METHODS: Cellular assays tested six different concentrations (up to 5%) of the PE for cell viability levels and reactive oxygen species (ROS) levels of human immortalised epidermal cells (HaCaTs). The identified non-cytotoxic concentration (0.5% PE) was then tested by gene assays. A commercial foundation containing 0.5% PE (PEF0.5) was tested for safety, skin protective effectiveness, and user satisfaction.
RESULTS: Compared to the control groups, 0.5% PE had a significant inhibitory effect on the expression level of MMP-1 but promoted the expression of COL1A1, COL3A1, ELN, and AQP3. PEF0.5 significantly (p 0.05) differences were detected in the foundation's effectiveness and usability.
CONCLUSION: Applying PEF0.5 for 28 days may improve the skin barrier function, as indicated by skin TEWL, hydration, wrinkle, elasticity, and sebum content, without any adverse effects.