A newly developed means of HPLC-fluorescence analysis for predicting the skin sensitization potential of multi-constituent substances using ADRA

Abstract

The Amino acid Derivative Reactivity Assay (ADRA) is an in chemico alternative to animal testing for skin sensitization potential, in which measurements of multi-constituent solutions were sometimes affected by co-elution with nucleophilic reagents. So, we established a means of using fluorescence detection and verified the utility of a newly developed ADRA-fluorescence detection (ADRA-FL) test method. We tested three types of plant extracts—aloe, green tea, and licorice—and although unable to quantify nucleophilic reagents using ultraviolet detection due to co-elution of multiple components, the use of fluorescence detection enabled us to detect nucleophilic reagents selectively and predict each of the extract solutions to be sensitizers. Given that plant extracts contain immunosuppressants, there is no reason to expect that positive results in ADRA-FL testing will always be concordant with in vivo results. But given its ability to predict the sensitization potential of cosmetics and other widely used multi-constituent substances that had previously been difficult to test, the newly developed ADRA-FL is expected to contribute to future assessments of sensitization risks.