Shanghai Institute of Technology, Shanghai 201418, China.
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China.
Microb Pathog. 2018 Mar;116:26-32. doi: 10.1016/j.micpath.2018.01.009. Epub 2018 Jan 9.
The objective of this study was to investigate the antibacterial effects of cinnamon (Cinnamomum zeylanicum) bark essential oil (CBEO) and its principal constituent cinnamaldehyde against Porphyromonas gingivalis and to elucidate the antibacterial mechanism. GC-MS analysis showed that cinnamaldehyde was the major constituent in CBEO (57.97%). The minimum inhibition concentrations (MICs) of CBEO and cinnamaldehyde were 6.25 μg/mL and 2.5 μM for P. gingivalis, respectively. Nucleic acid and protein leakage was observed with increasing concentrations of CBEO and cinnamaldehyde. Additionally, propidium iodide uptake assays revealed CBEO and cinnamaldehyde at 1 × MIC impaired P. gingivalis membrane integrity by enhancing cell permeability. Morphological changes in P. gingivalis cells were observed by scanning electron microscopy, which indicated cell membrane destruction. To further determine the anti-biofilm effect, relative biofilm formation and established biofilms were examined, which demonstrated that both CBEO and cinnamaldehyde at sub-MIC levels inhibited P. gingivalis biofilm formation by 74.5% and 67.3% separately, but only CBEO slightly decreased established biofilms by 33.5% at 4 × MIC. These results suggest the potential of CBEO as a natural antimicrobial agent against periodontal disease. Furthermore, cinnamaldehyde was confirmed to be the antibacterial substance of CBEO with inhibitory action against P. gingivalis.
本研究旨在探讨肉桂（Cinnamomum zeylanicum）树皮精油（CBEO）及其主要成分肉桂醛对牙龈卟啉单胞菌的抗菌作用，并阐明其抗菌机制。GC-MS 分析表明，肉桂醛是 CBEO 的主要成分（57.97%）。CBEO 和肉桂醛对牙龈卟啉单胞菌的最小抑菌浓度（MIC）分别为 6.25μg/mL 和 2.5μM。随着 CBEO 和肉桂醛浓度的增加，观察到核酸和蛋白质泄漏。此外，碘化丙啶摄取实验表明，CBEO 和肉桂醛在 1×MIC 时通过增强细胞通透性，破坏牙龈卟啉单胞菌的膜完整性。扫描电子显微镜观察到牙龈卟啉单胞菌细胞的形态变化，表明细胞膜破坏。为了进一步确定抗生物膜作用，检查了相对生物膜形成和已建立的生物膜，结果表明，CBEO 和肉桂醛在亚 MIC 水平分别抑制了 74.5%和 67.3%的牙龈卟啉单胞菌生物膜形成，但只有 CBEO 在 4×MIC 时略微降低了 33.5%的已建立生物膜。这些结果表明，CBEO 作为一种天然抗牙周病抗菌剂具有潜力。此外，已证实肉桂醛是 CBEO 的抗菌物质，对牙龈卟啉单胞菌具有抑制作用。
