Synergistic antibacterial effects of 5-fluorouracil or thioridazine in combination with phytopolyphenols on cultured Porphyromonas gingivalis

Background/purpose: 5-Fluorouracil (5FU) is a commonly used anticancer drug. However, the severe oral mucositis induced by 5FU in about 60–70% of patients was a major cause of discontinuous therapy. Since oral dysbiosis induced by 5FU was well correlated with severity of oral mucositis and Porphyromonas gingivalis (P.g.) was a keystone pathogen of dysbiosis. Thus, in this study, we aimed to explore the novel regimens of 5FU combined with phytopolyphenols (curcumin, green tea polyphenols) as well as ZnSO4 on antibacterial effects of cultured P.g. growth. In addition, similar regimens containing thioridazine (TRZ) were also tested for their antibacterial efficacy. Materials and methods: The synergistic (Combination Index (CI) < 1) antiproliferation and anti-protease efficacies (IC50) of novel regimens on cultured P.g. were evaluated by OD600 and colorimetric method respectively. Results: The results obtained indicated that both novel regimens of 5FU and TRZ exhibited potent synergistic antibacterial effects against growth and protease of P.g. Conclusion: These novel regimens of 5-FU and TRZ were potent antibacterial agents which merit for further preclinical and clinical trials in management of oral mucositis, cancers and infectious diseases.