Enhancing Antibiotic Efficacy: Synergy Between Medicinal Plant Extracts and Conventional Antibiotics in Combating MDR Infections

Multidrug-resistant (MDR) pathogens are becoming a major global concern, threatening human health, food security, and the effectiveness of modern medical treatments. As traditional antibiotics lose their potency, there is an urgent demand for alternative approaches to treat these resistant strains. This study explored the combined effects of plant-based and standard antibiotics on MDR pathogens. Four medicinal plants known for their antimicrobial properties were chosen: Allium sativum (garlic), Curcuma longa (turmeric), Ocimum sanctum (holy basil or tulsi), and Azadirachta indica (neem). Ethanolic extracts of these plants were prepared and tested against clinical isolates of Staphylococcus aureus (MRSA), Escherichia coli (MDR), Klebsiella pneumoniae, and Candida albicans, both individually and in combination with ciprofloxacin, amoxicillin, and amphotericin B. Antimicrobial susceptibility was evaluated by disk diffusion and checkerboard assays. All four plant extracts showed inhibitory effects against the MDR strains tested, with garlic and neem exhibiting the strongest standalone activity. When combined with antibiotics, the plant extracts displayed varying levels of interaction, with several combinations showing synergistic effects, as indicated by the Fractional Inhibitory Concentration Index (FICI) values. In these synergistic combinations, the minimum inhibitory concentrations (MICs) of antibiotics were significantly reduced by four- to 8-fold. These results suggest that plant-derived antimicrobials can enhance the effectiveness of conventional antibiotics, thereby providing a promising strategy for addressing MDR pathogens. Further studies are necessary to standardize the extraction methods, determine the optimal dosing regimens, and evaluate the efficacy and safety of these combinations in clinical settings.