具有防晒祛色素作用的天然中草药筛选初探

Preliminary selection of natural herbs with sunscreen and Pigment-removal effect

目的:通过多种方法从大量天然中草药中筛选出一组具有防晒祛色素作用的中草药,为色素增加性皮肤病的治疗提供一新途径。方法:首先联合中医古籍和现代文献筛选出一组可能具有防晒祛色素作用的中草药,然后应用紫外分光光度法在200nm^400nm波长内扫描药物UVA和UVB段紫外吸光度值、蘑菇酪氨酸酶活性抑制法在酶标仪490nm波长处检测产物吸光度值(A_(490)和DPPH自由基清除法测定药物DPPH清除率和DPPH半清除率(IC_(50))。结果:从中医古籍和现代文献筛选出人参、当归、茯苓、川芎、防风、白术、苡仁、桔梗、槐花、芦荟、黄芩、白芨、栀子、白芷、黄芪共15味中草药。其中槐花、芦荟、白芷UVA吸光度高于对照组(P<0.01),黄芩、槐花、芦荟UVB吸光度高于对照组(P<0.05);芦荟、白术、槐花、茯苓、白芨和人参的酪氨酸酶抑制率较高,而芦荟和白术酪氨酸酶抑制作用较对照组强(P<0.05);上述中药对DPPH均有不同程度的清除作用,槐化、黄芩DPPH清除率和IC_(50)接近于对照组(P>0.05)。最终筛选出人参、茯苓、白术、苡仁、桔梗、黄芪、黄芩、槐花、芦荟和白芨10味中草药。结论:本实验筛选出的10味中草药具有广谱紫外线吸收功能、抑制酪氨酸酶活性和抗自由基氧化作用,可为进一步色素增加性皮肤病的预防和治疗实验奠定重要基础。

Objective：To screen herbs with sunscreening and depigmenting effect from a large number of natural plants or herbs for providing new therapy of skin hyperpigmentation disorders. Methods： Firstly, ancient Chinese medical and contemporary literatures were reviewed to pick out herbs which may have depigmenting potential. Then, these herbs were screened by UV spectrophotometry 200 nm^400 nm wavelength scaning to determine UVA and UVB absorption, mushroom tyrosinase inhibitory activities assay to detect to detect the absorption value （A490） by a microplate reader at 490 nm wavelength,and DPPH radical scavenging method to detect DPPH clearance and DPPH half clearance （IC50）. Results：From ancient and modern literatures, 15 herbs were picked out.Among these herbs, the UVA absorption values of flos sophorae, aloes and angelica dahurica benth increased significantly compared with those of control group （P〈0.01）, while the UVB ones of scutellaria baicalensis georgi, flos sophorae and aloes remarkably excelled in those of control group （P 〈 0.05）. Meanwhile, the tyrosinase inhibition rate of aloes, atractylodes macrocephala koidz, flos sophorae, tuckahoe, rhizoma bletillae striatae and ginseng ascent moderately, especially that of aloes and atractylodes macrocephala koidz greatly outweighed the control group （P〈0.05）. In addition, the above-mentioned herbs played roles of DPPH scavenging on various degrees, among which the DPPH clearance and IC50 of flos sophorae and scutellaria baicalensis georgi were close to those of control group （P〉 0.05）. Eventually, 10 herbs were selected：ginseng, tuckahoe, atractylodes macrocephala koidz, semen coicis, platycodon grandiflorum, radix astragali mongolici, scutellaria baicalensis georgi, flos sophorae, aloes and rhizoma bletillae striatae. Conclusions： These 10 herbs have broad-spectrum UV absorption, tyrosinase activity inhibiton, and anti-free radical oxidation, which may lay an important foundation for further experiments of treating hyperpigmentation dermatoses.