• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.11-20
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• 2019

Ecklonia cava, an edible marine brown alga (Laminariaceae), is a rich source of bioactive compounds such as fucoidan and phlorotannins. Ecklonia cava extract (ECE) was prepared using 70% ethanol extraction and ECE contained 67% and 10.6% of total phlorotannins and dieckol, respectively. ECE treatment significantly inhibited receptor activator of nuclear $factor-{\kappa}B$ ligand (RANKL)-induced osteoclast differentiation of RAW 264.7 cells and pit formation in bone resorption assay (p <0.05). Moreover, it suppressed RANKL-induced $NF-{\kappa}B$ and mitogen-activated protein kinase signaling in a dose dependent manner. Downregulated osteoclast-specific gene (tartrate-resistant acid phosphatase, cathepsin K, and matrix metalloproteinase-9) expression and osteoclast proliferative transcriptional factors (nuclear factor of activated T cells-1 and c-fos) confirmed ECE-mediated suppression of osteoclastogenesis. ECE treatment ($100{\mu}g/ml$) increased heme oxygenase-1 expression by 2.5-fold and decreased intercellular reactive oxygen species production during osteoclastogenesis. The effective inhibition of RANKL-stimulated osteoclast differentiation and oxidative stress by ECE suggest that ECE has therapeutic potential in alleviating osteoclast-associated disorders.

• International Journal of Molecular Medicine
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• 제44권5호
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• pp.1979-1987
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• 2019

Sargassum thunbergii is a brown alga from which various bioactive compounds can be extracted. Among these, the activities of indole derivatives, particularly as potential inhibitors of matrix metalloproteinases (MMPs), and their underlying mechanisms have been rarely investigated. Therefore, we evaluated the inhibitory effects of indole-6-carboxaldehyde (I6CA) on MMP-9 by gelatin zymography and western blot anlaysis. We used phorbol 12-myristate 13-acetate (PMA), which is known to induce MMP-9 expression and secretion, to stimulate HT1080 cells. Our results revealed that I6CA significantly inhibited MMP-9 expression and secretion, without significantly affecting the viability of PMA-stimulated HT1080 cells. Our mechanistic studies indicated that I6CA suppressed the phosphorylation and activation of two mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 1/2 (ERK). Furthermore, I6CA inhibited the phosphorylation of inhibitor of κBα (IκBα) in response to PMA stimulation, which suppressed nuclear factor-κB (NF-κB) p65 subunit nuclear translocation. Collectively, I6CA was determined to suppress MMP-9 expression and secretion, and effects were proposed to be mediated via the inhibition of the MAPK and NF-κB p65 pathways. Therefore, we suggested I6CA to be a potential therapeutic agent for MMP-9-related processes, including tumor invasion and metastasis; however, further investigation is required.

• 한국해양바이오학회지
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• 제12권1호
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• pp.29-39
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• 2020

In this study, we investigated the inhibitory potential of an ethanol extract of Carpomitra costata (EECC) (Stackhouse) Batters, a brown alga, against neuroinflammatory responses in lipopolysaccharide (LPS)-stimulated BV2 microglia. Our results showed that EECC significantly suppressed the LPS-induced secretion of pro-inflammatory mediators, including nitric oxide (NO) and prostaglandin E₂, with no significant cytotoxic effects. EECC also inhibited the LPS-induced expression of their regulatory enzymes, such as inducible NO synthase and cyclooxygenase-2. In addition, EECC downregulated the LPS-induced expression and production of the proinflammatory cytokines, tumor necrosis factor-α and interleukin-1β. In the mechanistic assessment of the antineuroinflammatory effects, EECC was found to inhibit the nuclear translocation and DNA binding of nuclear factor-kappa B (NF-κB) by disrupting the degradation of the κB-α inhibitor in the cytoplasm. Moreover, EECC effectively suppressed the enhanced expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88, as well as the binding of LPS to TLR4 in LPS-treated BV2 cells. Furthermore, EECC markedly reduced the LPS-induced generation of reactive oxygen species (ROS), demonstrating a strong antioxidative effect. Collectively, these results suggest that EECC repressed LPS-mediated inflammatory action in the BV2 microglia through the inactivation of NF-κB signaling by antagonizing TLR4 and/or preventing ROS accumulation. While further studies are needed to fully understand the anti-inflammatory effects associated with the antioxidant activity of EECC, the current findings suggest that EECC has a potential advantage in inhibiting the onset and treatment of neuroinflammatory diseases.

• 생약학회지
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• 제41권1호
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• pp.43-47
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• 2010

In order to screen new receptor tyrosine kinase inhibitor which is expected to be anticancer drug lead, we have investigated receptor tyrosine kinase inhibitory activity on the marine alga-derived symbiotic microorganisms (500 strains). The significant activities (over 70% inhibition at $10\;{\mu}g/ml$) were observed in the extracts of ten strains (Strain No.: MFA018, 019, 206, 242, 325, 335, 343, 344, 354, 356), isolated from marine red algae, five strains (Strain No.: MFA030, 126, 213, 324, 339), isolated from the brown algae, and one strain (Strain No.: MFA272), isolated from the marine green algae, respectively. Among the active strains, MFA019 and 356 showed strong receptor tyrosine kinase inhibitory activity with $IC_{50}$ values of 0.6 and $0.9\;{\mu}g/ml$, respectively.

• 한국수산과학회지
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• 제23권6호
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• pp.439-442
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• 1990

우리나라 양식미역에 바늘구멍을 뚫는 요각류 유생을 동정하기 위하여 남해안의 양식미역에 서식하는 요각류를 조사하고 미역에 바늘구멍을 뚫는 요각류 유생을 실험실에서 직접사육했다. 남해안의 양식미역 엽체에 서식하고 있는 요각류는 여러 종이 있는데, 이들 중 Ho와 Hong이 기술한 Amenephia orientalis와 다른 미동정종인 Scutellidium sp.가 이번 연구중 미역엽체 세척액속에 계속적으로 많은 양이 출현하였다. 이 두 종에 속하는 암컷중에는 포난개체가 많았다. 사육실험 결과를 보면, $15^{\circ}C$에서 구멍을 뚫는 유생은 15일만에 성체 또는 성체에 가까운 미성체까지 성장했다. 이들 성체 혹은 미성체는 모두 Amenephia orientalis로 동정되었다. 그러므로 우리나라 양식미역에 기생하면서 미역엽체에 구멍을 뚫는 종은 Amenephia orientalis로 밝혀졌다.

• ALGAE
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• 제30권3호
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• pp.241-246
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• 2015

This research was conducted to develop effective and safe marine-derived antiviral compounds against norovirus. The ethyl acetate (EtOAc)-extract from Eisenia bicyclis exhibited strong antiviral activity against murine norovirus (MNV) as a norovirus surrogate. Among the phlorotannins from E. bicyclis, dieckol (DE) and phlorofucofuroeckol-A (PFF) were known to possess the strongest antibacterial activity. In this study, DE and PFF were evaluated for antiviral activity against MNV. DE and PFF exhibited strong anti-MNV activity with 50% effective concentration ($EC_{50}$) of $0.9{\mu}M$. However, PFF exhibited more effective antiviral activity against MNV with higher selective index (668.87) than that of DE (550.60), due to its lower cell toxicity against RAW 264.7. This is the first report on the anti-MNV activity of phlorotannins from seaweed. The results obtained in this study suggest that the phlorotannins could be used as a potential source of natural antiviral agents.

• Fisheries and Aquatic Sciences
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• 제14권3호
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• pp.192-197
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• 2011

The objective of this study was to select an effective microbial strain to improve the functional qualities of Eisenia bicyclis water extract by fermentation. For this purpose, several microorganisms isolated from traditional Korean fermented foods were inoculated and cultivated in E. bicyclis water extract. Ultimately, yeast strain YM-1 was selected for further study based on its total phenolic compound (TP) content and antioxidant activity, which were enhanced by microbial fermentation. The extract fermented by YM-1 exhibited a superior TP content and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity compared to extracts fermented by other microbes. The highest TP content and DPPH radical scavenging activity were observed after one day of YM-1 fermentation. Yeast strain YM-1 was identified as Candida utilis based on an analysis of its physiological characteristics. During fermentation of the extract by C. utilis YM-1, no significant difference was observed in the proximate composition, including moisture, crude lipid, crude protein, and crude ash. Fermentation by C. utilis YM-1 resulted in enhanced biological activity, including increases in the TP content and antioxidant activity. Thus, fermentation by C. utilis YM-1 is an attractive strategy for developing value-added food ingredients.

• 한국수산과학회지
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• 제47권3호
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• pp.274-282
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• 2014

We examined seasonal variation in the structure of marine macroalgal communities at five sites around the Byeonsan Peninsula, Korea, from January to October 2011. Sixty eight species were identified, including 11 green, 17 brown and 40 red algae. Species richness was highest at Gyeokpo (51 species) followed by Sambal (47), Gosapo (34), Byeonsan (33), and Habgoo (18). Seaweed biomass ranged from 12.98 to 145.33 g dry $wt/m^2$, with maximum and minimum biomasses at Gyeokpo and Habgoo, respectively. Sargassum thunbergii was the representative alga species occupying 47.89% of the total biomass. The dominant seaweeds were S. thunbergii, Corallina pilulifera, Ulva spp, Gracilaria vermiculophylla, and Carpopeltis affinis. No distinctive vertical distribution of seaweeds was found because S. thunbergii, Ulva spp, and G. vermiculophylla were all distributed from high to low shore. Community indices were as follows: dominance index (DI), 0.44-0.61; richness index (R), 6.27-10.35; evenness index (J'), 0.38-0.59; and diversity index (H'), 1.48-1.71. Gyeokpo had the most biomass and highest species richness, and the lowest percentage of Ulva species. However, species richness declined at Gyeokpo, from 78 to 51 species within 10 years, implying that eutrophication and sedimentation from Mankyeong and Dongjin rivers have reduced the stability of seaweed communities.

• 한국수산과학회지
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• 제47권3호
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• pp.204-210
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• 2014

The brown alga Saccharina japonica is consumed as a foodstuff in many countries. Carbon tetrachloride ($CCl_4$) is a potent hepatotoxin that is used to assess hepatotoxicity in animal models. This study assessed the protective effect of S. japonica extract (SJE) on $CCl_4$-induced acute liver injury in rats. Experimental rats were divided into the following three groups: control, $CCl_4$, and $CCl_4$+SJE; the latter two groups were given 150 or 300 mg SJE/kg orally for 10 days. Three hours after the final treatment, all rats-except for those in the control group-were administered intraperitoneal injections of $CCl_4$. One day later, blood and liver samples were collected for evaluation biomarker of levels. Aspartate transaminase (APT; GPT) and alanine aminotransferase (ALT; GOT) levels were markedly lower in the $CCl_4$+SJE group than the $CCl_4$ group. The hepatic superoxide dismutase (SOD) activity of the $CCl_4$+SJE group was significantly lower than that of the $CCl_4$ group. In comparison, glutathione S-transferase (GSH) and catalase (CAT) levels were significantly higher in the $CCl_4$+SJE group. Western blotting revealed that SJE attenuated the $CCl_4$-induced EGFR and MAPK activity in the liver. Thus, we conclude that SJE protects against $CCl_4$-induced hepatotoxicity.

• ALGAE
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• 제30권2호
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• pp.163-170
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• 2015

Tyrosinase inhibitors are an important component of cosmetic products. Our previous studies have proposed that eckol isolated from the brown alga Ecklonia cava, can be explored as a tyrosinase inhibitor. However, cellular activities and mechanism of action of eckol remain unknown. Therefore, the current study analyzed the eckol binding modes using the crystal structure of Bacillus megaterium tyrosinase. The effects of eckol on melanin synthesis induced by ${\alpha}$-melanocyte stimulating hormone in B16F10 melanoma cells were also investigated. We predicted the 3D structure of tyrosinase and used a docking algorithm to simulate binding between tyrosinase and eckol. These molecular modeling studies were successful (calculated binding energy value, $-115.84kcal\;mol^{-1}$) and indicated that eckol interacts with Asn205, His208, and Arg209. Furthermore, eckol markedly inhibited tyrosinase activity and melanin synthesis in B16F10 melanoma cells. We also found that eckol decreased the expression of tyrosinase, tyrosinase-related protein (TRP) 1, and TRP2. These results indicate that eckol is a potent inhibitor of melanogenesis, and this finding may be useful for the development of novel pharmaceutical and cosmetic agents.