Abstract Essential oils (EOs) extracted from botanical resources have greatly been appraised as antimicrobials against a broad spectrum of microorganisms. A panoply of experimental studies have pointed out the immense potency of EOs as natural antimicrobial agents at relatively low doses; largely attributed to the synergistic interactions of various bioactive components. In the present study, 10 EOs prepared from two endemic (Pittosporum senacia Putterl. subsp. Senacia and Syzygium coriaceum J. Bosser & J. Gueho) and seven exotic (Cinnamomum camphora (L.) Nees & Eberm, Citrus aurantium L., Curcuma longa L, Morinda citrifolia L., Petroselinum crispum (Mill.) Fuss, Plectranthus amboinicus (Lour.) Sprengel and Syzygium samarangense (Blume) Merr. & L. M. Perry) aromatic medicinal plants from Mauritius, were screened for their growth inhibitory activities against eight bacteria (ATCC strains and clinical isolates) using broth microdilution techniques. The EOs were found to possess varying degree of antibacterial potency. The most active EOs were found to have minimum inhibitory concentration (MIC) of 0.25–4 mg/mL and minimum bactericidal concentration (MBC) of 0.25–16 mg/mL. In particular, at its MIC values, P. amboinicus EO showed bactericidal effects against four strains. However, all tested bacteria were insensitive to P. senecia and C. aurantium fruit peel EOs. Bacillus spizizenii was found to be the most susceptible strain to the active EOs. Additionally, P. amboinicus and the two Syzygium spp. EOs showed antibiotic potentiating activities. Mostly synergistic and partial synergistic actions of the EOs in combination with the conventional antibiotics (streptomycin, chloramphenicol and ciprofloxacin) at a ratio of 1:1 were obtained against the tested bacteria. Thus, results from this study highlighted the antibacterial potential and the efficacy of the most active EOs as antibiotic potentiating agents that could potentially be used in combinational therapies along with conventional antibiotics for a synergistic approach in the treatment/management of clinically relevant bacterial infections.

中文翻译：

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来自毛里求斯的 9 种外来和地方药用植物的精油显示出体外抗菌和抗生素增强活性

摘要 从植物资源中提取的精油 (EOs) 已被广泛评价为抗广谱微生物的抗菌剂。大量的实验研究表明，在相对低的剂量下，EOs 作为天然抗菌剂的巨大效力；很大程度上归因于各种生物活性成分的协同相互作用。在本研究中，10 种 EOs 从两种地方性植物（Pittosporum senacia Putterl. subsp. Senacia 和 Syzygium coriaceum J. Bosser & J. Gueho）和 7 种外来植物（Cinnamomum camphora (L.) Nees & Eberm、Citrus aurantium L.、Curcuma longa L、Morinda citrifolia L.、Petroselinum splashum (Mill.) Fuss、Plectranthus amboinicus (Lour.) Sprengel 和 Syzygium samarangense (Blume) Merr. & LM Perry) 来自毛里求斯的芳香药用植物，使用肉汤微量稀释技术筛选了它们对八种细菌（ATCC 菌株和临床分离株）的生长抑制活性。发现 EO 具有不同程度的抗菌效力。发现最活跃的 EO 具有 0.25–4 mg/mL 的最小抑菌浓度 (MIC) 和 0.25–16 mg/mL 的最小杀菌浓度 (MBC)。特别是，在其 MIC 值下，P. amboinicus EO 显示出对四种菌株的杀菌作用。然而，所有测试的细菌都对 P. senecia 和 C. aurantium 果皮 EO 不敏感。发现 Bacillus spizizenii 是对活性 EO 最敏感的菌株。此外，P. amboinicus 和两个 Syzygium spp。EOs 显示出抗生素增强活性。EOs 与常规抗生素（链霉素、氯霉素和环丙沙星）以 1:1 的比例组合时，对受试细菌产生了大部分协同和部分协同作用。因此，这项研究的结果强调了最活跃的 EO 作为抗生素增强剂的抗菌潜力和功效，这些 EO 可能与常规抗生素一起用于联合治疗，以协同治疗/管理临床相关细菌感染。