이상의 실험 결과들을 요약하면, 포르말린을 측두하악관절 내로 주입하여 발생한 염증성 통증 행위반응은 QX-314의 투여로 감소할 수 있었다. 저농도의 QX-314의 진통작용은 TRPV1 통로를 이용하여 세포막 내로 이동하여 작용이 나타났으며 고농도의 QX-314는 TRPV1 통로와 무관하게 진통작용을 나타내었다. 이와 같은 결과는 측두하악관절 장애로 인해 발생되는 염증성 통증에 QX-314가 효과적인 치료제로 사용할 수 있다는 것을 말해주며, 특히 고농도의 QX-314가 세포막을 이동하는 경로에 대한 연구가 더 진행된다면 임상에서 QX-314가 진통제로서 사용할 수 있는 계기가 될 것으로 판단된다.
It has been established that berberine has strong antimicrobial effects. Little is known however regarding the antimicrobial activity of berberine against endodontic pathogenic bacteria or its cytotoxicity in human oral tissue cells. The antibacterial properties of berberine were tested against 5 strains of Enterococcus faecalis and type strains of Aggregatibacter actinomycetemcomitans, Prevotella nigrescens, Prevotella intermedia, and Tannerella forsythia, which are involved in endodontic infections. Antimicrobial activity was evaluated through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) measurements. The viability of normal human gingival fibroblast (NHGF) cells after exposure to berberine was measured using a methyl thiazolyl tetrazolium (MTT) assay. The data showed that berberine has antimicrobial effects against A. actinomycetemcomitans with an MIC and MBC of 12.5 μg/ml and 25 μg/ml, respectively. In the cytotoxicity studies, cell viability was maintained at 66.1% following exposure to 31.3 μg/ml berberine. Overall, these findings suggest that berberine has antimicrobial activity against the tested bacteria. Nevertheless, lower concentrations in combination with other reagents will need to be tested before these in vitro results can be translated to clinical use.
In general, oleanolic acid (OA) and ursolic acid (UA) have antimicrobial effect against Gram-positive bacteria but not Gram-negative bacteria whereas sophoraflavanone G has antimicrobial activity against both bacterial types. However, the antimicrobial effects of OA, UA, and sophoraflavanone G against periodontopathogens have not been studied to any great extent. The aim of this study was to investigate antimicrobial effect of OA, UA, and sophoraflavanone G against 15 strains (5 species) of oral Gram-negative bacteria, which are the major causative bacteria of periodontal disease. The antimicrobial activity was evaluated by minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determinations. OA and UA showed antimicrobial effects against all of the Porphyromonas gingivalis strains tested and also Prevotella intermedia ATCC 25611T. Interestingly, P. intermedia ATCC 49046 showed greater resistance to OA and UA than P. intermedia ATCC 25611T. In contrast, sophoraflavanone G had antimicrobial activity against all strains, with MIC and MBC values below 32 μg/ml, except Aggregatibacter actinomycetemcomitans. These results indicate that sophoraflavanone G may have potential for use in future oral hygiene products such as dentifrices and gargling solution to prevent periodontitis.
The major issue in the development of nucleic acid based therapeutics is the inefficient delivery of these agents into cells. We prepared cholesterol conjugated spermine and evaluated its usefulness as a delivery modality for antisense oligonucleotides in HeLa-Luc cells. A 2’-O-methyl antisense oligonucleotide sequence, designed to correct splicing at an aberrant intron inserted into a normal luciferase reporter gene, was used for complex formation with cholesterol conjugated spermine. Effective delivery of this antisense agent into nucleus would results in the expression of a luciferasereporter gene product. The cholesterol-spermine formed stable complexes with the antisense oligonucleotide and showed modest delivery activity. Furthermore, this delivery activity was maintained even in the presence of serum proteins, mimicking in vivo conditions. Cholesterol-spermine thus has potential as a delivery system for antisense oligonucleotides into cells.
Human dental pulp stem cells (DPSCs) are multi-potent mesenchymal stem cells that have several differentiation potentials. An understanding of thetissues that differentiate from these cells can provide insights for future regenerative therapeutics and tissue engineering strategies. The mesiodens is the most frequent form of supernumerary tooth from which DPSCs can differentiate into several lineages similar to cells from normal deciduous teeth. Recently, it has been shown that nanoscale structures can affect stem cell differentiation. In our presentstudy, we investigated the effects of a 250-nm nanoscale ridge/groove pattern array on the osteogenic and adipogenic differentiation of dental pulp cells from mesiodenscontaining human DPSCs. To this end, the expression of lineage specific markers after differentiation induction was analyzed by lineage specific staining and RT-PCR. The nanoscale pattern arrayed surface showed apositive effect on the adipogenic differentiation of DPSCs. There was no difference between nanoscale pattern arrayed surface and conventional surface groups onosteogenic differentiation. In conclusion, the nanoscale ridge/groove pattern arrayed surface can be used to enhance the adipogenic differentiation of DPSCs derived from mesiodens. This finding provides an improved understanding of the effects of topography on cell differentiation as well as the potential use of supernumerary tooth in regenerative dental medicine.
HyPer is the genetically encoded biosensor of intracellular hydrogen peroxide (H2O2), the most stable of the reactive oxygen species (ROS) generated by living cells. HyPer has a high sensitivity and specificity for detecting intracellular H2O2 by confocal laser microscopy. However, it was not known whether high speed ratiometric imaging of H2O2 by HyPer is possible. We thus investigated the sensitivity of HyPer in detecting changes to the intracellular H2O2 levels in HEK293 and PC12 cells using a microfluorometer imaging system. Increase in the HyPer ratio were clearly evident on stimulations of more than 100 μM H2O2 and fast changes in the HyPer ratio were observed on ratiometric fluorescent images after H2O2 treatment. These results suggest that HyPer is a potent biosensor of the fast temporal production of intracellular H2O2.
Xylitol is a five-carbon sugar alcohol that reduces the incidence of caries by inhibiting the growth of oral streptococci, including Streptococcus mutans. Since xylitol is transported via the fructose phosphotransferase system, we hypothesized that it could also affect the growth of other oral bacteria strains. We tested the effects of xylitol against non-periodontopathogenic oral bacteria frequently found in healthy subjects as well as periodontopathogens including Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. With 5% xylitol, Streptococcus vestibularis and Gemella morbillorum showed marked growth inhibition. With 10% xylitol, all of the tested periodontopathogens and Actinomyces naeslundii showed marked growth inhibition, whereas the growth inhibition of Neisseria mucosa, Neisseria sicca and Veillonella parvula was mild only. Xylitol is a widely used sweetener and the concentration used in our experiment is easily achieved in the oral cavity. If xylitol reduces the growth of periodontopathogens more preferentially, it could also reduce the prevalence of these pathogens and have clinical utility in the prevention or treatment of periodontal disease.
The presence of distinct bacterial species is found to be dependent on age, diet, and disease. We compared the detection rate of several oral bacterial strains in a cohort of 36 subjects including healthy volunteers, periodontal patients, and oral cancer patients. Gargling samples were obtained from these subjects from which DNA was then extracted. Specific primers for 29 bacterial species were used for PCR detection. In the oral cancer patients, Capnocytophaga ochracea, Gemella morbillorum, and Streptococcus salivarius were detected more frequently compared with the healthy volunteers and periodontitis patients. Fusobacterium nucleatum/ polymorphym and Prevotella nigrescens were significantly less prevalent in oral cancer patients than the other groups. In periodontitis patients, Porphyromonas gingivalis and Treponema denticola were more frequently found compared with the healthy volunteers. In the healthy volunteer group, Peptostreptococcus anaerobius was more frequently found than the other groups. The detection rate of several oral bacterial species was thus found to differ between healthy volunteers, periodontitis patients and oral cancer patients.