Discuss the main types of end point used in toxicity testing in cellular system ,indicating how they can be incorporated into ti - Essay Example

inbreeding of animals, gender/species differences, in turn causing differences in pharmacologic or toxin mode of actions), unrealistic dosages of toxins, small test populations, inefficiencies in obtaining sound results and the lack of other human factors such as diseases in the test subjects (Knight, 2008, p.214). The combination of inefficiencies and expenses that occur as the result of the need to comply with toxicity tests cause the release of chemicals that had little to no proper toxicity tests, and can be potentially lethal to users (Rotroff, et al., 2010). As a result, other non-animal solutions were developed, which use mostly cells and cultures in vitro, and in turn can expect faster results that better resemble human cellular processes (Andersen and Krewski, 2009). Despite these outlooks, other setbacks in the use of alternative methods of toxicity testing can still occur such as optimisation and standardisation of methods, validation of the results, and the relative expenses of performing only small to medium loads in assays especially with regards to automated processes such as sampling and readings (Wetmore, et al. 2012). Still, the use of cell lines in cell-based toxicity screening assays seem promising through the use of in vitro tests with increased loads in assay while using viable cells such as primary cells, immortalised cell lines, human cells and stem cell-derived systems, and these can improve both outcome paces and predictive value of the tests in relation to human cell system toxicity (Basketter, et al., 2012; Riss and Moravec, 2004). A point to consider when opting for cell-based toxicity assays is the expected endpoints of the tests, which are dependent on the objectives of the test, whether these tests are cost-effective, if the tests can provide high throughput results, the degree of uniformity needed in the cell assays, and reliability or reproducibility of the results (Judson, et al., 2013).For example, there are some assays which use viable cell counts to determine toxicity of chemicals, such as the use of basal cell culture for in vitro cytotoxicity tests. These tests determine cytotoxicity in chemicals without any information yet, and as such can be used to rank them in terms of potential toxicity based on observed cell deaths (Ekwall, et al., 1990). Because these tests mostly rely on cell counts and finding out the viability of the cells, results can be gathered in shorter time in comparison with other kinds of tests. In addition, the results can be predicted based on the known chemical structures of the chemical, and thus it can also be used as a confirmatory test. However because there has been much greater emphasis on biochemical pathways of toxic chemicals, establishing the lowest amount that could possibly cause cellular events and how these chemicals affect reproductive and developmental processes, the use of cytotoxicity has been determined to be insufficient in establishing chemical dosage rates(Basketter, et al., 2012, p.18). Another example of an in vitro assay that relies on primary cell lines, using neurotoxicity as an endpoint is the development of central nervous system (CNS) tissues using proliferation assays to observe cellular interactions and how neurotoxicity occurs (van Liet, Read More