Department of Biology, College of Sciences, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
Laboratory of Microbial Biotechnology and Bioactive Molecules, Sciences and Technologies Faculty, Sidi Mohamed Ben Abdellah University, Imouzzer Road, P.O. Box 2202, Fez, Morocco.
Biomed Pharmacother. 2023 Nov;167:115609. doi: 10.1016/j.biopha.2023.115609. Epub 2023 Oct 4.
Cupressus sempervirens is a known traditional plant used to manage various ailments, including cancer, inflammatory and infectious diseases. In this investigation, we aimed to explore the chemical profile of Cupressus sempervirens essential oil (CSEO) as well as their antibacterial mode of action. The volatile components were characterized using gas chromatography coupled to a mass spectrometer (GC-MS). The results revealed remarkable antibacterial properties of EO derived from C. sempervirens. GC-MS analysis indicated that C. sempervirens EO characterized by δ-3-carene (47.72%), D-limonene (5.44%), β-pinene (4.36%), β-myrcene (4.02%). The oil exhibited significant inhibitory effects against a range of bacteria, including Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 13048, Bacillus cereus (Clinical isolate), Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. These inhibitory effects surpassed those of conventional antibiotics. Furthermore, the EO demonstrated low minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs), indicating its bactericidal nature (MBC/MIC < 4.0). Time-kill kinetics analysis showed that CSEO was particularly effective at 2 × MIC doses, rapidly reduced viable count of B. subtilis and P. aeruginosa within 8 h. This suggests that the oil acts quickly and efficiently. The cell membrane permeability test further demonstrated the impact of CSEO on the relative conductivity of B. subtilis and P. aeruginosa, both at 2 × MIC concentrations. These observations suggest that EO disrupts the bacterial membrane, thereby influencing their growth and viability. Additionally, the cell membrane integrity test indicated that the addition of CSEO to bacterial cultures resulted in the significant release of proteins from the bacterial cells. This suggests that EO affects the structural integrity of the bacterial cells. Furthermore, the anti-biofilm assay confirmed the efficacy of CSEO as a potent anti-biofilm agent. It demonstrated the oil's ability to inhibit quorum sensing, a crucial mechanism for biofilm formation, and its competitive performance compared to the tested antibiotics.
柏科植物是一种已知的传统植物，用于治疗各种疾病，包括癌症、炎症和传染病。在这项研究中，我们旨在探索柏科植物精油（CSEO）的化学成分，并研究其抗菌作用模式。采用气相色谱-质谱联用仪（GC-MS）对挥发性成分进行了表征。结果表明，柏科植物精油具有显著的抗菌活性。GC-MS 分析表明，柏科植物精油的特征成分为δ-3-蒈烯（47.72%）、D-柠檬烯（5.44%）、β-蒎烯（4.36%）、β-月桂烯（4.02%）。该油对一系列细菌表现出显著的抑制作用，包括金黄色葡萄球菌 ATCC 29213、枯草芽孢杆菌 ATCC 13048、蜡样芽孢杆菌（临床分离株）、铜绿假单胞菌 ATCC 27853 和大肠杆菌 ATCC 25922。这些抑制作用超过了常规抗生素。此外，该精油表现出较低的最小抑菌浓度（MIC）和最小杀菌浓度（MBC），表明其具有杀菌作用（MBC/MIC<4.0）。时间杀伤动力学分析表明，CSEO 在 2×MIC 剂量下特别有效，可在 8 小时内迅速降低枯草芽孢杆菌和铜绿假单胞菌的活菌数。这表明该油作用迅速且高效。细胞膜通透性试验进一步表明，CSEO 对枯草芽孢杆菌和铜绿假单胞菌的相对电导率有影响，在 2×MIC 浓度下均如此。这些观察结果表明，精油破坏了细菌膜，从而影响了其生长和活力。此外，细胞膜完整性试验表明，向细菌培养物中添加 CSEO 会导致细菌细胞内的蛋白质大量释放。这表明精油会影响细菌细胞的结构完整性。此外，抗生物膜试验证实了 CSEO 作为一种有效的抗生物膜剂的功效。它证明了该油抑制群体感应的能力，群体感应是生物膜形成的关键机制，以及它与测试抗生素相比的竞争表现。
