背景:由于其抗菌作用,精油在医学应用中变得越来越流行。百里香L.(唇科)是一种众所周知的和广泛种植的药用植物,用作感冒的补救措施,咳嗽和胃肠道症状。百里香的精油含量负责其抗微生物活性,然而,据报道,精油的化学成分影响其生物活性。为了探讨开花物候期对百里香精油化学成分及其抗菌和抗生物膜活性的影响,在开花开始时收集植物材料,盛开和2019年开花期结束。
方法:蒸馏来自新鲜和干燥植物材料的精油,并用气相色谱-质谱(GC-MS)和气相色谱-火焰离子化检测(GC-FID)进行分析。通过肉汤微量稀释和薄层色谱-直接生物自显影(TLC-DB)测定法进行抗菌活性,并通过结晶紫测定法进行抗生物膜作用,分别。应用扫描电子显微镜来说明精油处理后细菌细胞的细胞变化。
结果:百里酚(52.33-62.46%)是百里香精油的主要成分。从新鲜植物材料中蒸馏并在开花期开始时收集的百里香油对流感嗜血杆菌具有最高的抗菌和抗生物膜活性,H.副流感和铜绿假单胞菌。
结论:不同开花期对胸腺精油的抗菌和抗生物膜活性有影响,因此,必须考虑收集时间,而不仅仅是盛开,但开花期开始可能提供生物活性百里香精油。
BACKGROUND: Essential oils are becoming increasingly popular in medicinal applications because of their antimicrobial effect. Thymus vulgaris L. (Lamiaceae) is a well-known and widely cultivated medicinal plant, which is used as a remedy for cold, cough and gastrointestinal symptoms. Essential oil content of thyme is responsible for its antimicrobial activity, however, it has been reported that the chemical composition of essential oils influences its biological activity. In order to explore flowering phenophases influence on the chemical composition of thyme essential oil and its antibacterial and anti-biofilm activity, plant materials were collected at the beginning of flowering, in full bloom and at the end of flowering periods in 2019.
METHODS: Essential oils from fresh and dried plant materials were distilled and analyzed with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID). The antibacterial activity was performed by broth microdilution and thin layer chromatography-direct bioautography (TLC-DB) assays and the anti-biofilm effect by crystal violet assay, respectively. Scanning electron microscopy was applied to illustrate the cellular changes of bacterial cells after essential oil treatment.
RESULTS: Thymol (52.33-62.46%) was the main component in the thyme essential oils. Thyme oil distilled from fresh plant material and collected at the beginning of flowering period exerted the highest antibacterial and anti-biofilm activity against Haemophilus influenzae, H. parainfluenzae and Pseudomonas aeruginosa.
CONCLUSIONS: The different flowering periods of Thymus vulgaris influence the antibacterial and anti-biofilm activity of its essential oils, therefore, the collection time has to be taken into consideration and not only the full bloom, but the beginning of flowering period may provide biological active thyme essential oil.