Mitigating PM2.5-induced skin injury and aging: botanical strategies targeting redox and inflammatory pathways

Exposure to fine particulate matter smaller than 2.5 μm in diameter (PM2.5) has emerged as a critical environmental factor contributing to skin injury. As the skin is the body's primary barrier against the external environment, it is directly susceptible to PM2.5, which induces oxidative stress, inflammation, premature aging, and disruption of skin barrier function. Increasing evidence demonstrates that PM2.5 damages both epidermal keratinocytes and dermal fibroblasts, leading to cellular dysfunction through alterations in major signaling pathways, including the aryl hydrocarbon receptor (AhR), nuclear factor kappa B (NF-κB), activator protein 1 (AP-1), mitogen-activated protein kinase (MAPK), and nuclear factor erythroid 2-related factor 2 (Nrf2). These molecular perturbations accelerate skin aging and impair protective functions, highlighting the need for effective intervention strategies. Botanicals and their bioactive phytochemicals have attracted growing interest for their antioxidant and anti-inflammatory properties, which may counteract PM2.5-induced damage. By targeting redox imbalance and inflammatory signaling, natural compounds represent a promising approach for protecting skin health. This review highlights the role of PM2.5 in skin injury and critically examines botanical strategies that may mitigate PM2.5-induced skin damage and premature aging.