植物防晒剂的筛选及防晒机制研究

Screen and mechanism of botanical sunscreen

目的:从31种植物中筛选有广谱紫外吸收作用和较强抗氧化能力的植物以开发研究。方法:提取有效成分后测定其紫外吸收性能、自由基清除能力以及抑制酪氨酸酶活性作用。结果:紫外线A(UVA)和紫外线B(UVB)吸光度值前7位从高到低分别依次为:UVA区:槐米>黄芩>檀香>远志>蛇床子>枳实>大黄,UVB区:黄芩>槐米>檀香>远志>大黄>枳实;大黄、槐米、黄芩、檀香提取物清除DPPH自由基作用较强;且在0.125～0.500g/L浓度范围内均有一定的抑制酪氨酸酶活性作用,大黄、槐米0.500g/L较强,抑制率分别为(33.04±4.74)%、(18.25±3.16)%,但低于对照药维生素C(VitC)(1.25μmol/L)。结论:槐米、大黄、檀香、黄芩紫外吸收性能较好,且有较强清除自由基功能及抑制酪氨酸酶活性作用,可进一步行安全性研究以确定其开发前景。

Objective: To filter out a group of plants which have strong absorption of UVA and UVB area, with a good activity of DPPH scavenging and inhibition of tyrosine, and find out target pants from 31 herbs. Methods: The UV absorbance, free radical scavenging activity and tyrosinase inhibitory activity of the active components in plant extracts were determined. Results: The first 7 positions of absorbance value from high to low are as follows: Flos Sophorae > Radix Scutellariae > Lignum Santali Albi > Radix Polygalae > Fructus Cnidii > Fructus Aurantii Immaturus > Radix et Rhizoma Rhei (UVA area), Radix Scutellariae > Flos Sophorae > Lignum Santali Albi > Radix Polygalae > Radix et Rhizoma Rhei > Fructus Aurantii Immaturus (UVB area). Four plants showed significant antioxidant activity including Radix et Rhizoma Rhei, Flos Sophorae, Radix Scutellariae and Lignum Santali Albi. These four herbs in the 0.125~0.500g/L range had some inhibitory effect of tyrosinase activity. Radix et Rhizoma Rhei and Flos Sophorae were stronger at 0.500g/L, the inhibition rates were (33.04±4.74)%, (18.25±3.16)% respectively, but they were both lower than the control drug vitamin C (1.25μmol/L). Conclusion: The ultraviolet absorption capacity, free radical scavenging activity and tyrosinase inhibitory activity of Radix et Rhizoma Rhei, Flos Sophorae, Radix Scutellariae and Lignum Santali Albi are relatively better. Further study on their safety could be conducted to find out the development prospect.