• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.261-265
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• 2013

The study was conducted to investigate the responses of the hepatic microsomal cytochrome P450 monooxygenase system in the rock bream Oplegnathus fasciatus after chronic exposure to 0, 1, 2, 4, and $8{\mu}g/L$ tributyltin (TBT) concentrations for 4 weeks. Hepatic cytochrome 450 content and ethoxyresorufin O-deethylation (EROD) activity were found to significantly increase in fish treated with the higher concentration of TBT (${\geq}4{\mu}g/L$); however, no significant changes were observed in penthoxyresorufin O-deethylation (PROD) activity in all treated groups compared to the control group. These findings suggest that exposure to a low TBT concentration (${\geq}4{\mu}g/L$) has the potential to induce cytochrome 450 content and EROD enzyme activity in hepatic tissue in the rock bream.

• Fisheries and Aquatic Sciences
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• 제9권4호
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• pp.175-178
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• 2006

An acidic ent-cyclic peroxide was isolated from a sponge, Plakotis sp., and showed activity against leishmaniasis and pathogenic fungi. To improve the activity of this compound, we coupled the acidic ent-cyclic at the C1 position of ircinol A. Compound 3 exhibited significant activity against Leishmania mexican a and fungi with $IC_{50}$ values of 0.7 and $0.3-34{\mu}g/mL$, respectively. The yield of compound 3 was 98%.

• Fisheries and Aquatic Sciences
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• 제15권3호
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• pp.215-220
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• 2012

The effects of inorganic mercury on hematological parameters and hepatic oxidative stress enzyme activity were studied in olive flounder Paralichthys olivaceus. Fish were injected twice intraperitoneally with mercuric chloride (2, 4, or 8 mg Hg/kg BW). The major hematological findings were significant decreases in the red blood cell count, hematocrit value, and hemoglobin level in olive flounder exposed to 8 mg Hg/kg BW. Remarkably low levels of calcium and chloride, and reduced osmolality, were also observed at 8 mg Hg/kg BW. In hepatic tissue, significant increases in glutathione peroxidase and catalase activity were observed above 4 mg Hg/kg BW Inorganic mercury also increased glutathione S-transferase and glutathione reductase activity at 8 mg Hg/kg BW in hepatic tissue. The present findings suggest that exposure to a low concentration (${\geq}4$ mg Hg/kg BW) of inorganic mercury can cause significant changes in hematological and antioxidant parameters.

• Fisheries and Aquatic Sciences
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• 제25권8호
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• pp.417-428
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• 2022

This study aimed to determine the antibacterial activity and toxicity of methanol and hexane extracts of Halymenia durvillei red seaweed which were found abundantly in Kayangan island, South Sulawesi. The antibacterial activity of the crude extract was tested against five gram-negative bacteria, namely Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, Aeromonas hydrophila, and Vibrio harveyi at a dose of 200 g/disk. Extract toxicity was tested on Artemia salina larvae at concentrations of 1,000, 500, 250, 125, 62.5, and 31.25 ㎍/mL. The results showed that the methanol and hexane extracts of H. durvillei had the highest activity against S. thypi and A. hydrophila, respectively, with inhibition zones of 26.2 mm and 21.0 mm. On the other hand, the two extracts did not show activity against E. coli and P. aeruginosa, respectively. The toxicity of the methanol extract of H. durvillei was twice as high as that of the hexane extract with half-maximal inhibitory concentration of 98.24 and 184.21 ㎍/mL, respectively. Thus, the methanol and hexane extracts of red seaweed H. durvillei have the potential as new antibacterial agents respectively against the pathogenic bacteria S. typhi and A. hydrophila, but also have the opportunity to be developed into antitumor herbal compounds.

• Fisheries and Aquatic Sciences
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• 제25권11호
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• pp.572-578
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• 2022

An organism's physiological processes and behaviors are regulated by neuropeptides and hormone peptides. The first neuropeptide identified from echinoderms is SALMFamide. The two most well-studied SALMFamide neuropeptides are S1 and S2, which possess myoactivity on apical muscle, tube feet, and the cardiac stomach of starfishes. However, neuropeptide candidates identified from SALMFamide's precursor protein sequence have not been investigated. This study aims to compare the bioactivity of SALMFamide neuropeptides from the starfish Asterias rubens using various starfish muscle preparations. In this study, the bioactivity of the L-type SALMFamide neuropeptides from the starfish A. rubens, AYHTGLPFamide (SALMFa-A) and the derivative AYHSALMFamide (SALMFa-B) was investigated. The neuropeptides were applied on Asterias amurensis apical muscle, tube feet, which revealed that the neuropeptides exhibit relaxing activity on apical muscle but no activity on tube feet. The native SALMFa-A peptide had lower relaxing activity on the apical muscle compared to the derivative peptide SALMFa-B. The relaxing activity of two neuropeptides also was compared with those on the apical muscle of Patiria pectinifera, which revealed relaxing activity as well as SALMFamide-S1 and S2 neuropeptides. Moreover, the investigation of SALMFa-A and SALMFa-B peptides' bioactivity on P. pectinifera cardiac stomach muscle also showed slight relaxing activity.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2006년도 제47회 학술심포지움 및 추계국제학술대회
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• pp.113.2-113.2
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• 2006

• Nutrition Research and Practice
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• 제3권3호
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• pp.200-207
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• 2009

This study examined the effects of com gluten (CG) and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet. Eight-month-old male Sprague-Dawley rats (n=40) were fed a high-fat diet (40% calorie as fat) for 4 weeks. They were then randomly divided into four groups and fed the isocaloric diets with different protein sources for 8 weeks. The protein sources were casein (control group), intact CG (CG group), CG hydrolysate A (CGHA group, 30% of protein as peptides and 70% as free amino acids) and CG hydrolysate P (CGHP group, 93% of protein as peptides and 7% as free amino acids). Body weight gain, adipose tissue weights, nitrogen balance, absorptions of energy, protein and fat, lipid profiles in plasma, liver and feces and hepatic activities of camitine palmitoyl transferase (CPT), fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PDH) were assessed. The CGHA diet had the highest amount of BCAAs, especially leucine, and most of them existed as free amino acid forms. The CGHA group showed significant weight reduction and negative nitrogen balance. Protein absorption and apparent protein digestibility in the CGHA group were significantly lower than those in other groups. Adipose tissue weights were the lowest in the CGHA group. Activity of CPT tended to be higher in the CGHA group than in other groups and those of FAS, ME and G6PDH were significantly lower in the CGHA group than in other groups. In conclusion, the CGHA diet which had relatively high amounts of free amino acids and BCAAs, especially leucine, had a weight reduction effect by lowering adipose tissue weight and the activities of FAS, ME and G6PDH in experimental animals, but it seemed to be a negative result induced by lowering protein absorption, increasing urinary nitrogen excretion and protein catabolism.

• Fisheries and Aquatic Sciences
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• 제12권3호
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• pp.194-202
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• 2009

Sulfated fucans are known to have both anti-thrombotic and anti-coagulant activities. In this study, the variation in platelet aggregation and anti-coagulant activities was investigated in vitro with regard to administered dose, molecular weight distribution, sulfate content, and sugar composition in two algal fucoidans from Eisenia bicyclis and Undaria pinnatifida sporophylls (Mekabu). The anti-coagulant activity largely correlated with sulfate content and with molecular weight distribution in a dose-dependent manner. However, both fucoidans demonstrated inhibitory responses to ADP-induced platelet aggregation in dose- and structure-dependent manners that contrasted with the anti-coagulant activity. Neither molecular weight distribution nor sulfate content greatly affected platelet-aggregation inhibition (PA-inhibition) by the fucoidan fractions, whereas anti-coagulant activity was sensitive to these structural factors. Interestingly, an E. bicyclis fucoidan fraction exhibited almost complete PA-inhibition at a treatment dose of 500 mg/mL while retaining weak anti-coagulant activity. In conclusion, these observations suggest that fucoidan may be a useful anti-thrombotic or anti-platelet agent in various arterial thrombotic disorders, including post-vascular intervention with controlled bleeding complications, due to its anti-coagulant modulating activity.

• Fisheries and Aquatic Sciences
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• 제14권2호
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• pp.89-92
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• 2011

We investigated the antioxidant and cholinesterase inhibitory activities of the aqueous extract of rainbow trout Oncorhynchus mykiss. The antioxidant activity of O. mykiss aqueous extract was determined by in vitro peroxynitrite scavenging activity and reducing power assays. The aqueous extract of O. mykiss showed potent peroxynitrite radical scavenging activity ($IC_{50}=0.12{\pm}0.001\;mg/mL$) and reducing power (absorbance=$0.47{\pm}0.001$) at the concentration of 1 mg/mL. The in vitro cholinesterase inhibitory activity of O. mykiss aqueous extract was examined using spectrophotometric analyses of acetyl- and butyrylcholinesterase. The aqueous extract of O. mykiss showed acetylcholinesterase inhibitory activity ($IC_{50}=1.61{\pm}0.13\;mg/mL$), but did not exhibit inhibitory activity against butyrylcholinesterase. These results suggest that O. mykiss possesses antioxidant and acetylcholinesterase inhibitory activities and provide scientific evidence for the health benefits of O. mykiss aqueous extract.

• Fisheries and Aquatic Sciences
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• 제8권1호
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• pp.10-16
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• 2005

Conditions for sufficient and rapid distribution of a cryoprotectant (sorbitol solution) into intact fish muscle (Oncorhynchus mykiss) were studied as changing in the residual Ca2+ ATPase activity during freeze/thaw cycling. Chunks of the fish muscle were immersed in 4 concentrations of sorbitol solutions ($20\%$, $30\%$, $45\%$, and $60\%$) by a shaker mechanism at 5$^${circ}C. Whole immersion samples (W) showed a higher value of the residual Ca2+ ATPase activity than those in the untreated controls (C), except in the treated controls (TC), while less effect of immersion concentration could be found. Comparing the extent of penetration of sorbitol into the surface layer to inner layer of immersed fish chunks, outer portion samples achieved excellent cryoprotection with $100\%$ of the residual ATPase activity values or more. For the inner portion samples, $30\%$ and $45\%$ sorbitol solution treatments indicated a higher ATPase activity than $60\%$ treatment. At high concentrations, mass transfer rates during osmotic dehydration might berapid and it causes faster surface drying by dewatering at surface solute layer. Periodically immersed and relaxed samples, W (5-3-1), led to good cryoprotection effect: W (5-3-1) indicated high residual Ca2+ ATPase activity values and the residual ATPase activity values excess $100\%$ in immersion of $30\%$ and $45\%$ sorbitol solutions.