• 제목/요약/키워드: FAS Activity

검색결과 307건 처리시간 0.022초

The Effects of Acute Osmotic Stress on Innate Immunity of Nile Tilapia (Oreochromis niloticus)

  • Choi, Sang-Hoon;Park, Kwan-Ha
    • Fisheries and Aquatic Sciences
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    • 제13권4호
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    • pp.343-349
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    • 2010
  • The effects of osmotic stress on the non-specific immune response of Nile tilapia, Oreochromis niloticus, were investigated. Osmoregulatory mechanism of tilapia has been studied, but less information is available about innate immune response of O. niloticus faced with hyperosmolality. Acute osmotic stress was elicited by transferring tilapia from freshwater (FW) to 24 psu seawater (SW). Non-specific immune parameters including lysozyme activities of plasma and head kidney (HK), alternative complement pathway (ACP) activity in plasma, phagocytic capacities of spleen and HK immune cells, and respiratory burst activity of immune cells in both HK and spleen were analyzed. Lysozyme activities were increased at 1 h and 30 h after transfer to SW, but decreased at 10 h after SW transfer. Conversely, ACP activity increased 10 h after SW transfer. Phagocytic capacity increased slightly at 1 h and 5 h after SW transfer, and respiratory burst activity showed an increase in superoxide release at 10 h after SW transfer. Taken together, these results indicate that the exposure of tilapia to hyperosmotic conditions has immunostimulatory effects on cellular and humoral immune reactions.

Antibacterial Activity of an Ethyl Acetate Extract of Pseudomonas sp. UJ-6 against Methicillin-Resistant Staphylococcus aureus

  • Lee, Dae-Sung;Eom, Sung-Hwan;Je, Jae-Young;Kim, Young-Mog;Lee, Myung-Suk;Kim, Young-Man
    • Fisheries and Aquatic Sciences
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    • 제16권2호
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    • pp.79-84
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    • 2013
  • In an effort to discover an alternative antibiotic for treating infections with methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas sp. UJ-6, a marine bacterium that exhibited antibacterial activity against MRSA, was isolated. The culture broth and its ethyl acetate extract exhibited bactericidal activity against MRSA. The extract also exhibited antibacterial activity against gram-negative bacteria, which were not susceptible to vancomycin. The treatment of MRSA with the extract resulted in abnormal cell lysis. The extract retained >95% of its anti-MRSA activity after heat treatment for 15 min at $121^{\circ}C$. Thus, although most antibiotics are unstable under conditions of thermal stress, Pseudomonas sp. UJ-6 produces a heat-stable anti-MRSA substance. The results of this study strongly suggest that Pseudomonas sp. UJ-6 can be used to develop a novel, heat-stable, broad-spectrum antibiotic for the treatment of MRSA infections.

Antioxidant and anti-inflammatory activities of phenolic compounds grafted with hyaluronic aicd derived from Liparis tessellatus eggs

  • Nguyen, Thanh Tri;Choi, Byeong-Dae
    • Fisheries and Aquatic Sciences
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    • 제25권6호
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    • pp.311-319
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    • 2022
  • Hyaluronic acid from Liparis tessellatus eggs (HALTE) was grafted with caffeic acid (CA-g-HALTE), ferulic acid (FA-g-HALTE), gallic acid (GA-g-HALTE), and nisin (Nisin-g-HALTE) and investigated for their anti-inflammatory and antioxidant potential in lipopolysaccharides-stimulated RAW 264.7 mouse macrophages. Nitric oxide (NO) generation and prostaglandin E2 activity were measured after treatment with the grafted HALTE samples. All grafted HALTE samples exhibited more antioxidant activity against 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radicals than 2,2-diphenyl-1-picrylhydrazyl radicals. Nisin-g-HALTE showed the least antioxidant activity. Additionally, the NO assay results showed that all grafted samples had no cytotoxic effect on RAW 264.7 macrophages and reduced macrophage activity after treatment. The most effective concentrations of CA-g-HALTE and FA-g-HALTE were found to be above 100 ㎍/mL. Increased sample concentration resulted in increased activity except with Nisin-gHALTE at 100 ㎍/mL. CA-g-HALTE, FA-g-HALTE, GA-g-HALTE, and Nisin-g-HALTE were found to have antioxidant and anti-inflammatory potential, which can be further explored for use in food, cosmetic, nutraceutical, and biomedical applications.

Hepatoprotective Effects of Gardenia jasminoides Ellis Extract in Nonalcoholic Fatty Liver Disease Induced by a High Fat Diet in C57BL/6 Mice

  • Nam, Mi-Kyung;Choi, Hye-Ran;Cho, Jin-Sook;Cho, Soo-Min;Lee, Young-Ik
    • Natural Product Sciences
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    • 제20권1호
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    • pp.65-70
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    • 2014
  • This study was carried out to investigate the potential effects of Gardenia jasminoides (GJ) extracts, on hepatic steatosis and lipid metabolism in mice fed with high-fat diet (HFD). GJ extracts (100 mg/kg, ${\times}10$ weeks) fed mice showed reduced body weight, adipose tissue weight, reduced aminotransferase level in plasma and hepatic lipid (triglyceride, total cholesterol) content. These effects were accompanied by decreased expression of lipogenic genes, sterol regulatory element binding protein-1c (SREBP-1c), liver X receptor (LXR), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), cluster of differentiation 36 (CD36), lipoprotein lipase (LPL) and decreased lipogenic enzyme FAS and HMG-CoAR enzyme activities while elevating carnitine palmitoyltrasferase-1 (CPT) activity. Based on these results, we speculated that the inhibitory effect on hepatic steatosis of GJ extract containing geniposide is the result of suppression of lipid synthesis in mice fed with HFD, suggesting that GJ extract may be beneficial in preventing hepatic steatosis.

Effects of Diethyl Phthalate on Acetylcholinesterase Activity in Olive Flounder (Paralichthys olivaceus) Following Short-term Exposure

  • Jee Jung-Hoon;Keum Yoo-Hwa;Kang Ju-Chan
    • Fisheries and Aquatic Sciences
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    • 제7권3호
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    • pp.171-173
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    • 2004
  • Activity of acetylcholinesterase (AChE) is well known as a biomarker of exposure to organophosphate compounds in aquatic organisms. However, the effect of diethyl phthalate (DEP), a widely used plasticizer, on the chance of AChE activity is not yet known. Olive flounder (Paralichthys olivaceus) were exposed to DEP 300 and 1,000 mg DEP/kg b.w. through three times of intraperitoneal injection and effects were assessed in AChE activity of brain, muscle, heart and eyes of the exposed fish. AChE activity in various tissues of flounder was inhibited after exposure to DEP as a concentration-dependent manner, especially in brain, muscle and heart. Among tissues examined, heart is supposed to be a major part of body which is seriously damaged by DEP exposure. It indicates that DEP induces toxic effects in various organs (brain, muscle and heart), and changes of AChE activities. Such changed activities of AChE might be a useful biomarker to assess the impacts induced by phthalate esters including DEP.

Antimicrobial Flavonoid, 3,6-Dihydroxyflavone, Have Dual Inhibitory Activity against KAS III and KAS I

  • Lee, Jee-Young;Lee, Eun-Jung;Jeong, Ki-Woong;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • 제32권9호
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    • pp.3219-3222
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    • 2011
  • Three types of ${\beta}$-ketoacyl acyl carrier protein synthase (KAS) are important for overcoming the bacterial resistance problem. Recently, we reported the discovery of a antimicrobial flavonoid, YKAF01 (3,6-dihydroxyflavone), which exhibits antibacterial activity against Gram-positive bacteria through inhibition of ${\beta}$-ketoacyl acyl carrier protein synthase III (KAS III). In this report, we suggested that YKAF01 can be an inhibitor ${\beta}$-ketoacyl acyl carrier protein synthase I (KAS I) with dual inhibitory activity for KAS I as well as KAS III. KAS I is related to the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and can be a good therapeutic target of designing novel antibiotics. We performed docking study of Escherichia coli KAS I (ecKAS I) and YKAF01, and determined their binding model. YKAF01 binds to KAS I with high binding affinity ($2.12{\times}10^6$) and exhibited an antimicrobial activity against the multidrug-resistant E. coli with minimal inhibitory concentration (MIC) value of 512 ${\mu}g$/mL. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

Antimicrobial Activity of Brown Alga Eisenia bicyclis against Methicillin-resistant Staphylococcus aureus

  • Eom, Sung-Hwan;Park, Jae-Hong;Yu, Dae-Ung;Choi, Ji-Il;Choi, Jong-Duck;Lee, Myung-Suk;Kim, Young-Mog
    • 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.

Antifreeze Activity in Temperate Fish from the East Sea, Korea

  • Kim, Hak Jun
    • Fisheries and Aquatic Sciences
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    • 제18권2호
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    • pp.137-142
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    • 2015
  • Antifreeze proteins and glycoproteins [AF(G)Ps] constitute a group of proteins that lower the freezing but not the melting points of aqueous solutions, enabling polar and north-temperate fish to survive in ice-laden environments. However, little is known about antifreeze activity in temperate fish; such work would extend our knowledge on the functions and evolution of AF(G)Ps. In the present study, we screened for antifreeze activity in temperate fish caught off the coast of Jumunjin ($37.89^{\circ}N$), Gangneung, Korea. Thermal hysteresis (TH) and the ability to inhibit ice recrystallization (IR) in blood, liver, and muscle samples from nine fish were examined to assess antifreeze activity. As the East Sea off the coast of Jumunjin is ice-free year round, we thought it most unlikely that the fish would express antifreeze proteins. Surprisingly, the blood of Pleurogrammus azonus and three types of tissue from Gymnocanthus herzensteini, Zoarces gilli and Kareius bicoloratus exhibited measurable TH values together with the ability to trigger characteristic morphological changes in ice crystals. Blood samples from the three species also evidenced ice recrystallization (IR) inhibition. This implies that AF(G)Ps or other antifreeze-like substances are present in temperate fish even under nonfreezing conditions. These results contribute to our understanding of the functions and origins of antifreeze activity in fish.

The Effect of Cryoprotectants on the Properties of Pacific Sand Lance Ammodytes personatus Girard Surimi During Frozen Storage

  • Yoo, Byung-Jin
    • Fisheries and Aquatic Sciences
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    • 제17권3호
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    • pp.291-298
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    • 2014
  • We investigate the effects of cryoprotectant mixtures on the quality of sand lance surimi (SLS) during storage at $-30^{\circ}C$. We monitored freeze-induced denaturation of myofibrillar protein in SLS and examined the texture profile of SLS gel. Freeze-induced denaturation was assessed by evaluating SLS $Ca^{+2}$-ATPase activity. SLS gels prepared with sorbitol or sucrose and a mixture of both as cryoprotectant. Higher concentrations of cryoprotectants resulted in significantly higher residual SLS $Ca^{+2}$-ATPase activity at the same storage time (P < 0.05). Residual $Ca^{2+}$-ATPase activity of SLS prepared with sorbitol was higher than that of sucrose when cryoprotectant concentration and storage period were same. A blend of sorbitol and sucrose resulted in a stronger cryoprptective effect of SLS myofibrillar protein than did sorbitol or sucrose alone. The presence of a phosphate compound in SOP (3% sorbitol + 0.2% phosphate compound) resulted in higher SLS $Ca^{2+}$-ATPase activity than that of did 5% sorbitol. The hardness, brittleness, and elasticity values and a folding test of the SLS gels were significantly affected by cryoprotectant concentrations and the storage time. Preference scores and acceptance for texture in a sensory evaluation of the SLS gels increased with increasing sorbitol or sucrose concentration.

Phaeophyta Extracts Exhibit Antiviral Activity against Feline Calicivirus

  • Choi, Yuri;Kim, Eunjung;Moon, Sunyoung;Choi, Jong-Duck;Lee, Myung-Suk;Kim, Young-Mog
    • Fisheries and Aquatic Sciences
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    • 제17권1호
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    • pp.155-158
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    • 2014
  • The objective of this study was to evaluate the antiviral activity of Phaeophyta extracts against feline calicivirus (FCV), used as a norovirus surrogate. A bioassay-guided cytotoxicity and virus infectivity assay revealed that methanolic extracts of Phaeophyta possessed significant antiviral activity against FCV. Among them, Eisenia bicyclis extract exhibited the highest antiviral activity against FCV. The 50% effective concentration of the extract ($EC_{50}$) inhibiting FCV viral replication by 50% was $80{\mu}g/mL$. The extract also showed the highest selectivity index, calculated from the ratio of the median cellular cytotoxicity concentration ($CC_{50}$) and $EC_{50}$, indicating antiviral efficacy against FCV. In addition, significant interruption of FCV infection was observed by pretreatment of host Crandall-Reese feline kidney cells with the E. bicyclis extract ($200{\mu}g/mL$) prior to virus infection, in a dosedependent manner.