Antibacterial Activity of Aqueous and Alcoholic Extracts of Nasturtium officinale against Some Pathogenic Bacteria

Although antibiotics are commonly used for treatment of infectious diseases, these treatments are often associated with several problems such as unwanted side effects and resistance to antibiotics. The aim of this study was to evaluate the antibacterial effect of aqueous and alcoholic extracts of Nasturtium officinale on Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes.
All experiments were performed using the well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the aqueous and alcoholic extracts of N. officinale against the pathogenic bacteria studied were determined by microdilution method.
In the well diffusion method, S. aureus and L. monocytogenes were the most sensitive bacteria with MIC of 8 μg/ml, while E. coli and S. typhimurium were the most resistant bacteria to the aqueous and alcoholic extracts. In addition, the inhibitory activity of the alcoholic and aqueous extracts of N. officinale was higher against gram-positive bacteria compared to gram-negatives. The lowest MIC (6.25 μg/ml) and MBC (12.5 μg/ml) of the plant extract were against S. aureus.
The aqueous and alcoholic extracts of N. officinale affect the growth of gram-positive bacteria (S. aureus and L. monocytogenes) but not the gram-negatives (S. typhimurium and E. coli). These extract could be used for treatment of infections.