Genistein Inhibits Fine-Dust-Induced Matrix Metalloproteinase-1 in Human Keratinocytes

Background/Objectives: Particulate matter (PM), which comprises airborne pollutants characterized by small sizes (typically from 5 to 8 μm in Korea), adversely affect skin health and accelerate aging by inducing oxidative stress and upregulating the expression of matrix metalloproteinase-1 (MMP-1), an enzyme responsible for collagen degradation. The skin, which is the largest organ and the primary barrier against harmful external stimuli such as air pollution, is particularly vulnerable to continuous PM exposure, which can cause skin aging and carcinogenesis. Given the effects of PM on skin aging, identifying compounds that can mitigate these adverse effects is crucial. Genistein is a naturally occurring isoflavone that has not been extensively studied in the context of PM-induced skin aging. Methods: In this study, we investigated the protective effects of genistein against PM-induced skin aging in HaCaT human keratinocytes. Results: Our results demonstrated that genistein treatment significantly reduced PM-induced MMP-1 expression, indicating a protective effect against collagen degradation. Additionally, genistein decreased the expression of the transcription factors activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB), both of which are involved in the regulation of MMP-1. Furthermore, genistein markedly reduced the production of reactive oxygen species (ROS), a key marker of oxidative stress induced by PM exposure. Conclusions: These findings suggest that genistein exerts protective effects against PM-induced skin aging by attenuating collagen degradation and oxidative stress, indicating its potential as a therapeutic agent for improving skin aging associated with PM exposure.