{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T05:20:39Z","timestamp":1766726439937,"version":"3.48.0"},"reference-count":37,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,23]],"date-time":"2025-12-23T00:00:00Z","timestamp":1766448000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Terminalia catappa L. (Family: Combretaceae) is used globally to treat various diseases, including bacterial infections. Whilst the antibacterial activity of T. catappa has previously been tested against antibiotic-sensitive bacterial strains, the antimicrobial activity against methicillin and \u03b2-lactam-resistant pathogens has been relatively ignored. The antibacterial activity of T. catappa extracts, both alone and combined with selected clinical antibiotics, was evaluated in this study. The inhibition of bacterial growth by the extracts was determined using agar diffusion and broth micro-dilution assays. Combinations of the extracts and several clinical antibiotics were also examined and the \u2211FICs were calculated to determine the interaction class. Synergistic combinations were further evaluated by isobologram analysis. The T. catappa leaf extracts were screened for toxicity using Artemia franciscana lethality bioassays (ALA). Orbitrap liquid chromatography\u2013mass spectrometry (LC-MS) profiling analysis was undertaken to identify flavonoid components of the extracts, putatively. The T. catappa methanolic extract inhibited all the tested bacterial strains. It displayed especially good inhibitory activity against E. coli (MIC = 130 \u00b5g\/mL). Combining the T. catappa extracts with some conventional antibiotics potentiated the inhibitory activity of the combinations compared to the activity of individual components. LC-MS profiling analysis identified multiple flavonoid components, including rutin, quercitin, orientin, the tannin component, and ellagic acid in the extracts. All extracts were non-toxic against Artemia nauplii. The phytochemical constituents present in the T. catappa leaf extracts warrant future investigation as potential antibacterial agents.<\/jats:p>","DOI":"10.3390\/ijms27010177","type":"journal-article","created":{"date-parts":[[2025,12,24]],"date-time":"2025-12-24T09:58:34Z","timestamp":1766570314000},"page":"177","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Phytochemical Evaluation of Terminalia catappa L. Extracts with Antibacterial and Antibiotic Potentiation Activities Against \u03b2-Lactam Drug-Resistant Bacteria"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-1965-6604","authenticated-orcid":false,"given":"Muhammad Jawad","family":"Zai","sequence":"first","affiliation":[{"name":"School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia"},{"name":"Centre for Planetary Health and Food Security, Griffith University, Brisbane, QLD 4111, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2306-0829","authenticated-orcid":false,"given":"Matthew James","family":"Cheesman","sequence":"additional","affiliation":[{"name":"School of Pharmacy and Medical Sciences, Griffith University, Southport, QLD 4222, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8732-8513","authenticated-orcid":false,"given":"Ian Edwin","family":"Cock","sequence":"additional","affiliation":[{"name":"School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia"},{"name":"Centre for Planetary Health and Food Security, Griffith University, Brisbane, QLD 4111, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1749","DOI":"10.1021\/jf980864s","article-title":"Evaluation of the antioxidant activity of environmental plants: Activity of the leaf extracts from seashore plants","volume":"47","author":"Masuda","year":"1999","journal-title":"J. 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