The purpose of this invention is to provide a method with which it is easy to perform screening for an agent that proliferates or an agent that minimizes the reduction in MCSP-positive basal epidermal stem cells. Provided is a screening method for a laminin 511 expression promoter, which takes the expression of laminin 511 as an indicator. Also provided is an agent for improving skin barrier function, elasticity, hydration and inflammation, said agent including at least one extract selected from among a group consisting of brown algae, red algae and green algae.本發明之目的在於提供一種簡單地進行使MCSP陽性表皮基底幹細胞增殖之藥劑、或抑制MCSP陽性表皮基底幹細胞減少之藥劑之篩選的方法。本發明提供一種將層黏連蛋白511之表現作為指標的層黏連蛋白511表現促進劑之篩選方法。又，本發明提供一種包含選自由褐藻、紅藻、及綠藻所組成之群中之至少1者之萃取物的皮膚阻隔性、緊實彈性、濕潤性、及炎症之改善劑。
