PURPOSE: A composition containing Ecklonia cava-derived mitol and fucoidan and an external use skin formulation are provided to ensure an anti-inflammatory effect and to treat atopic dermatitis. CONSTITUTION: A composition with an anti-inflammatory effect contains 0.3 wt% of Ecklonia cava-derived mitol and 0.5-2 wt% of fucoidan. The mitol contains polyphenol derived from Ecklonia cava as an active ingredient. A method for preparing fucoidan comprises: a step of drying Ecklonia cava and extracting Ecklonia cava with 80% ethyl alcohol at room temperature for 12 hours； a step of centrifuging the extract and collect pellet； a step of mixing the pellet with 80% ethyl alcohol and stirring at room temperature for 12 hours； a step of centrifuging and collecting pellet； a step of removing pigment, lipid, and low molecular proteins using acetone and drying to prepare Ecklonia cava powder； a step of adding distilled water to the Ecklonia cava powder and extracting at 60 Deg.C. for 2 hours, centrifuging, and collecting supernatant； a step of adding CaCl_2 to supernatant and incubating at 4 Deg.C. for 18 hours； a step of centrifuging and collecting supernatant； and a step of concentrating the supernatant and adding ethyl alcohol.본 발명은 갈조류 감태(Ecklonia cava) 유래 마이톨과 fucoidan을 유효성분으로 포함하는 항염증 활성 조성물 및 아토피 피부염 개선용 외용제에 관한 것으로, 본 발명에 따른 화장료 조성물은 마이톨과 fucoidan을 각각 단독으로 사용하는 것보다 높은 시너지 효과를 나타낸다.
