• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.6
• /
• pp.817-822
• /
• 1998

The biweekly monitoring of paralytic shellfish toxin on wild mussels (Mytilus corsucus) was carried out at Jangmok Bay, near Koje Island from Feb, 1996 to Feb. 1997. Toxicity and toxin composition were monitored by means of the mouse bioassay and HPLC. Paralytic shellfish toxin was detected from 27 March to 27 May and 28 November. This is the first record of paralytic shellfish toxin during autumn in Korean waters. Toxin composition between the two different season was similar and was composed of 5$\~$8 toxin fractions as GTXs STXs and PXs. The major toxin component in affected musssels shifted from GTXs in spring to PXs in autumn.

• Journal of Animal Science and Technology
• /
• v.56 no.1
• /
• pp.3.1-3.7
• /
• 2014

We examined the effects of Prunella vulgaris Labiatae (P. vulgaris L.) on specific and non-specific immune responses of Nile tilapia, Oreochromis niloticus. The optimal concentration without toxicity of P. vulgaris was determined to $30-40{\mu}g/ml$ in vitro and $120{\mu}g$/100 g of fish in vivo. P. vulgaris significantly elicited an antibody titer compared to FCA or ${\beta}$-glucan. ${\beta}$-glucan plus P. vulgaris group synergistically enhanced antibody production. No significant difference in antibody production was observed between P. vulgaris and P. vulgaris plus ${\beta}$-glucan group. A respiratory burst activity of head kidney (HK) leucocytes of tilapia administered with 300 or $500{\mu}g$ P. vulgaris was significantly (p < 0.05) enhanced compared with the PBS-injected control group and FCA-treated group. Maximum increase in the NBT reduction value was observed in $500{\mu}g$ P. vulgaris group but no significant difference was found between 300 and $500{\mu}g$ P. vulgaris group. The level of serum lysozyme activity was significantly (p < 0.05) higher in the 300 and $500{\mu}g$ P. vulgaris than $100{\mu}g$ P. vulgaris and FCA group. The phagocytic activities of HK leucocytes from tilapia administered with 300 and $500{\mu}g$ P. vulgaris were significantly (p < 0.05) higher than $100{\mu}g$ P. vulgaris and the control group. P. vulgaris was revealed with a good immunoadjuvant evoking the specific and non-specific immune responses of tilapia.

• Fisheries and Aquatic Sciences
• /
• v.21 no.6
• /
• pp.16.1-16.7
• /
• 2018

Background: Matrix metalloproteinases (MMPs) are linked with several complications such as metastasis of cancer progression, oxidative stress, and hepatic fibrosis. Brown seaweeds are being extensively studied for their bioactive molecule content against cancer progression. In this context, Sargassum horneri was reported to possess various bioactivities including antiviral, antimicrobial, and anti-inflammatory partly due to its phenolic compound content. Methods: In this study, potential of S. horneri was evaluated through anti-MMP effect in HT1080 fibrosarcoma cells. S. horneri crude extract was fractionated with organic solvents, namely, water ($H_2O$), n-buthanol (n-BuOH), 85% aqueous methanol (85% aq. MeOH), and n-hexane. The non-toxicity of fraction samples (Sargassum horneri solvent-partitioned extracts (SHEs)) was confirmed by cell-viability assay. SHEs were tested for their ability to inhibit MMP enzymatic activity through gelatin digestion evaluation and cell migration assay. Expressions of MMP-2 and MMP-9 and tissue inhibitors of MMP (TIMPs) were evaluated by reverse transcription and Western blotting. Results: All fractions inhibited the enzymatic activities of MMP-2 and MMP-9 according to gelatin zymography. Except $H_2O$ fraction, fractions hindered the cell migration significantly. All tested fractions suppressed both mRNA and protein levels of MMP-2, MMP-9, TIMP-1, and TIMP-2. Conclusion: Overall, current results suggested that S. horneri has potential to be a good source for anti-MMP agents, and further investigations are underway for better understanding of the action mechanism and isolation and elucidation of the bioactive molecules.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.1
• /
• pp.15-22
• /
• 2018

Alpha-pinene is an organic compound that possesses antibiotic and anti-parasitic activities. In this study, we developed a layered nanocomposite to combat against Miamiensis avidus which causes scuticociliatosis in the olive flounder Paralichthys olivaceus. We used a solid-solid reaction to develop the layered nanocomposite, incorporating-pinene ($C_{10}H_{16}$) into organically modified montmorillonite. We used cetyltrimethylammonium cations as the interlayered modifier for the adsorption of hydrophobic pinene molecules. The X-ray diffraction patterns of the nanocomposite structure showed that the basal spacing increased from $9.6{\AA}$ to $30.4{\AA}$. Interestingly, the fraction of ${\alpha}$-pinene released remained constant for a long period of time (228 h) due to the layered nature of the nanocomposite. Additionally, optical microscopic images of the treated scuticociliatids revealed that their cells were lysed, and this effect increased with the increasing concertration of ${\alpha}$-pinene. Histopathological assessment of ${\alpha}$-pinene nanocomposite-treated olive flounder gills revealed no significant morphological changes, even at the highest concentration of the ${\alpha}$-pinene. The nanocomposite has several advantages, including easy handling, high solubility, low toxicity, and the easy formulation of granules or powder, which improve the pesticidal activity of ${\alpha}$-pinene. Collectively, our results suggest that ${\alpha}$-pinene nanocomposite may be a useful treatment against scuticociliatosis.

• Journal of Korean Society on Water Environment
• /
• v.22 no.5
• /
• pp.796-804
• /
• 2006

The objective of this research was to develop ecological multi-metric models using natural fish assemblages for a diagnosis of current stream health condition, and apply the model to nationwide lotic ecosystems of the Geum River, the Youngsan River, and the Sumjin River. The ecological stream health model was based on the index of biological integrity (IBI), which was originally developed in North American streams by Karr (1981), and the Rapid Bioassessment Protocol (RBP), which was scientifically established by the US EPA (1999). The metric numbers and metric attributes were partially changed for the regional applications, so the scoring criteria was modified for the assessment. Overall, metric values, based on the IBI calculations, reflected conventional water quality characteristics, based on nutrient regime, and agreed with results of staticeco-toxicity tests. Some stations impaired in terms of stream health were identified by the IBI approach, and also major key stressors affecting the stream health were identified by additional evaluations of physical habitats. Our preliminary results suggested that biological integrity in stream ecosystems was largely disturbed by habitat degradation as well as chemical pollutions. This new approach would be used as a key tool for ecological restorations and species conservations in the degraded aquatic ecosystems in Korea and applied for elucidating major causes of ecological disturbances. Ultimately, this approach provides us an effective management strategy of stream ecosystems through establishments of ecological networks in various watersheds.

• Fisheries and Aquatic Sciences
• /
• v.12 no.1
• /
• pp.29-34
• /
• 2009

Fifty seven species of common seaweed from the coast of Korea were screened for antifungal activity against Malassezia species. Seaweeds as a source of bioactive compounds are able to produce a great variety of secondary metabolites with different activities. There are numerous reports on the biological activities of seaweeds against human pathogens, fungi, and yeasts, but only few contain data regarding inhibitory effects against Malassezia sp., a major cause of dandruff and seborrheic dermatitis. To help address this paucity of information, this work was carried out to examine the antifungal effects of seaweed extracts against M. furfur and M. restricta. Of the fifty seven species of marine algae screened for their potential antifungal activity, only 17 species (29.8%) exhibited inhibitory activity. In agar disc diffusion method, the ether extracts of Corallina pilulifera, Enteromorpha linza, Laminaria japonica, Symphyocladia latiuscula and Ulva sp. showed strong antifungal activity. To identify major constituents in seaweed extracts, four selected extracts were analyzed on' a GC-MS equipped with a flame ionization detector, and compared to spectral data from databases WILEY229.LIB and NIST107.LIB. Most constituents in seaweed extracts are fatty acid-related compounds. When we evaluated any acute toxicity, the ether extracts of the selected four species were not toxic in mice. According to these results, it can be suggested that these seaweed extracts are valuable for the development of therapeutic agents in treating dandruff and seborrheic dermatitis. Further investigations to determine its bioactive compound(s) are currently in progress.

• Fisheries and Aquatic Sciences
• /
• v.16 no.3
• /
• pp.159-164
• /
• 2013

The mouse bioassay and high performance liquid chromatography (HPLC) post-column oxidation method are different methods of quantifying paralytic shellfish poisoning toxins. In this study, we compared their ability to accurately quantify the toxicity levels in two types of field sample (oysters and mussels) with different toxin profiles for routine regulatory monitoring. A total of 72 samples were analyzed by both methods, 44 of which gave negative results, with readings under the limit of detection of the mouse bioassay ($40{\mu}g/100g$ saxitoxin [STX] eq). In 14 oysters, the major toxin components were gonyautoxin (GTX) 1, -2, -3, -4, -5, decarbamoylgonyautoxin-2 (dcGTX2), and decarbamoylsaxitoxin (dcSTX), while 14 mussels tested positive for dcSTX, GTX2, -3, -4, -5, dcGTX2, neosaxitoxin (NEO), STX, and dcSTX. When the results obtained by both methods were compared in two matrices, a better correlation ($r^2=0.9478$) was obtained for mussels than for oysters ($r^2=0.8244$). Additional studies are therefore needed in oysters to investigate the differences in the results obtained by both methods. Importantly, some samples with toxin levels around the legal limit gave inconsistent results using HPLC-based techniques, which could have a strong economic impact due to enforced harvest area closure. It should therefore be determined if all paralytic shellfish poisoning toxins can be quantified accurately by HPLC, and if the uncertainties of the method lead to doubts regarding regulatory limits.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.6
• /
• pp.606-613
• /
• 2003

This study investigated the effects of food type (condensed freshwater Chlorella, dried Chlorella, dried Spirulina, dried Schizochytrium, baker's yeast and $\omega-yeast$) and amount, and supplementation of vitamin $B_{12}$ on the growth of freshwater rotifer (Brachionus calyciflorus) in high density culture. Growth of rotifers fed condensed freshwater Chlorella was the highest and its density ranged $7.65-8.14{\times}10^3\;inds./mL.$ The primary lipid acids of rotifers fed condensed freshwater Chloyella were linoleic and linolenic, and their amount ($\%$ of total fatty acids) were $48.8\%\;and\;26.8\%,$ respectively. This suggests that condensed freshwater Chlorella would be an effective diet for high quality and quantity rotifers, which in turn serve as live food for freshwater fish larvae. Growth rate of rotifers with Chlorella supplementation increased as amount of supplementation increased up to 1.5 and 2.5 mg at 28 and $32^{\circ}C$, respectively. However, undissolved ammonia toxicity and packing volume of Chlorella in culture medium, reached the optimal conditions for the stable and effective cultivation of rotifers when amount of condensed freshwater Chlorella was 1.5 mg in dry weight per 1,000 rotifers at $28^{\circ}C\;and\;32^{\circ}C$ Growth of rotifers in condensed freshwater Chlorella with vitamin $B_{12}$ supplementation was significantly higher than that of rotifers without supplementation. However, no significant difference was found among the different concentrations of vitamin $B_{12}.$ Therefore, vitamin $B_{12}$ could improve the growth of rotifers (B. calyciflorus).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.2
• /
• pp.126-140
• /
• 2011

Genetic determinants of two metallothionein isoforms (MT-A and MT-B) were isolated and characterized from the perciform species, rockbream (Oplegnathus fasciatus). Rockbream MT-A and MT-B shared a high degree of homology at amino acid levels with representative orthologs from other perciform species, especially with respect to the conserved cysteine residues. At the genomic level, both MT-A and MT-B genes represent a tripartite structure typical of vertebrate MT genes. However, rockbream MT-B showed unusually large introns (1.2 kb and 0.8 kb for intron I and II, respectively), a phenomenon that has rarely been seen in other vertebrate MT genes. MT-A and MT-B transcripts were ubiquitously detected in a wide array of tissues, wherein brain and eye showed the highest basal expression levels, and the fin exhibited the lowest expression of both isoforms. The basal expression of MT-A in most tissues was significantly higher (ranging from 4- to 10-fold) than that of MT-B. Upon heavy metal exposures to Cd, Cu or Zn at 25 ppb for 48 h, MT-A and MT-B transcripts in the liver were significantly activated by Cd and moderately by Zn. On the other hand, exposure to Cu did not result in alterations of MT-A, nor in the significant suppression of MT-B. Following bacterial challenges with Escherichia coli, Edwardsiella tarda or Streptococcus iniae, MT isoforms in the liver, kidney and spleen were highly modulated and exhibited a pattern that was dependent on the bacterial species, tissues and isoforms. These results suggest that the two MT isoforms could be taken into account as potential indicators of metal toxicity and immune perturbations of this aquaculture-relevant species.

• Advances in environmental research
• /
• v.4 no.1
• /
• pp.39-48
• /
• 2015

Bisphenol A is widely used in plastic and other industrial consumer products. Release of bisphenol A and its analogues into the aquatic environment during manufacture, use and disposal has been a great scientific and public concern due to their toxicity and endocrine disrupting effects on aquatic wildlife and even human beings. More recent studies have shown that these alkylphenols may affect the molting processes and survival of crustacean species such as American lobster, crab and shrimp. In this study, we have developed gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometric (GC-MS) methods for the determination of bisphenol A and its analogues in shrimp Macrobrachium rosenbergii, blue crab Callinectes sapidus and American lobster Homarus americanus samples. Bisphenol A, 2,4-bis-(dimethylbenzyl)phenol and 4-cumylphenol were found in shrimp in the concentration ranges of 0.67-5.51, 0.36-1.61, and < LOD (the limit of detection)-1.96 ng/g (wet weight), and in crab of 0.10-0.44, 0.13-0.62, and 0.26-0.58 ng/g (wet weight), respectively. In lobster tissue samples, bisphenol A, 2-t-butyl-4-(dimethylbenzyl)phenol, 2,6-bis-(t-butyl)-4-(dimethylbenzyl)phenol, 2,4-bis-(dimethybenzyl)phenol, 2,4-bis-(dimethylbenzyl)-6-t-butylphenol and 4-cumylphenol were determined at the concentration ranges of 4.48-7.01, 1.23-2.63, 2.71-9.10, 0.35-0.91, 0.64-3.25, and 0.44-1.00 ng/g (wet weight), respectively. At these concentration levels, BPA and its analogs may interfere the reproduction and development of crustaceans, such as larval survival, molting, metamorphosis and shell hardening.