Developmental toxicity and antiinflammatory effect of the soft coral Dendronephthya gigantea collected from Jeju Island in zebrafish model

이승홍 한국수산과학회 2017 Fisheries and Aquatic Sciences Vol.20 No.4

Recent in vitro studies have demonstrated that extract of soft coral Dendronephthya gigantea (SCDE) had strong anti-inflammatory activities. However, the direct effects of SCDE on anti-inflammatory activities in vivo model remained to be determined. Therefore, the present study was designed to assess in vivo anti-inflammatory effect of SCDE using lipopolysaccharide (LPS)-stimulated zebrafish model. We also investigated whether SCDE has toxic effects in zebrafish model. The survival, heart beat rate, and developmental abnormalities were no significant change in the zebrafish embryos exposed to at a concentration below 100 μg/ml of SCDE. However, lethal toxicity was caused after exposure to 200 and 400 μg/ml of SCDE. Treating zebrafish model with LPS treatment significantly increased the reactive oxygen species (ROS) and nitric oxide (NO) generation. However, SCDE inhibited this LPS-stimulated ROS and NO generation in a dose-dependent manner. These results show that SCDE alleviated inflammation by inhibiting the ROS and NO generation induced by LPS treatment. In addition, SCDE has a protective effect against the cell damage induced by LPS exposure in zebrafish embryos. This outcome could explain the profound anti-inflammatory effect of SCDE both in vitro as well as in vivo, suggesting that the SCDE might be a strong anti-inflammatory agent.

수평 원관의 비등 열전달에서 강제대류의 영향

이승홍,이억수,정은행 대한설비공학회 1998 설비공학 논문집 Vol.10 No.5

This paper presents the results of experiments involving external forced convection on boiling heat transfer from electrically heated horizontal tube to water in cross flow. In these experiments, all of the following primary variables were varied: heat flux, cross flow velocity, pressure and degree of subcooling. Local surface temperatures were measured at nine peripheral positions. Surface temperature distributions are classified into four groups as a function of heat flux. The characteristics of the boiling curve at different velocity, degree of subcooling and pressure are examined.

Antioxidant and Anti-inflammatory Activities of the Ethanolic Extract of Fermented Red Ginseng Marc

이승홍,오미래,박재현,장세영,정선희,이형일,문상호 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.2

Red ginseng marc (RGM) is generally discarded as waste, even though it contains bioactive components. Hence, this study aimed to evaluate the bioactive components and properties of RGM extracts prepared via the fermentation of Bacillus subtilis (BSRGM) and Saccharomyces cerevisiae (SCRGM). Polyphenols were not detected in non-fermented RGM (NRGM) extracts, whereas the polyphenol levels in RGM extracts significantly increased with fermentation. The BSRGM and SCRGM extracts showed significantly higher free radicals scavenging activity than those of NRGM extracts. Treatment with the fermented RGM extracts also increased IgA levels compared to that of NRGM extracts, whereas it decreased IgE production by the mesenteric lymph node, spleen, and Peyer’s patch lymphocytes. These results suggest that fermented RGM extracts may ameliorate inflammation. In addition, the phenolic compounds in fermented RGM extracts may have biological activity, making fermented RGM extracts a potential natural resource that could be used in the functional foods industry.

Potential of Benthic Diatoms Achnanthes longipes, Amphora coffeaeformis and Navicula sp. (Bacillariophyceae) as Antioxidant Sources

이승홍,Rohan Karawita,Abu Affan,Joon-Baek Lee,Ki-Wan Lee,이배진,Dong-Woo Kim,전유진 한국조류학회I 2009 ALGAE Vol.24 No.1

Recently, interest in plant-derived food additives has developed natural antioxidants, in order to alternate synthetic antioxidants with several disadvantages. In the present study, different organic fractions from solvent partitions of 80% methanol extract from Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis was assessed for their potential antioxidant effects. Among the solvent fractions tested, n-hexane (80.4%) and 80% methanol extract (76.6%) from A. longipes, chloroform (63.2%) from Navicula sp. and n-hexane (67.4%) from A. coffeaeformis were effective in DPPH free radical scavenging. Fractions of chloroform (53.4%) and n-hexane (53.1%) from A. longipes exhibited higher activities on H2O2 scavenging. Fraction of n-Hexane from A. longipes exhibited the highest hydroxyl radical scavenging activity and NO· scavenging activity (56.5% and 75.6%, respectively). Aqueous residue from A. coffeaeformis (75.6%) showed the highest metal chelating effect. Chloroform and ethyl acetate fraction of all the diatoms exhibited significant antioxidant activities in lipid peroxidation inhibitory activity. In particular, both chloroform and the ethyl acetate fraction from A. longipes and A. coffeaeformis exhibited lipid peroxidation inhibitory activity significantly higher than that of α- tocopherol. These data suggest that the Jeju benthic diatoms tested are rich in hydrophilic and hydrophobic antioxidative compounds with different antioxidative properties that can be applied in food industry.

‘전공의 특별법’ 통과, 한국 의료체계를 변화시킬 지렛대가 될 것인가

이승홍 연구공동체 건강과대안 2016 의료와사회 Vol.- No.3

Bioactive Compounds Extracted from Gamtae (Ecklonia cava) by Using Enzymatic Hydrolysis, a Potent α-Glucosidase and α-Amylase Inhibitor, Alleviates Postprandial Hyperglycemia in Diabetic Mice

이승홍,박미화,한지숙,정윤화,김미숙,전유진 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.4

This study was designed to investigate whether the brown alga gamtae (Ecklonia cava) may inhibit α-glucosidase and α-amylase activities, and alleviate postprandial hyperglycemia in streptozotocin-induced diabetic mice. For that purpose, we prepared an enzymatic hydrolysate from gamtae (EHG) by using the carbohydrase, Celluclast. EHG evidenced prominent inhibitory effect against α-glucosidase and α-amylase. The IC50 values of EHG against α-glucosidase and α-amylase were 0.62 and 0.59mg/mL, respectively, which evidenced the higher activities than that of acarbose. EHG did not exert any cytotoxic effect in human umbilical vein endothelial cells (HUVECs)at various concentrations (from 0.25 to 2 mg/mL). The increase of postprandial blood glucose levels were significantly suppressed in the EHG administered group than those in the streptozotocin-induced diabetic or normal mice. Moreover, the area under curve (AUC) was significantly reduced via EHG administration (6,102 vs. 10,425 mg·min/dL) in the diabetic mice as well as it delays absorption of dietary carbohydrates. These result indicated that EHG might be a potent inhibitor for α-glucosidase and α-amylase.

Antidiabetogenic and Antioxidative Effects of Octaphlorethol A Isolated from the Brown Algae Ishige foliacea in Streptozotocininduced Diabetic Mice

이승홍,강나래,김은아,허수진,문상호,전병태,전유진 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.4

The antidiabetogenic and antioxidative effectsof octaphlorethol A (OPA) isolated from the brown algaeIshige foliacea in streptozotocin (STZ)-induced diabeticmice were analyzed. STZ-induced diabetic mice showed asignificant (p<0.05) increase in blood glucose and lipidperoxidation levels and a significant (p<0.05) decrease inthe plasma insulin level and body weight, compared withcontrols. Diabetic mice also showed a significant (p<0.05)decrease in the activities of the antioxidant enzymes catalase(CAT), superoxide dismutase (SOD), and glutathioneperoxidase (GSH-px), compared with controls. Oral treatmentwith OPA (5 and 10 mg/kg) showed protective effectsagainst all the biochemical parameters studied. OPA-treatedmice exhibited suppression of apoptosis, and treatment withOPA was associated with an increase in antiapoptotic BclxLexpression and a reduction in pro-apoptotic Bax andcleaved caspase-3 expressions. OPA has antidiabetogenicand antioxidative effects, and potential for use in therapiesas both

Antioxidative Effect of Ecklonia cava Dried by Far Infrared Radiation Drying

이승홍,고석천,강성명,차선희,Gin-Nae Ahn,You-Jin Jeon,Byung-Hyun Um 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.1

Far infrared radiation drying (FIRD) of Ecklonia cava was tried in order to reduce drying time and save money in an industrial processing of wet seaweeds. FIRD was carried out at temperature range of 40-80℃ with the examination of antioxidant activities as compared to freeze drying (FD). FIRD showed the shorter drying times and higher polyphenolic contents than FD. Most FIRD extracts had IC50 values than FD extracts. Among them, absolute methanolic extract (ME) from E. cava dried by FIRD at 40℃(FIRD40-ME) possessed the highest radical scavenging activity. Moreover, FIRD40-ME enhanced cell viability and H2O2 scavenging activity in Vero cell. Thus, FIRD40-ME was separated by high performance liquid chromatography (HPLC) and radical scavenging activities of the separated compounds were directly evaluated by on-line coupled ABTS·+ radical scavenging detection system. From the result, it was found that dieckol was the major antioxidant compound. These results illustrate that antioxidant activity of FIRD were more effective than FD and industrial application of FIRD process can be useful in seaweeds.

Cellular activities and docking studies of eckol isolated from Ecklonia cava (Laminariales, Phaeophyceae) as potential tyrosinase inhibitor

이승홍,Sung-Myung Kang,Chang Hyun Sok,홍진태,오재영,You-Jin Jeon 한국조류학회I 2015 ALGAE Vol.30 No.2

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 α-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, -115.84 kcal 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.

원형 실린더 주위의 공기로 국소 대류 열전달에 대한 열전도의 영향

이승홍,이억수 대한설비공학회 1998 설비공학 논문집 Vol.10 No.4

This paper considers the influence of circumferential wall heat conduction for the case of forced convection around a circular cylinder in cross flow of air. Keeping uniform heat generation from the inner surface of the cylinder in radial direction, heat is transferred by wall conduction in the circumferential direction due to the asymmetric nature of the temperature distribution of the cylinder and by convection around the perimeter of the cylinder. The wall conduction depends on conductivity of the cylinder and size of the cylinder radius and thickness and affects the local convective heat transfer rate significantly for geometrically similar surfaces and flow conditions. A nondimensional conjugation parameter K. (=k$_t$R/k$_w$b) has been used to characterize the effect of the circumferntial wall heat conduction. The small values of conjugation parameter K are found to be associated with large effect of wall conduction on the local convective heat transfer rate.