• Molecular & Cellular Toxicology
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• v.3 no.2
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• pp.90-97
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• 2007

8-Hydroxyquinoline is used as antibacterial agent and antioxidant based on its function inducing the chelation of ferrous ion present in host resulting in production of chelated complex. This complex being transported to cell membrane of bacteria and fungi exerts antibacterial and antifungal action. In this study, we have carried out in vitro genetic toxicity tests and microarray analysis to understand the underlying mechanisms and the mode of action of toxicity of 8-hydroxyquinoline. TA1535 and TA98 cells were treated with 8-hydroxyquinoline to test its toxicity by basic genetic toxicity test, Ames and two new in vitro micronucleus and COMET assays were applied using CHO cells and L5178Y cells, respectively. In addition, microarray analysis of differentially expressed genes in L5178Y cells in response to 8-hydroxyquinoline were analyzed using Affymatrix genechip. The result of Ames test was that 8-hydroxyquinoline treatment increased the mutations in base substitution strain TA1535 and likewise, 8-hydroxyquinoline also increased mutations in frame shift TA98. 8-Hydroxyquinoline increased micronuclei in CHO cells and DNA damage in L5178Y. 8-Hdroxyquinoline resulted in positive response in all three tests showing its ability to induce not only mutation but also DNA damage. 783 Genes were initially selected as differentially expressed genes in response to 8-hydroxyquinoline by microarray analysis and 34 genes among them were over 4 times of log fold changed. These 34 genes could be candidate biomarkers of genetic toxic action of 8-hydroxyquinoline related to induction of mutation and/or induction of micronuclei and DNA damage. Further confirmation of these candidate markers related to their biological function will be useful to understand the detailed mode of action of 8-hydroxyquinoline.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.92-97
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• 2006

The liquid culture extract of Coriolus versicolor was prepared by directly boiling the whole culture broth 7 days after incubation in 12% citrus extract medium. After removal of mycelial debris through filtration, this extract was further extracted with equal volume of ethyl acetate (1 : 1, v/v). The ethyl acetate extracts showed significant antibacterial activities against Stapylococcus aureus CCARM3230 and Psudomonas aeruginosa CCARM2171, which are resistant to several antibiotics. The most active fraction was eluted from a silica gel column with a mixture of dichloromethane and methanol (9 : 1, v/v) and the purity of this active substance was confirmed by HPLC analysis. The results suggest that the purified active substance could be a good source for the development of a new antimicrobial agent, especially for the treatment of antibiotic resistant bacteria.

• Biomaterials Research
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• v.22 no.4
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• pp.328-336
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• 2018

Background: Biogenic fabrication of silver nanoparticles from naturally occurring biomaterials provides an alternative, eco-friendly and cost-effective means of obtaining nanoparticles. It is a favourite pursuit of all scientists and has gained popularity because it prevents the environment from pollution. Our main objective to take up this project is to fabricate silver nanoparticles from lichen, Usnea longissima and explore their properties. In the present study, we report a benign method of biosynthesis of silver nanoparticles from aqueous-ethanolic extract of Usnea longissima and their characterization by ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses. Silver nanoparticles thus obtained were tested for antimicrobial activity against gram positive bacteria and gram negative bacteria. Results: Formation of silver nanoparticles was confirmed by the appearance of an absorption band at 400 nm in the UV-vis spectrum of the colloidal solution containing both the nanoparticles and U. longissima extract. Poly(ethylene glycol) coated silver nanoparticles showed additional absorption peaks at 424 and 450 nm. FTIR spectrum showed the involvement of amines, usnic acids, phenols, aldehydes and ketones in the reduction of silver ions to silver nanoparticles. Morphological studies showed three types of nanoparticles with an abundance of spherical shaped silver nanoparticles of 9.40-11.23 nm. Their average hydrodynamic diameter is 437.1 nm. Results of in vitro antibacterial activity of silver nanoparticles against Staphylococcus aureus, Streptococcus mutans, Streptococcus pyrogenes, Streptococcus viridans, Corynebacterium xerosis, Corynebacterium diphtheriae (gram positive bacteria) and Escherichia coli, Klebsiella pneuomoniae and Pseudomonas aeruginosa (gram negative bacteria) showed that it was effective against tested bacterial strains. However, S. mutans, C. diphtheriae and P. aeruginosa were resistant to silver nanoparticles. Conclusion: Lichens are rarely exploited for the fabrication of silver nanoparticles. In the present work the lichen acts as reducing as well as capping agent. They can therefore, be used to synthesize metal nanoparticles and their size may be controlled by monitoring the concentration of extract and metal ions. Since they are antibacterial they may be used for the treatment of bacterial infections in man and animal. They can also be used in purification of water, in soaps and medicine. Their sustained release may be achieved by coating them with a suitable polymer. Silver nanoparticles fabricated from edible U. longissima are free from toxic chemicals and therefore they can be safely used in medicine and medical devices. These silver nanoparticles were stable for weeks therefore they can be stored for longer duration of time without decomposition.

• Journal of Life Science
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• v.29 no.7
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• pp.755-761
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• 2019

Kojic acid (KA) is produced by Aspergillus oryzae-sort of like mushrooms, which is commonly called as koji in Japan. KA is used as a chelation agent and a preservative preventing oxidative browning of fruits. KA also shows antibacterial and antifungal properties. Because KA stops the production of melanin by inhibiting tyrosinase in the biosynthetic pathway from tyrosine to melanin in skin, it has been applied as a skin lightening ingredient in cosmetics. Since some animal studies have shown that high amounts of KA had side effects such as in liver, kidney, reproductive, cardiovascular, gastrointestinal, respiratory, brain, and nervous system, more efficient KA derivatives are needed to be developed in order to safely apply as a skin lightening ingredient. A series of KA derivatives via conjugated with triazole by click reaction were synthesized and their in vitro tyrosinase inhibitory activities were evaluated. Most of all KA derivatives have shown in moderate tyrosinase inhibitory activities. In case of KA-hybrid compound, 1~3 have shown tyrosinase inhibitory activities about 50~10,000 times more effective tyrosinase inhibitor compared to KA itself. Specifically, the $IC_{50}$ value of KA-hybrid compound, 2 was $0.0044{\pm}0.74{\mu}M$ against tyrosinase. It is about 10,000 times more effective tyrosinase inhibitor compared to KA itself ($IC_{50}=45.2{\pm}4.6{\mu}M$).

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.70-75
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• 2007

In the present study, we has been isolated the anti-cariogenic component, stigmasterol, from Aralia continentalis (A. continentalis) and identified by MS, $^1$H-NMR and $^{13}$C-NMR and also investigated the anti-cariogenic properties of stigmasterol. The methanol extract of ,A. continentalis showed concentration-dependent inhibitory activity against the growth and acid production of S. mutans. The MeOH extract was suspended in H$_2$O and sequentially partitioned with n-hexane, CHCl$_3$, EtOAc, and n-BuOH. The CHCl$_3$ fraction showed remarkable antibacterial activity against S. mutans. The anti-cariogenic compound, stigmasterol, has been isolated successively through the screening system and various chromatography methods. Anti-cariogenic properties of stigmasterol were also investigated. From this active chloroform subfraction, isolation and identification finally gave (24E)-stigmasta-5,22-dien-3${\beta}$-ol (stigmasterol) {[a]$_D\;^{25}$ -48.33$^{\circ}C$(C 0.28, CHCl$_3$)} by spectroscopic methods (MS, $^1$H-NMR and $^{13}$C-NMR) as an active principle. The compound, stigmasterol, showed significant growth, acid production, adhesion and water-insoluble glucan synthesis inhibitory effect against S. mutans. These results suggest that stigmasterol from ,A. continentalis may inhibit cariogenic properties of S. mutans and these properties may provide some scientific rationales that the local inhabitants used the extracts for treatment of dental diseases.

• Journal of Environmental Health Sciences
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• v.33 no.2 s.95
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• pp.137-144
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• 2007

Yam, Prunella was stepwise extracted with hexane, chloroform, ethyl acetate, butanol, and water. Anti-microbial activity of each extract was investigated. Hexane extract was tested for anti-microbial effect on Streptocaccus mutans, one of causative factor of dental caries. Methanol extracts of 7 plants were investigated to anti-microbial effects on S. mutans KCTC 5316, P. gingivalis KCTC 5352, S. aureus KCTC 1927 by means of agar diffusion method. Methanol extract of Yam and Prunella revealed anti-microbial activity against S. mutans, P. gingivalis, and S. aureus. Also, hexane fraction of Yam revealed anti-microbial activity against S. mutans. In sequence of hexane, chloroform, ethylacetate, butanol fraction by Prunelia acted as potent anti-microbial agent on P. gingivalis. The measured MIC of hexane fraction of Yam and Prunella on S. mutans KCTC 5316 strain was 0.25 mg/ml and 0.5 mg/ml and the MIC of hexane fraction of Prunella on S. aureus was 0.5 mg/ml. The hexane fraction of Yam and Prunella suppressed viable ceil counts(VCC) of S. mutans, especially after 24 hrs. The Prunella hexane fraction suppressed VCC of S. aureus, after 12 and 24 hrs. Tested concentrations were 0.1, 0.25 and 0.5 mg/ml. the results were compared with control (0 mg/ml). The pH of S. mutans media and GTase activity were determined to evaluate the anticariogenic activity of Yam, Prunella hexane fraction. The pH were increased from 5.6 to 7.0-7.2 in concentration of 2.0 mg/ml. Yam hexane extraction revealed 35% inhibition to GTase activity and Punella inhibited 25% of GTase. These results suggest that the hexane extracts of Yam and prunella have Antibacterial activities against S. mutans, P. gingivalis, S. aureus and have preventive effect on dental caries.

• Polymer(Korea)
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• v.39 no.3
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• pp.480-486
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• 2015

The adhesion of tissue and organ occur with frequency after surgery. Theomosensitive hydrogel was prepared from poloxamer/chitosan/epidermal growth factor as adhesion barrier agent. The prepared hydrogel showed sol-gel transition temperatures around human temperature and gelation temperature was the faster within 1 min. The hydrogel sustained the release of epidermal grow factor during 7 days. The hydrogel was highly effective for the prevention of tissue and organ adhesion in rat model. The thermosensitive and antibacterial chitosan hydrogel can be useful to consider the anti-adhesion barrier with increased adhesion of organ and sustained release of epidermal growth factor.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2487-2490
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• 2013

In Thai traditional medicine, Plumbago indica or Jetamul-Pleung-Dang in Thai is known to have health benefit especially for anti-inflammatory, antibacterial, and antitumor activities. However, the mechanisms of its action are still uncertain. One of which might be genotoxic effects. In the present study, we investigated the genotoxicity of an ethanolic extract of Plumbago indica root (EEPIR) by sister chromatid exchange (SCE) assay in human lymphocytes. Results have shown that all treatments with EEPIR ($12.5-100{\mu}g/ml$) could induce cell cycle delay as shown by significant increase in the number of metaphase cells in the first cell cycle but neither in the second nor the third cell cycle. Only at concentrations of 25, 50, and $100{\mu}g/ml$ were SCE levels significantly increased above that of the control (p<0.05). EEPIR at a concentration of $500{\mu}g/ml$ induced cell death as few mitotic cells were shown. Accordingly, EEPIR ($25-100{\mu}g/ml$) is genotoxic in human lymphocytes and cytotoxic at concentrations of ${\geq}500{\mu}g/ml$ in vitro. Therefore, these activities of the EEPIR could serve its potential therapeutic effects, especially as an anticancer agent. Further study of EEPIR in vivo is now needed to support this in vitro evidence.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.367-373
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• 2016

The aim of this study was to evaluate the anti-caries effect of the essential oils and chlorhexidine mouth rinse. 42 subjects were randomized allocated to the chlorhexidine (n=22) and essential oils group (n=20). Subjects were instructed to rinsing each mouthwash by 15 ml once a day during the 7 days. The CRT and Cariview scores were recorded at baseline and 4 weeks after treatment. Data was analysed by using PASW 18.0 program with independent t-test and paired t-test. After 1 month, Cariview score was shown reducing compare to baseline. However, there were no significant differences between the groups. High risk level of MS and LB was decreased to 9~15% after treatment in two groups. Both of the chlorhexidine and essential oils mouth wash showed an antiplaque effect. Although chlorhexidine continues to be the "gold standard" in terms of antiplaque effect, essential oils could be considered a reliable alternative antimicrobial agent.

• Proceedings of the KACD Conference
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• 2002.11a
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• pp.720-720
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• 2002

A number of investigations have shown that the presence of bacteria is prerequisite for developing pulpal and/or periradicular pathosis. Depending on the stage of pulpal pathosis, various species of bacteria can be cultured from infected root canals. Kakehashi et al. showed that exposure of pulpal tissue in germ-free rats was characterized by minimal inflammation and dentinal bridging while exposure of pulpal tissue in conventional rats with normal oral flora was characterized by pulpal necrosis, chronic inflammation, and periapical lesions. Currently used methods of cleaning and shaping, especially rotary instrumentation techniques, produce a smear layer that covers root canal walls and the openings to the dentinal tubules. The smear layer contains inorganic and organic substances that include fragments of odontoblastic processes, microorganisms, their by products and necrotic materials. Because of its potential contamination and adverse effect on the outcome of root canal therapy, it seems reasonable to suggest removal of the smear layer for disinfection of the entire root canal system. Presence of this smear layer prevents penetration of intracanal medications into the irregularities of the root canal system and the dentinal tubules and also prevents complete adaptation of obturation materials to the prepared root canal surfaces. Removal of the smear layer by an intracanal irrigant and placement of an antibacterial agent in direct contact with the content of dentinal tubules should allow disinfection of this complex system and better outcome for the root canal therapy. A new solution, which was a mixture of a tetracycline, an acid, and a detergent(MTAD), was developed in the Department of Endodontics, Dental School. Lorna Linda University, USA. It has been demonstrated that MTAD was an effective solution for the removal of the smear layer and does not significantly change the structure of the dentinal tubules when used as a final irrigant in conjunction with 1 % NaOCl as a root canal irrigant. Studies are in progress to compare the anti- microbial properties of this newly developed solution with those of sodium hypochlorite and EDTA that are currently used to irrigate the root canals and remove the smear layer from the surfaces of instrumented root canals.canals.