Department of Crop Sciences and Agroforestry, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, 16500 Prague, Czech Republic.
Department of Sustainable Technologies, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, 16500 Prague, Czech Republic.
Molecules. 2023 Jun 7;28(12):4625. doi: 10.3390/molecules28124625.
Essential oils (EOs) have great potential in inhalation therapy for the treatment of respiratory infections. However, innovative methods for evaluation of antimicrobial activity of their vapors are still needed. The current study reports validation of the broth macrodilution volatilization method for assessment of the antibacterial properties of EOs and shows the growth-inhibitory effect of Indian medicinal plants against pneumonia-causing bacteria in liquid and vapor phase. Among all samples tested, EO exhibits the strongest antibacterial effect against , with minimum inhibitory concentrations of 128 and 256 µg/mL in the liquid and vapor phases, respectively. Furthermore, EO is found to be nontoxic to normal lung fibroblasts assessed by modified thiazolyl blue tetrazolium bromide assay. Chemical analysis performed using gas chromatography-mass spectrometry identified α-citral, cyperotundone, and thymol as the main constituents of , , and EOs, respectively. In addition, β-cymene is identified as the major compound of EO vapors when analyzed using solid-phase microextraction and gas-tight syringe sampling techniques. This study demonstrates the validity of the broth macrodilution volatilization method for antimicrobial screening of volatile compounds in the vapor phase and suggests the therapeutic potential of Indian medicinal plants in inhalation therapy.
精油（EOs）在呼吸道感染的吸入治疗中具有巨大的潜力。然而，仍需要创新的方法来评估其蒸气的抗菌活性。本研究报告了肉汤宏观稀释挥发法评估 EO 抗菌特性的验证，并显示了印度药用植物在液体和蒸气相中对引起肺炎的细菌的生长抑制作用。在所测试的所有样品中，[特定精油名称]对[细菌名称]表现出最强的抗菌作用，在液体和蒸气相中最小抑菌浓度分别为 128 和 256μg/mL。此外，通过改良噻唑蓝溴化四氮唑比色法评估，发现[特定精油名称]对正常肺成纤维细胞无毒。使用气相色谱-质谱联用仪进行的化学分析确定[特定精油名称]、[特定精油名称]和[特定精油名称]的主要成分分别为α-柠檬醛、环戊酮和百里酚。此外，当使用固相微萃取和气体密封注射器采样技术分析时，β-月桂烯被确定为[特定精油名称]蒸气的主要化合物。本研究证明了肉汤宏观稀释挥发法在蒸气相中对挥发性化合物进行抗菌筛选的有效性，并提示了印度药用植物在吸入治疗中的治疗潜力。
