Phytotherapy and One Health: The Role of Medicinal Plants in Combating Antimicrobial Resistance Worldwide

Abstract

The aim of this study was to evaluate the role of medicinal plants and their bioactive compounds in combating antimicrobial resistance (AMR) within the One Health framework. This work was designed as a narrative integrative review. The study was conducted at the Veterinary Diagnostic Laboratory, Michigan State University, between January and October 2025. A structured literature search was performed in PubMed, Scopus, Web of Science, SciELO, ScienceDirect, and Google Scholar using predefined inclusion and exclusion criteria. Studies published between 2010 and 2025 were screened for relevance to human, veterinary, and environmental health. A total of 1,240 records were identified, and after screening and eligibility assessment, 20 studies met the inclusion criteria. Most studies originated from Asia and South America, focusing on plant families such as Lamiaceae, Asteraceae, and Rutaceae. Bioactive compounds including flavonoids, terpenoids, alkaloids, tannins, and saponins exhibited antimicrobial activity against multidrug-resistant pathogens such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. Several studies reported synergistic effects with conventional antibiotics, reduced minimum inhibitory concentrations, and inhibition of biofilm formation and quorum sensing. These findings support the therapeutic potential of phytotherapy as an adjunct or alternative approach in human and veterinary medicine. However, significant limitations were identified, including lack of standardized methodologies, limited in vivo and clinical studies, and fragmented regulatory frameworks. Addressing these gaps through interdisciplinary collaboration, chemical standardization, and regulatory harmonization is essential to support the safe and effective integration of phytotherapy into AMR mitigation strategies.