• Food Science and Biotechnology
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• v.18 no.3
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• pp.813-817
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• 2009

The effect of 4 seaweed extracts (Desmarestia viridis, Dictyopteris divaricata, Scytosiphon lomentaria, and Ishige okamurae) on pro-inflammatory mediators as well as nuclear factor $(NF)-{\kappa}B$ in the stimulated Raw 264.7 cells was investigated. They reduced iNOS and interlukin $(IL)-1{\beta}$ expressions at transcription level. Of those, 3 extracts (D. divaricata, I. okamurae, and S. lomentaria) inhibited the COX-2 expression at translation level. $I{\kappa}B-{\alpha}$ degradation was inhibited by D. divaricata and S. lomentaria extracts. Therefore, we concluded that the extracts from D. divaricata and S. lomentaria could inhibit the activation of murine macrophage through the blocking of $NF-{\kappa}B$ activation.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.2
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• pp.59-66
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• 2023

Dictyopteris divaricata, a type of marine brown algae, has been studied for its various biological properties, including anti-inflammatory, antidiabetic, and whitening effects. However, its potential antiobesity effects have not been extensively explored. This study aimed to examine the impact of D. divaricata ethanol extract (DDE) on adipocyte differentiation and adipogenesis using 3T3-L1 preadipocytes. Our results showed that when 3T3-L1 preadipocytes were treated with noncytotoxic concentrations of DDE there was a concentration-dependent decrease in fat accumulation rate and triglycerid production compared with the control. Furthermore, DDE significantly reduced the expression of transcription factors (PPARγ, C/EBPα, and SREBP-1) and fatty acid transport protein (FABP4), which are crucial for 3T3-L1 preadipocyte differentiation. These findings suggest that DDE may exhibit antiobesity effects by suppressing the expression of lipogenic transcription factors and fatty acid transport proteins. Therefore, DDE holds potential as a therapeutic agent for obesity.

• ALGAE
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• v.19 no.3
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• pp.161-174
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• 2004

Phonological, morphological and molecular characteristics of Spatoglossum pacificum Yendo are examined. S. pacificum has an annual life cycle composed of saprophytes with apparent absence of male and female gametophytes in Korea. The seasonal growth of this species explains that the annual growth is closely related to the monthly variation of water temperature. S. pacificum has protruding reproductive structures above the outmost cortical layer. Although this observation is restricted to several species, reproductive structures on the thallus can make S. pacificurn distinguishable from S. crassum and S. lacturn. The morphogenesis of a midrib at the base of S. pacificum in this study is the same as those of Dictyopteris but different from those of S. crassum and S. lacturn, suggesting that S. pacificum is closely related to Dictyopteris. In the comparison of plastid gene sequences among species of Spatoglossum and Dictyopteris, S. pacificum is more similar to D. divaricata and D. undulate than those of S. crassum in rbcL, rbcS, psbA and psaA. This result is congruent with the anatomical characteristic of a midrib at the base of the thallus and the protrusion of reproductive organs on the thallus. The phylogenetic relationship based on these plastid genes also shows that S. pacifism is included in Dictyotpteris Glade and separated from S. crassum. We propose the new combination of Dictyopteris pacifica (Yendo) I.K. Hwang, H.S. Kim et W.J. Lee, comb. nov. based on the differences of anatomical characteristics of the midrib, the existence of reproductive organs on thallus and the molecular analyses.

• ALGAE
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• v.18 no.4
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• pp.365-369
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• 2003

Algal flora and community structure of benthic marine algae in the subtidal zone, Yeongil Bay area were studied. The number of algal species in the quadrats were identified totally 78: 2 Cyanophyta, 10 Chlorophyta, 19 Phaeophyta, and 47 Rhodophyta. The dominant species based on biomass were Sargassum hornerii, Undaria pinnatifida, and Sargassum thunbergii. Vertical distribution was clear by the representative algae such as, Undaria pinnatifida, Sargassum thunbergii, Sargassum horneri, Corallina spp. in the upper subtidal zone, Undaria pinnatifida, Sargassum horneri, Caulerpa okamurae in the middle zone, and Dictyopteris divaricata in the lower zone.

• Natural Product Sciences
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• v.18 no.2
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• pp.130-136
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• 2012

In the present work, we have collected 19 species of macroalgae (9 Phaeophta and 10 Rhodophyta) f rom all around of Korea: Dictyopteris divaricata, D. prolifera, Myelophycus cavus, Papenfussiella kuromo, Petalonia zosterifolia, Petrospongium rugosum, Rugulopteryx okamurae, Sargassum fulvellum, S. muticum, Callophyllis japonica, Gloiopeltis tenax, Gracilaria longissima, Gracilaria vermiculophylla, Grateloupia asiatica, Grateloupia lanceolata, Grateloupia sparsa, Grateloupia turuturu, Grateloupia sp, and Polyopes affinis. The macroalgal species were extracted by 70% ethanol (EtOH) for 24 h and evaluated its inhibitory effects on ${\alpha}$-glucosidase. Among ethanol extracts, Myelophycus cavus showed the most effectively inhibitory activity ($IC_{50}$, 2.17 ${\mu}g/ml$) against ${\alpha}$-glucosidase, followed by Sargassum fulvellum (<$IC_{50}$, 8.13 ${\mu}g/ml$), Dictyopteris prolifera ($IC_{50}$, 16.66 ${\mu}g/ml$), Rugulopteryx okamurae ($IC_{50}$, 50.63 ${\mu}g/ml$), and Petrospongium rugosum ($IC_{50}$, 101.62 ${\mu}g/ml$). Furthermore, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay showed no cytotoxicity on mouse pre-adipocytes cell line (3T3-L1). These results suggest that some edible macroalgae merit further evaluation for clinical usefulness as anti-diabetic functional foods.

• Ocean Science Journal
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• v.43 no.1
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• pp.31-37
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• 2008

As a part of an ongoing search for antioxidants from marine sources, antioxidant activities of 24 kinds of seaweeds (4 green algae, 8 brown algae, and 12 red algae) were investigated. The seaweeds were extracted by acetone/dichloromethane and methanol, respectively. The antioxidant properties of both extracts were evaluated using four different activity tests, including degree of occurrence of intracellular reactive oxygen species (ROS), NO, lipid peroxidation, and GSH (glutathione) in mouse macrophage Raw 264.7 cells. The levels of intracellular reactive oxygen species (ROS) and GSH were measured using 2',7'-dichlorofluorescin diacetate (DCFDA) and monobromobimane as fluorescence probe, respectively. Moreover, the generation of NO and lipid peroxidation products were determined by each method based on the Griess reaction and TBARS assay. Solvent extracts from seaweeds such as Scytosiphon lomentaria, Prionitis cornea, Laruencia okamurae, Callophyllis japonica, Sargassum horneri, Dictyopteris divaricata, Lomentaria catenata, Corallina confuse, Ishige okamurae, and Ahnfeltiopsis flabelliformi exhibited high antioxidant activities in cellular oxidizing systems.

• ALGAE
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• v.21 no.4
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• pp.463-470
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• 2006

Studies have been made of the species composition and variation of benthic marine algae at subtidal zone of Uljin on the east coast of Korea. Destructive method was employed to measure biomass over four seasons (2000-2002). Of 87 marine algae species identified, 11 were Chlorophyta, 29 were Phaeophyta and 47 were Rhodophyta. Dominant species in biomass were Ulva pertusa, Undaria pinnatifida and Sargassum piluliferum in summer, Laminaria religiosa, Sargassum fulvellum and Gigartina tenella in autumn, Codium fragile, Undaria pinnatifida, Sargassum horneri, S. piluliferum and S. ringgoldianum in winter, and Undaria pinnatifida, Dictyopteris divaricata, Sargassum confusum and S. horneri in spring. In general, green algae (Ulva pertusa, Codium fragile) and brown algae (Undaria pinnatifida, Sargassum fulvellum, S. horneri, S. piluliferum) appeared predominantly in the 3, 6 m depths and red algae (Gelidium amansii, Plocamium telfairiae) in the 9, 12 m depths. The barren ground of the rocky shore might provide the decrease of benthic marine algae biomass and species.

• ALGAE
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• v.36 no.1
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• pp.51-60
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• 2021

The sea urchin, Mesocentrotus nudus, is widely distributed in North West Pacific regions. It has a substantial impact on macroalgal communities as a generalist herbivore. This study examined various aspects of its feeding ecology, including algal preference, foraging behaviors, and possible effects of past feeding history on its algal preference. We used six common algal species (Ulva australis, Undaria pinnatifida, Sargassum confusum, Dictyopteris divaricata, Grateloupia elliptica, and Grateloupia angusta) from the east coast of Korea as food choice in a series of indoor aquarium experiments. The first choice of starved M. nudus was exclusively U. pinnatifida, followed by G. elliptica and S. confusum. Unlike large urchins, small urchins equally preferred U. pinnatifida and G. elliptica. On the other hand, Undaria-fed urchins preferred to feed only G. elliptica, although its preference slightly differed over time. We then grouped sea urchins into three categories (starved, Undaria-fed, mixed species-fed) to observe 12-days feeding preference as well as early foraging movements. Foraging behaviors of the three groups were distinctively different, although they could not completely reflect the actual consumption. For example, U. australis was highly attractive, but rarely eaten. Undaria-fed urchins seemed to stay with only S. confusum and U. australis. This study demonstrates that M. nudus shows high flexibility in food preference depending on past feeding history and body size. Its foraging behaviors are also affected by past feeding conditions, exhibiting active chemoreceptive movements.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.613-622
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• 2008

Cancer chemopreventive effects can be exerted through the induction of phase II detoxification enzymes and the inhibition of inflammatory responses. In this study, the cancer chemopreventive effects and anti-inflammatory responses of 30 seaweed extracts were examined. The extracts of Dictyota coriacea and Cutleria cylindrica exhibited the high chemoprevention index, having 4.36 and 4.66, respectively. They also activated antioxidant response element at $100\;{\mu}g/mL$ by about 3-fold while did not activate xenobiotic response element. Seven seaweed extracts, Ishige okamurae, Desmarestia ligulata, Desmarestia viridis, Dictyopteris divaricata, D. coriacea, Sargassum horneri, and Sargassum yezoense, showed significant inhibition on nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) production in a dose-dependant manner in $5-20\;{\mu}g/mL$. These seaweed extracts could be used as food materials for cancer chemoprevention. D. coriacea could contain potential chemopreventive agents not only that regulate genes via an ARE-dependent mechanism but also prevent the inflammation through inhibition of NO and $PGE_2$ production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.1007-1016
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• 2021

This study examined the characteristics and seasonal distribution patterns of subtidal marine algal communities along the east coast of Korea, from 2016 to 2017, and recorded the coverage ratio (%) by the algal type. During the study period, 134 marine algae species (16 green, 29 brown, and 89 red) were identified at the survey sites. The maximum number of species was observed at the Nagok site (70 species), and the minimum at the Gisamoon site (50 species). The total average biomass (dry weight) during the survey period was 66.22 g/m², including green algae (2.19 g/m²), brown algae (38.10 g/m²), and red algae (25.94 g/m²). The dominant seaweeds in the vertical distribution based on coverage rates (%) were Sargassum yezoense and Dictyopteris divaricata at the upper, Symphyocladia latiuscula and Undaria pinnatifida at the middle, and Agarum clathratum subsp. yakishiriense and Plocamium telfairiae at the lower sections of the distribution. Richness, evenness, and diversity index, calculated based on the biomass of the abundant species, were estimated to be 6.36, 0.55, and 1.98, respectively, over the entire sea area. Based on the evaluation of the environmental states using community indices, the ecological evaluation index (EEI-c) of subtidal marine algal communities along the east coast of Korea was marked as 'good-moderate'.