• 한국해양바이오학회지
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• 제12권2호
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• pp.115-122
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• 2020

Eisenia bicyclis, a perennial macroalga is a primary producer of in the ocean, It has been identified as a key species that plays a vital role in maintaining the ecosystem stability. Also, it is an important target in marine afforestation projects and useful marine organisms. In addition, E. bicyclis is used as a health food for humans. This study investigated the effect of water temperature, light (photon irradiance), and duration of light (photoperiod) on the growth of gametophytes and young sporophytes of E. bicyclis. The germination and growth of the zoospores of E. bicyclis were examined at five temperatures (5℃, 10℃, 15℃, 20℃ and 25℃), four intensities of photon irradiance (10, 20, 40, and 80 μmol m-2s-1), and photoperiods (14:10 and 10:14 light/dark cycles). The zoospores released from mature plant germinated into the gametophytes under all experimental conditions. The gametophytes were able to grow at water temperature 5℃-25℃ and mature at 10℃-20℃. The optimal range of water temperature for the maturation of the gametophyte was 15℃-20℃. At 25℃, E. bicyclis gametophytes grew rapidly but did not mature. The optimal culture conditions for the growth of young sporophytes grew slowly in low temperature and photon irradiances.

• 한국식품저장유통학회지
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• 제23권1호
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• pp.97-103
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• 2016

미역과에 속하는 대황 물 추출물의 항산화활성과 탄수화물 및 단백질 소화효소 저해능을 추출방법을 달리하여 비교 검토하였다. 환류냉각추출물(RE), 초음파추출물(SE), 고온가압추출물(AE), 저온고압추출물(LE)의 수율과 주요 성분함량은 AE, RE, SE, LE 순으로 높았다. 고온가압추출물(AE)의 수율, 라미나린, 후코이단, 폴리페놀, 플라보노이드 함량은 각각 55.21%, 39.03%, 24.75%, 115.68 mg GAE/g, 36.67 mg RHE/g을 나타내었다. DPPH radical 소거능 모든 시료에서 농도 의존적으로 증가하였으며, 500 mg% 농도에서 AE(86.60%), RE(83.09%), SE(84.41%), LE(80.45%) 순이었다. ABTS radical 소거능은 50 mg% 농도에서 모두 98% 이상의 높은 활성을 나타내었다. 아질산염 소거능은 모든 실험군에서 농도 의존적으로 증가하였고 AE, RE, SE, LE 순으로 높았으며, 500 mg% 농도에서 추출방법에 관계없이 98% 이상의 높은 활성을 나타내었다. 탄수화물 소화효소 중 amylase 저해 효과는 50 mg% 농도에서 AE(64.76%), RE(58.57%), SE(54.76%), LE(45.48%)순으로 나타났으며, ${\alpha}$-glucosidase 저해효과는 5 mg% 농도에서 AE(86.71%), RE(81.87%), SE(75.21%), LE(72.65%) 순으로 나타났다. 단백질 분해 효소 중 trypsin 저해 효과는 50 mg% 농도에서 AE(24.37%), RE(22.76%), SE(19.97%), LE(15.95%)순으로 나타났으며, ${\alpha}$-Chymotrypsin 저해효과는 50 mg% 농도에서 AE(49.05%), RE(43.60%), SE(40.63%), LE(38.10%) 순이었으며, 대황 추출방법은 $121^{\circ}C$에서 15분간 열처리하는 고온가압 추출방법이 가장 양호하였다.

• Fisheries and Aquatic Sciences
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• 제18권2호
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• pp.165-171
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• 2015

Abalone containing phlorotannins is produced by feeding the phlorotannin-rich brown seaweed Eisenia bicyclis after 4 days of starvation. Reverse-phase high-performance liquid chromatography (RP-HPLC) was used to isolate and quantify phlorotannins, which were identified by mass spectrometry and [$^1H$]-nuclear magnetic resonance to be the P1 compound, 7-phloroeckol, and eckol. When E. bicyclis was used as feed, P1 compound accumulated to an average of 1.60 mg/g dry weight of abalone muscle tissue after 18 d, 7-phloroeckolol to 0.21 mg/g after 16 d, and eckol to 0.22 mg/g after 12 d. Saccharina japonica was used as a control feed, and the abalone showed little or no accumulation of phlorotannins in muscle tissue. Feed consumption and growth rate were very similar when either E. bicyclis or S. japonica was fed for 20 d. Half-maximal reductions in the levels of P1 compound, 7-phloroeckol, and eckol accumulation were attained in 1.5, 1.9, and 3.4 days, respectively, after the feed was switched from E. bicyclis to S. japonica. Value-added abalone containing bioactive phlorotannins can be produced by simply changing the feed to the phlorotannin-rich E. bicyclis 18 d prior to harvesting.

• 한국수산과학회지
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• 제48권2호
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• pp.151-157
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• 2015

This study was conducted to evaluate the effect of lactic acid bacterial fermentation on the antioxidant and anti-inflammatory activity of an edible brown alga, Eisenia bicyclis. Lactic acid bacteria were inoculated into and cultivated in E. bicyclis water extract. The antioxidant activity of the extract was assayed before and following fermentation. Antioxidant activity was determined by assaying the levels of radical scavenging activity against 2,2'-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical and alkyl radical. The lactic acid bacterial fermentation of E. bicyclis extract resulted in enhanced antioxidant activity. The greatest enhancement of antioxidant activity was seen in the DPPH radical scavenging assay, in which E. bicyclis extract was fermented by Pediococcus pentosaceus MBP-34 strain for 12 h. This fermented extract also exhibited higher inhibitory activity (96.66%) on nitric oxide production compared with other lactic acid bacterial fermented extracts or raw extract (189.60%). In conclusion, fermentation by bacterial strain is an attractive strategy for developing value-added food ingredients.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.262-266
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• 2010

This study was performed to investigate the anti-obesity effect of Eisenia bicyclis in mice fed a high-fat diet (HFD). Male C57BL/6J mice were divided into three groups that were fed a normal diet, an HFD, or an HFD supplemented with a 5% powder of Eisenia bicyclis (PEB) for 8 weeks. The PEB group showed lower body weight gains than the HFD group. The PEB group also exhibited reduced body fat mass and adipose cell size in epididymal adipose tissue. The concentrations of serum cholesterol, leptin, and insulin in the PEB group were significantly lower than those in the HFD group. Liver triglyceride content was significantly decreased by PEB supplementation. Furthermore, hematoxylin and eosin staining revealed that PEB supplementation reduced lipid droplet formation in the liver induced by HFD. These results suggest that PEB supplementation reduces body weight gain and fat accumulation in HFD-induced obese mice.

• 한국수산과학회지
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• 제54권2호
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• pp.152-161
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• 2021

Eisenia bicyclis is known to have secondary metabolites exhibiting various biological activities. In a preliminary study, the n-hexane fraction obtained from the ethanolic extract of E. bicyclis showed higher anti-inflammatory activity than the ethyl acetate and butyl alcohol fractions based on the inhibition of lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production in RAW 264.7 cells. Using this fraction (E. bicyclis hexane fraction, EHF), we investigated the molecular mechanisms underlying its anti-inflammatory effect in LPS-stimulated RAW 264.7 cells. Pretreatment of the cells with up to 50 ㎍/mL EHF significantly inhibited NO and prostaglandin E₂ production as well as their responsible enzyme proteins and mRNAs, in a dose-dependent manner (P<0.05). Similarly, EHF markedly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α as well as their mRNA levels. Nuclear translocation of nuclear factor-kappa B (NF-κB) was strongly suppressed by EHF treatment. EHF significantly reduced the phosphorylation of mitogen-activated protein kinases and phosphatidylinositol 3-kinase/Akt in LPS-stimulated cells. Moreover, EHF reduced ear edema in phorbol myristate acetate (PMA)-induced mice. These results indicate that EHF contains potent anti-inflammatory compounds, which may be used as a dietary supplement for the prevention of inflammatory diseases.

• Fisheries and Aquatic Sciences
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• 제14권3호
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• pp.179-185
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• 2011

The antioxidant activities of a methanolic extract of Eisenia bicyclis and its organic solvent fractions, including dichloromethane ($CH_2Cl_2$), ethyl acetate (EtOAc), n-butanol (n-BuOH), and water ($H_2O$) fractions, were investigated. Scavenging activities against DPPH, hydroxyl, superoxide anion, and peroxynitrite radicals were evaluated using electron spin resonance spectrometry; intracellular reactive oxygen species (ROS) were evaluated by a 2',7'-dichlorofluorescein diacetate assay using RAW264.7 mouse macrophages. The antioxidant activities of the individual fractions were: EtOAc>n-BuOH>$CH_2Cl_2$ >$H_2O$. The EtOAc fraction exhibited strong radical scavenging activity and a significantly reduced ROS level in RAW264.7 cells. Moreover, the phenolic contents of the extract and fractions followed the same order as their radical scavenging activities. Our results indicate that E. bicyclis is a valuable natural source of antioxidants that may be applicable to the functional food industry.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.251-256
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• 2011

We screened for antibacterial substances against methicillin-resistant Staphylococcus aureus (MRSA). Methanolic extract of Eisenia bicyclis exhibited anti-MRSA activity according to a disk diffusion assay. To identify the active compound(s), the methanolic extract was further fractionated using hexane, dichloromethane, ethyl acetate, and n-butanol. The ethyl acetate-soluble fraction showed both the greatest anti-MRSA activity and the highest polyphenol content. The minimum inhibitory concentrations of the ethyl acetate fraction ranged from 32 to 64 ${\mu}g$ per mL against methicillin-susceptible S. aureus and MRSA strains. High-performance liquid chromatography analysis revealed that both the methanolic extract and the ethyl acetate soluble fraction contained sizeable quantities of dieckol, which is a known anti-MRSA compound. Thus, these data strongly suggest that the anti-MRSA activity of E. bicyclis may be mediated by phlorotannins such as dieckol.

• Fisheries and Aquatic Sciences
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• 제21권11호
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• pp.35.1-35.7
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• 2018

Background: The aim of this study was to investigate the in vitro inhibitory effects of Fucofuroeckol-A isolated from Eisenia bicyclis against tyrosinase activity and 3-isobutyl-1-methylxanthine (IBMX)-induced melanin biosynthesis in B16F10 melanoma cells. Result: Among the ethanolic (EtOH) extract of E. bicyclis and its organic solvent fractions, the ethyl acetate (EtOAc) soluble fraction showed a noticeable inhibitory effect on mushroom tyrosinase with an $IC_{50}$ value of $37.6{\pm}0.1{\mu}g/mL$. Repeated column chromatography of the active EtOAc fraction resulted in the isolation of Fucofuroeckol-A. It evidenced more potent tyrosinase inhibitory effect with an $IC_{50}$ value of $11.4{\pm}1.4{\mu}M$ than arbutin ($IC_{50}=1076.6{\pm}44.3{\mu}M$), which was used as a positive control. Lineweaver-Burk plots suggest that Fucofuroeckol-A plays as a noncompetitive inhibitor against tyrosinase. Furthermore, we have evaluated the inhibitory effects of Fucofuroeckol-A on IBMX-induced melanin formation in B16F10 melanoma cells. Fucofuroeckol-A ($12.5-100{\mu}M$) exhibited a significant inhibition of melanin production in the melanoma cells. Conclusion: In the present study, we suggested that Fucofuroeckol-A might prove possibility as a novel inhibitor of melanin biosynthesis in cosmetic applications.

• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.209-214
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• 2014

With the continuing demand for new solutions in the development of effective and safe candidiasis therapies, we investigated the efficacy of an antifungal agent from the marine brown alga Eisenia bicyclis. The methanolic extract of E. bicyclis evinced potential antifungal activity against Candida species. The ethyl acetate (EtOAc)-soluble extract from E. bicyclis demonstrated the strongest antifungal activity against Candida species among five solvent-soluble extracts. Indeed, the EtOAc-soluble extract showed minimum inhibitory concentrations (MICs) ranging from 4 to 8 mg/mL. Furthermore, the EtOAc-soluble extract considerably reversed high-level fluconazole resistance of Candida species. The MIC values of fluconazole against Candida species decreased substantially (from 64 to $4{\mu}g/mL$) in combination with the MIC of the EtOAc-soluble extract (4 mg/mL). The fractional inhibitory concentration indices of fluconazole ranged from 0.531 to 0.625 in combination with 4, 2, or 1 mg/mL of the EtOAc-soluble extract against Candida isolates, indicating that these combinations exert a marked synergistic effect against Candida isolates. These findings imply that compounds derived from E. bicyclis can be a potential source of natural antifungal agents against Candida species.