Effectiveness of mentha extracts against oral microorganisms: an in vitro study / 대한구강보건학회지

Objectives@#Dental caries and periodontal disease are infectious and chronic diseases. The aim of the study was to investigate the antimicrobial effect of mentha extracts against Streptococcus mutans (S. mutans ) and Porphyromonas gingivalis (P. gingivalis ). @*Methods@#This activity of mentha extracts were confirmed by the disk diffusion test and minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and colony forming unit (CFU) assays. @*Results@#S. mutans and P. gingivalis showed the highest antimicrobial activity within the inhibition zones. The antimicrobial activity was interrupted as the MIC and MBC of the herbal extracts against the two bacteria were 1 mg/ml and 10 mg/ml, respectively. The antimicrobial effect was determined by the CFU assay. @*Conclusions@#Mentha herb extract demonstrated potential antimicrobial activity against S. mutans and P. gingivalis that cause dental caries and periodontal disease.

Effect of apoptosis on G361 cells by Cimicifuga rhizoma extract / 대한구강보건학회지

OBJECTIVES: To investigate whether the cytotoxic effect of Cimicifuga rhizoma extract is associated with cell death in the human keratinocyte (HaCaT) and human melanoma cell lines (G361). METHODS: Apoptosis induced by Cimicifuga rhizoma extract was confirmed by water-soluble tetrazolium salts-1 (WST-1) assay, immunocytochemistry, and western blot. Additionally, the release of cytochrome c and apoptosis-inducing factor (AIF) was visualized by confocal laser scanning microscopy. RESULTS: The results showed that Cimicifuga rhizoma extract significantly reduced the viability of G361 cells with half-maximal inhibitory concentration (IC 50) of 200 µg/ml, and the apoptotic process was found to occur via the activation of caspase-3 and caspase-9 pathways. Besides, the release of cytochrome c and AIF was also detected. CONCLUSIONS: This study suggests that Cimicifuga rhizoma extract causes apoptosis of human melanoma cells through the intrinsic apoptotic pathway.

Induction of Melanoma Cell-Selective Apoptosis Using Anti-HER2 Antibody-Conjugated Gold Nanoparticles

PURPOSE: This study was conducted to verify the induction and mechanism of selective apoptosis in G361 melanoma cells using anti-HER2 antibody-conjugated gold nanoparticles (GNP-HER2). MATERIALS AND METHODS: Following GNP-HER2 treatment of G361 cells, cell cycle arrest and apoptosis were measured by WST-1 assay, Hemacolor staining, Hoechst staining, immunofluorescence staining, fluorescence-activated cell sorting analysis, and Western blotting.

Antimicrobial Effect of Low Temperature Atmospheric Plasma against Oral Pathogens

The purpose of this study was to investigate the antibacterial effect of the low temperature atmospheric plasma device with needle tip designed for easy approach to the oral cavity and root canal against Streptococcus mutans, Enterococcus faecalis and Candida albicans. The antibacterial activities evaluated by measuring clear zone of agar plate smeared with each bacteria after plasma treatment. To quantify antibacterial effects, dilution plate method was used. In addition, scanning electron microscope (SEM) was used for observation of changes in bacterial morphology. As treatment time of plasma increased, the clear zone was enlarged. The death rate was more than 99%. The SEM results showed that the globular shape of bacteria was distorted. These results suggest that needle tip plasma could be an innovative device for prevention of dental caries, and treatment of apical infection and soft tissue diseases.

S Phase Cell Cycle Arrest and Apoptosis is Induced by Eugenol in G361 Human Melanoma Cells

Eugenol is an essential oil found in cloves and cinnamon that is used widely in perfumes. However, the significant anesthetic and sedative effects of this compound have led to its use also in dental procedures. Recently, it was reported that eugenol induces apoptosis in several cancer cell types but the mechanism underlying this effect has remained unknown. In our current study, we examined whether the cytotoxic effects of eugenol upon human melanoma G361 cells are associated with cell cycle arrest and apoptosis using a range of methods including an XTT assay, Hoechst staining, immunocytochemistry, western blotting and flow cytometry. Eugenol treatment was found to decrease the viability of the G361 cells in both a time- and dose-dependent manner. The induction of apoptosis in eugenol-treated G361 cells was confirmed by the appearance of nuclear condensation, the release of both cytochrome c and AIF into the cytosol, the cleavage of PARP and DFF45, and the downregulation of procaspase-3 and -9. With regard to cell cycle arrest, a time-dependent decrease in cyclin A, cyclin D3, cyclin E, cdk2, cdk4, and cdc2 expression was observed in the cells after eugenol treatment. Flow cytometry using a FACScan further demonstrated that eugenol induces a cell cycle arrest at S phase. Our results thus suggest that the inhibition of G361 cell proliferation by eugenol is the result of an apoptotic response and an S phase arrest that is linked to the decreased expression of key cell cycle-related molecules.