The present invention provides a method for modulating the expressions of the group of genes, comprising administering to a subject a composition comprising an effective amount of an Ascophyllum nodosum extract, wherein the gene group includes: (i) a Group A gene selected from the group consisting of TGM1, KRT14, FLG, AQP3, GBA, HAS3, and combinations thereof； or (ii) a Group B gene selected from the group consisting of HAS2, MMP2, LOX, and combinations thereof. The Ascophyllum nodosum extract improves skin moisture, skin elasticity, and resistance to ultraviolet radiation.
