2018 年 23 巻 2 号 p. 47-52
Conventional methods of skin stimulus evaluation for cosmetics are performed by animal tests. Alternatives to animal tests are proposed to achieve animal welfare and for example, reconstructed human epidermis (RHE) models are approved officially. However, they are based on endpoint assay using a dye causing large test errors. Furthermore, no single method is proposed for all tests of skin corrosion, irritation and sensitization. Epidermal keratinocyte communicates with other cells using mitochondria exotically emitting both intracellular and extracellular danger signals depending on the stimulus. Here, we monitored mitochondrial membrane potential (MMP) change in keratinocyte by a cosmetic compound addition real-timely without labeling using our original in vivo-like technology of high–precision surface plasmon resonance (HP-SPR)-three dimension (3D). We compared MMP signal trend to the conventional methods results and examined the feasibility of HP-SPR-3D for the universal method against various skin stimuli. Using five cosmetic compounds, the MMP trends until 10 min and after 30 min of the compound addition expressed the acute mode of action and In vivo score values including sensitization, respectively. These were further confirmed by the cell morphological observation after the test. Many compounds are expected to be measured using the HP-SPR-3D system for the cosmetics universal validation.
