Synergism between α-mangostin and TRAIL induces apoptosis in squamous cell carcinoma of the oral cavity through the mitochondrial pathway.

Mangosteen (Garcinia mangostana) is a tree found in South-East Asia and the pericarp of its fruit has been used in folk medicine for the treatment of many human illnesses. Mangosteen fruit rinds contain a high concentration of xanthone, which is a type of polyphenol. One type of xanthone, α-mangostin, has been reported to exert chemopreventive effects against chemically-induced colon cancer through the decrease of c-Myc expression, suppressing tumor growth in a mouse model of mammary cancer. A recent study demonstrated the inhibitive effect of α-mangostin on the growth of prostate cancer. However, it remains unclear whether α-mangostin induces cell death in oral cancer. The present study examined the impact of α-mangostin on human oral squamous cell carcinoma (HOSCC). Firstly we analyzed the expression of c-Myc in five HOSCC cell lines. The highest expression level of c-Myc mRNA was observed in SAS cells and the lowest in HSC-4 cells. Therefore, SAS cells were treated with α-mangostin, which was found to exert a weak cytocidal effect. Since α-mangostin has been reported to exert synergistic effects on cancers when combined with anticancer drugs, we attempted to evaluate such synergistic effects of α-mangostin when used with a cytokine, tumor necrosis factor (TNF)-related apoptosis­inducing ligand (TRAIL). We found that the combination of α-mangostin with TRAIL induced apoptosis of SAS cells through the mitochondrial pathway via activation of caspase-9 and -3/7, following release of cytochrome c. This apoptosis was induced by S/G2/M-phase arrest. Immunopositivity for c-Myc was observed in the cytoplasm of tumor cells in 16 (40%) of the 40 cases of HOSCC. These data revealed that the combination of α-mangostin and TRAIL may have a considerable potential for the treatment of oral cancer.

Anti-Halitosis Effect of Toothpaste Supplemented with Alkaline Extract of the Leaves of Sasa senanensis Rehder.

BACKGROUND: Previous studies have shown activity against viruses, bacteria, inflammation and oral lichenoid dysplasia of alkaline extract of the leaves of Sasa senanensis Rehder (SE), suggesting its possible application to oral diseases. In the present study, we performed a small-scale clinical test to investigate whether SE is effective against halitosis and in oral bacterial reduction. MATERIALS AND METHODS: A total of 12 volunteers participated in this study. They brushed their teeth immediately after meals three times each day with SE-containing toothpaste (SETP) or placebo toothpaste. Halitosis in the breath and bacterial number on the tongue were measured by commercially available portable apparatuses at a specified time in the morning. RESULTS: Some relationship was observed between halitosis and bacterial number from each individual, especially when those with severe halitosis were included. Repeated experiments demonstrated that SETP significantly reduced halitosis but not the bacterial number on the tongue. CONCLUSION: The present study provides for the first time the basis for anti-halitosis activity of SE.

Dendritic effects on the ordered assembly and the interfacial one-electron oxidation of redox-active dendron-functionalized gold nanoparticles.

A higher generation dendron with a long-alkyl chain thiol (DA2-SH) induced the formation of nanoparticles with a small core with quite a narrow size distribution (1.5 +/- 0.1 nm), the self-assembly of one-dimensional arrays of these gold nanoparticles (DA2-Au), and the stabilization for the formation of the radical cation of the phenothiazine of DA2-Au nanoparticles from the interfacial one-electron oxidation of the nanoparticles with NOBF4.