Antimicrobial potential of selected medicinal plants against drug-resistant pathogens: a systematic review.

BACKGROUND: Antimicrobial resistance (AMR) poses a critical global health threat, necessitating the discovery of novel antimicrobial agents. Traditional medicinal plants have long been used for managing infectious diseases, yet scientific validation of their efficacy remains limited for many species. This systematic review synthesizes existing evidence on the antimicrobial activities of nine medicinal plants traditionally used: Lepidium sativum, Saussurea costus, Rhus tripartita, Chenopodium murale, Pyrus communis, Argemone ochroleuca, Trigonella hamosa, Galium odoratum, and Erucaria hispanica.

METHODS: Following PRISMA guidelines, a comprehensive search was conducted in Google Scholar for studies published between 1 January 2000-1 August 2025. Search terms combined each plant's scientific name with antimicrobial-related keywords ("antimicrobial," "antibacterial," "antifungal") and study type filters ("in vitro," "in vivo"). Only English-language studies investigating the antibacterial or antifungal activity of extracts or isolated metabolites from the target species were included. Clinical trials, reviews, case reports, and non-English publications were excluded. Data extraction captured microorganism type and strain, plant part studied, extraction method, antimicrobial assay, and reported activity (MIC, MBC, or inhibition zone).

RESULTS: A total of fifty-six eligible studies were included in the review. The evidence indicated that antibacterial and antifungal activities varied among the studied species. L. sativum, S. costus, R. tripartita, and C. murale were relatively well investigated, with findings showing broad-spectrum activity against both Gram-positive and Gram-negative bacteria. In contrast, P. communis, A. ochroleuca, and T. hamosa demonstrated antibacterial effects on both bacterial groups; however, they require further research. Several plants displayed notable antifungal effects, particularly against Candida spp., though results varied depending on extraction method, plant part, and microbial strain. Notably, studies employing advanced extraction techniques such as supercritical fluid extraction and green synthesis of nanoparticles, particularly silver nanoparticles, frequently reported enhanced antimicrobial efficacy compared to conventional solvent extracts. These nanoparticle formulations often exhibited larger inhibition zones and lower MIC values, highlighting their potential to potentiate the bioactivity of plant extracts.

CONCLUSION: This review highlights the antimicrobial potential of the selected medicinal plants and supports their traditional use in managing infectious diseases. Standardized methodologies and bioactive compound isolation are recommended to facilitate their future development as candidates for combating AMR pathogens.

SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD420251047619.