Lanette o

Octocrylene was purchased from Sigma-Aldrich, and ethanol absolute for analysis was obtained from Merck. Tween^® 60, Lanette^® O, Cetiol^® CC, Captex^® 335 and Cosmedia^® Guar were purchased from BASF. Tegosoft^® TN was obtained from Evonik Industries, whereas paraffinum liquidum and glycerol were provided by Chempur (Piekary Śląskie, Poland). The concentrated PRISMA HTTM solution, hydration solution, and skin-PAMPA plates were obtained from Pion Inc. (Billerica, MA, USA). Cell culture media (high-glucose DMEM, melanocyte growth medium, fetal bovine serum, trypsin–EDTA solution, and penicillin–streptomycin solution), Triton X100, and DMSO were purchased from Sigma-Aldrich (Seelze, Germany). Human epidermal melanocytes (HEM) and dermal fibroblasts (HDF) were purchased from Sigma-Aldrich, while HaCaT human skin keratinocytes were kindly provided by Prof. Marta Michalik from the Department of Cell Biology, Jagiellonian University in Kraków, Poland. Both (+)- and (−)-usnic acid were isolated, from Cladonia arbuscula and C. uncialis, respectively, as described previously [4 (link)]. Lactate dehydrogenase (LDH) assay kits were obtained from Clontech (Mountain View, CA, USA).

As ingredients of masks, the following materials were used:

Cetearyl Alcohol, Lanette O from BASF Poland;

Sweet Almond Oil from PPH Standard Poland;

Cera Alba from PPH Standard Poland;

Caprylic/Capric Triglicerides, Crodamol GTCC from Croda Poland;

Urea from PPH Standard Poland;

Sodium Benzoate and Potassium Sorbate, KEM BS from Pol Nil S.A.;

Lactic Acidfrom HSH Chemie Poland;

Polyglyceryl-4 Laurate, Natragem E145 NP from Croda Poland;

Lonicera Caerulea Fruit Powder from Admor Poland (Figure 5).