Resveratrol dimer, Gnetin-C, inhibits the growth and virulence of Porphyromonas gingivalis

Abstract

Abstract Gnetin-C, a dimer of resveratrol, is a polyphenol that has been reported to have various health-promoting effects. In periodontal tissue, Gnetin-C has also been demonstrated to promote alveolar bone healing in animal experiments. However, its effects on bacteria have not yet been investigated. In this study, we have compared the effect of Gnetin-C, monomeric resveratrol, and Melinjo seed extract, the source of Gnetin-C, on the periodontopathic bacteria, Porphyromonas gingivalis, and examined its mechanism of action. The results illustrated that Gnetin-C more strongly inhibited bacterial growth, bacterial cell adhesion, and biofilm binding than monomeric resveratrol. Melinjo seed extract also displayed greater effectiveness than monomeric resveratrol but lower effectiveness than Gnetin-C. RNA sequencing analysis and quantitative polymerase chain reaction highlighted marked changes in the gene expression profiles of P. gingivalis. The expression of genes related to fimbriae, iron metabolism, protease, and amino acid and vitamin metabolic pathways were significantly suppressed, whereas a significant increase in the expression of oxidative stress-related genes was observed. Reactive oxygen species levels were also significantly decreased by Gnetin-C treatment. These results revealed that Gnetin-C could inhibit the growth of P. gingivalis while may also attenuate its pathogenesis.