Using a newly developed cell line, the reaction of skin cells to allergenic substances can now be demonstrated in the test tube.
"Combining the new method with two additional alternative methods to investigate skin sensitization allows us not only to significantly reduce the number of animal studies, but also to predict a possible allergic potential more reliably than before," said Dr Robert Landsiedel, head of the short-term Toxicology unit at BASF.
It is an important step forward in the fight against animal testing in cosmetics, particularly following the REACH regulation, which states that several thousand substances have to be tested for their skin sensitizing action by 2018.
Furthermore, since March 2013 animal testing on cosmetic ingredients for the European market have been completely prohibited.
This means that developing effectiuve alternative methods to test for allergic skin reactions is more important now than ever.
Allergic skin reactions involve a variety of biochemical processes. BASF says these include the binding of a substance to one of the skin's proteins and a resulting stress reaction.
Both are early and reliable indicators of a possible allergenic potential of the test substance. In the newly developed cell line, scientists of RWTH Aachen University Hospital have modified a reporter gene from Promega, so that the stress reactions are coupled to a light signal.
This gene construct was then stably inserted into human skin cell lines. Dr Katarina Bohm, Marketing Manager of Promega: "Our luciferase vectors translate cellular changes into a luminescent signal. This allows stress reactions in skin cells to be easily detected with our luciferase assay systems."
The new cell line has been extensively tested at BASF and a standardized method has been developed to reliably assess the allergenic potential of a substance.
The alternative method was submitted to the European Commission (European Center for the Validation of Alternative Methods, ECVAM) to determine whether it can be recognized as a standard method for toxicological studies in Europe.