An in vitro study of the effects of Phellodendron bark extract and berberine chloride on periodontal pathogenic bacteria in the oral microbiome.

OBJECTIVES: Periodontal disease is triggered by oral microbiome dysbiosis. Thus, to prevent its onset, it is important to maintain relative abundance of periodontal pathogenic bacteria in the oral microbiome at a low level. While Phellodendron bark extract (PBE) and its active ingredient, berberine, exert antibacterial effects on periodontal pathogenic bacteria, such as Porphyromonas gingivalis, their effects on the oral microbiome as a whole remain unknown. Therefore, we aimed to clarify the potential of PBE and berberine chloride (BC) in regulating the relative abundance of periodontal pathogenic bacteria in the oral microbiome. METHODS: Saliva was collected from 20 participants. Each participant's saliva was combined separately with P. gingivalis suspension and either PBE or BC in a modified basal medium. The samples were then incubated under anaerobic conditions for 24 h. After cultivation, we determined the total bacterial concentration using quantitative polymerase chain reaction analysis and the bacterial composition using 16 S ribosomal RNA gene sequencing. RESULTS: The total bacterial concentration was reduced because of treatment with PBE and BC. Bacterial 16 S ribosomal RNA gene sequencing confirmed that treatment with PBE and BC significantly reduced the relative abundance of periodontal pathogenic bacteria, including red and orange complex bacteria. CONCLUSIONS: Our findings suggest that PBE and BC reduce the relative abundance of periodontal pathogenic bacteria in the oral microbiome. Thus, PBE and BC can aid in preventing periodontal disease, given their ability to regulate the oral microbiome composition and their anti-inflammatory effects.

High-Throughput LC-MS/MS Method for Chiral Amino Acid Analysis Without Derivatization.

D-Amino acids have recently attracted much attention in various research fields including medical, clinical, and food industry due to their important biological functions that differ from L-amino acid. Most chiral amino acid separation techniques require complicated derivatization procedures in order to achieve the desirable chromatographic behavior and detectability. This chapter describes a highly sensitive analytical method for the enantioseparation of chiral amino acids without any derivatization process using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method allows the simultaneous analysis of 18 D-amino acids with high sensitivity and reproducibility. Additionally, this chapter also focuses on the application of the method to real samples for the quantification of targeted amino acids.