• Journal of Life Science
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• v.30 no.3
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• pp.298-303
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• 2020

This study aimed to investigate possible applications of Rodgersia podophylla in the food and cosmetic industry. Ethanol extracts of leaves (RP-L), branches (RP-B), and root (RP-R) were prepared, and their antimicrobial, antioxidant, and anti-diabetic activities were evaluated. The polyphenol content in the RP-R, RP-L, and RP-B extracts was 79.6, 30.4, and 16.9 mg/g, respectively. An antimicrobial activity assay showed that the RP-L and RP-R extracts exhibited strong growth inhibition of pathogenic and food spoilage Gram-positive bacteria. Furthermore, the RP-R extract inhibited the growth of the Gramnegative E. coli and P. vulgaris bacteria. All extracts showed strong scavenging activity for DPPH, ABTS, nitrite, and reducing power determined by A 700 nm. In particular, the RC₅₀s of the RP-R extract for the DPPH anion and ABTS cation were 23.0-29.7 and 15.0-18.2 ㎍/ml, respectively, which are comparable to those of vitamin C (9.8 and 8.0 ㎍/ml, respectively). An activity assay of α-glucosidase and β-amylase suggested a high potential for the RP-R extract as an anti-diabetic agent. Its inhibition levels of α-glucosidase and β-amylase at 0.5 mg/ml were 6.9 and 48.5%, respectively. This is the first report of the antimicrobial and anti-diabetic activities of R. podophylla. Our results suggest that RP-L and RP-R extracts could be developed as novel cosmeceutical and functional food resources.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.405-411
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• 2005

Chitosan, second largest biomass after cellulose on earth, has potential for use as functional food package due to its antibacterial activity. However, due to high melting temperature of chitosan, chitosan films have been made by casting method. Because gelatin has relatively low molting temperature depending upon amount of plasticizer added, it was added to chitosan to produce commercially feasible film. The objective of the current study was to determine optimum blend ratio and amount of chitosan/gelatin blend solutions against antibacterial activities for extruder resin. Gram-positive bacteria (Bacillus cereus ATCC 14579 and Listeria monocytogenes ATCC 15313) and -negative bacteria (Escherichia coli ATCC 25922 and Salmonella enteritidis IFO 3313) were used. Paper (8 mm) diffusion and optical density methods were used to evaluate effect of different blending ratio solutions on the inhibition of bacterial growth. Measured clear none size ranged from 8 mm to 18.07 mm in paper diffusion test. For B. cereus, E. coli, and S. enteritidis, addition of $50\;{\mu}L$ blend solution (chitosan/gelatin = 2/8: 0.3 mg) resulted in clear zone on paper disc. In L. monocytogenes, inhibition effect was observed with 0.6 mg chitosan (chitosan/gelatin=4/6). Minimum inhibitory concentration (MIC) values of B. cerues, L. monocytogenes, E. coli, and S. enteritidis with addition of chitosan were 0.1461, 0.2419, 0.0980, and 0.0490 mg/mL, respectively, These results indicate possibility of producing commercially feasible film with addition of optimum chitosan/gelatin amount.

• Journal of Life Science
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• v.29 no.4
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• pp.402-409
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• 2019

Korean red ginseng made from steaming and drying fresh ginseng has long been used as a traditional herbal medicine due to its effects on the immune, endocrine, and central nerve systems and its anti-inflammatory activity. In this study, we investigated the molecular mechanism responsible for the anti-inflammatory effects of a formulated Korean red ginseng extract (RGE) in response to lipoteichoic acid (LTA), a cell wall component of gram-positive bacteria. RGE inhibited LTA-induced nitric oxide (NO) secretion and inducible nitric oxide synthase (iNOS) expression in BV-2 microglial cells, without affecting cell viability. RGE also inhibited nuclear translocation of nuclear factor kappa B ($NF-{\kappa}B$) p65 and degradation of $I{\kappa}B-{\alpha}$. In addition, RGE increased the expression of heme oxygenase-1 (HO-1) in a dose-dependent manner, and the inhibitory effect of RGE on iNOS expression was abrogated by small interfering RNA-mediated knockdown of HO-1. Moreover, RGE induced nuclear translocation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates HO-1 expression. Furthermore, the phosphoinositide-3-kinase (PI-3K) inhibitor and mitogen-activated protein kinase (MAPK) inhibitors suppressed RGE-mediated expression of HO-1, and RGE enhanced the phosphorylation of Akt, extracellular signal-regulated kinases (ERKs), p38, and c-JUN N-terminal kinases (JNKs). These results suggested that RGE suppressed the production of NO, a proinflammatory mediator, by inducing HO-1 expression via PI-3K/Akt- and MAPK-dependent signaling in LTA-stimulated microglia. The findings indicate that RGE could be used for the treatment of neuroinflammation induced by grampositive bacteria and that it may have therapeutic potential for various neuroinflammation-associated disorders.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.97-106
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• 2022

Listeria monocytogenes (L. monocytogenes) is one of gram-positive foodborne pathogens with a very high fatality rate. Unlike most foodborne pathogens, L. monocytogenes is capable of growing at low temperatures, such as in refrigerated foods. Thus, various physical and chemical prevention methods are used in the manufacturing, processing and distribution of food. However, there are limitations to the methods such as possible changes to the food quality and the consumer awareness of synthetic preservatives. Thus, the aim of this study was to evaluate the anti-listeria activity of lactic acid bacteria (LAB) isolated from kimchi and characterize the bacteriocin produced by Lactococcuslactis which is one of isolated strains from kimchi. The analysis on the anti-listeria activity of a total of 36 species (Lactobacillus, Weissella, Lactobacillus, and Lactococcus) isolated from kimchi by the agar overlay method revealed that L. lactis NJ 1-10 and NJ 1-16 had the highest anti-listeria activity. For quantitatively analysis on the anti-listeria activity, NJ 1-10 and NJ 1-16 were co-cultured with L. monocytogenes in Brain Heat Infusion (BHI) broth, respectively. As a result, L. monocytogenes was reduced by 3.0 log CFU/mL in 20 h, lowering the number of bacteria to below the detection limit. Both LAB strains showed anti-listeria activity against 24 serotypes of L. monocytogenes, although the sizes of clear zone was slightly different. No clear zone was observed when the supernatants of both LAB cultures were treated with proteinase-K, indicating that their anti-listerial activities might be due to the production of bacteriocins. Heat stability of the partially purified bacteriocins of NJ 1-10 and NJ 1-16 was relatively stable at 60℃ and 80℃. Yet, their anti-listeria activities were completely lost by 60 min of treatment at 100℃ and 15 min of treatment at 121℃. The analysis on the pH stability showed that their anti-listeria activities were the most stable at pH 4.01, and decreased with the increasing pH value, yet, was not completely lost. Partially purified bacteriocins showed relatively stable anti-listeria activities in acetone, ethanol, and methanol, but their activities were reduced after chloroform treatment, yet was not completely lost. Conclusively, this study revealed that the bacteriocins produced by NJ 1-10 and NJ 1-16 effectively reduced L. monocytogenes, and that they were relatively stable against heat, pH, and organic solvents, therefore implying their potential as a natural antibacterial substance for controlling L. monocytogenes in food.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.452-460
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• 2016

This study was designed to develop a functional pharma-food using Salicornia europaea (SE). Tiny seeds from the mature SE were collected, and their biological activities were evaluated. The extraction yield of the seed in hot water was found to be 29.6% and the hot water extract (HWE) contained 25.7 mg/g total polyphenol (TP) and 11.5 mg/g total flavonoid (TF), which are similar to those contained in leaf and stem of SE. Among the subsequent organic solvent fractions, the ethylacetate (EA) fraction exhibited the highest content of TP (158.3 mg/g), TF (136.2 mg/g), and total sugar (228.3 mg/g). The EA fraction exhibited broad-range antibacterial activities against gram-positive bacteria, and the butanol fraction exhibited growth inhibitory effect against only Staphylococcus epidermidis. An antioxidation activity assay of the HWE and its fractions showed the EA fraction to have the highest radical scavenging activity with $RC_{50}$ values of 57.0, 29.0, and $28.9{\mu}g/ml$ against DPPH anion, ABTS cation, and nitrite, respectively. The $RC_{50}$ values of vitamin C against DPPH anion, ABTS cation, and nitrite were 10.7, 4.0, and $18.0{\mu}g/ml$, respectively, indicating that the EA fraction of SE has potent antioxidant compounds. In an anticoagulation assay, the EA fraction exhibited a 15-fold extended thrombin time at 5 mg/ml and activated partial thromboplastin time at 7 mg/ml, which are comparable to the activities of aspirin. The HWE and its fractions had no hemolysis activities against human RBCs at up to 1 mg/ml. These results suggest that the EA fraction from SE has a great potential as a new antibacterial and anticoagulation agent.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.452-460
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• 2018

This study was conducted to investigate the physiological activities of Houttuynia cordata extracts and fractions. H. cordata extracts were extracted with 50% ethanol and the ethyl acetate fractions were obtained from the extracts. Minimum inhibitory concentration (MIC) values of the ethyl acetate fraction for S. aureus and B. subtilis were $78{\mu}g/mL$ and $312{\mu}g/mL$, respectively, indicating the high activity against gram-positive bacteria. The free radical scavenging activity ($FSC_{50}$) for 1,1-diphenyl-2-picrylhydrazyl (DPPH) was higher in the ethyl acetate fraction with $12.00{\mu}g/mL$ compared to that of $27.15{\mu}g/mL$ for 50% ethanol extract. The total antioxidant activity ($OSC_{50}$) values for reactive oxygen species (ROS) produced in $Fe^{3+}-EDTA/H_2O_2$ system by a luminol-dependent chemiluminescence method were 2.91 and $0.983{\mu}g/ml$ for the 50% ethanol extract and ethyl acetate fraction, respectively. To investigate cellular protective effects on the HaCaT cell, the intracellular ROS scavenging activity was measured after UVB irradiation and the ethyl acetate fraction of H. cordata showed the activity in a concentration-dependent from $1.6{\mu}g/mL$ and a reduction rate of 54.3% at a maximum concentration of $12.5{\mu}g/mL$. Also, HaCaT cell protective effect against $H_2O_2$-mediated decreased the cell viability of the ethyl acetate fraction of H. cordata which significantly increased the cell viability from $0.8{\mu}g/mL$ and the maximum cell viability showed 86.9%. The ethyl acetate fraction of the H. cordata extracts was analyzed by TLC and HPLC. As a result, quercitrin, isoquercitrin, hyperoside, chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, rutin and afzelin were identified. From the above results, it was suggested that the extracts and fractions of H. cordata have a potential to be applied in the field of cosmetics as a natural antioxidant/preservative capable of protecting the cell membrane from the oxidative stress by eliminating ROS and exhibiting the antimicrobial effect.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.201-209
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• 2014

This study was carried out in order to develop a biological control of anthracnose of red pepper caused by fungal pathogens. In particular, this study focuses on the Colletotrichum species, which includes important fungal pathogens causing a great deal of damage to red pepper. Antagonistic bacteria were isolated from the soil of pepper fields, which were then tested for biocontrol activity against the Colletotrichum gloeosporioides anthracnose pathogen of pepper. Based on the 16S rRNA sequence analysis, the isolated bacterial strain CS-52 was identical to Bacillus sp. The culture broth of Bacillus sp. CS-52 had antifungal activity toward the hyphae and spores of C. gloeosporioides. Moreover, the substances with antifungal activity were optimized when Bacillus sp. CS-52 was grown aerobically in a medium composed of 0.5% glucose, 0.7% $K_2HPO_4$, 0.2% $KH_2PO_4$, 0.3% $NH_4NO_3$, 0.01% $MnSO_4{\cdot}7H_2O$, and 0.15% yeast extract at $30^{\circ}C$. The inhibition of spore formation resulting from cellulase, siderophores, and indole-3-acetic acid (IAA), were produced at 24 h, 48 h, and 72 h, respectively. Bacillus sp. CS-52 also exhibited its potent fungicidal activity against anthracnose in an in vivo test, at a level of 70% when compared to chemical fungicides. These results identified substances with antifungal activity produced by Bacillus sp. CS-52 for the biological control of major plant pathogens in red pepper. Further studies will investigate the synergistic effect promoting better growth and antifungal activity by the formulation of substances with antifungal activity.

• Journal of Life Science
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• v.21 no.3
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• pp.375-384
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• 2011

This study was performed to evaluate the antioxidant and antimicrobial activity of methanol extract from Rosmarinus officinalis L. and its fractions. The ethyl acetate fraction of rosemary had a higher antioxidant activity in both DPPH ($3.22\;{\mu}g/ml$) and ABTS ($5.05\;{\mu}g/ml$) compared to other extracts and fractions. Based on the results of the FRAP assay, the ethyl acetate fraction of rosemary showed a value of $5.9{\pm}0.3\;{\mu}M/{\mu}g$, and buthanol fraction and rosmarinic acid exhibited values of $4.8{\pm}0.2\;{\mu}M/{\mu}g$ and $5.1{\pm}0.1\;{\mu}M/{\mu}M$, respectively. Measurements of the antimicrobial activities of the extracts, fraction against gram positive, negative bacteria revealed that the methanol extract, hexane, ethyl acetate, and chloroform fraction of rosemary caused Staphylococcus aureus and Escherichia coli to form clear zones greater than 12 mm. Furthermore, the methanol extract and chloroform fraction showed high antibacterial activity, with inhibition zone exceeding 13 mm. The methanol extract and chloroform fraction of rosemary had broad antimicrobial spectrums and low MIC values. Therefore, methanol extracts of rosemary could serve as potential antibacterial agents to inhibit pathogen growth in food and hand sanitizers.

• Journal of Life Science
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• v.27 no.2
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• pp.202-210
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• 2017

As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, ${\alpha}$-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to $100^{\circ}C$ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.502-508
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• 2009

Antimicrobial activity of Sargassum thunbergii was determined by paper disc assay and minimum concentration inhibitor (MIC) test. A water extract of S. thunbergii did not show the antimicrobial activity, but an ethanol extract of S. thunbergii (SHE) inhibited Serratia liquefaciens, Salmonella Typhimurium, Pseudomonas aerogenosa and all of the tested gram-positive bacteria at 4 mg/mL. Especially, Bacillus subtilis, Clostridium perfringens and Listeria monocytogenes were susceptible to SHE. As the results of MIC test, SHE inhibited the growth of B. subtilis, Staphylococcus aureus and Listeria monocytogenes at concentration of $0.1{\sim}0.3%$, and inhibited C. perfringens at 0.01%. In the thermal and pH stability test for SHE, antibacterial activities of SHE were maintained when the SHE was treated at $121^{\circ}C$ for 15 minutes or under pH $2{\sim}8$. SHE was partitioned in the order of n-hexane, chloroform, ethyl acetate and butanol. As the results of the MIC test for each obtained fraction, no fraction exhibited higher antibacterial activity than that of the crude SHE. However, a mixture of chloroform, ethylacetate and ethanol fractions showed higher antibacterial activity than SHE.