Drug and Herbal Research Centre, Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia.
Department of Clinical oral Biology, Faculty of Dentistry, Universiti Kebangsaan Malaysia, Kuala Lumpur 50300, Malaysia.
Molecules. 2017 Dec 5;22(12):2135. doi: 10.3390/molecules22122135.
In this study, the essential oils of Benth and Jack were evaluated for their antibacterial activity against invasive oral pathogens, namely , , , , , and . Chemical composition of the oils was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of the oils and their major constituents were investigated using the broth microdilution method (minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)). Susceptibility test, anti-adhesion, anti-biofilm, checkerboard and time-kill assays were also carried out. Physiological changes of the bacterial cells after exposure to the oils were observed under the field emission scanning electron microscope (FESEM). and oils mainly consisted of sesquiterpenoids (44.6% and 60.9%, respectively), and β-caryophyllene was the most abundant compound in both oils (26.3% and 36.3%, respectively). Other compounds present in were α-humulene (5.1%) and eugenol (8.1%), while α-humulene (5.5%) and germacrene D (7.7%) were dominant in . The oils of both plants showed moderate to strong inhibition against all tested bacteria with MIC and MBC values ranging 0.63-2.5 mg/mL. However, none showed any inhibition on monospecies biofilms. The time-kill assay showed that combination of both oils with amoxicillin at concentrations of 1× and 2× MIC values demonstrated additive antibacterial effect. The FESEM study showed that both oils produced significant alterations on the cells of Gram-negative bacteria as they became pleomorphic and lysed. In conclusion, the study indicated that the oils of and possessed moderate to strong antibacterial properties against the seven strains pathogenic oral bacteria and may have caused disturbances of membrane structure or cell wall of the bacteria.
在这项研究中，评估了 Benth 和 Jack 的精油对侵袭性口腔病原体的抗菌活性，即 、 、 、 、 和 。使用气相色谱（GC）和气相色谱-质谱联用（GC-MS）分析油的化学成分。使用肉汤微量稀释法（最小抑菌浓度（MIC）和最小杀菌浓度（MBC））研究了油及其主要成分的抗菌活性。还进行了药敏试验、抗黏附、抗生物膜、棋盘和时间杀伤试验。用场发射扫描电子显微镜（FESEM）观察细菌细胞在暴露于油后的生理变化。 和 油主要由倍半萜烯组成（分别为 44.6%和 60.9%），β-石竹烯是两种油中最丰富的化合物（分别为 26.3%和 36.3%）。 中的其他化合物为α-葎草烯（5.1%）和丁香酚（8.1%），而 中的主要化合物为α-葎草烯（5.5%）和大根香叶烯 D（7.7%）。两种植物的油对所有测试的细菌均表现出中度至强抑制作用，MIC 和 MBC 值范围为 0.63-2.5 mg/mL。然而，它们都没有对单种生物膜表现出任何抑制作用。时间杀伤试验表明，将两种油与阿莫西林以 1×和 2×MIC 值的浓度组合使用，显示出相加的抗菌作用。FESEM 研究表明，两种油都会导致革兰氏阴性菌的细胞发生显著变化，使其形态变得不规则并裂解。总之，该研究表明 和 的精油对七种致病性口腔细菌具有中度至强的抗菌特性，可能导致细菌的膜结构或细胞壁受到干扰。
