Samani Faezeh Nabizadeh, Ghavam Mansureh, Tavili Ali, Mirzaei Rouhollah
Department of Nature Engineering, Faculty of Natural Resources and Earth Sciences, University of Kashan, Kashan, Iran.
Department of Reclamation of Arid and Mountainous Regions, Faculty of Natural Resources, University of Tehran, Karaj, Iran.
PLoS One. 2025 Jun 5;20(6):e0323296. doi: 10.1371/journal.pone.0323296. eCollection 2025.
Melissa officinalis L. as a medicinal plant used in traditional medicine to treat headaches caused by stress, anemia, nausea, dizziness, indigestion, colic, epilepsy, hysteria, cancer, and heart failure. The present study aimed to evaluate the effect of foliar spraying of silver and iron nanoparticles as fertilizers on yield, type, chemical compounds, and antimicrobial properties of M. officinalis leaf essential oil. For this purpose, plant cultivation was conducted in May 2020 as a completely random design. After one year of establishment, foliar spraying was conducted at the beginning of flowering, the peak of flowering, and the end of flowering at the levels of 20, 40, 60, 80, and 100 mg/L, and the control of iron and silver nanoparticles. After collecting and drying the leaves, the essential oil was extracted by water distillation, and the compounds were identified by Gas chromatography-mass spectrometry. The antibacterial activity of essential oils was evaluated by using agar diffusion method, Minimum growth inhibitory concentration, and Minimum concentration of bacterial lethality. The results showed that foliar spraying with different nano iron and silver treatments had a significant effect on the yield, percentage of compounds, and antimicrobial activity of M. officinalis leaf essential oil (p ≤ 0.01). The 60 mg/L of FeNPs concentration with 1.70% (w/w) had the highest yield of M. officinalis leaf essential oil. The neral (33.5-0%), citral (28.53-0%), geranial (28.25-0%), caryophyllene (20.71-0%), caryophyllene-oxide (19.73-7.36%), and geranial acetate (5.99-11.84%) were the dominant compounds of essential oil. The results of antimicrobial test showed that the lowest MIC value belongs to the treatments of nano iron 100, nano silver 20, and nano silver 60 mg/L with a value of <62.5 μg/mL. against Pseudomonas aeruginosa, that it was one times weaker than rifampin and three times more potent than the control treatment. However, the best treatment in terms of of the essential oil efficiency was for the samples sprayed with nanoiron 60 mg/L. In terms of the essential oil componds, was for the nanoiron treatment 100 mg/L with the predominance of caryophyllene oxide and geranyl acetate, and in terms of the antimicrobial activity, was for the nano silver treatment, 60 mg/L. Therefore, they can be promising and potential natural options for the production of M. officinalis essential oil under foliar spraying with economical and environmentally friendly fertilizers for consumption in various pharmaceutical and cosmetic industries.
香蜂草（Melissa officinalis L.）作为一种药用植物，在传统医学中用于治疗由压力引起的头痛、贫血、恶心、头晕、消化不良、绞痛、癫痫、癔症、癌症和心力衰竭。本研究旨在评估叶面喷施银和铁纳米颗粒作为肥料对香蜂草叶片精油的产量、类型、化学成分和抗菌性能的影响。为此，于2020年5月进行了植物栽培，采用完全随机设计。定植一年后，在开花初期、盛花期和花期末期，分别以20、40、60、80和100 mg/L的浓度进行叶面喷施铁和银纳米颗粒，并设置铁和银纳米颗粒的对照。叶片采集干燥后，采用水蒸馏法提取精油，并用气相色谱 - 质谱联用仪鉴定化合物。采用琼脂扩散法、最低抑菌浓度和最低杀菌浓度评估精油的抗菌活性。结果表明，不同的纳米铁和银处理叶面喷施对香蜂草叶片精油的产量、化合物百分比和抗菌活性有显著影响（p≤0.01）。60 mg/L的FeNPs浓度下，香蜂草叶片精油产量最高，为1.70%（w/w）。精油的主要成分有橙花醛（33.5 - 0%）、柠檬醛（28.53 - 0%）、香叶醛（28.25 - 0%）、石竹烯（20.71 - 0%）、石竹烯氧化物（19.73 - 7.36%）和乙酸香叶酯（5.99 - 11.84%）。抗菌试验结果表明，最低MIC值属于纳米铁100、纳米银20和纳米银60 mg/L处理，对铜绿假单胞菌的值<62.5 μg/mL，比利福平弱一倍，比对照处理强三倍。然而，就精油效率而言，最佳处理是喷施60 mg/L纳米铁的样品。就精油成分而言，最佳处理是100 mg/L纳米铁处理，以石竹烯氧化物和乙酸香叶酯为主；就抗菌活性而言，最佳处理是60 mg/L纳米银处理。因此，在叶面喷施经济环保型肥料的情况下，它们有望成为生产香蜂草精油的有潜力的天然选择，可用于各种制药和化妆品行业。
