Jurkovic Polona, Sentjurc Marjeta, Gasperlin Mirjana, Kristl Julijana, Pecar Slavko
Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
Eur J Pharm Biopharm. 2003 Jul;56(1):59-66. doi: 10.1016/s0939-6411(03)00062-6.
UV irradiation induces free radical formation in the skin. UV filters and antioxidants can be used for protection. In the present work, the amphiphilic antioxidant ascorbyl palmitate has been investigated and its effectiveness against free radical formation in porcine skin determined with electron paramagnetic resonance (EPR) spectroscopy with a spin trapping technique. 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO) was used as spin trap. In this study, three different radicals were identified in UV irradiated porcine ear skin: two originated from sulphur centred radicals (SO(3)), while the third was the carbon-centred acyl (C=O) radical. Ascorbyl palmitate applied on the skin decreased the level of formation of free radicals. Its effectiveness depended significantly on the carrier system - the type of microemulsion and its concentration, while the time of application had no influence on its effectiveness. Oil in water microemulsions delivered ascorbyl palmitate to the skin significantly better than water in oil microemulsions. In both types of microemulsions, the effectiveness increases at higher concentrations of ascorbyl palmitate.
紫外线照射会诱导皮肤中自由基的形成。紫外线过滤剂和抗氧化剂可用于防护。在本研究中，对两亲性抗氧化剂棕榈酸维生素C酯进行了研究，并用自旋捕获技术通过电子顺磁共振（EPR）光谱法测定了其对猪皮肤中自由基形成的抑制效果。5-（二乙氧基磷酰基）-5-甲基-1-吡咯啉-N-氧化物（DEPMPO）用作自旋捕获剂。在本研究中，在紫外线照射的猪耳皮肤中鉴定出三种不同的自由基：两种源自硫中心自由基（SO(3)），而第三种是碳中心酰基（C=O）自由基。涂抹在皮肤上的棕榈酸维生素C酯降低了自由基的形成水平。其效果在很大程度上取决于载体系统——微乳液的类型及其浓度，而涂抹时间对其效果没有影响。水包油型微乳液将棕榈酸维生素C酯输送到皮肤的效果明显优于油包水型微乳液。在两种类型的微乳液中，随着棕榈酸维生素C酯浓度的升高，其效果增强。
