Potato Peel Extract Attenuates the Reduction in Type I Collagen in Normal Human Dermal Fibroblast Cells Induced by Oxidative Stress

Oxidative stress contributes to skin aging. Potato peels contain various functional components, and potato peel extract (PPE) promotes type I collagen synthesis in normal human dermal fibroblasts (NHDFs). In this study, we investigated the effects of PPE under oxidative stress conditions. NHDFs were exposed to hydrogen peroxide, followed by treatment with PPE prepared by ethanol extraction of potato peel residues. Exposure to hydrogen peroxide reduced type I collagen secretion in NHDF. However, this reduction was suppressed by the addition of PPE. The expression level of the type I collagen gene, COL1A2, showed a tendency to improve with PPE treatment. The promotion of collagen synthesis by PPE appears to involve the TGFBR2, ERK, and Akt signaling pathways. PPE also reduced the increased production of MMP-1 induced by hydrogen peroxide exposure and suppressed the upregulation of AP-1, a transcription factor upstream of MMP-1. While PPE exhibited antioxidant activity at high concentrations, it did not reduce intracellular ROS levels at the concentrations used for cell treatment. These findings suggest that PPE suppresses the reduction in collagen levels under oxidative stress conditions by promoting type I collagen synthesis and modulating MMP-1/AP-1/TIMP-1-related pathways, suggesting decreased collagen breakdown under oxidative stress conditions. PPE may serve as a potential material for maintaining collagen levels.