• Restorative Dentistry and Endodontics
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• v.40 no.4
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• pp.290-298
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• 2015

Objectives: Sodium hypochlorite (NaOCl) is an excellent bactericidal agent, but it is detrimental to stem cell survival, whereas intracanal medicaments such as calcium hydroxide ($Ca[OH]_2$) promote the survival and proliferation of stem cells. This study evaluated the effect of sequential NaOCl and $Ca(OH)_2$ application on the attachment and differentiation of dental pulp stem cells (DPSCs). Materials and Methods: DPSCs were obtained from human third molars. All dentin specimens were treated with 5.25% NaOCl for 30 min. DPSCs were seeded on the dentin specimens and processed with additional 1 mg/mL $Ca(OH)_2$, 17% ethylenediaminetetraacetic acid (EDTA) treatment, file instrumentation, or a combination of these methods. After 7 day of culture, we examined DPSC morphology using scanning electron microscopy and determined the cell survival rate with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We measured cell adhesion gene expression levels after 4 day of culture and odontogenic differentiation gene expression levels after 4 wk using quantitative real-time polymerase chain reaction. Results: DPSCs did not attach to the dentin in the NaOCl-treated group. The gene expression levels of fibronectin-1 and secreted phosphoprotein-1 gene in both the $Ca(OH)_2$- and the EDTA-treated groups were significantly higher than those in the other groups. All $Ca(OH)_2$-treated groups showed higher expression levels of dentin matrix protein-1 than that of the control. The dentin sialophosphoprotein level was significantly higher in the groups treated with both $Ca(OH)_2$ and EDTA. Conclusions: The application of $Ca(OH)_2$ and additional treatment such as EDTA or instrumentation promoted the attachment and differentiation of DPSCs after NaOCl treatment.

• International Journal of Oral Biology
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• v.35 no.4
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• pp.191-195
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• 2010

Oleanolic acid is a natural triterpenoid that exists widely in foods and some medicinal herbs. The purpose of this study was to determine the antimicrobial activity of oleanolic acid against Streptococcus mutans strains isolated from a Korean population. Antimicrobial activity against these bacteria was evaluated by minimal inhibitory concentration (MIC) and time kill curves. The tolerance of human gingival fibroblasts and human periodontal ligaments to oleanolic acid was tested using a methyl thiazolyl tetrazolium (MTT) assay. The $MIC_{90}$ value of oleanolic acid for both S. mutans and S. sobrinus isolated from Koreans was 8 ${\mu}g/ml$. Oleanolic acid showed bactericidal effects against S. mutans ATCC $25175^T$ and S. sobrinus ATCC $33478^T$ at $1\;{\times}\;MIC$ ($8{\mu}g/ml$) and had no cytotoxic effects against KB cells at this dose. The results suggest that oleanolic acid could be useful in the future development of oral hygiene products for the prevention of dental caries.

• International Journal of Oral Biology
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• v.38 no.3
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• pp.127-134
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• 2013

Xylitol is a sugar alcohol with a variety of functions including bactericidal and anticariogenic effects. However, the cellular mechanisms underlying the role of xylitol in bone metabolism are not yet clarified. In our present study, we exploited the physiological role of xylitol on osteoclast differentiation in a co-culture system of osteoblastic and RAW 264.7 cells. Xylitol treatment of these co-cultures reduced the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells induced by 10 nM $1{\alpha},25(OH)_2D_3$ in a dose-dependent manner. A cell viability test revealed no marked cellular damage by up to 100 mM of xylitol. Exposure of osteoblastic cells to xylitol decreased RANKL, but not OPG, mRNA expression in the presence of $10^{-8}M$ $1{\alpha},25(OH)_2D_3$ in a dose-dependent manner. Furthermore, bone resorption activity, assessed on bone slices in the coculture system, was found to be dramatically decreased with increasing xylitol concentrations. RANKL and OPG proteins were assayed by ELISA and the soluble RANKL (sRANKL) concentration was decreased with an increased xylitol concentration. In contrast, OPG was unaltered by any xylitol concentration in this assay. These results indicate that xylitol inhibits $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis by reducing the sRANKL/OPG expression ratio in osteoblastic cells.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.288-295
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• 2014

Objectives: This study was designed to evaluate the synergistic antibacterial effect of xylitol and ursolic acid (UA) against oral biofilms in vitro. Materials and Methods: S. mutans UA 159 (wild type), S. mutans KCOM 1207, KCOM 1128 and S. sobrinus ATCC 33478 were used. The susceptibility of S. mutans to UA and xylitol was evaluated using a broth microdilution method. Based on the results, combined susceptibility was evaluated using optimal inhibitory combinations (OIC), optimal bactericidal combinations (OBC), and fractional inhibitory concentrations (FIC). The anti-biofilm activity of xylitol and UA on Streptococcus spp. was evaluated by growing cells in 24-well polystyrene microtiter plates for the biofilm assay. Significant mean differences among experimental groups were determined by Fisher's Least Significant Difference (p < 0.05). Results: The synergistic interactions between xylitol and UA were observed against all tested strains, showing the FICs < 1. The combined treatment of xylitol and UA inhibited the biofilm formation significantly and also prevented pH decline to critical value of 5.5 effectively. The biofilm disassembly was substantially influenced by different age of biofilm when exposed to the combined treatment of xylitol and UA. Comparing to the single strain, relatively higher concentration of xylitol and UA was needed for inhibiting and disassembling biofilm formed by a mixed culture of S. mutans 159 and S. sobrinus 33478. Conclusions: This study demonstrated that xylitol and UA, synergistic inhibitors, can be a potential agent for enhancing the antimicrobial and anti-biofilm efficacy against S. mutans and S. sobrinus in the oral environment.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.54-63
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• 2019

Rubus coreanus Miquel (RCM), also known as Korean blackberry or bokbunja, is used as a South Korean traditional medicine to treat acne and inflammatory skin conditions. The antimicrobial activity of RCM root and its active compounds remain unclear. In this study, we prepared a 50% ethanol fraction, ethyl acetate fraction, and acid-treated ethyl acetate fraction (aglycone fraction) of RCM root, and evaluated antibacterial activities against the skin pathogens Staphylococcus aureus, Pseudomonas acnes, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. In a paper disc assay, all fractions of RCM root showed antimicrobial activities against the five skin pathogens. The ethyl acetate fraction displayed 6-, 12-, and 2-fold higher minimal inhibitory concentration (MIC) than the 50% ethanol fraction against S. aureus, E. coli, and P. acnes, respectively. The aglycone fraction displayed 2-fold higher MIC than methyl paraben against P. acnes, S. aureus, E. coli, and P. aeruginosa. The ethyl acetate fraction displayed a minimal bactericidal concentration (MBC) similar to that of methyl paraben, and the aglycone fraction showed 2- to 4-fold higher MBCs than those of methyl paraben. In particular, the ethyl acetate fraction was not cytotoxic and showed thermal stability after incubation at high temperatures ($60-121^{\circ}C$). Finally, the ethyl acetate fraction was separated and four components were identified: procyanidin C, propelagonidin dimer, ellagic acid, and methyl ellagic acid acetyl pentose. The compounds showed high antibacterial activities. These results suggest that RCM root is potentially applicable as a natural preservative in cosmetics.

• Journal of dental hygiene science
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• v.21 no.2
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• pp.119-126
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• 2021

Background: Dental caries is mainly composed of various cellular components and is deposited around the tooth surface and gums, causing a number of periodontal diseases. Streptococcus mutans is commonly found in the human oral cavity and is a significant contributor to tooth decay. The use of antibacterial ingredients in oral hygiene products has demonstrated usefulness in the management of dental caries. This study investigated the anticaries effect of the ethanol extract of Terminalia chebula (EETC) against S. mutans and their cytotoxicity to gingival epithelial cells. Methods: The EETC was prepared from T. chebula fruit using ethanol extraction. Disk diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and colony forming unit (CFU) were analyzed to investigate the antimicrobial activity of the EETC. Glucan formation was measured using the filtrate of the bacterial culture medium and sucrose. Gene expression was analyzed using reverse transcription-polymerase chain reaction (RT-PCR). Cytotoxicity was analyzed via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Results: The antibacterial activity of the EETC was explored using disc diffusion and CFU measurements. The MIC and MBC of the EETC were 10 and 20 ㎍/ml, respectively. EETC treatment decreased insoluble glucan formation by S. mutans enzymes and also resulted in reduced glycosyltransferase B (gtf B), gtf C, gtf D, and fructosyltransferase (ftf), expressions on RT-PCR. In addition, at effective antibacterial concentrations, EETC treatment was not cytotoxic to gingival epithelial cells. Conclusion: These results demonstrate that the EETC is an effective anticaries ingredient with low cytotoxicity to gingival epithelial cells. The EETC may be useful in antibacterial oral hygiene products for the management of dental caries.

• Journal of Veterinary Science
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• v.24 no.2
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• pp.20.1-20.13
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• 2023

Background: As Actinobacillus pleuropneumonniae (APP) infection causes considerable losses in the pig industry, there is a growing need to develop effective therapeutic interventions that leverage host immune defense mechanisms to combat these pathogens. Objectives: To demonstrate the role of microRNA (miR)-127 in controlling bacterial infection against APP. Moreover, to investigate a signaling pathway in macrophages that controls the production of anti-microbial peptides. Methods: Firstly, we evaluated the effect of miR-127 on APP-infected pigs by cell count/enzyme-linked immunosorbent assay (ELISA). Then the impact of miR-127 on immune cells was detected. The cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6 were evaluated by ELISA. The expression of cytokines (anti-microbial peptides [AMPs]) was assessed using quantitative polymerase chain reaction. The expression level of IL-6, TNF-α and p-P65 were analyzed by western blot. The expression of p65 in the immune cells was investigated by immunofluorescence. Results: miR-127 showed a protective effect on APP-infected macrophage. Moreover, the protective effect might depend on its regulation of macrophage bactericidal activity and the generation of IL-22, IL-17 and AMPs by targeting sphingosine-1-phosphate receptor3 (SIPR3), the element involved in the Toll-like receptor (TLR) cascades. Conclusions: Together, we identify that miR-127 is a regulator of S1PR3 and then regulates TLR/nuclear factor-κB signaling in macrophages with anti-bacterial acticity, and it might be a potential target for treating inflammatory diseases caused by APP.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.386-392
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• 2014

The present study was aimed at investigating the antimicrobial activities of licorice's active ingredients. Four samples of licorice ingredients (glycyrrhizin, liquiritin, liquiritigenin, and isoliquiritigenin) were evaluated for their antimicrobial activities against six skin microorganisms. The bioassay applied for determining the antimicrobial effects employed a disc diffusion assay, the minimum inhibitory concentration, and the challenge test. The ingredients showed antibacterial activities. Especially, isoliquiritigenin has significant antimicrobial activities against two Gram-positive (Bacillus subtilis, Propionobacterium acnes) and two Gramnegative (Escherichia coli, Pseudomonas aeruginosa) bacteria. These samples had much higher antimicrobial activities than synthetic preservatives. Our results reveal that liquiritigenin and isoliquiritigenin could be useful compounds for the development of antibacterial agents for the preservation of cosmetics and foods. The two flavonoids, liquiritigenin and isoliquiritigenin, sourced from Korea, China, Uzbekistan, were quantified using HPLC. The results demonstrated that Korean licorice has two flavonoids (liquiritigenin, isoliquiritigenin) in much higher quantities than was observed in the licorice obtained from the two other countries. Thus, isoliquiritigenin and Korean licorice extract represent new candidates for antimicrobial agents.

• Journal of Veterinary Clinics
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• v.31 no.6
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• pp.502-506
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• 2014

Recently nano particles have proven for wide array of bioactive properties. In the present study, antibacterial properties of chitosan silver nano composites (CAgNCs) were investigated against fish pathogenic Edwardsiella tarda. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of CAgNCs against E. tarda were $25{\mu}g/mL$ and $125{\mu}g/mL$, respectively. The field emission scanning electron microscope (FE-SEM) image of CAgNCs treated E. tarda showed the strongly damaged bacteria cells than non-treated bacteria. Furthermore, treatment of CAgNCs induced the level of intracellular reactive oxygen species (ROS) in E. tarda cells in concentration and time dependent manner suggesting that it may generate oxidative stress leading to bacterial cell death. In addition, MTT assay results showed that the lowest cell viability at $100{\mu}g/mL$ of CAgNCs treated E. tarda. Overall results of this study suggest that CAgNCs is a potential antibacterial agent to control pathogenic bacteria.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1776-1788
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• 2019

Objective: The demands for measures to improve disease resistance and productivity of livestock are increasing, as most countries prohibit the addition of antibiotics to feed. This study therefore aimed to uncover functional feed additives to help enhance livestock immunity and disease resistance, using Acanthopanax sessiliflorus fruit extract (ASF). Methods: ASF was extracted with 70% EtOH, and total polyphenolic and catechin contents were measured by the Folin-Ciocalteu and vanillin assay, respectively. The 3D4/31 porcine macrophage cells ($M{\Phi}$) were activated by phorbol 12-myristate 13-acetate (PMA), and cell survival and growth rate were measured with or without ASF treatment. Flow-cytometric analysis determined the lysosomal activity, reactive oxygen species levels (ROS), and cell cycle distribution. Nuclear factor kappa B ($NF-{\kappa}B$) and superoxide dismutase (SOD) protein expression levels were quantified by western blotting and densitometry analysis. Quantitative polymerase chain reaction was applied to measure the lipid metabolism-related genes expression level. Lastly, the antibacterial activity of 3D4/31 $M{\Phi}$ cells was evaluated by the colony forming unit assay. Results: ASF upregulated the cell viability and growth rate of 3D4/31 $M{\Phi}$, with or without PMA activation. Moreover, lysosomal activity and intracellular ROS levels were increased after ASF exposure. In addition, the antioxidant enzyme SOD2 expression levels were proportionately increased with ROS levels. Both ASF and PMA treatment resulted in upregulation of $NF-{\kappa}B$ protein, tumor necrosis factor $(TNF){\alpha}$ mRNA expression levels, lipid synthesis, and fatty acid oxidation metabolism. Interestingly, co-treatment of ASF with PMA resulted in recovery of $NF-{\kappa}B$, $TNF{\alpha}$, and lipid metabolism levels. Finally, ASF pretreatment enhanced the in vitro bactericidal activity of 3D4/31 $M{\Phi}$ against Escherichia coli. Conclusion: This study provides a novel insight into the regulation of $NF-{\kappa}B$ activity and lipid metabolism in $M{\Phi}$, and we anticipate that ASF has the potential to be effective as a feed additive to enhance livestock immunity.