Nenadovich Milica, Kubal Molly, Hopp Maci R, Crawford Abigail D, Hardewig Megan E, Sedlock Madison G, Jawad Rida, Khan Zarrar A, Smith Adrianna M, Mroueh Mia A, DuBrava Matthew, Jones Ellie C, Rahe Cael, Berthrong Sean T, Wilson Anne M, Trombley Michael P, Tietje Ashlee H, Stobart Christopher C
Department of Biological Sciences, Butler University, Indianapolis, IN 46208, USA.
Clowes Department of Chemistry and Biochemistry, Butler University, Indianapolis, IN 46208, USA.
Pathogens. 2025 Aug 5;14(8):776. doi: 10.3390/pathogens14080776.
The increasing prevalence of antibiotic resistance and the limited availability of antiviral therapeutics for pathogens such as human respiratory syncytial virus (hRSV) underscore the need for novel, plant-derived antimicrobial substances. In this study, we evaluated the antiproliferative, antibacterial, and antiviral activities of aqueous leaf extracts from two plants commonly found in North America, Osage orange () and spearmint (). Both extracts exhibited no significant cytotoxic or morphologic impact on HEp-2 human cancer cells up to 25 mg/mL. However, both extracts demonstrated strong dose-dependent antibacterial activity, significantly inhibiting replication of and at concentrations ≥ 1 mg/mL. Antiviral assays revealed that both extracts inhibited hRSV infectivity, with spearmint extract showing higher potency (EC = 1.01 mg/mL) compared to Osage orange (EC = 3.85 mg/mL). Gas chromatography-mass spectrometry (GC-MS) identified three major extract constituents: 3-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol (Osage orange), and R-(-)-carvone (spearmint). Among these, only carvone significantly inhibited hRSV in vitro, suggesting its key role in spearmint's antiviral activity. These findings highlight the therapeutic potential of Osage orange and spearmint leaf extracts, particularly as sources of water-soluble compounds with antimicrobial properties, and support further investigation into their mechanisms of action and broader clinical relevance.
抗生素耐药性的日益普遍以及针对人类呼吸道合胞病毒（hRSV）等病原体的抗病毒治疗药物供应有限，凸显了对新型植物源抗菌物质的需求。在本研究中，我们评估了北美常见的两种植物——桑橙（Maclura pomifera）和留兰香（Mentha spicata）叶水提取物的抗增殖、抗菌和抗病毒活性。两种提取物在浓度高达25 mg/mL时，对HEp-2人癌细胞均未表现出明显的细胞毒性或形态学影响。然而，两种提取物均表现出强烈的剂量依赖性抗菌活性，在浓度≥1 mg/mL时，能显著抑制金黄色葡萄球菌（Staphylococcus aureus）和大肠杆菌（Escherichia coli）的复制。抗病毒试验表明，两种提取物均能抑制hRSV感染性，与桑橙提取物（半数有效浓度[EC50]=3.85 mg/mL）相比，留兰香提取物的效力更高（EC50=1.01 mg/mL）。气相色谱-质谱联用（GC-MS）鉴定出三种主要的提取物成分：3-羟基苯甲醇、4-羟基苯甲醇（桑橙）和R-（-）-香芹酮（留兰香）。其中，只有香芹酮在体外能显著抑制hRSV，表明其在留兰香抗病毒活性中起关键作用。这些发现突出了桑橙和留兰香叶提取物的治疗潜力，特别是作为具有抗菌特性的水溶性化合物来源，并支持进一步研究它们的作用机制和更广泛的临床相关性。
