Soulaimani Bouchra, Abbad Imane, Dumas Emilie, Gharsallaoui Adem
Laboratory of Microbial Biotechnologies, Agrosciences and Environment, Labeled Research Unit-CNRST N°4, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech 40000, Morocco.
Laboratory of Microbial Biotechnologies, Agrosciences and Environment, Labeled Research Unit-CNRST N°4, Faculty of Sciences Semlalia, Cadi Ayyad University, Marrakech 40000, Morocco.
Int J Pharm. 2025 Feb 10;670:125144. doi: 10.1016/j.ijpharm.2024.125144. Epub 2024 Dec 27.
The antimicrobial and antibiofilm properties of plant essential oils (EOs) have aroused significant interest for their potential as effective alternatives or supplements in combating microbial infections and biofilm-associated challenges. For these applications, EOs must be encapsulated to overcome some key technical limitations, including high volatility, poor stability, and low solubility. This study aimed to develop microencapsulated EOs derived from two valuable Moroccan medicinal plants, Lavandula stoechas L. and Thymus pallidus Batt., both individually and in combination, using the spray drying method. The antimicrobial and antibiofilm effects of these encapsulated EOs were evaluated against various pathogenic microorganisms using microdilution and crystal violet assays. Key physico-chemical characteristics of the EO microcapsules, including optimal particle size, favorable zeta potential, low water content, and high encapsulation yield and efficiency were observed, indicating strong stability and effective encapsulation. The major chemical compounds identified in the studied EOs were thymol (26.72 %), γ-terpinene (23.26 %), and p-cymene (19.07 %) in T. pallidus EO; and camphor (47.67 %), fenchone (20.78 %), and 1.8-cineole (12.17 %) in L. stoechas EO. The results from antimicrobial assays demonstrated that the encapsulated T. pallidus EO exhibited stronger inhibitory and microbicidal effects against all tested strains, with MIC and MMC values ranging from 0.312 mg/mL to 2.50 mg/mL. The encapsulated EOs combination demonstrated interesting antimicrobial effect, with varying type of interactions depending on the target microorganisms. Additionally, the antibiofilm activity of the microencapsulated EOs combination, evaluated against Staphylococcus aureus, Klebsiella pneumoniae and Bacillus subtilis, showed significant biofilm inhibition with percentages reaching up to 92.68 % at MIC concentration and BIC ranging from 0.05 ± 0.00 mg/mL to 0.17 ± 0.01 mg/mL. The eradication of preformed biofilms was also measured, showing a notable effect with eradication rates exceeding 78 % at concentrations of 4MIC, and BEC values ranging from 0.16 ± 0.02 mg/mL to 1.30 ± 0.37 mg/mL. Overall, these finding indicate that the encapsulated EO combination derived from these two Moroccan medicinal plants presents a promising formulation capable of overcoming the limitations associated with free EOs and contributing to the fight against antimicrobial resistance and biofilm-related challenges.
植物精油(EOs)的抗菌和抗生物膜特性因其作为对抗微生物感染和生物膜相关挑战的有效替代品或补充剂的潜力而引起了极大的关注。对于这些应用,必须对精油进行微胶囊化处理,以克服一些关键的技术限制,包括高挥发性、稳定性差和低溶解度。本研究旨在采用喷雾干燥法,开发源自两种珍贵摩洛哥药用植物——薰衣草(Lavandula stoechas L.)和苍白百里香(Thymus pallidus Batt.)的微胶囊化精油,包括单独的以及两者组合的。使用微量稀释法和结晶紫测定法,评估了这些微胶囊化精油对各种致病微生物的抗菌和抗生物膜效果。观察到精油微胶囊的关键物理化学特性,包括最佳粒径、良好的zeta电位、低含水量以及高包封率和效率,表明其具有很强的稳定性和有效的包封效果。在所研究的薰衣草精油中鉴定出的主要化学成分是百里香酚(26.72%)、γ-萜品烯(23.26%)和对伞花烃(19.07%);在苍白百里香精油中鉴定出的主要化学成分是樟脑(47.67%)、小茴香酮(20.78%)和1,8-桉叶素(12.17%)。抗菌试验结果表明,微胶囊化的苍白百里香精油对所有测试菌株均表现出更强的抑制和杀菌作用,其最低抑菌浓度(MIC)和最低杀菌浓度(MMC)值范围为0.312mg/mL至2.50mg/mL。微胶囊化精油组合表现出有趣的抗菌效果,根据目标微生物的不同,相互作用类型也有所不同。此外,针对金黄色葡萄球菌、肺炎克雷伯菌和枯草芽孢杆菌评估的微胶囊化精油组合的抗生物膜活性显示,在MIC浓度下对生物膜有显著抑制作用,抑制率高达92.68%,生物膜抑制浓度(BIC)范围为0.05±0.00mg/mL至0.17±0.01mg/mL。还测定了对预先形成的生物膜的消除情况,结果表明在4倍MIC浓度下消除率超过78%,生物膜消除浓度(BEC)值范围为0.16±0.02mg/mL至1.30±0.37mg/mL,显示出显著效果。总体而言,这些发现表明,源自这两种摩洛哥药用植物的微胶囊化精油组合是一种有前景的制剂,能够克服与游离精油相关的局限性,并有助于对抗抗菌药物耐药性和生物膜相关挑战。
Front Cell Infect Microbiol. 2025-3-3