A framework for the safety evaluation of peptides in cosmetics

As the cosmetic industry replaces traditional animal safety studies with next generation risk assessment approaches, the approach to safety substantiation for peptides used in cosmetic products must also evolve. While the need to provide assurances of safety for local and systemic toxicity endpoints remains the same, adoption of bioinformatic tools developed in the food, agricultural biotechnology, and drug development industries may add to the weight of evidence for the safety substantiation of peptides in cosmetics. Here we review the historical development and safety evaluation of peptides utilized in the cosmetic industry and provide a new safety evaluation framework that incorporates six bioinformatic tools. To test the framework, a variety of peptides (palmitoyl hexapeptide-12, caffeoyl hexapeptide-9, palmitoyl pentapeptide-4, amanitin alpha, conotoxin ArlB, bradykinin, and enkephaline) are evaluated with NCBI BLASTp, ToxinPred3.0, Peptipedia, BIOPEP-UWM, AllerCatPro 2.0, and IEDB bioinformatic tools. The results correctly identified safety concerns (toxins) for amanitin and conotoxin peptides and the biological actions of bradykinin and enkephaline, while palmitoyl hexapeptide-12, caffeoyl hexapeptide-9, and palmitoyl pentapeptide-4 demonstrated sequence homology with extracellular matrix proteins in the skin (collagen, elastin, fibronectin) without the safety concerns of the other peptides. The incorporation of bioinformatic tools into the safety framework provides an additional means to screen for toxins and allergens as well as insights into potential biological activities when sequence homology with existing proteins and peptides occurs. Further testing of the framework by the cosmetic industry is needed to lend support and reveal opportunities for refinements that advance the safety substantiation of peptides.