JOURNAL OF COSMETIC SCIENCE 110 effect in reducing dark circles around the eyes caused by blood leakage and heme ac- cumulation. EFFECT OF FUCUS EXTRACT ON ANTIOXIDATION BY DPPH ASSAY Antioxidants help to prevent and repair damage to your body’s tissue by slowing or pre- venting the effect of free radicals, and help to protect your skin from the damaging effects of the sun (21). DPPH is a common abbreviation for the organic chemical compound 2,2-diphenyl-1- picrylhydrazyl. It is a dark-colored crystalline powder composed of stable free-radical molecules. It is used in a common assay for determining the antioxidant capacity of active cosmetic ingredients. Figure 5. Fucus extract increased HO-1 content in fi broblast by western blot. Mean ± SD on 3 assays – Paired Student’s t test -**: p 0.01 - ***: p 0.001. Figure 6. Fucus extract: Anti-oxidation effect Mean + SD of triplicate assays - Paired Student’s t test - ***: p 0.001.

FUCUS EXTRACT: COSMETIC TREATMENT FOR UNDER-EYE DARK CIRCLES 111 Trolox is a water-soluble form of vitamin E. It is commonly used as a benchmark for an- tioxidant capacity evaluation, especially for water extracts like Fucus extract. As analyzed by the DPPH assay, Fucus extract showed dose-dependent antioxidation ac- tivity at concentrations from 0.5% to 5%. As shown in Figure 6, 1% Fucus extract is equivalent to about 50 μM Trolox in its antioxidation capacity. When compared to a negative control using a paired Student’s t-test, the p values for all concentrations tested are less than 0.001, which is statistically signifi cant. EFFECT OF FUCUS EXTRACT ON ANTI-INFLAMMATION IN KERATINOCYTES (IN VITRO TEST) Interleukin-8 (IL-8) is a chemokine produced by macrophages and other cell types such as epithelial cells. This chemokine is one of the major mediators of the infl ammatory re- sponse. Under normal growth conditions, a very low level of IL-8 cytokine is detected in the medium of normal keratinocyte cultures. But when cells were treated with IL-1β, the IL-8 level secreted to media is elevated. The anti-infl ammation property of Fucus extract was evaluated by IL-8 ELISA under the treatment of IL-1β (Figure 7). Control is the treatment without Fucus extract added. As shown in Figure 7, the IL-8 level induced by IL-1β was reduced by the Fucus extract treatment in a dose-dependent manner at concentrations from 0.5% to 2%. At 1%, Fucus extract reduced IL-8 level to about 40% of control, and at 2%, to about 25% of control. Since IL-8 is often associated with infl ammation, reduction of chemokine IL-8 is a posi- tive indicator of anti-infl ammation effi cacy. EFFECT OF FUCUS EXTRACT ON COLLAGEN I IN FIBROBLAST CELLS (IN VITRO TEST) In this experiment, we evaluate the capacity for Fucus extract to stimulate collagen I synthesis in cultured human fi broblast cells. The assay shown below measures collagen I deposited in the ECM as opposed to secreted collagen. Figure 7. Fucus extract decreases IL-8 content compared to control Mean ± SEM on 3 assays in triplicate - Student’s t test - *: p0.05 - ***: p0.001.