Department of Integrated Biomedical and Life Science, Graduate School, Korea University, Seoul 02841, Korea.
Department of Food Science and Nutrition, Jeju National University, Jeju 63243, Korea.
Molecules. 2022 Apr 14;27(8):2545. doi: 10.3390/molecules27082545.
Reactive oxygen species (ROS) generated by ultraviolet (UV) exposure cause skin barrier dysfunction, which leads to dry skin. In this study, the skin moisturizing effect of sphingomyelin-containing milk phospholipids in UV-induced hairless mice was evaluated. Hairless mice were irradiated with UVB for eight weeks, and milk phospholipids (50, 100, and 150 mg/kg) were administered daily. Milk phospholipids suppressed UV-induced increase in erythema and skin thickness, decreased transepidermal water loss, and increased skin moisture. Milk phospholipids increased the expression of filaggrin, involucrin, and aquaporin3 (AQP3), which are skin moisture-related factors. Additionally, hyaluronic acid (HA) content in the skin tissue was maintained by regulating the expression of HA synthesis- and degradation-related enzymes. Milk phospholipids alleviated UV-induced decrease in the expression of the antioxidant enzymes superoxidase dismutase1 and 2, catalase, and glutathione peroxidase1. Moreover, ROS levels were reduced by regulating heme oxygenase-1 (HO-1), an ROS regulator, through milk phospholipid-mediated activation of nuclear factor erythroid-2-related factor 2 (Nrf2). Collectively, sphingomyelin-containing milk phospholipids contributed to moisturizing the skin by maintaining HA content and reducing ROS levels in UVB-irradiated hairless mice, thereby, minimizing damage to the skin barrier caused by photoaging.
活性氧（ROS）是由紫外线（UV）照射产生的，会导致皮肤屏障功能障碍，从而引发皮肤干燥。本研究评估了含神经鞘磷脂的牛奶磷脂对 UV 诱导无毛小鼠皮肤保湿的作用。无毛小鼠接受 UVB 照射 8 周，每天给予牛奶磷脂（50、100 和 150mg/kg）。牛奶磷脂抑制了 UV 诱导的红斑和皮肤增厚的增加，减少了经表皮水分流失，并增加了皮肤水分。牛奶磷脂增加了与皮肤水分相关的因子丝聚合蛋白、兜甲蛋白和水通道蛋白 3（AQP3）的表达。此外，通过调节 HA 合成和降解相关酶的表达，维持了皮肤组织中的透明质酸（HA）含量。牛奶磷脂还通过调节血红素加氧酶-1（HO-1），一种 ROS 调节剂，缓解了 UV 诱导的超氧化物歧化酶 1 和 2、过氧化氢酶和谷胱甘肽过氧化物酶 1 等抗氧化酶表达的降低。此外，ROS 水平通过牛奶磷脂介导的核因子红细胞 2 相关因子 2（Nrf2）的激活而降低。总之，含神经鞘磷脂的牛奶磷脂通过维持 UVB 照射无毛小鼠的 HA 含量和降低 ROS 水平来保湿皮肤，从而最大程度地减少光老化对皮肤屏障的损伤。
