• Korean Journal of Pharmacognosy
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• v.42 no.4
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• pp.354-360
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• 2011

In order to screen new allogeneic mixed lymphocyte culture (allo-MLR) inhibitor which is expected to be immunomodulating drug lead, we have investigated allo-MLR inhibitory activity on the marine-derived symbiotic microorganisms (1,895 strains) from the marine algae. The potent inhibitory activities (over 45% inhibition of proliferation at 10 and 2 ${\mu}g/ml$) without cytotoxicity were observed in the extracts of 46 strains. While, the significant stimulating activities (over 100% proliferation at 10 and 2 ${\mu}g/ml$) without cytotoxicity were observed in the extracts of 5 strains. In the second assay using 46 bioactive strains, 14 strains exhibited again significant allo-MLR inhibitory activity. Finally, 11 strains among the 14 strains inhibited proliferation and IFN-${\gamma}$ production of CD4+ T cells during the stimulation with specific antigen in the third assay. On the basis of above results, the marine algae is nice source for isolation of immunomodulating microorganism, and the marine algae-associated microorganism is also nice target for development of the new immunomodulating drug lead.

• Food Science and Preservation
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• v.21 no.1
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• pp.62-68
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• 2014

This study was performed in order to investigate the functional components of 5 kinds of marine algae. We have collected 5 samples of marine algae, such as the sea mustard (Undaria pinnatifida), sea tangle (Laminaria iaponice), sea weed fusiforme (Hizikia fusiforme), green laver (Entetomotpha), laver (Phophyratenera), which have been harvested in Jeollanam-do. In order to examine the functional effects, 5 kinds of marine algae were extracted with hot water ($80^{\circ}C$, 4 hr), ethanol and methanol (R.T., 4 hr), and subcritical water extract (SWE, 3 MPa, $90^{\circ}C$, $150^{\circ}C$, $210^{\circ}C$). A higher yield of extract was obtained through SWE method (3 MPa, $210^{\circ}C$) in all of the samples obtained. The highest total sugar content was 427.4 mg/g in green laver extracted with SWE (3 MPa, $210^{\circ}C$). The content of the SWE total phenolic compounds was higher than that of the water and solvent (methanol, ethanol) extracts. The anti-oxidative activities of the extracts from 5 kinds of marine algae were examined through the DPPH radical scavenging activity test. The SWE (3 MPa, $150^{\circ}C$ and $210^{\circ}C$) of the marine algae was the highest among all of the extracts. As per the results, the SWE of the marine algae contained more functional components and it had a higher antioxidant activity than those of the other extracts. The $IC_{50}$ value of tyrosinase in seaweed fusiforme and laver were higher than those of the other samples. These results strongly support the possible use of marine algae as functional materials.

• Journal of Integrative Natural Science
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• v.11 no.2
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• pp.69-75
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• 2018

The red algae Gracilaria vermiculophylla is widely spread around seaside areas across the globe, and has been used as a food resource in Southeast Asian countries. Previous studies have shown that Gracilaria red algae extracts have beneficial antihypercholesterolemic, antioxidant, anti-inflammatory, and antimicrobial effects. In this study, we investigated the antioxidant effects of Gracilaria vermiculophylla extracts (GV-Ex) on human bone marrow mesenchymal stem cells (hBM-MSCs). The acetone and DMSO/ethanol solvents of the tested GV contain higher total flavonoid and polyphenolic contents that can strongly scavenge reactive oxygen species (ROS). Pre-treatment with GV-Ex protected hBM-MSCs against oxidative stress induced by hydrogen peroxide treatment. The protective effects of GV-Ex treatment were confirmed by MTT assay. The elevated levels of ROS in hBM-MSCs caused by hydrogen peroxide induced oxidative stress were significantly decreased by GV extract treatment. The levels of the antioxidant proteins superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), and catalase (CAT) were also restored or protected by GV-Ex treatment, suggesting that GV extracts moderate excess ROS levels and prevent cells from oxidative damage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.833-840
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• 2023

In this study, the antioxidant and anti-skin aging properties of the Korean marine algae Ishige foliacea were investigated. Solvent extracts from I. foliacea were prepared with 70% ethanol, 80% methanol, and water. The extraction yields of various solvent extracts ranged from 9.55% to 35.12%. In terms of antioxidant activity, the ethanol extract showed the highest ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) radical scavenging activity, nitrite oxide scavenging activity, reducing power, and FRAP (ferric reducing antioxidant power). Regarding anti-skin aging activity, evaluation of the skin whitening and anti-wrinkle activities revealed that the methanol, water, and ethanol extracts possessed the highest tyrosinase (IC₅₀=0.98 mg/mL), elastase (IC₅₀=0.15 mg/mL), and collagenase (IC₅₀=0.06 mg/mL) inhibitory activities, respectively. These results suggest that I. foliacea holds potential as an antioxidant and anti-skin aging substance in food and cosmetic materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.3
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• pp.209-215
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• 2024

Ishige foliacea belongs to class Phaeophyceae and family Ishigeaceae. This study investigated the physiological activities of the Korean marine algae I. foliacea. Its solvent extracts were prepared with 70% ethanol, 80% methanol, and distilled water. The ethanol and methanol extracts had higher α-glucosidase (half-maximal inhibitory concentration, IC₅₀: 0.67-0.73 mg/mL), xanthine oxidase (IC₅₀: 0.25-0.28 mg/mL), and angiotensin-converting enzyme (IC₅₀: 25.29-38.28 ㎍/mL) inhibitory activities than those of the water extract. The ethanol and methanol extracts possessed high acetylcholinesterase inhibitory activity (IC₅₀: 0.78c0.97 mg/mL). Conversely, the water extract exhibited the highest β-secretase inhibitory activity (IC₅₀: 0.48 mg/mL). These results indicate that I. foliacea may be useful as a functional substance in food and pharmaceuticals with anti-diabetic, anti-gout, anti-hypertension, and anti-dementia properties.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.54-59
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• 2020

The inconsistent methods of harvest, identification, and preparation of brown algae samples make it difficult to compare the results of certain measurements across different studies, such as total phenolic contents (TPC), total flavonoid contents (TFC), and total antioxidant capacities (TAC). Therefore, this study aims to systematically measure and compare TPC, TFC, and TAC in 10 types of standardized brown algae extracts provided by the Bio-Resource Information System of Korea. Among the ten brown algae extracts, Ishige foliacea exhibited the highest levels of TPC and TAC, followed by Sargassum nigrifolium. TAC was measured by the following four assays: ABTS, DPPH, superoxide radical scavenging activities, and ferric reducing antioxidant power. TAC was found to be positively correlated with TPC (p<0.05) but not TFC, indicating that Ishige foliacea and Sargassum nigrifolium have potential use as marine antioxidative food material.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.191-195
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• 2002

In previous reports the authors have screened the inhibition effects of marine algae extracts on halitosis, and demonstrated that a brown algae, Eisenia bicyclis (' Daehwang') possess not only strong deodorant effect bug also considerable anticariogenic activities. In this study, we screened antibacterial effects of various marine algae, and measured minimum inhibitory concentration (MIC) value of them against mutans streptococci in vitro. Among the 27 species of marine algae, $80\%$ ethanol extract of dried sea-mustard, Laminaria japonica ('Dasima') showed the strongest inhibition activity against Streptococcus mutans KCTC 3300. The extracts of Ulva lactuca ('Galparae'), Codium fragile ('Cheonggak'), Ecklonia cava ('Gamtae'), E. stolonifera ('Gompi') and Undalia Pinnatifida ('Miyeok') showed slightly weaker inhibitory potency than L. japonica. Differences of MIC values in $80\%$ ethanol extract of some species of marine algae were observed depending on test bacterial species, i.e., S. mutans KCTC 3300 or S. sobrinus KCTC 3307. Eighty percent ethanol extract of dried L japonica was fractionated with diethyl ether, chloroform, ethyl acetate, n-buthanol and water successively, The ether-soluble fraction had inhibitory effect on S. mutans KCTC 3300, however the inhibitory effects were not found in the other fractions. The MIC values of $80\%$ ethanol extract and ether fraction were 180 and 105 $\mu$g/mL respectively, while no significant inhibition activity of water-soluble fraction was found even when the fraction was added up to 5,500 $\mu$g/mL.

• ALGAE
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• v.21 no.1
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• pp.149-156
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• 2006

The aim of the present study was to evaluate the antioxidant activity of red algae in Jeju Island. The algal extracts were obtained with MeOH and fresh water at 20 and 70°C, and screened for antioxidant activities using hydroxyl radical (HO·), superoxide anion (O2–), hydrogen peroxide (H2O2) and DPPH free radical scavenging assays. Among them, Gracilaria verrucosa methanolic extract at 20°C (20ME, 96.85%), G. textorii aqueous extract at 20°C (20AE, 88.01%), Grateloupia filicina 20AE (85.35%), and Polysiphonia japonica 20ME (94.92%) exhibited the highest scavenging activities against HO·, O2–, H2O2, and DPPH free radicals, respectively. Moreover, P. japonica (20ME and 70ME) is correlated between DPPH free radical scavenging activity and polyphenolic contents. These results indicate that some red algae in Jeju Island could be potential candidates for development of antioxidants.

• ALGAE
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• v.28 no.4
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• pp.371-378
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• 2013

Water and methanolic extracts of Ecklonia cava, a marine brown alga, were prepared by ultrasonic extraction (UE) and conventional extraction (CE) methods. The radical-scavenging activity and the inhibitory effects against hydrogen peroxide ($H_2O_2$)-induced DNA damage of the extracts were investigated. All extracts prepared by CE exhibited higher total polyphenolic content than that in the extracts prepared by UE. Extraction yield and total phenolic content increased as the UE time increased. The radical-scavenging activities increased as the UE time increased. All extracts prepared by CE exhibited higher 1,1-diphenyl-2-pricrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities than did those prepared by UE. Extracts prepared by UE showed stronger scavenging activities on alkyl radical and $H_2O_2$ than those prepared by CE did. Methanolic extract with UE 12 h (100MEU-12h) and methanolic extract with CE 24 h (100MEC-24h) were selected and evaluated by comet assay for their inhibitory effect against $H_2O_2$-induced DNA damage. 100MEU-12h showed slightly greater protective effect against $H_2O_2$-induced DNA damage than 100MEC-24h. Thus, UE can be effectively used as a seaweed extraction technique, and there is potential for scale-up of the extraction process.

• ALGAE
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• v.20 no.3
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• pp.251-260
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• 2005

Antioxidative activities of Chlorophyta and Phaeophyta in Jeju Island were measured by superoxide anion ($O_2^{{\cdot}-}$), hydroxyl radical ($HO^{\cdot}$), hydrogen peroxide ($H_2O_2$) and DPPH free radical scavenging assays. Methanolic and aqueous extracts of the seaweeds were prepared at both temperatures, higher (70$^{\circ}C$) and room temperature (20$^{\circ}C$), and screened for the construction of an extract bank from seaweeds in Jeju Island. A variety of extracts showed positive effect against reactive oxygen species (ROS). Especially, Sargassum thunbergii methanolic extract at 70$^{\circ}C$ (70ME, 97.41%), S. fulvellum methanolic extract at 20$^{\circ}C$ (20ME, 84.66%), Codium fragile aqueous extract at 70$^{\circ}C$ (70AE, 96.61%) and S. thunbergii 20ME (97.44%) exhibited the highest scavenging activities against $O_2^{{\cdot}-}$, $HO^{\cdot}$, $H_2O_2$ and DPPH free radicals, respectively. Total phenolic contents also examined but did not show a positive correlation with ROS scavenging abilities (except for a few extracts). These results indicate that further investigation is needed to identify and purify the responsible antioxidative components.