• Korean Journal of Plant Resources
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• v.28 no.2
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• pp.145-152
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• 2015

The present study aimed to investigate comparative anti-inflammatory effects of Litsea japonica fruit and leaf extract considering the balance of safety and efficacy. Dose response studies were performed to determine the inhibitory effects of 70% EtOH extract of leaf (L70%) on the pro-inflammatory enzymes expression, COX-2/PGE2 and NO/iNOS, and pro-inflammatory cytokines production, IL-$1{\beta}$, IL-6, and TNF-$\alpha$ in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. We also examined comparative effects of 30 and 70% EtOH extract of fruits (F30% and F70%) at low concentration ($10{\mu}g/ml$ ) in the same conditions. L70% at 50 and $100{\mu}g/ml$ showed inhibitory effects on almost all the inflammatory mediators we examined except for COX-2 regulation, but there were no effects at $10{\mu}g/ml$. Since $100{\mu}g/ml$ of L70% have 18.2% cytotoxicity, we compared the effects of fruit extract, F30% and F70% at $10{\mu}g/ml$ on the regulation of NO/iNOS, PGE2, IL-$1{\beta}$, IL-6, and TNF-$\alpha$ and obtained that fruit extacts are more efficacious and safe than leaf. This study suggests that the 30% EtOH fraction of L. japonica fruit could be a good candidate for development as a functional food supplement in the prevention of inflammatory disorders.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.1
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• pp.1-7
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• 2001

Total upland area for cultivating the vegetable crops in the Alpine soils of Northeastern South Korea has been extending its limit to meet the increasing demand of vegetable food in recent decades. About 70% of these alpine soils are located in over 7% of the slope and most of vegetable crops have been cultivated intensively without practicing the best management systems. Thus, soil erosion and continuous cropping system have degenerated the soil fertility and shown detrimental effects on water quality. We initiated an intensive and extensive investigation to characterize the fertility problems encountered in these uplands. Objectives of this paper were to characterize the fertility status in the Alpine soils cultivated with vegetable crops for many years and to provide the recommendations for adequate soil management measures including fertilization and erosion control. Soils in general have good drainage with textural classes of loam or sandy loam. Their topographical characteristics tended to lead them to shallow plow layers, and the steepness of the terrain created erosion hazard. Of the soils examined, about 11% of uplands over 30% gradient was found in need of an urgent reforestation. A high content of gravel and firm hardness of soil attributed to inhibit the utilization of farm machinery and plant-root development. The average soil pH 5.6 was slightly low relative to pH 5.70 of the national average. Organic matter content was high compared with 2.0% of national average, but decreased with the prolonged cultivation periods. Available $P_2O_5$ concentration was unusually high due to the consequence of over dose application with chemical and organic fertilizers. Exchangeable cations as Ca, Mg, and K were appeared to be decreased in these regions with prolonging the cultivation periods. There were no significant differences in cation exchange capacity (CEC) and electrical conductivity (EC) among locations. Heavy metal contents were mostly lower than the threshold of danger level designated by Soil Environment Conservation Law of South Korea. Results indicated that a proper countermeasure and the best management practice should be immediately implemented to conserve the top soil and fertility in the Alpine regions.

• Journal of Life Science
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• v.29 no.4
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• pp.410-420
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• 2019

Citrus unshiu peel extracts possess a variety of beneficial effects, and studies on their anticancer activity have been reported. However, the exact mechanisms underlying this activity remain unclear. In the current study, the apoptotic effect of ethanol extract of C. unshiu peel (EECU) on human breast adenocarcinoma MDA-MB-231 cells and related mechanisms were investigated. The results showed that the survival rate of MDA-MB-231 cells treated with EECU was significantly inhibited in a concentration-dependent manner, which was associated with the induction of apoptosis. EECU-induced apoptosis was associated with the activation of caspase-8 and caspase-9, which initiate extrinsic and intrinsic apoptosis pathways, respectively, and caspase-3, a representative effect caspase. EECU suppressed the expression of the inhibitor of apoptosis family of proteins, leading to an increased Bax/Bcl-2 ratio and proteolytic degradation of poly (ADP-ribose) polymerase. EECU also enhanced the loss of the mitochondrial membrane potential and cytochrome c release from the mitochondria to the cytosol, along with truncation of Bid. In addition, EECU activated AMP-activated protein kinase (AMPK), and compound C, an AMPK inhibitor, significantly weakened EECU-induced apoptosis and cell viability reduction. Furthermore, EECU promoted the generation of reactive oxygen species (ROS), which acted as upstream signals for AMPK activation as pretreatment of cells, with the antioxidant N-acetyl cysteine reversing both EECU-induced AMPK activation and apoptosis. Collectively, these findings suggest that EECU inhibits MDA-MB-231 adenocarcinoma cell proliferation by activating intrinsic and extrinsic apoptotic pathways, which was mediated through ROS/AMPK-dependent pathways.

• Journal of Life Science
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• v.28 no.11
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• pp.1301-1315
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• 2018

We purified an antimicrobial peptide from the acidified hemocyte extract of Mytilus coruscus by $C_{18}$ reversed-phase high-performance liquid chromatography (RP-HPLC). The peptide was 4041.866 Da based on matrix-assisted laser desorption ionization time-of-flight mass spectrophotometer (MALDI-TOF/MS) and the 25 amino acids of the N-terminus sequence were identified. Comparison of this sequence of the purified peptide with the N-terminus sequences of other antimicrobial peptides revealed 100% identity with the mytilin B precursor of Mytilus coruscus. We also identified a 312 bp open-reading frame (ORF) encoding 103 amino acids based on the obtained amino acid residues. The nucleotide sequence of this ORF and the amino acid sequence also revealed 100% identity with the mytilin B precursor of Mytilus coruscus. We synthesized two antimicrobial peptides with an alanine residue in the C-terminus, and designated them mytilin B1 and B2. These two antimicrobial peptides showed antimicrobial activity against gram-positive bacteria, including Bacillus cereus and Streptococcus parauberis (minimal effective concentration, MECs $41.6-89.7{\mu}g/ml$), gram-negative bacteria, including Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Providencia stuartii, Pseudomonas aeruginosa, and Vibrio ichthyoenteri (MECs $7.4-39.5{\mu}g/ml$), and the fungus Candida albicans (MECs $26.0-31.8{\mu}g/ml$). This antimicrobial activity was stable under heat and salt conditions. Furthermore, the peptides did not exhibit significant hemolytic activity or cytotoxic effects. These results suggest that mytilin B could be applied as alternative antibiotic agent, and they add to the understanding of the innate immunity of hard-shelled mussels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.331-337
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• 2018

The content of nutrients, proteins, and oils of crop seeds is affected by global climate change due to the increase in temperature. Information regarding the effects of increased temperature on soybean seed nutrition is limited despite its vital role in seed quality and food security. The objective of this study was to determine the effect of increasing temperature on seed nutrient, protein, and oil content in two soybean [Glycine max (L.) Merr] cultivars (Daewonkong and Pungsannamulkong during the reproductive period in a temperature-gradient chamber. Four temperature treatments, Ta (near ambient temperature), $Ta+1^{\circ}C$ (ambient temperature+$1^{\circ}C$), $Ta+2^{\circ}C$ (ambient temperature+$2^{\circ}C$), $Ta+3^{\circ}C$ (ambient temperature+$3^{\circ}C$), and $Ta+4^{\circ}C$ (ambient temperature+$4^{\circ}C$), were established by dividing the rows along the temperature gradient. At maturity, increased temperature did not significantly affect the concentration of P, K, Ca, and Mg. The protein and oil content was significantly correlated with temperature. At maturity, the protein content of DWK and PSNK was reduced at $Ta+4^{\circ}C$. The oil content was the highest at $Ta+4^{\circ}C$ in DWK, whereas it decreased in PSNK at $Ta+4^{\circ}C$. Consequently, the biochemical composition of soybean seeds changed with the increase in temperature. These results illustrate the effects of temperature on soybean seed nutrient, protein, and oil content, which can help improve soybean quality at different temperatures. Thus, the biochemical composition of crop seeds can be changed in accordance with nutritional requirements for the benefit of human health in the future.

• Journal of Life Science
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• v.31 no.8
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• pp.699-709
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• 2021

Muscle mass improvement through lifestyle modification has been shown to reduce the risk of metabolic syndrome. This study examined the capacity of ethanol extracts of Scytosiphon lomentaria (SLE) to suppress the bioactivity of myostatin, a potent negative regulator of skeletal muscle mass, as well as the effect of SLE treatment on metabolic homeostasis in obese zebrafish induced by high feeding. A total of 10 ㎍/ml SLE completely blocked myostatin (1 nM/ml) signaling in the pGL3-(CAGA)₁₂ luciferase assay and suppressed myostatin-induced Smad2 phosphorylation in the Western blot analysis. In the zebrafish larvae analysis, the whole body glucose concentration of the high feeding control (HFC) group was significantly higher than that of the normal feeding control (NFC) group. However, the glucose levels of the high feeding group treated with 12.5 ug SLE and of the high feeding group treated with 18.75 ug SLE were similar to those of the NFC group. The mRNA expression level of the GLUT2 gene of the HFC group was significantly lower than that of the NFC group. SLE treatment restored the expression of the GLUT2 gene to a level that was close to that of the NFC group, indicating that SLE is capable of regulating glucose levels in zebrafish larvae. The current results highlight the potential of SLE as a natural MSTN inhibitor and supplement that can be used to facilitate the treatment of metabolic syndrome.

• Journal of fish pathology
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• v.34 no.1
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• pp.71-80
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• 2021

Cephalexin, a semi-synthetic cephalosporin antibiotic, has long been used in fish aquaculture in various countries under legal authorization. The drug is thus widely available for use in other aquatic species except fishes like the crustacean whiteleg shrimp. This study aims to develop a sensitive method for laboratory residue studies to adopt in withdrawal period determinations. Through repeated trials from the existing methods developed for other food animal tissues, it was possible to achieve a sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. The results showed that at a concentration of 0.1 mg/kg, the recovery rate was 81.79%, and C.V. value was 8.2%, which meet the recovery rate and C.V. recommended by Codex guideline. After satisfactory validation of analytical procedures, applicability to the shrimp tissue was confirmed in experimentally cephalexin-treated whiteleg shrimp. As a result, most muscle samples were detected below the limit of quantification (0.05 mg/kg) after day 3, and most hepatopancreas samples were detected below the limit of quantification after day 14. In particular, the limit of quantification 0.05 ppm with the presently developed method suggests sufficient sensitive over the current legal maximum residue limit of 0.2 mg/kg set for fishes.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.69-79
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• 2020

In this study, the anti-inflammatory and cytotoxic effects of hot-water extracts from 10 kinds of macroalgae in Korea were investigated. It was selected materials in consideration of biological activity and industrial potential as follows: Caulerpa okamurae; Codium fragile; Ulva australis; Ishige foliacea; Saccharina japonica; Sargassum horneri; Undaria pinnatifida; Gloiopeltis tenax; Gracilaria verrucosa; Porphyra tenera. Results showed that S. japonica and G. tenax significantly decreased NO productionn in LPS-stimulated Raw 264.7 cells at concentrations of 100, 1000 ㎍/mL and 1000 ㎍/mL, respectively. However, most of the other macroalgae used in the experiment did not affect NO production. It was observed that all macroalgae extracts except for the highest concentration (1000 ㎍/mL) treatment group of P. tenera did not affect the viability in Raw 264.7 cells. In addition, there was not significant decrease in cell viability by macroalgae extracts treatment in HINAE cells. These results suggest that S. japonica and G. tenax could be used as potential safe natural anti-inflammatory agents for food and feed additives. Also, the results of this study are expected to be used as basic data for the development of functional materials for 10 kinds of macroalgae resources in Korea.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.67-76
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• 2022

This study aimed to determine the photosynthesis and growth characteristics of Peucedanum japonicum T. grown under aquaponics in a plant factory (AP) by comparing those grown under hydroponic cultivation system (HP). The AP system raised 30 fishes at a density of 10.6 kg·m^-3 in a 367.5 L tank, and at HP, nutrient solution was controlled with EC 1.3 dS·m^-1 and pH 6.5. The pH level ranged from 4.0 to 7.1 for the AP system and 4.0 to 7.4 for the HP system. The pH level in the AP began to decrease with an increase in nitrate nitrogen (NO₃-N) and lasted bellower than pH 5.5 for 15-67 DAT. It was found that ammonium nitrogen (NH₄-N) continued to increase even under low pH conditions. EC was maintained at 1.3 to 1.5 dS·m^-1 in both systems. The concentration of major mineral elements in the fish tank was higher than that of the hydroponics, except for K and Mg. There was no significant difference in the photosynthesis characteristics, but the PIABS parameters were 30.4% lower in the AP compared to the HP at the 34DAT and 12.0% lower at the 74DAT. There was no significant difference in the growth characteristics, but the petiole length was 56% longer in the leaf grown under the AP system. While there was no significant difference in the fresh and dry weights of leaf and root, the leaf area ratio was 36.43% higher in the AP system. All the integrated results suggest that aquaponics is a highly-sustainable farming to safely produce food by recycling agricultural by-products, and to produce Peucedanum japonicum as much as hydroponics under a proper fish density and pH level.

• Analytical Science and Technology
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• v.35 no.3
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• pp.136-142
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• 2022

According to media reports, the carcasses of euthanized abandoned dogs were processed at high temperature and pressure to make powder, and then used as feed materials (meat and bone meal), raising the possibility of residuals in the feed of the anesthetic ketamine and dexmedetomidine used for euthanasia. Therefore, a simultaneous analysis method using QuEChERS combined with high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry was developed for rapid residue analysis. The method developed in this study exhibited linearity of 0.999 and higher. Selectivity was evaluated by analyzing blank and spiked samples at the limit of quantification. The MRM chromatograms of blank samples were compared with those of spiked samples with the analyte, and there were no interferences at the respective retention times of ketamine and dexmedetomidine. The detection and quantitation limits of the instrument were 0.6 ㎍/L and 2 ㎍/L, respectively. The limit of quantitation for the method was 10 ㎍/kg. The results of the recovery test on meat and bone meal, meat meal, and pet food showed ketamine in the range of 80.48-98.63 % with less than 5.00 % RSD, and dexmedetomidine in the range of 72.75-93.00 % with less than 4.83 % RSD. As a result of collecting and analyzing six feeds, such as meat and bone meal, prepared at the time the raw material was distributed, 10.8 ㎍/kg of ketamine was detected in one sample of meat and bone meal, while dexmedetomidine was found to have a concentration below the limit of quantitation. It was confirmed that the detected sample was distributed before the safety issue was known, and thereafter, all the meat and bone meal made with the carcasses of euthanized abandoned dogs was recalled and completely discarded. To ensure the safety of the meat and bone meal, 32 samples of the meat and bone meal as well as compound feed were collected, and additional residue investigations were conducted for ketamine and dexmedetomidine. As a result of the analysis, no component was detected. However, through this investigation, it was confirmed that some animal drugs, such as anesthetics, can remain without decomposition even at high temperature and pressure; therefore, there is a need for further investigation of other potentially hazardous substances not controlled in the feed.