红花椒精油对致口臭菌的抗菌和抗生物膜活性研究

Antibacterial and antibiofilm activities of Zanthoxylum bungeanum essential oils against the halitosis-causing bacteria

该研究通过水蒸汽蒸馏法从甘肃(ZB_(1))、云南(ZB_(2))、山西(ZB_(3))和陕西(ZB_(4))4个产地的红花椒中提取精油,利用全二维飞行时间质谱分析红花椒精油(Zanthoxylum bungeanum essential oils,ZBEOs)的主要化学成分,并采用微量肉汤稀释法测定ZBEOs对具核梭杆菌(Fusobacterium nucleatum)和牙龈卟啉单胞菌(Porphyromonas gingivalis)的最小抑菌浓度和最小杀菌浓度,筛选出抑制效果最佳的ZB xEO,通过扫描电子显微镜和激光共聚焦显微镜进一步观察其对受试菌菌体和生物膜的影响。结果表明,受试ZBEOs中均富含芳樟醇(4.68%~22.75%)、β-月桂烯(5.31%~17.02%)和柠檬烯(5.76%~9.78%)。ZBEOs对受试菌的生长均具有不同程度的抑制效果,其中从云南红花椒中提取的精油(ZB_(2)EO)对2种受试菌的抗菌活性最强,可破坏受试菌的形态结构,对菌体造成不可逆的损伤。此外,经ZB 2EO处理后,受试菌生物膜结构变得松散,生物量减少。综上,ZBEOs对致口臭菌具有良好的抗菌和抗生物膜活性,为ZBEOs在口臭防治方面的开发和利用提供了理论参考依据。

Plant essential oil is considered as an effective potential substitute for chemical antibacterial agents since it has many superior properties.Zanthoxylum bungeanum is used to treat oral diseases in traditional Chinese medicine.However,there were few studies on the application of Z.bungeanum essential oils(ZBEOs)in the treatment of halitosis.To study the antibacterial and antibiofilm activities of ZBEOs against the halitosis-causing bacteria,ZBEOs were extracted by steam distillation from different provinces of Chine,i.e.Gansu(ZB 1),Yunnan(ZB 2),Shanxi(ZB 3),and Shaanxi(ZB 4).The chemical composition of ZBEOs were analyzed by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry(GC×GC-TOFMS).The minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC)of ZBEOs against the halitosis-causing bacteria were determined by the broth dilution methods.The most effective one was selected to further investigate its antibacterial and antibiofilm activities.The microstructure of the halitosis-causing bacteria and biofilm were observed by scanning electron microscopy(SEM)and confocal laser scanning microscopy(CLSM),respectively.The results showed that 55,67,67,and 80 components(relative content greater than 0.10%)were identified from ZB 1EO,ZB 2EO,ZB 3EO and ZB 4EO,respectively,accounting for 95.98%to 97.16%of the total components.The tested ZBEOs were rich in linalool(4.68%-22.75%),β-myrcene(5.31%-17.02%)and limonene(5.76%-9.78%).Among them,ZB 2EO exhibited excellent inhibitory activities against the halitosis-causing bacteria.The MIC value of ZB 2EO against Fusobacterium nucleatum and Porphyromonas gingivalis were 1 and 2 mg/mL,and the MBC value were 1 and 4 mg/mL,respectively.ZB 2EO(1×MIC)added in the lag phase and log phase of the halitosis-causing bacteria can effectively inhibit their proliferation.ZB 2EO(1×MIC)could be irreversibly damaged the microstructure of F.nucleatum and P.gingivalis.50%minimum biofilm eradication concentration(MBEC 50)of ZB 2EO against F.nucleatum and P.gingivalis were 4 and 8 mg/mL,respectively.After ZB 2EO(1×MBEC 50)treatment,the biofilms of the halitosis-causing bacteria were thin,and the biomass decreased.This study shows that ZBEOs can effectively inhibit the growth of the halitosis-causing bacteria and eradicate the preformed biofilm.In conclusion,ZBEOs have effective antibacterial and antibiofilm activities against the two halitosis-causing bacteria,which may provide a theoretical basis for the development and utilization of ZBEOs in the prevention and treatment of halitosis.