8种植物精油对肠道常见微生物体外抑菌效果的研究

Evaluation of the In Vitro Antimicrobial Effects of Eight Plant Essential Oils against Common Intestinal Microorganisms

通过测定抑菌圈直径、最低抑菌浓度和最小杀菌浓度,研究八种植物精油(肉桂油、牛至油、百里香油、桉叶油、茶树油、薄荷油、迷迭香油和茴香油)对肠道致病菌和益生菌的体外抑菌活性并与五种抗生素比较。结果表明:八种植物精油均对肠道致病菌和益生菌具有一定的抑杀能力,其中综合抑菌效果最好的是肉桂和牛至,其对黄曲霉和肠道益生菌的抗菌效果远远优于抗生素;肉桂与牛至进行复配时,其对肠道致病菌的抑制作用全表现相加作用(FICI≤0.75),而对肠道益生菌的生长却没有影响(FICI=1)。通过GC-MS分析,肉桂油的主要活性成分为肉桂醛(52.17%)、邻甲氧基肉桂醛(15.18%)和香豆素(2.83%);牛至油的主要活性成分为香芹酚(51.73%)、对伞花烃(8.50%)和γ-松油烯(7.66%)。实验表明,肉桂和牛至复合精油的抗细菌效果可与抗生素媲美,且有着抗生素不可替代的抗真菌效果,为开发新型绿色、安全、高效的抗生素替代品提供有效的理论依据。

The in vitro antimicrobial activities of eight edible plant essential oils（cinnamon oil, oregano oil, thyme oil, eucalyptus oil, tea tree oil, peppermint oil, rosemary oil, and anise oil） against intestinal pathogens and probiotics were investigated by measuring the inhibition zone diameter, minimum inhibitory concentration（MIC）, and minimum bactericidal concentration（MBC）, and the results were compared with those of five antibiotics. All eight plant essential oils had an inhibitory effect on the intestinal pathogens and probiotics. Among them, the best overall antibacterial effect was shown by cinnamon oil and oregano oil, whose inhibitory effects on Aspergillus flavus and probiotics were far superior to those of the antibiotics. The combination of cinnamon oil with oregano oil resulted in asynergetic effect on the inhibition of the intestinal pathogens（fractional inhibitory concentration index [FICI]≤0.75）, but had no impact on the growth of probiotics（FICI=1）. Gas chromatography-mass spectrometry analysis revealed that the major components of cinnamon oil were cinnamaldehyde（52.17%）, o-methoxycinnamaldehyde（15.18%）, and coumarin（2.83%）. The main components of oregano oil were carvacrol（51.73%）, p-cymene（8.50%）, and γ-terpinene（7.66%）. The mixture of cinnamon oil and oregano oil had an equivalent antibacterial effect with the antibiotics, and had a unique antifungal effect that the antibiotics did not possess. This study provides an effective theoretical basis for the development of a new, green, safe, and effective alternative to antibiotics.