Niacinamide Protects Skin Cells from Oxidative Stress Induced by Particulate Matter

Niacinamide (NIA) is a water-soluble vitamin that is widely used in the treatment of skin diseases. Moreover, NIA displays antioxidant effects and helps repair damaged DNA. Recent studies showed that particulate matter 2.5 (PM2.5) induced reactive oxygen species (ROS), causing disruption of DNA, lipids, and protein, mitochondrial depolarization, and apoptosis of skin keratinocytes. Here, we investigated the protective effects of NIA on PM2.5-induced oxidative stress in human HaCaT keratinocytes. We found that NIA could inhibit the ROS generation induced by PM2.5, as well block the PM2.5-induced oxidation of molecules, such as lipids, proteins, and DNA. Furthermore, NIA alleviated PM2.5-induced accumulation of cellular Ca2+, which caused cell membrane depolarization and apoptosis, and reduced the number of apoptotic cells. Collectively, the findings show that NIA can protect keratinocytes from PM2.5-induced oxidative stress and cell damage.