The Antibacterial Effect of Some Medicinal Plant Extracts and their Synergistic Effect with Antibiotics

Abstract

The aim of the study was to assess the antibacterial effect of some medicinal plant extracts and their synergistic antibiotics against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The extract of medicinal plants were prepared using Soxhlet apparatus for alcoholic extract, and water reflux for aqueous extracts. The antibacterial activities of extracts were evaluated using the disk diffusion method as well as well diffusion method; the inhibitory zones were recorded in millimeters. The minimal inhibitory concentration (MIC) of the plant extracts against E. coli, S. aureus and P. aeruginosa were assessed using microdilution method. The synergistic effect between plants and extraction of antibiotics was assessed using disk diffusion method. The results of this study showed that ethanolic extracts used against E. coli, S. aureus and P. aeruginosa were showed antimicrobial and synergistic effect with most antibiotics better than methanolic and aquatic extracts. The results of this study showed that there is a decrease in MIC in case of methanolic extract of E. camaldulensis against E. coli (3.125 mg/ml), and the methanol and aquatic extract of F. sycomorus (leaves) against S. aureus varying from 6.25 to 3.125 mg/ml, and the ethanol extract of E. camaldulensis against P. areuginosa (6.25 mg/ml). Thereby, our results indicate the possibility of using these extracts in the treatment of bacterial infections, and the results of this study was encouraging, despite the need for clinical studies to determine of the real effectiveness and potential toxic effects in vivo. These results was revealed the importance of plant extracts when associated with antibiotic and Non-antibiotic drugs in control of bacteria.

Keywords: Plant extracts, Synergistic effects, Antimicrobial, Microdilution method