New alternative method to identify allergenic substances

According to Promega, a life sciences company, and BASF, a chemical giant and a leading supplier of ingredients for the cosmetics and personal care industries, their fully in vitro new method can reliably detect the allergenic potential of natural or chemical substances.

New cell line

The method is based on the use of a cell line newly developed by scientists of the RWTH Aachen University Hospital. Indeed, the researchers have modified a reporter gene [1] 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. “Our luciferase [2]vectors translate cellular changes into a luminescent signal. This allows stress reactions in skin cells to be easily detected with our luciferase assay systems,” explains Dr. Katarina Bohm, Marketing Manager of Promega.

Then, the new cell line has been tested at BASF and a standardized method has been developed to reliably assess the allergenic potential of a substance.

According to the two companies, “the reaction of skin cells to allergenic substances can now be demonstrated in the test tube.” Indeed, allergic skin reactions involve a variety of biochemical processes. 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 an allergenic potential of the test substance.

Alternative to animal testing

Previously, the skin sensitizing action of substances had to be determined in animal studies. As animal studies on cosmetic ingredients for the European market have been completely prohibited since March 2013, developing the method at the present time is particularly important. In particular in a context where REACH regulation simultaneously requires several thousand substances to be tested for their skin sensitizing action by 2018.

“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 risk more reliably than before,” says Dr. Robert Landsiedel, Head of the short-term Toxicology unit at BASF.

The alternative method was therefore submitted to the European Commission (European Center for the Validation of Alternative Methods, ECVAM) to decide whether it can be recognized as a standard method for toxicological studies in Europe.