<i>Talinum fruticosum</i> (L.) Juss. (Talinaceae), an Edible and Medicinal Plant, Enhances the Activity of Antibiotics Against Multidrug-Resistant Gram-Negative Bacteria

Abstract

The rapid acquisition of multidrug-resistant (MDR) phenotypes by bacteria creates life-threatening complications in infection control. Accordingly, this study aims to investigate the antibacterial activity of the methanol extract of<i> Talinum fruticosum </i>leaves and its interaction effects with antibiotics against MDR Gram-negative bacteria<i>.</i> The broth microdilution method was used to evaluate the antibacterial activity and antibiotic-resistance modulation effects of the extract. The interaction between antibiotics and <i>T. fruticosum</i> leaf<i> </i>extract (TFLE) was conducted using the checkerboard assay. Phytochemical screening was assessed using standardized qualitative tests. TFLE displayed low antibacterial activity, with MICs ranging from 512 to 2048 µg/mL against the tested bacteria. Interestingly, TFLE at its subinhibitory concentration (MIC/8) enhanced the efficacy of antibiotics by 2-to 64-fold, particularly tetracycline, doxycycline, imipenem, kanamycin, and ciprofloxacin, against at least one of the examined MDR bacteria. In addition, TFLE displayed a synergistic effect (ƩFIC < 0.5) with kanamycin and doxycycline against <i>K. pneumoniae </i>K2 and <i>E. aerogenes </i>EA298. The phytochemical screening indicated that TFLE contained flavonoids, saponins, tannins, terpenoids, phenols, and anthocyanins. Overall, this study shows that <i>T. fruticosum</i> leaf extract could be used in combination with commonly used antibiotics to fight infections involving MDR bacteria. Therefore, further studies are needed to identify in this plant a likely nontoxic antibiotic modulator.