Are coffee silverskin extracts safe for topical use? An in vitro andin vivo approachF

Recent changes in regulatory requirements and social views on animal testing have incremented thedevelopment of reliable alternative tests for predicting skin and ocular irritation potential of productsbased on new raw materials. In this regard, botanical ingredients used in cosmetic products are amongthose materials, and should be carefully reviewed concerning the potential presence of irritant con-stituents. In particular, cosmetic products used on the face, in vicinity of the eyes or that may comein contact with mucous membranes, should avoid botanical ingredients that contain, or are suspectedto contain, such ingredients. In this study, we aimed to evaluate the effect of a new cosmetic ingredi-ent, namely, coffee silverskin (CS), with an in vitro skin and ocular irritation assay using reconstructedhuman epidermis, EpiSkinTM, and human corneal epithelial model, SkinEthicsTMHCE, and an in vivoassay. Three different extracts of CS were evaluated. The histology of the models after extracts applica-tions was analysed. The in vitro results demonstrated that extracts were not classified as irritant and thehistological analyses proved that extracts did not affect both models structure. The content of caffeine,5-hydroxymethyl furfural and chlorogenic acid was quantified after the epidermal assay. The in vivo testcarried out with the most promising extract (hydroalcoholic) showed that, with respect to irritant effects,these extracts can be regarded as safe for topical application.