• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1263-1269
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• 2013

This study was conducted in order to investigate the inhibitory effects of natural materials on histamine production in mackerel. Antimicrobial activities on Photobacterium phosphoreum of medicinal herbs and seaweeds were investigated using the paper disc assay and MIC (minimum inhibitory concentration) test. According to the results, Sargassum sagamianum and Ecklonia cava ethanol extracts exhibited antibacterial activity. In particular, Sargassum sagamianum ethanol extract showed excellent antibacterial activity at 0.015625 mg/mL by the MIC test. Anti-histamine release activities of natural materials were further investigated by examining their inhibitory effects on histidine decarboxylase (HDC) activity in the crude enzyme preparation from Photobacterium phosphoreum. The ethanol extracts of Ecklonia cava and Eisenia bicyclis exhibited the strongest HDC inhibitory activity, with 32% and 22%, at a concentration of 1 mg/mL, respectively. Therefore, natural materials may reduce histamine poisoning through decrease of histamine production in mackerel.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.379-386
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• 1997

Recombinant plasmid, pBKH4, containing NPT II and P35S-BcHSP17.6 was constructed by ligation of Bum H I -digested pBKSl-l and BcHSP 17.6 (thermotolerance gene) 6om pBLH4. The tobacco leaf disc was cocultivated with transformed Agmbacterium tumefaciens bearing pBKH4 for 24 hours and transformed shoots were selected on MS-n/B medium containing $100\;{\mu\textrm{g}}/ml$ of kanamycin. Heat-killing temperature of Nicotima tabacum was $50^{\circ}$ for >15min, and transformed tobacco plants with BcHSP17.6 cDNA exhibited thermotolerance at the heat-killing temperature. The transgenic plants were analyzed by Southern blot hybridization with the probe of ${\alpha}^{_32}P$ labelled BcHSP17.6 cDNA. Transcription and expression level of BcHSP17.6 cDNA were also continued by Northern blot analysis and Ouchterlony double immunodiffusion assay. In this study, we suggest that the BcHSP17.6 cDNA introduced to tobacco plant is related to thenuoto-lerance and 17.6-kD LMW HSP acts as a protector from heat damage in plants.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.2
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• pp.1-13
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• 2015

Objectives Methicillin-Resistant Staphylococcus aureus (MRSA) is a human pathogen and a major cause of hospital-acquired infections. New antibacterial agents that have not been compromised by bacterial resistance are needed to treat MRSA-related infections. In this study, we investigated the antimicrobial activity ofethanol extract of Haedokgeumhwa-san (HGH) which prescription is composed of korean medicine against MRSA. Methods The antibacterial activity of HGH extract was evaluated against MRSA strains by using the Disc diffusion method, broth microdilution method (minimal inhibitory concentration; MIC), checkerboard dilution test, and time-kill test; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors. The checkerboard dilution test was used to examined synergistic effect of ampicillin, oxacillin, ciprofloxacin, vancomycin, gentamicin and norfloxacin in combination with HGH ethanol extract. A time-kill assay was performed a survival curve which was obtained by plotting viable colony counts depending on time on bacterial growth. Results The minimum inhibitory concentration (MIC) of ethanol extract (HGH) ranged from 1,000 to $2,000{\mu}g/mL$ against all the tested bacterial strains, respectively. We are able to confirm that HGH extract has potentially strong antibacterial activity. In the checkerboard dilution test, fractional inhibitory concentration index of HGH in combination with antibiotics indicated synergy or partial synergism against S. aureus. A time-kill study showed that the growth of the tested bacteria was considerably inhibited after 8 hr of treatment with the combination of HGH with selected antibiotics. For measurement of cell membrane permeability, HGH $250{\sim}1,000{\mu}g/mL$ along with concentration of Triton X-100 (TX) and Tris-(hydroxymethyl) aminomethane (Tris) were used. In the other hand, N,N-dicyclohexylcarbodimide (DCCD) and Sodium azide ($NaN_3$) was used as an inhibitor of ATPase. TX, Tris, DCCD and $NaN_3$ cooperation against S. aureus showed synergistic action. Accordingly, antimicrobial activity of HGH was affected by cell membrane and inhibitor of ATPase. Conclusions These results suggest that Haedokgeumhwa-san extract has antibacterial activity, and that HGH extract offers a potential as a natural antibiotic against MRSA.

• The Korea Journal of Herbology
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• v.31 no.5
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• pp.93-98
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• 2016

Objectives : Hwangheuk-san is a complex prescription composed of oriental traditional medicine and has been reported for antioxidant, antimicrobial and anticancer effects in the recent study. Methicillin-resistant Staphylococcus aureus (MRSA) is one of important causes of fatal infectious diseases such as septicemia, endocarditis, toxic shock syndrome, pneumonia, skin and soft tissue infections (SSTIs). S. aureus is reported as being for a variety of human diseases and its epidemiological relevance is mainly due to their ability of becoming highly resistant to common antimicrobials such as tetracycline, penicillin, cphalosporin and aminoglycoside. The objective of this study is to determine the antimicrobial effect of Hwangheuk-san ethanol extracts (HHS) and synergistic effects with antibiotics oxacillin against MRSA.Methods : The antimicrobial activity of HHS was measured by the disc diffusion method, broth microdilution method and the checkerboard dilution test, time-kill curve assay was performed to investigate synergistic effects with antibiotics oxacillin against MRSA.Results : HHS showed antimicrobial activity against MRSA with a MIC value of 125 ㎍/㎖. In the checkerboard test, the interaction of HHS with antibiotics oxacillin produced almost synergy or partial synergy against MRSA. This study showed that HHS reduced the MICs of oxacillin tested, and a remarkable antibacterial effect of HHS, with membrane permeability enhancers.Conclusions : These results suggest that HHS has the antimicrobial effect and synergistic effects with antibiotics oxacillin against MRSA. This study thus can be a valuable source for the development of a new drug with low MRSA resistance.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.14-14
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• 2010

Vitamin C (ascorbic acid) is an essential component for collagen biosynthesis and also for the proper functioning of the cardiovascular system in humans. Unlike most of the animals, humans lack the ability to synthesize ascorbic acid on their own due to a mutation in the gene encoding the last enzyme of ascorbate biosynthesis. As a result, vitamin C must be obtained from dietary sources like plants. In this study, we have developed two different kinds of transgenic potato plants (Solanumtuberosum L. cv. Taedong Valley) overexpressing strawberry GalUR and mouse GLoase gene under the control of CaMV 35S promoter with increased ascorbic acid levels. Integration of the these genes in the plant genome was confirmed by PCR and Southern blotting. Ascorbic acid(AsA) levels in transgenic tubers were determined by high-performance liquid chromatography(HPLC). The over-expression of these genes resulted in 2-4 folds increase in AsA intransgenic potato and the levels of AsA were positively correlated with increased geneactivity. The transgenic lines with enhanced vitamin C content showed enhanced tolerance to abiotic stresses induced by methyl viologen(MV), NaCl or mannitol as compared to untransformed control plants. The leaf disc senescence assay showed better tolerance in transgenic lines by retaining higher chlorophyll as compared to the untransformed control plants. Present study demonstrated that the over-expression of these gene enhanced the level of AsA in potato tubers and these transgenics performed better under different abiotic stresses as compared to untransformed control. We have also investigated the mechanism of the abiotic stress tolerance upon enhancing the level of the ascorbate in transgenic potato. The transgenic potato plants overexpressing GalUR gene with enhanced accumulation of ascorbate were investigated to analyze the antioxidants activity of enzymes involved in the ascorbate-glutathione cycle and their tolerance mechanism against different abiotic stresses under invitro conditions. Transformed potato tubers subjected to various abiotic stresses induced by methyl viologen, sodium chloride and zinc chloride showed significant increase in the activities of superoxide dismutase(SOD, EC 1.15.1.1), catalase, enzymes of ascorbate-glutathione cycle enzymes such as ascorbate peroxidase(APX, EC 1.11.1.11), dehydroascorbate reductase(DHAR, EC 1.8.5.1), and glutathione reductase(GR, EC 1.8.1.7) as well as the levels of ascorbate, GSH and proline when compared to the untransformed tubers. The increased enzyme activities correlated with their mRNA transcript accumulation in the stressed transgenic tubers. Pronounced differences in redox status were also observed in stressed transgenic potato tubers that showed more tolerance to abiotic stresses when compared to untransformed tubers. From the present study, it is evident that improved to lerance against abiotic stresses in transgenic tubers is due to the increased activity of enzymes involved in the antioxidant system together with enhanced ascorbate accumulated in transformed tubers when compared to untransformed tubers. At moment we also investigating the role of enhanced reduced glutathione level for the maintenance of the methylglyoxal level as it is evident that methylglyoxal is a potent cytotoxic compound produced under the abiotic stress and the maintenance of the methylglyoxal level is important to survive the plant under stress conditions.

• Food Science and Preservation
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• v.21 no.4
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• pp.593-599
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• 2014

This study was conducted to determine the antioxidant potentials of some available plants to source alternate antioxidants and antibiotics. The antioxidant activity was evaluated by determining the antioxidant activity reducing powers and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities of extracts from some local edible native plants. The DPPH radical scavenging activity of the extracts was found to have been 0.41-94.84%. The Elsholtziasplendens NAKAI extract ($85^{\circ}C$, ethanol, accelerated solvent extraction) showed the highest level of antioxidant activity. Eight samples of plant extracts were evaluated for their antimicrobial activities against three microflora (Bacillus subtilis, Escherichia coli, and Candida albicans) using disc diffusion assay. Two samples (Geranium krameri FR. Et SAV. and Cleyera japonica Thunb.) had much more intensive antimicrobial activities than the control. However, their DPPH free radical scavenging activity levels were only 14.50 and 13.85, respectively. It is suggested that they could be used as natural preservatives against bacterial contamination in cosmetics and foods, in place of the common synthetic preservatives currently used.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.443-449
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• 2020

This study was performed to investigate total phenolic contents, anti-oxidant, biological disease-related enzyme inhibitory, and anti-microbial effects of extracts of Lonicera morrowii leaves prepared with water and 40% ethanol. Anti-oxidative activities of the extracts increased in a dose-dependent manner and were very high even at low phenolic concentration. At phenolic concentrations ranging between 50 and 200 ㎍/mL, the water and ethanol extracts inhibited 39.34-76.35 and 47.53-99.83% of xanthine oxidase activity, 30.21-79.06, and 59.40-87.14% of angiotensin converting enzyme activity, and 59.81-80.35 and 36.06-63.58% of α-glucosidase activity, respectively. All inhibitory effect were increased in a dose-dependent manner. In the paper disc agar diffusion assay against seven microbes, L. morrowii extracts had anti-bacteria activities against Helicobacter pylori, Propionibacterium acne but no effect against other bacteria. These results indicate that the extracts from L. morrowii leaves have the possibility to be developed as a physiologically functional source for prevention of adult diseases.

• Journal of Food Hygiene and Safety
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• v.36 no.6
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• pp.520-527
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• 2021

In this study, toxin gene and antibiotic resistance of food poisoning strains isolated from indoor air in the cafeteria were analyzed to prevent food poisoning. Staphylococcus aureus (16 strains) and Bacillus cereus (37 strains) isolated from indoor air in child care center were tested. The toxin genes of S. aureus and B. cereus were detected by PCR assay. The antimicrobial susceptibility test followed the disc diffusion method described by the Clinical and Laboratory Standard Institute. The seg and sei toxin genes were detected in 11 of 16 S. aureus strains (68.6%). The nheA and nheB toxin genes were detected in 37 B. cereus strains. In this study, a total of 12 toxin gene patterns of B. cereus were found, among which the nheA-nheB-nheC toxin gene was found to be the most frequent pattern. The result of the antimicrobial susceptibility test of S. aureus revealed 93.8% and 87.5% resistance to ampicillin and penicillin antibiotics, but methicillin resistance S. aureus and vancomycin resistance S. aureus were not detected. All 37 B. cereus tested in this study were resistant to ampicillin and penicillin antibiotics. Based on the result of this study, it was judged that regular ventilation and air quality management were necessary to prevent food poisoning caused by S. aureus and B. cereus contaminated in the indoor air of child care centers.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.155-159
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• 2010

The antimicrobial activity of Sargassum fulvellum (SF) was investigated using the agar diffusion assay and MIC test. In addition, the stability of this activity under extreme heat and pH conditions was examined. The SF ethanol extract was shown to display strong antimicrobial activities against B. subtilis, C. perfringens, L. plantarum, S. aureus, L. monocytogenes, S. cerevisae and C. tropicalis in the agar diffusion assay at the concentration of 4 mg/mL. The MIC value of the SF ethanol extract against the tested microbes ranged from 0.05 to 0.0063%. In the heat and pH stability test, the antimicrobial activity of the SF ethanol extract was not altered when the temperature was maintained at $121^{\circ}C$ for 15 min, and it was also not affected in the pH range of 2-10. These results suggest that the SF ethanol extract is highly stable against drastic changes in temperature and pH.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.673-680
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• 2009

This study was conducted to screen for plant food materials that improve human intestinal microflora, especially microorganisms associated with obesity. Among 30 tested plant food materials, the extract of Schizandra chinensis inactivated Eubacterium limosum, Bacteroides fragilis and Clostridium spp. Additionally, S. chinensis extract was also found to have a growth-promoting effect on Bifidobacterium spp.. The antimicrobial activity and antioxidant activity of the water extract did not decrease in respond to heating. Additionally, the water extract of S. chinensis did not show a toxic effect on the growth of Caco-2 cells. In vivo feeding tests were performed to investigate the influence of extract on the intestinal microflora in rats. Although the extract did not reduce obesity induced by a high fat diet, it led to significant increase in the population of Bifidobacterium spp. and a decrease in the population of Clostridium spp. in rats. Taken together, these results indicate that S. chinensis could be useful as a functional food component to control intestinal microbial flora.