EDIT: A New International Multicentre Programme to Develop and Evaluate Batteries of In Vitro Tests for Acute and Chronic Systemic Toxicity

Abstract

The Multicenter Evaluation of In Vitro Cytotoxicity (MEIC) programme provided a battery of three basal cytotoxicity tests with a good (R2 = 0.77) prediction of human acute lethal blood concentrations. The predictive power of this battery would be considerably improved by the addition of new supplementary in vitro tests. The development of these new tests will be facilitated by a close coupling of test development to evaluation. The Cytotoxicology Laboratory, Uppsala (CTLU), is therefore inviting all interested in vitro toxicologists to take part in the Evaluation-guided Development of In Vitro Toxicity and Toxicokinetic Tests (EDIT). All EDIT activities (subprojects) will be designed on a case-by-case basis, but will follow a common pattern. The CTLU will use the accumulated MEIC/EDIT data, and its experience from the previous MEIC evaluation, to suggest priority areas, i.e. the need for certain in vitro toxicity data/tests as supplements to existing in vitro models/batteries on human systemic toxicity. Detailed research programmes corresponding to these areas will be published on the Internet. The CTLU will also try to raise funds for some projects and will coordinate multilaboratory studies. Interested laboratories developing or already using priority tests are encouraged to join the subprojects and to test specific sets of substances (usually sets of MEIC reference chemicals) in their new assays. The CTLU will provide adequate human reference data and will also evaluate results as single components of complex models, together with the laboratory conducting the test. At present, ten priority areas have been identified: a) repeat dose toxicity in vitro; b) urgent mechanistic information from in vitro studies of protein denaturation, morphology of cell injury, differential toxicity between various rapidly measured end-points (10–60 minutes) and 24-hour cytotoxicity, toxicity to aerobic cells, and discrimination between rapid and slow cytotoxic mechanisms; c) in vitro tests on vitally important, specific receptor toxicity in humans; d) excitatory cytotoxicity; e) reversibility of cell toxicity; f) in vitro tests on passage across the blood–brain barrier; g) in vitro tests on absorption in the gut; h) protein binding in vitro; i) in vitro tests on distribution volumes (Vd); and j) in vitro tests on bio-transformation to more-toxic metabolites (hepatocytes plus target cells). This paper gives a short presentation of the rationale for each subproject and reports on ongoing activities.

Some aspects of in vitro studies of neurotoxicity: from choice of biochemical and molecular markers to the confirmation of their informativity

“…Beside that, the use of cell cultures allows to establish the nature of the biological activity of the compounds directly at the cellular level and helps to account the complex synergistic and / or multidirectional effects of mixtures of chemical compounds. Major contribution to the development of a new field of toxicology was made by B. Ekwall [14,15]. He formulated the concept of basic cytotoxicity, that is used for determination of the acute toxicity of chemicals on cell cultures instead of animals.…”

“…Study of neurotoxicity in vitro may be used of determinition of some molecular markers of the morphofunctional state of the nervous tissue [15,16]:…”

“…Its well known, that mitochondria is a priority target in the implementation of the toxicodynamics of many drugs (cytostatics, antibiotics, cardiac glycosides, etc). So, it is useful to assess the "mitodestructive effect" in toxicological studies in vitro [15].…”

An alternative method for in vitro fire smoke toxicity assessment of polymers and composites using human lung cells

“…These techniques have become routine in product development, drug discovery, safety evaluation 24–31, and for predicting acute lethality in vivo 32. High relevance and correlation between in vitro methods in predicting human acute toxicity has been demonstrated by a large number of studies 33–47.…”

Toxicity of Some Phenolic Derivatives—In Vitro Studies

“…At present, in in vitro toxicology, the toxic effects of compounds are evaluated in stages. The first stage consists in determining general (basal) cytotoxicity [1,2,3,4,5,6].…”