3R Principle and
Alternative Toxicity Testing Methods
Pinar ERKEKOGLU*, Belma Kocer GIRAY*, Nurŝen BAŜARAN*,°
* To whom correspondence should be addressed at Hacettepe
University, Faculty of Pharmacy, Department of
Toxicology, 06100 Ankara Turkey
° Corresponding Author E-mail: nbasaran@hacettepe.edu.tr
Summary
Toxicity tests are essential for evaluating the safety or
hazards of several substances. Many of the current toxicity
testing methods include the use of animals, especially
rodents. However, in the last three decades, there has been
an inclination towards using less animals and performing
alternative methods that reduce, refine and replace animal
use (3R principle). The viewpoint of reduction is to
decrease the number of animals required for a test method,
while remaining consistent with scientific practices that
are necessary to aquire valid results. The standpoint of
refinement is using procedures that bring less pain or
distress in animals. The aspect of replacement is to use
non-animal systems instead of animals, or to use a
phylogenetically lower species of live animals. Among all
approaches, the use of alternative techniques replacing
animals has a potential for the future research. The
alternative test methods include in vitro models like cell
cultures, and tissue/organ assays and in silico testing.
Cell cultures have several advantages and scientist expect
that in vitro testing will succeed against in vivo testing
in the forthcoming years. This review will focus on the 3R
principle and alternative test methods.
Key Words
3R principle, reduction, refinement, replacement,
alternative test methods, cell lines, in silico.
