ABSTRACT
The ever-increasing number of chemical compounds synthesized by chemical and pharmaceutical industries has prompted the development of research methods for rapid cytotoxicity screening. In addition, public concern about pain and suffering to animals has encouraged toxicologists to develop substitute approaches for toxicity assessment. Present research efforts are directed at developing a series of in vitro assays that could serve as reliable, reproducible, and inexpensive alternatives to in vivo animal testing. In recent years, new approaches show promise for effective and inexpensive toxicity assessment that will minimize use of animals and that will increase the selection of lead candidate compounds. In vitro methods for toxicity assessment need to provide reproducible and informative data that are equivalent to accepted methods using live animals, such as the median lethal dose (LD50). LD50 testing is expensive, consumes large numbers of animals, and has been criticized as inhumane. Optional approaches have been suggested and are beginning to be adopted by manufacturers of pharmaceuticals, pesticides, cosmetics, and household products to reduce the number of animals used in toxicity screening. To validate the use of in vitro models for cytotoxicity assessments, attempts should be made to standardize methodology and, more importantly, to define criteria for lethality assessment. In this review, we present some new ideas and methodologies that may aid in increasing the effectiveness and efficiency of cytotoxicity assessments.
