Nattapong Snitmatjaro, Omboon Luanratana
Faculty of Pharmacy, Department of Pharmacognosy, Mahidol University, Thailand.
Nat Prod Res. 2008 Jun 15;22(9):727-34. doi: 10.1080/14786410601130794.
Protection of human body against the harmful ultraviolet exposure is nowadays more important and interesting. Melanin, a group of bio-pigments, acts as a natural solar filter absorbing and reflecting most of the UV radiation passing through the layer of skin. Over production of the pigments can create a health problem, hyperpigmentation. Tyrosinase is a key enzyme, which catalyzes the conversion of L-tyrosine to L-dihydroxyalanine (L-Dopa), therefore tyrosinase inhibitors are used in various skin preparations due to its pronounced effect on anti-hyperpigment. In this study, an in vitro anti-tyrosinase activity study of the extracts from a hybrid Mulberry plant obtained from Morus alba L. and Morus rotundiloba Koidz, is shown to prove as new source of Thai whitening agent. The presence of betulinic acid, as an anti-inflammatory and anti-tyrosinase activity agent, is also reported. The study develops the technique of HPLC quantitation of betulinic acid and its relation to anti-tyrosinase activity of the whole parts of Thai Mulberry.
如今，保护人体免受有害紫外线照射变得越发重要且引人关注。黑色素是一类生物色素，它充当天然的防晒剂，吸收并反射大部分穿过皮肤层的紫外线辐射。色素过度生成会引发健康问题，即色素沉着过度。酪氨酸酶是一种关键酶，它催化L - 酪氨酸转化为L - 二羟基丙氨酸（L - 多巴），因此酪氨酸酶抑制剂因其对抗色素沉着有显著效果而被用于各种皮肤制剂中。在本研究中，对源自白桑（Morus alba L.）和圆叶桑（Morus rotundiloba Koidz）的杂交桑树植物提取物进行了体外抗酪氨酸酶活性研究，结果表明其可作为泰国美白剂的新来源。此外，还报道了桦木酸作为一种具有抗炎和抗酪氨酸酶活性的物质的存在。该研究开发了桦木酸的高效液相色谱定量技术及其与泰国桑树全株抗酪氨酸酶活性的关系。
