In chemico skin sensitization risk assessment of botanical ingredients

Skin sensitization risk assessment of botanical ingredients is necessary for consumers' protection and occupational hazard identification. There are currently very few available alternative methods that can assist in the evaluation of complex mixtures. Chemical methods can provide essential information in a timely manner and thus help to reduce the need for in vivo testing, and they can complement and facilitate targeted in vitro assays. In the present work, the applicability of the high-throughput screening with dansyl cysteamine (DCYA) method for the systematic evaluation of skin sensitization of complex botanicals was explored. Botanical ingredients of four unrelated plant species were obtained and tested with the high-throughput fluorescence method at three concentrations. To illustrate the minimal matrix effects of the tested extracts on the developed method, the least DCYA-reactive extract (Rosa canina) was spiked with known sensitizers at different concentrations. The data obtained from the four plant extracts and the spiking experiments with known sensitizers, suggest that the high-throughput screening-DCYA method can be successfully applied for estimating the skin sensitization potential of complex botanical matrices. This is the first report of an attempt to develop a versatile in chemico method for the rapid detection of reactive skin sensitizers in complex botanical extracts, which could complement the battery of existing validated, non-animal methods.