Abstract
Particulate matter 2.5 (PM(2.5)) exposure can trigger adverse health outcomes in the human skin, such as skin aging, wrinkles, pigment spots, and atopic dermatitis. PM(2.5) is associated with mitochondrial damage and the generation of reactive oxygen species (ROS). Hesperidin is a bioflavonoid that exhibits antioxidant and anti-inflammatory properties. This study aimed to determine the mechanism underlying the protective effect of hesperidin on human HaCaT keratinocytes against PM(2.5)-induced mitochondrial damage, cell cycle arrest, and cellular senescence. Human HaCaT keratinocytes were pre-treated with hesperidin and then treated with PM(2.5). Hesperidin attenuated PM(2.5)-induced mitochondrial and DNA damage, G(0)/G(1) cell cycle arrest, and SA-βGal activity, the protein levels of cell cycle regulators, and matrix metalloproteinases (MMPs). Moreover, treatment with a specific c-Jun N-terminal kinase (JNK) inhibitor, SP600125, along with hesperidin markedly restored PM(2.5)-induced cell cycle arrest and cellular senescence. In addition, hesperidin significantly reduced the activation of MMPs, including MMP-1, MMP-2, and MMP-9, by inhibiting the activation of activator protein 1. In conclusion, hesperidin ameliorates PM(2.5)-induced mitochondrial damage, cell cycle arrest, and cellular senescence in human HaCaT keratinocytes via the ROS/JNK pathway.