• Korean Journal of Plant Resources
• /
• v.26 no.5
• /
• pp.526-532
• /
• 2013

In this study, we investigated the effect of 88 marine algae extracts on melanin synthesis to develop new whitening agents. Among varieties of marine algae tested, the ethyl acetate extracts from Endarachne binghamiae (EB), Scytosiphon lomentaria, Sargassum yezoense, Ecklonia cava and Sargassum fusiforme inhibited melanin synthesis in melan-a cells. EB treatment showed the strongest inhibitory activity in melanin synthesis, compared with that of other extracts. EB-mediated inhibition of melanin synthesis appeared to be associated with inhibition of ${\alpha}$-glucosidase-dependent glycosylation of tyrosinase in melan-a cells. In addition, EB treatment did not affect mushroom tyrosinase or cell-extracted tyrosinase activity in vitro. Taken together, our findings suggest that anti-browning effect of EB on skin is mediated through regulation of ${\alpha}$-glucosidase activity and subsequent inhibition of tyrosinase activity and melanin synthesis, and further development of EB as a potential agent for skin whitening.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.7
• /
• pp.966-972
• /
• 2016

We investigated that methanolic extracts of 20 kinds of seaweeds from Jeju Island for their antioxidant activities, acetylcholinesterase and ${\beta}$-secretase inhibitory activities, and neuronal survival in order to evaluate their potentials as anti-dementia agents. Ecklonia cava extracts had the highest total polyphenol content among the 20 seaweed extracts. The antioxidant activity of seaweed extracts was measured by using 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. It was found that Ecklonia kurome extracts had the highest ABTS scavenging activity ($IC_{50}=0.07{\pm}0.01mg/mL$). As a result, Ecklonia cava, Ecklonia kurome, and Myelophycus simplex extracts were found to be the most effective in terms of acetylcholinesterase inhibitory activity. In the ${\beta}$-secretase activity assay, Ecklonia cava and Ecklonia kurome extracts were effectively inhibited ($84.41{\pm}1.70%$ and $81.17{\pm}2.43%$, respectively). As expected, neuronal cell death induced by $H_2O_2$ in SH-SY5Y cells was diminished by Ecklonia cava, Ecklonia kurome, and Sargassum yezoense extracts. Taken together, these results showed that Ecklonia cava extract has potential anti-dementia activity, which suggests that it might provide an effective strategy for improving dementia.