Antibacteria activities of phenolics from "Jinshiji" thinned-young apple on halitosis-related bacteria

This article aims to explain the inhibitory mechanism of thinned-young apple polyphenols (YAP) toward Fusobacterium nucleatum (F. nucleatum), Porphyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intermedia). YAP has optimal antibacterial concentration against F. nucleatum (10.00 mg/mL), P. gingivalis (8.00 mg/mL) and P. intermedia (8.00 mg/mL), with viability of 47.97%, 38.01% and 36.94%, respectively. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) observation revealed that YAP could cause the morphological changes of the halitosis-related bacterial cells and induce cell apoptosis. With the increase of YAP treatment concentrations, the permeability of the outer membranes (OM) and inner membranes (IM) of halitosis-related bacteria dramatically increased, resulting in the release of proteins and nucleic acids. In addition, bacterial cell membrane potential (MP) decreased after exposure to YAP. The results of this study provide new antibacterial agents for halitosis-related bacteria and find a new way for the development of thinned-young apples.