Cells ◽  
Basal Cytotoxicity ◽  
Linear Contrast ◽  
Different Cell Types

Results from tests of the first 30 MEIC reference chemicals in 68 different toxicity assays are presented as a prerequisite to subsequent in vitro/in vivo comparisons of acute toxicity data. A comparative cytotoxicity study was also carried out. Firstly, the variability of all of the results was analysed by using principal components analysis (PCA), analyses of variance (ANOVAs) and pairwise comparisons of means according to Tukey's method. The first PCA component described 80% of the variance of all of the cytotoxicity data. Tukey's ANOVA indicated a similar sensitivity for the assays, of approximately 80%. Secondly, the influence of five major methodological components on the general variability of the results was evaluated by linear regression and ANOVA linear contrast analyses. The findings were that: a) the toxicity of many chemicals increased with exposure time; b) in general, human cytotoxicity was predicted well by animal cytotoxicity tests; c) this prediction was poor for two chemicals; d) the prediction of human cytotoxicity by the ecotoxicological tests was only fairly good; e) one organotypic endpoint used, i.e. contractility of muscle cells, gave different results to those obtained according to viability/growth toxicity criteria; f) twelve comparisons of similar test systems involving different cell types (including highly differentiated cells) showed similar toxicities regardless of cell type; and g) nine out often comparisons of test systems with identical cell types and exposure times revealed similar toxicities, regardless of the viability or growth endpoint measurement used. Factors b, f and g must be the main causes of the remarkable similarity between the total results, while factors a, c, d and e, together with other minor factors that were not analysed, contributed to the 20% dissimilarity. The findings strongly support the basal cytotoxicity concept, and will facilitate future in vitro toxicity testing.

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.

scholarly journals Synthesis of Gold Nanoparticles by Using Green Machinery: Characterization and In Vitro Toxicity

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 808
Author(s):  
Ahmed Al Saqr ◽  
El-Sayed Khafagy ◽  
Ahmed Alalaiwe ◽  
Mohammed F. Aldawsari ◽  
Saad M. Alshahrani ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Average Particle Size ◽  
In Vitro Cytotoxicity ◽  
In Vitro Toxicity ◽  
Cervical Cancer Cell Line ◽  
Average Particle ◽  
Anticancer Activities ◽  
Tem Analysis ◽  
Benincasa Hispida

Green synthesis of gold nanoparticles (GNPs) with plant extracts has gained considerable interest in the field of biomedicine. Recently, the bioreduction nature of herbal extracts has helped to synthesize spherical GNPs of different potential from gold salt. In this study, a fast ecofriendly method was adopted for the synthesis of GNPs using fresh peel (aqueous) extracts of Benincasa hispida, which acted as reducing and stabilizing agents. The biosynthesized GNPs were characterized by UV–VIS and Fourier transform infrared spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering. In addition, the in vitro antibacterial and anticancer activities of synthesized GNPs were investigated. The formation of gold nanoparticles was confirmed by the existence of a sharp absorption peak at 520 nm, corresponding to the surface plasmon resonance (SPR) band of the GNPs. TEM analysis revealed that the prepared GNPs were spherical in shape and had an average particle size of 22.18 ± 2 nm. Most importantly, the synthesized GNPs exhibited considerable antibacterial activity against different Gram-positive and Gram-negative bacteria. Furthermore, the biosynthesized GNPs exerted remarkable in vitro cytotoxicity against human cervical cancer cell line, while sparing normal human primary osteoblast cells. Such cytotoxic effect was attributed to the increased production of reactive oxygen species (ROS) that contributed to the damage of HeLa cells. Collectively, peel extracts of B. hispida can be efficiently used for the synthesis of GNPs, which can be adopted as a natural source of antimicrobial and anticancer agent.

Sign in / Sign up

Export Citation Format

Share Document