Department of Pharmaceutical Biology, Faculty of Pharmacy, University of Pécs, H-7624, Rókus u. 2, Pécs, Hungary.
Department of Pharmacognosy, Faculty of Pharmacy, University of Pécs, H-7624, Rókus u. 2, Pécs, Hungary.
BMC Complement Med Ther. 2021 Nov 24;21(1):287. doi: 10.1186/s12906-021-03461-5.
Pseudomonas aeruginosa is the most common Gram-negative bacterium associated with nosocomial respiratory infections. Lavender essential oil is mainly used in aromatherapy, but it has several pharmacological and therapeutic properties. Furthermore, it possesses antifungal and antibacterial activities. The anti-inflammatory activity of essential oils may depend on the composition and the ratio of the compounds. The constitution of the essential oils extracted from the different stages of flowering period varies, which makes it plausible that the collection time of the flowers influences the anti-inflammatory effects. Different types of essential oils reduce inflammation acting similarly by modulating the activity and action of the NFκB signalling pathway, which is the major regulator of the transcription of pro-inflammatory cytokines.
Lavender essential oils were distilled from lavender plant cultivated in Hungary and the flowers were harvested at the beginning and at the end of flowering period. The experiments were carried out on THP-1 human monocyte/macrophage cell line as in vitro cell culture model for monitoring the effects of lavender essential oils and the main compound linalool on P. aeruginosa LPS stimulated inflammation. The mRNA and protein levels of four pro-inflammatory cytokines, IL-6, IL-1β, IL-8 and TNFα were determined by Real Time PCR and ELISA measurements. The effects of essential oils were compared to the response to two NFκB inhibitors, luteolin and ACHP.
Linalool and lavender essential oil extracted from plants at the beginning of flowering period were successful in decreasing pro-inflammatory cytokine production following LPS pretreatment. In case of IL-8 and IL-1β lavender oil showed stronger effect compared to linalool and both of them acted similarly to NFκB inhibitors. Pretreatments with linalool and lavender essential oil/beginning of flowering period prevented pro-inflammatory cytokine production compared to LPS treatment alone. Although lavender essential oil/end of flowering period decreased IL-6, IL-1β and IL-8 mRNA expression in case of LPS pretreatment, it was not capable to reduce cytokine secretion.
Based on our results it has been proven that lavender essential oil extracted at the beginning of flowering period is a potent inhibitor of the synthesis of four pro-inflammatory cytokines IL-6, IL-8, IL-β and TNFα of THP-1 cells. This supports the relevance of the collection of the lavender flowers from early blooming period for essential oil production and for the utilization as an anti-inflammatory treatment.
铜绿假单胞菌是医院获得性呼吸道感染最常见的革兰氏阴性菌。薰衣草精油主要用于芳香疗法，但它具有多种药理学和治疗特性。此外，它具有抗真菌和抗菌活性。精油的抗炎活性可能取决于化合物的组成和比例。不同开花期提取的精油的组成不同，这使得收集花朵的时间影响抗炎效果成为合理的假设。不同类型的精油通过调节 NFκB 信号通路的活性和作用来减轻炎症，NFκB 信号通路是促炎细胞因子转录的主要调节剂。
从匈牙利种植的薰衣草植物中提取薰衣草精油，在开花初期和末期收获花朵。实验在 THP-1 人单核/巨噬细胞系上进行，作为监测薰衣草精油和主要化合物芳樟醇对铜绿假单胞菌 LPS 刺激炎症的体外细胞培养模型。通过实时 PCR 和 ELISA 测量确定四种促炎细胞因子（IL-6、IL-1β、IL-8 和 TNFα）的 mRNA 和蛋白水平。将精油的作用与两种 NFκB 抑制剂（木樨草素和 ACHP）的反应进行比较。
在 LPS 预处理后，从开花初期植物中提取的芳樟醇和薰衣草精油成功地降低了促炎细胞因子的产生。在 IL-8 和 IL-1β的情况下，薰衣草油的作用强于芳樟醇，它们的作用与 NFκB 抑制剂相似。与 LPS 单独处理相比，用芳樟醇和薰衣草精油/开花初期预处理可预防促炎细胞因子的产生。尽管薰衣草精油/开花末期可降低 LPS 预处理时的 IL-6、IL-1β和 IL-8 mRNA 表达，但不能降低细胞因子分泌。
根据我们的结果，已经证明从开花初期提取的薰衣草精油是 THP-1 细胞四种促炎细胞因子（IL-6、IL-8、IL-β和 TNFα）合成的有效抑制剂。这支持了在开花初期采集薰衣草花朵进行精油生产和作为抗炎治疗的应用的相关性。
