• Journal of Nutrition and Health
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• v.56 no.2
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• pp.123-139
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• 2023

Purpose: This study was conducted to establish whether an ethanol extract of Lycium barbarum leaves (LLE) and an ethanol extract of Lycium barbarum leaves from which chlorophyll has been removed, denoted as LLE(Ch^-), have a protective effect against hepatic fat accumulation. Methods: The inhibitory effects of LLE and LLE(Ch^-) on liver fat accumulation were examined in C57BL/6 mice with non-alcoholic fatty liver disease (NAFLD) induced by an methionine and choline deficient diet and in HepG2 cells with palmitic acid-induced fat accumulation. Results: The plasma triglyceride, aspartate aminotransferase, and alanine aminotransferase levels were lower in the LLE(Ch^-) group, whereas the plasma ALT activity decreased significantly in the LLE group. In both the LLE and the LLE(Ch^-) groups, the triglyceride and cholesterol contents in the hepatic tissue were significantly reduced. A greater inhibitory effect on tissue fat accumulation was observed in the LLE(Ch^-) group than in the LLE group. In HepG2 cells, LLE and LLE(Ch^-) were non-toxic up to a concentration of 1,000 ㎍/mL. Compared to the control group, intracellular fat accumulation in the LLE and LLE(Ch^-) groups were significantly reduced at concentrations of 200 ㎍/mL and 500 ㎍/mL, respectively. The expression of phosphorylated adenosine monophosphate-activated protein kinase and phosphorylated acetyl-CoA carboxylase in both LLE groups increased at the concentrations of 100 ㎍/mL and 500 ㎍/mL. The fatty acid synthase expression was suppressed in a concentration-dependent manner at 10 ㎍/mL. Conclusion: The examined two ethanol extracts of LLE inhibit hepatic fat accumulation in NAFLD. This effect was more pronounced in the LLE(Ch^-) group. Therefore, these 2 extracts have an anti-steatosis effect and can be used for NAFLD treatment.

• Fisheries and Aquatic Sciences
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• v.25 no.11
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• pp.579-586
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• 2022

Research on the potential biological activity of red alga Symphyocladia spp. has been limited to Symphyocladia latiuscula, which is widely used as a food ingredient in Korea. Here, we examined the biological activity of another species, Symphyocladia linearis, which is found in Korea and was reported as a new species in 2013. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antibacterial properties of a 70% ethanol extract of S. linearis. Antioxidant activity, which was evaluated using radical scavenging assays, revealed half maximal inhibitory concentration values for 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) of 34.57 and 11.70 ㎍/mL algal extract, respectively. Anti-inflammatory activity of the S. linearis ethanolic extract was evaluated using RAW 264.7 cells by measuring the inhibition of lipopolysaccharide-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. The potential cytotoxicity of NO and PGE₂ was first examined, confirming no toxicity at concentrations ranging from 10-100 ㎍/mL. NO production was inhibited 61.1% and 78.0% at 50 and 100 ㎍/mL S. linearis extract, respectively; and PGE₂ production was inhibited 69.1%, 83.2%, and 94.8% at 25, 50, and 100 ㎍/mL S. linearis extract, respectively. Thus, the S. linearis extract showed very strong efficacy against PGE₂ production. The cellular production of reactive oxygen species, measured using 2',7'-dichlorofluorescin diacetate fluorescence, was inhibited 48.8% by the addition of 100 ㎍/mL S. linearis extract. Antibacterial activity was evaluated using the disc diffusion method and minimum inhibitory concentration (MIC). S. linearis was effective only against gram-positive bacteria, exhibiting antibacterial activity against Staphylococcus aureus with a MIC of 256 ㎍/mL extract and against Bacillus cereus with a MIC of 1,024 ㎍/mL extract. Based on these results, we infer that a 70% ethanolic extract of S. linearis possesses strong anti-inflammatory properties, and therefore has the potential to be used in the prevention and treatment of inflammatory and immune diseases.

• Fisheries and Aquatic Sciences
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• v.26 no.8
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• pp.500-513
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• 2023

The effects of prolonged photoperiod (additional night lighting) were investigated on the production of Ocimum basilicum (lemon basil) and fish/crayfish raised in a nutrient film technique aquaponic system. Hybrid lemon fin barb and red claw crayfish juveniles were co-cultured with O. basilicum and subjected to 12 h of ambient natural daylight and additional 0, 4, 8, and 12 h of night lighting for 14 weeks (two batches of 7 weeks each). The water quality parameters and the performance characteristics of the fish/crayfish/plant were evaluated, and the nutri- ent uptake (nitrogen, phosphorus, and potassium) in the system by the three organisms was also measured. The fish growth performance showed no significant differences (p > 0.05) in all the growth parameters measured across the treatments. The body proximate and nitrogen, phosphate, and potassium (NPK) composition of the fish and crayfish were not significantly (p > 0.05) different across the treatments. Similarly, there was no significant difference (p > 0.05) in the NPK uptake by the fish and crayfish across the treatments. The plant growth performance showed that there were no significant (p > 0.05) differences in the plant growth parameters measured, except for % plant height gained in the 12 h-light treatment (403.2 ± 26.0%) which was significantly (p < 0.05) higher than other treatments and cycles. Hence, this study demonstrat- ed that varying supplementary night lighting has no significant effect on the growth performance of O. basilicum, hybrid lemon fin barb, and red claw crayfish. This study, therefore, suggests that supplementary night lighting should not be considered for O. basilicum production as it does not significantly improve the performance characteristics of the plant nor the fish co-cultured with it in a polyculture aquaponic system.

• Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.105-116
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• 2023

Improved fish post-harvest technologies (IFPT) have been promoted as more efficient methods of fish processing, preservation, and value addition than the traditional methods prevalent in developing countries. The adoption rates, however, do not appear to be convincing. The purpose of this study was to determine the socio-demographic and psychological factors that influence intention of Kenyan farmed fish traders to use IFPT. The technology acceptance model (TAM) was used to properly explain the impact of TAM constructs such as perceived usefulness (PU), perceived ease of use (PEOU), and attitude (ATT), as well as socio-demographic factors such as gender, age, education level and fish trading experience on traders' intention to use the technologies. A cross-sectional survey was conducted to collect data using a semi-structured questionnaire from 146 traders in Busia, Siaya and Kakamega counties. At a significance level of p = 0.05, a linear regression model was used to examine the socio-demographic and psychological determinants of the traders' behavioral intention to use the improved technologies. The regression analysis revealed that PU (β = 0.443; p = 0.000), PEOU (β = 0.364; p = 0.000) and ATT (β = 0.615; p = 0.000) influence traders' intention to use IFPT, with ATT having the highest influence on intention. However, the traders' socio-demographic characteristics have no effect on their intention to use the technologies, as the coefficients for gender (β = 0.148; p = 0.096), age (β = 0.016; p = 0.882), level of education (β = -0.135; p = 0.141) and fish trading experience (β = 0.017; p = 0.869) are all insignificant. These findings show that the traders intend to use IFPT and will use them when it is in their best economic interests.

• Fisheries and Aquatic Sciences
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• v.25 no.12
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• pp.626-636
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• 2022

Shellfish are exoskeleton-bearing aquatic invertebrates that consume various organic and inorganic substances floating in seawater through filter feeding. Heavy metals are known as absorbed and accumulated in seawater. Some of the toxic heavy metals are highly accumulated in seawater, and exposure to them can cause a variety of risks to the human body. Since Koreans like to eat seafood, they are more likely to be exposed to contaminated seafood with heavy metals. In this study, nine types of heavy metals were analyzed on ten different shellfish species in the coastal area of South Korea. The risk assessment was also done on shellfish in which heavy metals were detected. Zinc (Zn) and copper (Cu) were identified at an average of 56.7 mg/kg (6.70 to 466 mg/kg) and 13.2 mg/kg (0.064 to 143 mg/kg), respectively. Lead (Pb) average of 0.208 mg/kg (0.000750 to 1.02 mg/kg), cadmium (Cd) average of 0.454 mg/kg (0.0388 to 1.56 mg/kg) and mercury (Hg) average of 0.0266 mg/kg (0.00548 to 0.174 mg/kg) were identified. Additionally, arsenic (As), chromium (Cr), nickel (Ni), and silver (Ag) were also identified as average concentrations of 4.02 (0.460 to 15.0 mg/kg), 0.167 (< limit of quantification [LOQ] to 0.820 mg/kg), 0.281 (< LOQ to 1.46 mg/kg), and 0.158 mg/kg (< LOQ to 1.15 mg/kg). The result indicates that the monitoring results of heavy metals in most shellfish satisfied the Korean standard. However, Pb and Cd have exceeded some foreign standards, such as the United States and the EU. The permissible human exposure calculated using the heavy metal intake and detection amount was lower than the Joint FAO/WHO Expert Committee on Food Additives human safety standard, and the risk of heavy metals from shellfish consumption was at an acceptable level.

• Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.204-215
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• 2023

The thermolabile haemolysin (tlh) of Vibrio parahaemolyticus (Vptlh) from V. parahaemolyticus is a multiple-function enzyme, initially describes as a haemolytic factor activated by lecithin and phospholipase A2 enzymatic activity (Shinoda, 1991; Vazquez-Morado, 2021; Yanagase et al., 1970). Until now, the tlh structure has hypothesized including N-terminal and C-terminal domain, but what domain of the Vptlh structure does the haemolytic activity has not been refined yet. In this study, a 450-bp VpTLH nucleotide sequence of the entire Vptlh gene encoded the C-terminal domain cloned firstly to examine its responsibility in the activity of the Vptlh. The C-terminal domain fused with a 6-His-tag named the His-tag-VpC-terminal domain was expressed successfully in soluble form in the BL21 (DE3) PlysS cell. Remarkably, both expression and purification results confirmed a high agreement in the molecular weight of the His-tag-VpC-terminal domain was 47 kDa. This work showed the His-tag-VpC-terminal domain lysed the erythrocyte membranes in the blood agar and the phosphate buffered saline (0.9%) media without adding the lecithin substrate of the phospholipase enzyme. Haemolysis occurred at all tested diluted concentrations of His-tag-VpC-terminal domain (p < 0.05), providing evidence for the independent haemolytic activity of the His-tag-VpC-terminal domain. The content of 100 ㎍ of the His-tag-VpC-terminal domain brought the highest haemolytic activity of 80% compared to that in the three remaining contents. Significantly, the His-tag-VpC-terminal domain demonstrated not to involve the phospholipase activity in Luria-Bertani agar supplemented with 1% (vol/vol) egg yolk emulsion. All results proved the vital responsibility of the His-tag-VpC-terminal domain in causing the haemolytic activity without the required activation by the phospholipase enzyme. Raw extracts of Phellinus igniarus and Phellinus pipi at 10^-1 mg/mL inhibited the haemolytic activity of the His-tag-VpC-terminal domain from 67.7% to 87.42%, respectively. Hence applying the His-tag-VpC-terminal domain as a simple biological material to evaluate quickly potential derivatives against the Vptlh in vivo conditions will accessible and more advantageous than using the whole of the Vptlh.

• The Korea Journal of Herbology
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• v.37 no.2
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• pp.1-11
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• 2022

Objectives : Although the anti-obesity effect of Schizandrae Fructus water extract has been demonstrated, its underlying mechanism is still unclear. Therefore, we aimed to evaluate the anti-obesity effect of Schizandrae Fructus water extract through the p-AMP-activated protein kinase (p-AMPK), sirtuin1 (Sirt1), and peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) signaling in 60% high-fat diet (HFD)-induced obese mouse model. Methods : Male C57BL/6 mice were divided into four groups. The Normal group was fed a normal diet and the obese groups were fed 60% HFD. Except for the Control group, the GG group was supplemented with 0.5% Garcinia gummigutta and the SCW group was supplemented with 0.5% Schizandrae Fructus water extract. After 6 weeks, obesity-related biomarkers in serum were measured and the expressions of protein for lipid-related factors in liver tissue were analyzed by western blot. Results : Treatment with SCW significantly down-regulated body weight compared to the Control group. SCW down-regulated levels of triglyceride and total cholesterol in serum and significantly increased p-AMPK, Sirt1, and PGC-1α in liver tissue. In addition, the expressions of fatty acid oxidation-related proteins such as peroxisome proliferator-activated receptor α (PPARα), carnitine palmitoyltransferase 1A (CPT-1A), uncoupling protein 1 (UCP1), and uncoupling protein 3 (UCP3) were significantly up-regulated. However, fatty acid synthesis-related proteins including sterol regulatory element-binding protein-1 (SREBP-1), phospho-Acetyl-CoA Carboxylase (p-ACC), and fatty acid synthase (FAS) were significantly down-regulated. Conclusions : Taken together, SCW treatment showed anti-obesity effect by regulating both fatty acid oxidation-related and fatty acid synthesis-related proteins through AMPK/Sirt1/PGC-1α signaling in 60% HFD-induced obese mice.

• Fisheries and Aquatic Sciences
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• v.26 no.9
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• pp.558-568
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• 2023

Vibrio vulnificus is an aquatic bacterium causing septicemia and wound infection in humans. To understand this pathogen at the genomic level, it was performed whole genome sequencing of a cefoxitin-resistant strain, V. vulnificus 1908-10 possessing virulence-related genes (vvhA, viuB, and vcgC) isolated from Gadeok island coastal seawater in South Korea. The genome of V. vulnificus 1908-10 consisted of two circular contigs and no plasmid. The total genome size was estimated to be 5,018,425 bp with a guanine-cytosine (GC) content of 46.9%. We found 119 tRNA and 34 rRNA genes respectively in the genome, along with 4,352 predicted protein sequences. Virulence factor (VF) analysis further revealed that V. vulnificus 1908-10 possess various virulence genes in classes of adherence, antiphagocytosis, chemotaxis and motility, iron uptake, quorum sensing, secretion system, and toxin. In the comparison of the presence/absence of virulence genes, V. vulnificus 1908-10 had fur, hlyU, luxS, ompU, pilA, pilF, rtxA, rtxC, and vvhA. Of the 30 V. vulnificus comparative strains, 80% of the C-genotype strains have all of these genes, whereas 40% of the E-genotype strains have all of them. In particular, pilA were identified in 80% of the C-type strains and 40% of the E-type strains, showing more difference than other genes. Therefore, V. vulnificus 1908-10 had similar VF characteristics to those of type C strains. Multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin of V. vulnificus 1908-10 contained 8 A-type repeats (GXXGXXXXXG), 25 B.1-type repeats (TXVGXGXX), 18 B2-type repeats (GGXGXDXXX), and 7 C-type repeats (GGXGXDXXX). The National Center for Biotechnology Information (NCBI) Basic Local Alignment Search Tool (BLAST) showed that the RtxA protein of V. vulnificus 1908-10 had the effector domain in the order of cross-liking domain (ACD)-C58_PaToxP-like domain- α/β hydrolase-C58_PaToxP-like domain.

• Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.145-158
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• 2024

Life history characteristics, habitat landscape, and historical events are believed to have shaped the patterns of genetic variation in many taxa. The bony lip barb, Osteohilus vittatus, represent a potamodromous fish that complete all life cycle in freshwater and is widely distributed in Southeast Asia. It usually lives in small rivers and other freshwater habitats, and movement between habitats for either food or reproduction has been typical. These life history characteristics may promote gene flow, leading to less structured populations. However, many freshwater habitats are fragmented, which restricts gene flow. We investigate how this interplay has shaped patterns of genetic variation and phylogeographic structure within this species in the Sundaland, a biodiversity hotspot with a complex geological history, using mitochondrial cytochrome oxidase I (mtCOI) as a genetic marker. Forty-six mtCOI sequences of 506 bp long were collected from ten localities, eight geographically isolated and two connected. The sequences were used for population genetic and phylogeographic analyses. Our results showed a low genetic diversity within populations but high between populations. There was a deep phylogeographic structure among geographically isolated populations but a lack of such structure in the connected habitats. Among geographically isolated populations, sequence divergence was revealed, ranging from 1.8% between Java and Sumatra populations to 12.2% between Malaysia and Vietnam. An indication of structuring was also observed among localities that are geographically closer but without connectivity. We conclude that despite high dispersal capacity, the joint effects of historical events, long-term geographic isolation associated with sea level oscillation during the Pleistocene, and restricted gene flow related to lack of habitat connectivity have shaped the phylogeographic structure within the O. vittatus over the Sundaland.

• Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.180-194
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• 2024

Mass mortalities of mud crab Scylla spp. larvae due to pathogenic Vibrio spp. outbreaks have frequently occurred in hatcheries. To overcome this problem, probiotics containing Bacillus subtilis bacteria are applied to inhibit pathogenic ones. We tested different doses of probiotic-containing B. subtilis (10⁸ CFU/g) on the Scylla tranquebarica larvae and investigated the microbiota population, including Vibrio. Water quality, larvae development, and crablet production were also monitored. The recently hatched larvae were grown in twelve conical fiber tanks filled with 200 L sterile seawater, with a salinity of 30 ppt at a stocking density of 80 ind/L. Four different doses of probiotics were applied in the larvae rearing, namely, A = 2.5 mg/L, B = 5 mg/L, C = 7.5 mg/L, and D = 0 mg/L, with three replicates. Next-generation sequencing analysis was used to obtain the abundance of microbes in the whole body of megalopa and the water media for larvae rearing after applying probiotics. Sixteen Raw Deoxyribonucleic Acid samples (eight from a whole body of megalopa extraction from four treatments of probiotics defined as A, B, C, D, and eight from water media extraction from four treatments of probiotic defined as E, F, G, H) were prepared. Then, they were sent to the Genetics Science Laboratory for NGS analysis. Ammonia, nitrite, total organic matter (TOM), larvae, and crablet production were monitored. Based on the Next-generation sequencing analysis data, the Vibrio spp. decreased significantly (p < 0.05) than control test (D) in megalopa-applied probiotics at the doses of 2.5 mg/L (A) and 7.5 mg/L (C) and in the water media for megalopa rearing treated with probiotics at the dosage of 5.0 mg/L (F). Ammonia in the zoea stage in B treatment and TOM in the zoea and megalopa stage in B and C treatments were decreased significantly (p < 0.05). It impacts the higher number of zoea survival in treatments B and C. Finally, it results in a significantly high crablet production in treatments B and C. Therefore, the dosage of 5 mg/L to 7.5 mg/L improves crablet S. tranquebarica production significantly.