Expression promoter of antioxidant regulatory factor gene NRF2

The invention provides an expression promoter of a keratinocyte antioxidant regulatory factor gene NRF2, which is a selaginella tamariscina aqueous extract, and has a total sugar content of more than or equal to 32 wt%, a total polyphenol content of more than or equal to 2.34 wt%, and/or a total flavone content of more than or equal to 1.76 wt%. The invention also relates to a preparation method of the expression promoter of the keratinocyte antioxidant regulatory factor gene NRF2 and an application of the expression promoter in a skin external preparation. 本发明提供了一种角质形成细胞抗氧化调节因子基因NRF2的表达促进剂，其中，所述表达促进剂是卷柏水提物，总糖含量≥32wt％，总多酚含量≥2.34wt％，和/或总黄酮含量≥1.76wt％。本发明还涉及角质形成细胞抗氧化调节因子基因NRF2的表达促进剂的制备方法及其在皮肤外用剂中的应用。