The Chinese herbal medicine kouboku could help physicians manage periodontitis-causing Porphyromonas gingivalis bacteria.
P gingivalis is known to generate compounds that contribute to disease pathogenesis, including methyl mercaptan. The compound is a known marker of halitosis severity and periodontal disease—the degree of which is often proportional to the quantity of volatile sulfur compounds present in the oral cavity. Prior research has demonstrated that expression of the MGL protein may signal methyl mercaptan production in patients with halitosis. Kouboku has been previously found to inhibit both methyl mercaptan production and MGL mRNA expression. Nonetheless, the effects of kouboku on periodontal disease have been poorly studied.
In a study published in Molecular Oral Microbiology, researchers examined methyl mercaptan production, biofilm formation, P gingivalis-host cell interactions, and antibiotic effects following treatment with or without kouboku. They used the OralChroma device to measure methyl mercaptan production as well as quantitative polymerase chain reaction to assess the mRNA expression of MGL and FimA.
There were no statistically significant differences in the suppression of methyl mercaptan production between the P gingivalis strains included in the study following kouboku treatment. The medicine was effective at inhibiting biofilm formation as well as adhesion of the bacteria to gingival epithelial cells and other bacteria.
Additionally, kouboku’s active ingredients could decrease the minimum inhibitory concentrations of several antibiotics—including ampicillin, gentamicin, erythromycin, and tetracycline.
The researchers further evaluated how kouboku influenced biofilm formation by quantifying FimA mRNA expression in wild-type and MGL-deletion mutant strains. Kouboku was found to suppress FimA expression in both strains, suggesting that the target molecule for biofilm formation may be FimA rather than MGL.
The use of kouboku may enhance the antibacterial effects of antibiotics in clinical settings. However, future studies using more types of P gingivalis isolates from patients with periodontal disease are needed to better understand the benefits of the treatment.
The study authors reported no conflicts of interest.
