Molybdenum ion inhibits the production of volatile sulfur compounds

Methods: The kind and concentration of metal ions solved in San-Roku-Go^®, which was purchased from Mirai Energy Co., Kofu, Japan, was determined using particle-induced X-ray emission analysis. The inhibitory effect of the detected metals on VSC production was quantitatively examined by spectrophotometric assay and gas chromatography analysis, where the recombinant L-cysteine desulfhydrase of Streptococcus anginosus and L-methionine-α-deamino-γ-mercaptomethane-lyase of Porphyromonas gingivalis were used for production of H₂S and methyl mercaptan, respectively. In in vivo studies, VSC from oral cavity of volunteers was measured using gas chromatography before and after rinsing with molybdenum-containing water.

Results: San-Roku-Go^® has an inhibitory effect on H₂S production at a dose-dependent manner. Of 13 metals solved in the solution, molybdenum was one of the most effective metals for inhibition of H₂S production. In addition, the production of methyl mercaptan was reduced by the metal. The inhibition was due to result of the high affinity of molybdenum for sulphide anions (S^2– and CH₃S^–). The inhibitory effect of molybdenum on the VSC production was also confirmed using human volunteers.

Conclusion: Both in vitro and in vivo studies demonstrated that molybdenum has an inhibitory effect on VSC production, suggesting that this metal is useful for treatment of halitosis.