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Jeju, South Korea

Kang M.-C.,Jeju National University | Wijesinghe W.A.J.P.,Jeju National University | Lee S.-H.,Jeju National University | Kang S.-M.,Jeju National University | And 8 more authors.
Food and Chemical Toxicology | Year: 2013

In the present study, the attenuation of type II diabetes by dieckol, a phlorotannin derivative isolated from brown seaweed, Ecklonia cava was investigated in C57BL/KsJ-db/db, a type II diabetes mouse model. Dieckol was administered intraperitoneal injection at doses of 10 and 20. mg/kg body weight diabetes mice for 14 days. The blood glucose level, serum insulin level and body weight were significantly reduced in the dieckol administered group, compared to that of the saline administered group. Furthermore, reduced thiobarbituric acid reactive substraces (TBARS), as well as increased activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-px) in liver tissues were observed in the dieckol administered group. In addition, increased levels of the phosphorylation of AMPK and Akt were observed in the muscle tissues of the dieckol administered group in a Western blotting analysis. According to the findings of this study, it could be suggested that, dieckol can be developed as a therapeutic agent for type II diabetes. © 2012 Elsevier Ltd.

Kang G.-J.,Jeju National University | Han S.-C.,Jeju National University | Koh Y.-S.,Jeju National University | Kang H.-K.,Jeju National University | And 2 more authors.
Biomolecules and Therapeutics | Year: 2012

Prostaglandin (PG) E2, the most abundant prostaglandin in the human body, is synthesized from arachidonic acid via the actions of cyclooxygenase (COX) enzymes. PGE2 exerts homeostatic, cytoprotective, inflammatory, and in some cases anti-inflammatory effects. Also, it has been reported that PGE2 is involved in hair growth. Diphlorethohydroxycarmalol (DPHC) is a phlorotannin compound isolated from the brown algae Ishige okamurae, with various biological activities in vitro and in vivo. In this study, the biological effect and mechanism of action of DPHC on prostaglandin synthesis in HaCaT human keratinocytes was examined. The results showed that, in these cells, DPHC significantly and dose-dependently induced PGE2 synthesis by increasing the protein and mRNA levels of COX-1 and COX-2. Interestingly, DPHC-induced COX-1 expression preceded that of COX-2. Also, while both rofecoxib and indomethacin inhibited PGE2 production, the latter was seems to be the more potent. From above results, we can expect that DPHC has some beneficial effects via increasing of PGE2 production. © 2012 The Korean Society of Applied Pharmacology.

Manzoor Z.,Jeju National University | Mathema V.B.,Jeju National University | Chae D.,Jeju National University | Kang H.-K.,Jeju National University | And 4 more authors.
Bioscience, Biotechnology and Biochemistry | Year: 2013

Octaphlorethol A is a phenolic compound isolated from the marine alga Ishige foliacea. In the present study, we investigated the anti-inflammatory activity of octaphlorethol A in CpG-stimulated primary murine bone marrow-derived macrophages and dendritic cells. It exhibited anti-inflammatory activity by regulating the mitogen-activated protein kinase and NF-κB pathways.

Kang J.-I.,Jeju National University | Kim S.-C.,Jeju National University | Kim M.-K.,Jeju National University | Boo H.-J.,Jeju National University | And 6 more authors.
International Journal of Molecular Sciences | Year: 2012

This study was conducted to evaluate the effect of Ecklonia cava, a marine alga native to Jeju Island in Korea, on the promotion of hair growth. When vibrissa follicles were cultured in the presence of E. cava enzymatic extract (which contains more than 35% of dieckol) for 21 days, E. cava enzymatic extract increased hair-fiber length. In addition, after topical application of the 0.5% E. cava enzymatic extract onto the back of C57BL/6 mice, anagen progression of the hair-shaft was induced. The treatment with E. cava enzymatic extract resulted in the proliferation of immortalized vibrissa dermal papilla cells (DPC). Especially, dieckol, among the isolated compounds from the E. cava enzymatic extract, showed activity that increased the proliferation of DPC. When NIH3T3 fibroblasts were treated with the E. cava enzymatic extract and the isolated compounds from the E. cava enzymatic extract, the E. cava enzymatic extract increased the proliferation of NIH3T3 fibroblasts, but the isolated compounds such as eckol, dieckol, phloroglucinol and triphlorethol-A did not affect the proliferation of NIH3T3 fibroblasts. On the other hand, the E. cava enzymatic extract and dieckol significantly inhibited 5α-reductase activity. These results suggest that dieckol from E. cava can stimulate hair growth by the proliferation of DPC and/or the inhibition of 5α-reductase activity. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Kang M.-C.,Jeju National University | Kim K.-N.,Korea Basic Science Institute | Kang S.-M.,Jeju National University | Yang X.,Jeju National University | And 8 more authors.
Environmental Toxicology and Pharmacology | Year: 2013

In the present study, the protective effects of phlorotannins isolated from Ecklonia cava against ethanol-induced cell damage and apoptosis were investigated both in vitro and in vivo. Three phlorotannin compounds, namely phloroglucinol, eckol and dieckol, were successively isolated and identified from the extract. Dieckol showed the strongest protective effect against ethanol-induced cell apoptosis in Chang liver cells, with the lowest cytotoxicity. It was observed that dieckol reduced cell apoptosis through activation of Bcl-xL and PARP, and down-regulation of Bax and caspase-3 in Western blot analyses. In the in vivo study, the protective effect of ethanol induced by dieckol was investigated in a zebrafish model. The dieckol treated group scavenged intracellural reactive oxygen species and prevented lipid peroxidation and ethanol induced cell death in the zebrafish embryo. In conclusion, dieckol isolated from E. cava might possess a potential protective effect against ethanol-induced liver diseases. © 2013 Elsevier B.V.

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