• Mycobiology
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• v.35 no.1
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• pp.25-29
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• 2007

A newly synthesized Nickel (II) tyrosine complex was screened as potential antimicrobial agent against a number of medically important bacteria (Bacillus subtilis, Streptococcus ${\beta}$-haemolytica, Escherichia coli, Shigella dysenterae) and fungi (Aspergillus fumigatus, Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium sp.) strains. were used for antifungal activity. The antimicrobial activity was evaluated using the Agar Disc method. Moreover, the minimum inhibitory concentration of the complexes was determined against the same pathogenic bacteria and the values were found between $4{\sim}64\;{\mu}g\;ml^{-1}$. Brine shrimp bioassay was carried out for cytotoxicity measurements of the complexes. The $LC_{50}$ values were calculated after probit transformation of the resulting mortality data and found to be 6 ${\mu}g\;ml^{-1}$.

• International Journal of Oral Biology
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• v.44 no.3
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• pp.101-107
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• 2019

The purpose of this study was to investigate the antimicrobial activity of the ethanol extract of Garcinia mangostana L. (mangosteen) against Cutibacterium acnes (6 strains) and Staphylococcus aureus (6 strains). The antimicrobial activity of the mangosteen extract was evaluated based on its minimal bactericidal concentration. Cytotoxicity of the mangosteen extract against human embryonic kidney 293 (HEK 293) cells was determined using the cell counting method. The data showed that the mangosteen extract was not toxic to HEK 293 cells at a concentration of up to $16{\mu}g/mL$ and killed 87.0% and 99.9% of C. acnes and S. aureus after 10 minutes and 1 hour of treatment, respectively. These results suggest that ethanol extract of mangosteen can be used as an anti-acne agent.

• Advances in Traditional Medicine
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• v.9 no.2
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• pp.182-185
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• 2009

Amoora cucullata (Meliaceae), a mangrove plant, has folkloric reputation as a medicinal agent in Bangladesh. In this study, the n-hexane, ethyl acetate and methanolic extracts of the stem bark of this plant were subjected to microbiological investigation and brine shrimp lethality bioassay. In case of antimicrobial screening, the ethyl acetate and methanolic extracts appeared to be potent in terms of both zone of inhibition and spectrum of activity showing the average zones of inhibition 8 - 14 mm and 9 - 16 mm, respectively. In the brine shrimp lethality bioassay, the methanolic extract demonstrated highest cytotoxicity having $LC_{50}$ of $0.549{\mu}g/ml$, whereas the ethyl acetate and n-hexane extract showed $LC_{50}$ of 7.943 and $17.180{\mu}g/ml$, respectively.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.65-77
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• 2000

The purpose of this study was to evaluate the antimicrobial activity of Crassirhzimae rhizoma and its possible use as an oral antiseptics for prevention of periodontitis. Its antibacterial activity against periodontopathic microorganisms including Actinobacillus actiomycetem - comitans, Capnocytophaga ochracea, Streptococcus mutans, Porphyromonas gingivalis, Prevotella intermedia, Actinomyces viscosus, Fusobacterium nucleatumwas evaluated via modified stab culture method. The cytotoxicity against gingival fibroblasts and rat osteoblasts was investigated via [$^3H$]thymidine incorporation and cellular activity was investigated via MTT assay. Chlorhexidine was used as control group. Crassirhizomae rhizoma was prepared at concentrations of 0.2, 0.15, 0.1, 0.05%. Chlorhexidine was also prepared at the same concentration. Crassirhizomae rhizoma showed lower antimicrobial antivity against these microorganism than chlorhexidine, but this difference was not significant. And, Crassirhzomae rhizoma showed more cellular activity and less cytotoxicity than chlorhexidine on human gingival fibrablast and rat osteoblast. This study suggests that Crassirhzomae rhizoma might be a candidate for a safe oral antiseptic for the prevention and treatment of periodontal disease.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1199-1202
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• 2011

Infection of surgical wounds is a severe problem. Conventional tissue reattachment methods have limits of incomplete sealing and high susceptibility to infection. Medical adhesives have several advantages over traditional tissue reattachment techniques, but still have drawbacks, such as the probability of infection, low adhesive strength, and high cytotoxicity. Recently, a new medical adhesive (new-adhesive) with high adhesive strength and low cytotoxicity, composed of aldehyded dextran and ${\varepsilon}$-poly(L-lysine), was developed. The antimicrobial activity of the new-adhesive was assayed using agar media and porcine skin. In the agar diffusion method, inoculated microorganisms that contacted the new-adhesive were inactivated, but this was not dependent on the amount of new-adhesive. Similar to the agar media results, the topical antimicrobial effect of new-adhesive was confirmed using a porcine skin antimicrobial assay, and the effect was not due to physical blocking based on comparison with the group whose wounds were wrapped.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.1-8
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• 2011

The antimicrobial effects of silver (Ag) ion or salts are well known. Recently, silver nanoparticle is attracting an interest in a wide variety of fields since it has been known to be safe and effective as an antimicrobial agent against a broad spectrum of microorganisms. Although silver nanoparticle has been applied to various kinds of products owing to its potent antimicrobial activity, the effects of silver nanoparticle on microorganisms and antimicrobial mechanism have not been revealed clearly. In this paper, we summarized the characteristics, antimicrobial activities and mechanisms, cytotoxicity and applicability of silver nanoparticle.

• Journal of dental hygiene science
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• v.18 no.3
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• pp.147-154
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• 2018

This study aimed to evaluate the antimicrobial effects of Acanthopanax sessiliflorum fruit (ASF; Ogaza) extracts on Streptococcus mutans and Streptococcus sobrinus, which are agents that cause dental caries, and on Streptococcus mitis and Streptococcus salivarius, the microbial flora of the oral cavity. The ASF extracts obtained using 70% ethanol were fractionated in the order of ethyl acetate and n-Butanol, concentrated under reduced pressure, and lyophilized to give powdery solvent extracts. The antimicrobial activity of ASF extracts from each solvent was examined using the disk diffusion method. As a result, only those extracts obtained using an ethyl acetate solvent showed antimicrobial activity. These extracts were selected, and the minimum inhibitory concentration was measured by disk diffusion method at various extract concentrations. Results showed a minimum inhibitory concentration of 32 mg/ml. The viable cell count was measured to confirm the minimum bactericidal concentration. Results showed a minimum bactericidal concentration of 64 mg/ml. In the cytotoxicity test using normal human dermal fibroblast cells, the absorbance value of the test group was similar to that of the control group at 0.64, 1.28, and 6.4 mg/ml. The bacteria and their colonies were examined using a scanning electron microscope. Boundaries between the antimicrobial activity region and non-antimicrobial activity region were observed around the paper disk, which was immersed in the extract with 32 mg/ml concentration. Bacterial colonization was not observed in the area with antimicrobial activity. This finding suggests that ASF extracts can inhibit the growth of some microorganisms in the oral cavity, in addition to the effects of these extracts known to date. In particular, ASF extracts may be used as a preparation for preventing dental caries by adding the extract to the toothpaste or oral mouthwash.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.381-390
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• 2018

We have previously derived a novel antimicrobial peptide, LPcin-YK3(YK3), based on lactophoricin and have successfully studied and reported on the relationship between its structure and function. In this study, antimicrobial peptides with improved antimicrobial activity, less cytotoxicity, and shorter length were devised and characterized on the basis of YK3, and named YK5, YK8, and YK11. The peptide design was based on a variety of knowledge, and a total of nine analog peptides consisted of one to three amino acid substitutions and C-terminal deletions. In detail, tryptophan substitution improved the membrane perturbation, lysine substitution increased the net charge, and excessive amphipathicity decreased. The analog peptides were examined for structural characteristics through spectroscopic analytical techniques, and antimicrobial susceptibility tests were used to confirm their activity and safety. We expect that these studies will provide a platform for systematic engineering of new antibiotic peptides and generate libraries of various antibiotic peptides.

• Restorative Dentistry and Endodontics
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• v.28 no.5
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• pp.425-430
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• 2003

The purpose of this study was to evaluate the clinical applications of the Sodium Dichloroisocyanurate effervescent tablet as a routine root canal irrigant by performing several in vitro tests such as $Cl^{-}$ content. cytotoxicity. antimicrobial effect as well as its pH level compared to the equivalent concentration of sodium hypochlorite solution. 1. Sodium Dichloroisocyanurate demonstrated lower level of $Cl^{-}$ concentration than each dilution of sodium hypochlorite solution. Both solution has increased level of $Cl^{-}$ as the concentration of each solution increased. There was no significant change of $Cl^{-}$ concentration in sodium hypochlorite as time goes by. However. $Cl^{-}$ concentration in Sodium Dichloroisocyanurate was increased. 2. The antimicrobial effects of both solutions were increased when their concentrations were increased. One day after dilution. antimicrobial effect of Sodium Dichloroisocyanurate was slightly higher than sodium hypochlorite. however. there was no difference in 1 week dilution solution. One month dilution solution of sodium hypochlorite still retain its activity. but antimicrobial effect of Sodium Dichloroisocyanurate was drastically decreased 1 month after dilution. 3. The cytotoxicity of Sodium Dichloroisocyanurate was rather higher than same concentration of sodium hypochlorite solution until 1 week after dilution. Then in 1 month. cytotoxicity of Sodium Dichloroisocyanurate was decreased than that of 1 week dilution solution. especially 4% Sodium Dichloroisocyanurate solution has almost no toxicity. However. 1% and 2% sodium hypochlorite solution has unchanged moderate degree of cytotoxicity after the dilution. Furthermore. 4% sodium hypochlorite solution showed high level of toxicity. 4. The pH level of Sodium Dichloroisocyanurate showed that the solution was weak acid (pH5). On the other hand. sodium hypochlorite was revealed as a strong alkaline solution (pH12). There was no change in pH following the dilution of each solution. As results. Sodium Dichloroisocyanurate solution fully satisfy the basic requirements as a root canal irrigation solution. However. we strongly recommend to use this solution clinically in low concentration and try to apply into the root canal within 1 week after dilution.

• Korean Journal of Veterinary Service
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• v.36 no.2
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• pp.87-93
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• 2013

This study was conducted to investigate the antimicrobial, antivirus properties of Saururus chinensis extracts. The n-hexane extracts from Saururus chinensis showed the active antimicrobial activity against gram-positive bacteria. Minimum inhibitory concentration (MIC) of Saururus chiensis n-hexane extracts was 1.25 mg/ml against B. subtilis and 2.5 mg/ml against S. aureus. The cytotoxicity effects on MDBK (Madin-Darby bovine kidney) cell were observed at the various n-hexane extract concentrations. In $TCID_{50}$ assay, 0.6 mg/ml of n-hexane extracts decreased BVD (bovine viral diarrhea) virus by 1.4 log, whereas other extracts did not show antiviral activity. In this study, The results suggested that n-hexane extracts and fractions of Saururus chinensis can be a candidate materal of feed additive to chemical antibiotics and antivirus substances.