Methodologies for interpretation of short-term test results which may allow reduction in the use of animals in carcinogenicity testing

Use of a complex approach for assessment of metamizole sodium and acetylsalicylic acid toxicity, genotoxicity and cytotoxicity

A complex approach based on the use of test organisms belonging to different systematic groups (plants, invertebrates and vertebrates), as well as the nucleolar biomarker and the micronucleus test on their cells, was applied to assess the toxicity, cytotoxicity and genotoxicity of two pharmaceutical substances (metamizole sodium and acetylsalicylic acid) applied at ic(50) concentrations for mammalian cells. The compound acetylsalicylic acid was evaluated at a concentration (1.6 x 10(3) mg l(-1)) that was non-toxic for bioassays based on fish (Carassius auratus gibelio) and hydra (Hydra attenuata) and acutely toxic for bioassays with ceriodaphnia (Ceriodaphnia affinis) and onion (Allium cepa). The metamizole sodium solution (6.25%) demonstrated acute toxicity for the whole set of test organisms. Both drugs, after their 30-360 min influence on the test organisms, first changed the nucleolar size in plant and animal cells (i.e. the transcriptional activity of ribosomal genes was affected most significantly). Moreover, the metamizole sodium solution caused nucleolar structural damage in 90% of hydra cells as early as after 30 min of exposure. The acetylsalicylic acid solution inhibited essentially the rate of cell division in the meristem of onion roots (the mitotic index decreased to 9.6 per thousand, as compared 51.7 per thousand for the control). The carp incubation and the onion germination in the acetylsalicylic acid solution showed a reproducible increase in the frequency of cells with micronuclei (2 and 5.5 times, respectively) and double nuclei (3 and 1.5 times, respectively). The approach described herein may be applied for obtaining rapid, cost-efficient and useful supplementary data on different types of toxicity for marketed drugs as well as for drugs under development.

Quality of water types in Ukraine evaluated by WaterTox bioassays

The quality of river, ground-, and tap water was analyzed using the basic set of WaterTox bioassays [Daphnia (Daphnia magna), Hydra (Hydra attenuata), and lettuce (Lactuca sativa)] as well as two additional bioassays, onion (Allium cepa) and microalga (Selenastrum gracile). Samples of these waters were also concentrated fivefold using a solid-phase procedure. The results of the Daphnia and Hydra bioassays showed that the winter and spring concentrated and nonconcentrated samples from the Dnieper and Desna rivers, the main water supply sources for Kiev, were nontoxic. In spring, after concentration, the two river samples brought about the same relative decrease in the lettuce root length (by 35%, p < 0.001), where the Desna River sample considerably reduced (by 79.1%, p < 0.001) the number of microalga cells. Samples of groundwater from countryside wells studied in autumn in several villages of the Kiev region were toxic mainly to Hydra (sublethal effects were found in 11%-78%) and lettuce (the root length decreased 15%-56%). Studies of tap water samples from two of the largest cities of Ukraine, Kiev and Kharkiv, were found to be nontoxic to both plants, lettuce and onion, but showed increased sublethal and lethal effects on both animals, Daphnia and Hydra, as well as a reduced number of microalgae. Different bioassays were sensitive to varying degrees to different water types. This reinforces the necessity of using sets of bioassays in toxicity evaluation. In general, all the tested water samples demonstrated some toxicity. These data suggest that drinking water quality in Ukraine needs improvement.

CASE, the computer-automated structure evaluation system, as an alternative to extensive animal testing

CASE, an artificial intelligence system with demonstrated ability to predict biological activity based on structural considerations, correctly predicts animal carcinogenicity. It can, therefore, play a pivotal role in classifying chemicals as carcinogens and prioritizing them for further testing. Additionally, CASE shows promise in the design of pharmacologically active agents by reducing the number of drugs that need to be synthesized and tested. For both of these applications, CASE provides a mechanism to conserve animal and other testing resources.