Combined antibacterial effects of turmeric and cinnamon ethanolic extracts with ampicillin against resistant-microbial strains: In vitro and molecular docking approaches

Background Antimicrobial resistance refers to the phenomenon in which microorganisms cease to respond to antibiotic therapy. Plants are known to possess antimicrobial effects. Method: The inhibitory effects of turmeric and cinnamon were tested using the agar diffusion method on Staphylococcus aureus and Escherichia coli , respectively, while molecular docking analyses were carried out using the Gold software (version 2.2) and Discovery Studio (2016 version). Results Staphylococcus aureus exhibited sensitivity to turmeric extract alone and a combination of turmeric and ampicillin, while demonstrating moderate sensitivity to ampicillin alone. Similarly, Escherichia coli exhibited moderate sensitivity to both cinnamon extract and ampicillin but demonstrated higher sensitivity to the combination of cinnamon extract and ampicillin. Furthermore, molecular docking studies of curcumin, bisdemethoxycurcumin, demethoxycurcumin, tetrahydrocurcumin, zingiberene, curcumenol, and curcumol in turmeric extract with Sortase-A indicated binding efficiencies, evidenced by fitness scores of 65.72%, 63.46%, 62.37%, 61.80%, 49.19%, 41.26%, and 37.47%, respectively. In the same manner, molecular docking investigations of eugenol, cinnamyl acetate, linalool, β-caryophyllene, and cinnamaldehyde in cinnamon extract with extended-spectrum β-lactamase (ESBL) indicated better binding efficiencies, evidenced by fitness scores of 40.64%, 39.62%, 38.03%, 36.86%, and 35.25%, respectively. Conclusion Synergistic inhibitory effects of turmeric and cinnamon extracts with ampicillin were effective against Staphylococcus aureus and Escherichia coli resistant strains.