• International Journal of Oral Biology
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• v.39 no.2
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• pp.75-79
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• 2014

The aim of this study was to investigate antimicrobial effect of oleanolic acid (OA), ursolic acid (UA), and sophoraflavanone G against Enterococcus faecalis and Propionibacterium acnes, which are the major causative bacteria of endodontic infections. The antimicrobial activity was evaluated by the minimal inhibitory concentration (MIC). The data showed that the OA, UA, and sophoraflavanone G had antimicrobial effect on all the strains use in the study with $16-64{\mu}g/ml$, $8-64{\mu}g/ml$, and $1-8{\mu}g/ml$ of MIC values, respectively. These results indicate that OA, UA, and sophoraflavanone G could be useful in the development of antiseptic solution for washing the root canal in endodontic treatments.

• International Journal of Oral Biology
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• v.33 no.1
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• pp.25-31
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• 2008

Inhibition of proteasome activity may reduce many types of cancer, so it's pathway is effective in cancer as well as in clinical fields. Here the author has carried out experiment targeting on the elevation of apoptosis in oral cancer cells by combination of proteasome inhibitor, lactacystin, and DNA replication inhibitor, etoposide. The growth of KB cells was measured by MTT methods and apoptosis was analyzed by DNA fragmentation and Hochest nucleus staining. The proteasome activity was analyzed by fluorescent tagged peptide and cellular protein expression was detected by Western hybridization. Though lactacystin and etoposide inhibited KB cell growth alone, but low combined doses inhibited cell growth more strongly and induced apoptosis. The proteasome activity was also seriously inhibited by the combination of both chemicals. Tumor suppressor proteins and apoptosis inducing proteins were highly increased under the combination of both chemicals. From above studies we can conclude that proteasome inhibitors may be used for the treatment of oral cancer and proteasome inhibitors with DNA replication inhibitors may be effective in clinical trials of oral cancer.

• International Journal of Oral Biology
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• v.32 no.4
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• pp.127-133
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• 2007

Oral squamous cell carcinoma (OSCC) is the most common malignancy and is a major cause of worldwide cancer mortality. The proto-oncogene c-myb plays an important role in regulation of cell growth and differentiation, and it is expressed at high levels in hematopoietic cells and many other types of cancers. However, the function of c-myb is not well known in OSCC. The present study aimed to reveal the function of c-myb and to test the alternation of cell growth and signaling by c-myb in OSCC. In this study, c-myb and dominant-negatibe myb(DNmyb) were expressed in an adenovirus-mediated gene delivery system to KB cells. The over-expressed c-myb brought increased cellular proliferation compared with control cells. However, DN-myb infected KB cells showed significant reduction of cell growth and enhanced induction of apoptosis to activate PARP and caspase 9. c-myb induced increase of IGF-I, -II and IGF-IR expressions while DN-myb down-regulated these expression. Activation of ERK and Akt/PKB pathway was shown only in c-myb transduced cells. These findings suggest that the role of c-myb in cell growth of oral cancer cells is partially mediated through the modulation of IGFs, ERK and Akt/PKB. From this results, DN-myb is strongly recommended as a curable gene for the treatment of c-myb dependent malignancies such as OSCC.

• International Journal of Oral Biology
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• v.47 no.4
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• pp.63-63
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• 2022

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.269.2-269.2
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• 2003

• International Journal of Oral Biology
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• v.39 no.4
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• pp.201-206
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• 2014

This study investigated the antimicrobial activity of methanol extract of mulberry leaf against 16 strains of mutans streptococci and four species of periodontopathogens: Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Aggregatibacter actinomycetemcomitans. The antimicrobial activities of the crude extracts or silica gel chromatography fractions of methanol-extracted mulberry leaf were evaluated by determining minimal inhibitory concentrations using an established microdilution method. The cytotoxicity of the extracts of mulberry leaf on KB cells was tested by the methyl thiazolyl tetrazolium assay. Chromatography fraction 12 displayed the most potent antimicrobial activity against all 16 strains of mutans streptococci, P. gingivalis, and P. intermedia. No KB cell cytotoxicity was evident up to $128{\mu}g/ml$ of fraction 12. The methanol extract had no antimicrobial activity against F. nucleatum and A. actinomycetemcomitans. These results suggest chromatography fraction 12 methanol extract of mulberry leaf could be useful in the development of oral hygiene products, such as dentifrice and oral hygiene solution, for the prevention of dental caries.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.1093-1100
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• 2013

Background: p53 gene variants i.e. 16 bp duplication in intron 3, Arg72Pro in exon 4 and G>A in intron 6 have been reported to modulate susceptibility to various malignancies. Therefore, the present study evaluated the role of these p53 polymorphisms in oral cancer susceptibility in a population from Gujarat, West India. Method: Genotype frequencies at the three p53 loci in 110 controls and 79 oral cancer cases were determined by the PCR-RFLP method. Results: Heterozygous individuals at exon 4 showed protection from developing oral cancer. Homozygous wild and heterozygous individuals at intron 3 and those heterozygous at exon 4 in combination appeared to be at lowered risk. Furthermore, carriers of the 16 bp duplication allele at intron 3, proline allele at exon 4 and G allele at intron 6 were protected from oral cancer development. Conclusion: p53 polymorphisms, especially Arg72Pro in exon 4 could significantly modify the risk of oral cancer development in Gujarat, West Indian population.

• 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.

• Journal of dental hygiene science
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• v.22 no.2
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• pp.115-125
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• 2022

Background: In the dental hygiene curriculum, efforts are being made to introduce an integrated curriculum based on the competency of a dental hygienist. Because there is a connection and overlap in learning contents between Dental Nutrition and Oral Biochemistry, which are basic dental hygiene subjects, it is possible to integrate these two subjects. This study aims to derive Nutritional Biochemistry as an integrated curriculum for Dental Nutrition and Oral Biochemistry, and to develop learning goals and competencies for Dental Nutritional Biochemistry. Methods: The learning contents of the integrated curriculum were composed by referring to the contents of the Dental Nutrition and Oral Biochemistry textbooks, and learning goals were derived from the learning contents. Moreover, competency was developed by analyzing the duties of a dental hygienist that can be performed through the learning goals. The Delphi survey was conducted twice to verify the content validity ratio (CVR) of the competence and the learning goal of the integrated curriculum. Results: In the first Delphi survey, the CVR for two competencies was 0.56 or higher. Moreover, it was revised based on expert's opinions, and as a result of the second Delphi survey after the revision, the CVR was either increased or maintained. Eighty-five learning goals were derived by referring to the textbook. According to CVR and expert opinions, after the first Delphi survey, the number of learning goals was reduced to 69. After the second Delphi survey, 68 learning goals were finally derived. Conclusion: The development process of the integrated curriculum conducted in this study can be utilized for integration between subjects in basic dental hygiene.

• International Journal of Oral Biology
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• v.36 no.1
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• pp.7-11
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• 2011

Ursolic acid is a triterpenoid compound present in many plants. This study examined the antimicrobial activity of ursolic acid against mutans streptococci (MS) isolated from the Korean population. The antimicrobial activity was evaluated by the minimum inhibitory concentration (MIC) and time kill curves of MS. The cytotoxicity of ursolic acid against KB cells was tested using an MTT assay. The $MIC_{90}$ values of ursolic acid for Streptococcus mutans and Streptococcus sobrinus isolated from the Korean population were $2 {\mu}g$/ml and $4 {\mu}g$/ml, respectively. Ursolic acid had a bactericidal effect on S. mutans ATCC $25175^T$ and S. sobrinus ATCC $33478^T$ at > $2 \;{\times}\; MIC (4 {\mu}g$/ml) and $4 \;{\times}\; MIC (8 {\mu}g$/ml), respectively. Ursolic acid had no cytotoxic effect on KB cells at concentrations at which it exerted antimicrobial effects. The results suggest that ursolic acid can be used in the development of oral hygiene products for the prevention of dental caries.