• Journal of Life Science
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• v.22 no.10
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• pp.1420-1427
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• 2012

We investigated the physiological activity and solvent-partitioned fractions of methanol extracts from the green seaweed Sargassum fulvellum. The methanol extract from S. fulvellum was sequentially fractionated with n-hexane (SFMH), methanol (SFMM), buthanol (SFMB), and water (SFMA). We investigated the antioxidant activities of solvent fractions from S. fulvellum by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and an SOD activity assay. DPPH radical scavenging capacity of SFMM was 79.5% at 10 mg/ml. SOD activity of SFMM was 79.9% at 10 mg/ml. Nitrite scavenging activities of solvent fractions from S. fulvellum were investigated under different pH conditions and showed the most remarkable effect at pH 1.2. In particular, the activity of SFMB was higher than the other fractions. ADH activity and ALDH activity of SFMM were 177.0% and 167.4% at 10 mg/ml, respectively. ${\alpha}$-Glucosidase inhibitory activity of SFMH increased in a dose-dependent manner and was about 94.1% at 2 mg/ml. Elastase inhibitory activity was 93.2% at 2 mg/ml. These results revealed that S. fulvellum extracts have strong antioxidant and alcohol dehydrogenase activities and ${\alpha}$-glucosidase inhibitory activity, suggesting that S. fulvellum extracts have potential as a source of natural products for health and beauty.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.427-431
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• 1999

This study was conducted to investigate the inhibitory activity of water extracts and its enzymatic hydrolysates from algae against angiotensin-I converting enzyme (ACE). The 7 kinds of algae were extracted with water at $50^{\circ}C,\;70^{\circ}C$ and $98^{\circ}C$. ACE inhibitory activities of water extracts were the highest at $70^{\circ}C$, and those of ceylon moss, layer, green layer, sea mustard, seaweed fusiforme sea tangle and sea staghorn were $10.9\%,\;9.3\%,\;8.9\%,\;8.2\%,\;7.5\%,\;7.1\%$ and $7.0\%$, respectively. Layer, green laver sea mustard and ceylon moss of high ACE inhibitory activities among the 7 kinds of water extracts were hydrolyzed by maxazyme and papain during 24hrs. ACE inhibitory activity of enzymatic hydrolysates was higher than that of water extracts, and was the highest in enzymatic hydrolysates of laver among the tested samples. In laver hydrolysates by proteases, the highest ACE inhibitory activity and peptide-nitrogen contents were observed at 8 hours hydrolysis and the hydrolysates by maxazyme showed relatively higher activity than those by papain(31.3 and $27.9\%$, respectively). But peptide-nitrogen contents were greater in papain hydrolysates than in maxazyme.

• Korean journal of food and cookery science
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• v.26 no.5
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• pp.499-502
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• 2010

This study compared the total phenolic contents and antioxidant activities of two seaweed cultivars, Undaria pinnatifida (UP) and Capsosiphon fulvescens (CF), subjected to different drying methods. UP and CF were dried under two different conditions: vacuum drying (VD) at $20^{\circ}C$ and hot-air drying (HD) at $60^{\circ}C$. After drying, the total phenolic content, DPPH, and nitrite scavenging activities of the water extracts were determined. Total phenolic contents were 101.94 mg/100 g for UP and 171.35 mg/100 g for CF upon VD-20, and these values were significantly decreased to 67.59 mg/100 g for UP and 141.48 mg/100 g for CF upon HD-60. UP upon VD-20 and HD-60 had 46.17% and 35.20% DPPH radical scavenging activity, whereas CF upon VD-20 and HD-60 scavenged 57.73% and 35.22%, respectively. UP upon VD-20 and HD-60 had 40.36% and 40.01% nitrite scavenging activity at pH 1.2, whereas CF upon VD-20 and HD-60 scavenged 72.35% and 55.24%, respectively. Nitrite scavenging activities of UP and CF were reduced at pH 3.0.

• Environmental Analysis Health and Toxicology
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• v.14 no.3
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• pp.75-79
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• 1999

Due to increasing marine pollution there is a great possibility that seaweed is contaminated with polycyclic aromatic hydrocarbons (PAHs). To investigate the effect of processing on PAM removal from Porphyra tenera (laver) contaminated PAH, laver was contaminated with fluoranthene known to have a strong photoinduced toxicity, followed by washings and drying, which are usual processes for dried laver preparation. Sample at each step was collected and its toxicity was evaluated using cultured animal cells as well as analyzing PAH contents. Fluoranthene level in laver was significantly lowered by sequential washings with sea water and distilled water, but not by drying. Fluoranthene content in raw laver right after contamination was 221 ppm and decreased to 130 ppm by washings with seawater plus distilled water while its level was not lurker lowered by drying process. Cytotoxicity and photoinduced cytotoxicity in mammalian cells were significantly elevated in laver extracts containing fluoranthene. Cellular arylhydrocarbon hydroxylase (AHH), one of the biomarkers for cellular accumulation of PAH, was greatly induced by laver extract contaminated with fluoranthene. These results suggest that photoinduced toxicity and AHH activity can be used to monitor contamination of seafood by PAHs. Fluoranthene accumulated in laver was efficiently removed by sequential washings with seawater and tap water for 24 hrs and 12 hrs, respectively.

• Nutrition Research and Practice
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• v.5 no.2
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• pp.93-100
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• 2011

Inhibition of angiotensin I-converting enzyme (ACE) activity is the most common mechanism underlying the lowering of blood pressure. In the present study, five organic extracts of a marine brown seaweed Ecklonia cava were prepared by using ethanol, ethyl acetate, chloroform, hexane, and diethyl ether as solvents, which were then tested for their potential ACE inhibitory activities. Ethanol extract showed the strongest ACE inhibitory activity with an $IC_{50}$ value of 0.96 mg/ml. Five kinds of phlorotannins, phloroglucinol, triphlorethol-A, eckol, dieckol, and eckstolonol, were isolated from ethanol extract of E. cava, which exhibited potential ACE inhibition. Dieckol was the most potent ACE inhibitor and was found to be a non-competitive inhibitor against ACE according to Lineweaver-Burk plots. Dieckol had an inducible effect on the production of NO in EAhy926 cells without having cytotoxic effect. The results of this study indicate that E. cava could be a potential source of phlorotalnnins with ACE inhibitory activity for utilization in production of functional foods.

• Archives of Pharmacal Research
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• v.27 no.2
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• pp.194-198
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• 2004

Reactive oxygen species (ROS) play an important role in the pathogenesis of many human degenerative diseases such as cancer, aging, arteriosclerosis, and rheumatism. Much attention has been focused on the development of safe and effective antioxidants. To discover sources of antioxidative activity in marine algae, extracts from 17 kinds of seaweed were screened for their inhibitory effect on total ROS generation in kidney homogenate using 2',7'-dichlorofluorescein diacetate (DCFH-DA). ROS inhibition was seen in three species: UIva pertusa, Symphyocladia latiuscula, and Ecklonia stolonifera. At a final concentration of 25 $\mu\textrm{g}$/mL, U. pertusa inhibited 85.65$\pm$20.28％ of total ROS generation, S. latiscula caused 50.63$\pm$0.09％ inhibitory, and the Ecklonia species was 44.30$\pm$7.33％ inhibition. E. stolonifera OKAMURA (Lam-inariaceae), which belongs to the brown algae, has been further investigated because it is commonly used as a foodstuff in Korea. Five compounds, phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5), isolated from the ethyl acetate soluble fraction of the methanolic extrclct of E. stolonifera inhibited total ROS generation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.909-915
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• 1997

The nitrite scavenging effect of methanol extracts of marine algae were evaluated to discover new natural nitrite scavengers. Among the tested seaweeds, Ecklonia stolonifera, an edible brown algae, showed the strongest scavenging effect. The MeOH extract was then sequentially partitioned into $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, EtOAc, n-BuOH, and $H_2O$ layers. The EtOAc and n-BuOH fraction demonstrated high levels of nitrite-scavenging activity while the $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, and $H_2O$ fractions were inactive. A column chromatography of the EtOAc fraction through silica gel and Sephadex LH-20 yielded phloroglucinol and a new compound tentatively named phlorotannin A. The nitrite scavenging activity of phloroglucinol $(IC_{50}=3.9{\mu}g/ml)$ was more potent than that of L-ascorbic acid $(IC_{50}=65.0{\mu}g/ml)$. However, phlorotannin A $(IC_{50}=193.2{\mu}g/ml)$ showed only low levels of activity. From the above results, it is possible to suggest that both the MeOH extract and their fractions and isolated phloroglucinol and phlorotannin A obtained from E. stolonifera may be applicable as scavengers of nitrite, which is a precursor for the formation of carcinogenic N-nitroso compounds.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.244-247
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• 2010

This study was performed to evaluate the effect of drying methods on the polyphenol contents and antioxidant activities of Hizikia fusiformis. The seaweed was dried using four different conditions: vacuum drying (VD) at $20^{\circ}C$ and $30^{\circ}C$ and hot-air drying (HD) at $40^{\circ}C$ and $60^{\circ}C$. After drying, the total phenol content, DPPH and nitrite scavenging activities of the water extracts were determined. The total phenol contents were significantly (p<0.05) higher in the vacuum dried samples than the hot-air dried samples. DPPH radical was scavenged 82.67% and 83.45% by VD-20 and VD-30, and 70.44% and 71.23% by HD-40 and HD-60, respectively. At pH 1.2, Hizikia fusiformis scavenged 87.43%, 88.45%, 72.14% and 73.45% of nitrite by the treatment VD-20, VD-30, HD-40 and HD-60, respectively. Interestingly, the nitrite scavenging activity was much more reduced at pH 3.0 than at pH 1.2. Through these experiments, we were able to show that the drying conditions affect the total phenol contents and antioxidant capacities of Hizikia fusiformis.

• Archives of Pharmacal Research
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• v.28 no.12
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• pp.1376-1380
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• 2005

In this study, ethanolic extracts from 18 seaweed variants were assessed for hepatoprotective activity against tacrine-induced cytotoxicity in Hep G2 cells. Only one of these, Ecklonia stolonifera Okamura (Laminariaceae), a member of the brown algae, exhibited promising hepatoprotective activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction obtained from the ethanolic extract of E. stolonifera, resulted in the isolation of several phlorotannins [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds 2 and 4 were determined to protect Hep G2 cells against the cytotoxic effects of tacrine, with $EC_{50}$ values of 62.0 and 79.2 $\mu$g/mL, respectively. Silybin, a well characterized hepatoprotective agent, was used as a positive control, and exhibited an $EC_{50}$ value of 50.0 $\mu$g/mL. It has been suggested that the phlorotannins derived from marine brown algae might prove useful sources in the development of novel hepatoprotective agents.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.144-151
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• 2012

In the course of this study aimed at the development of functional food ingredients from seaweeds, the in vitro antimicrobial activities of methanol extracts prepared from 35 different seaweeds (17 phaeophyta, 11 rhodophyta and 7 chlorophyta) were determined against food-borne diseases and pathogenic microorganisms including multi-drug resistant (MDR) Pseudomonas sp. and Candida sp. Based on disc-diffusion assays at 500 g/disc concentration of the methanol extracts, Ishige okamurai, I. foliacea, Sargassum confusum, and S. yamade exhibited strong antibacterial activities in a broad-spectrum, except against Pseudomonas aeruginosa. In addition to the latter four seaweeds, Ecklonia stolonifera, E. cava and Eisenia bicyclis also demonstrated antifungal activity against C. albicans. Among these 8 selected seaweeds, I. okamurai, I. foliacea, and S. yamade exhibited strong hemolytic activity (55-93%) at 500 g/ml against human RBC. Organic solvent sequential fractions using hexane, ethylacetate and butanol, and water residues were prepared from the 8 selected seaweeds and their anti-Candida sp. activities were further determined. The ethylacetate and butanol fraction of I. okamurai, and the hexane fraction of I. foliacea demonstrated antifungal activity against MDR-pathogenic Candida sp. Although the solvent fractions had no activity against MDR-Pseudomonas sp., our results suggest that seaweeds, especially Ishige okamurai, I. foliacea, S. confusum, and S. yamade could be developed as broad-spectrum antimicrobial ingredients.