Evaluation of Antibacterial Activity of Aqueous and Hydroalcoholic Extracts of Physalis alkekengi Fruit against Four Standard Strains in vitro

Abstract

Background & objectives: Due to the increasing resistance of bacteria to antibiotics and the presence of antibacterial compounds in plants, in this study, the effect of hydro-alcoholic and aqueous extracts of Physalis alkekengi on some pathogenic bacteria was investigated. Methods: In this experimental study, the dried fruits of the Physalis alkekengi were purchased from a medicinal plant shop and after extraction, the antibacterial effect of the aqueous, ethanolic, and methanolic extracts of the plant against standard strains of Escherichia coli, Salmonella typhimurium, Bacillus subtilis, Staphylococcus aureus were evaluated. Antibacterial activity, Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC) of the extracts were determined using serial dilution and disk diffusion methods. Results: In the disk diffusion method, all concentrations of the methanolic extract of Physalis alkekengi had an inhibitory effect on Bacillus subtilis and Staphylococcus aureus. However, the inhibitory effect of the methanolic extract was considerably higher than the aqueous extract. The lowest inhibitory concentration of the methanolic extract was 12.5 mg/ml, and the minimum lethal concentration was 25 mg/ml. Aqueous and ethanolic extracts of the plant had the minimal effect on the standard strain of Staphylococcus aureus. Conclusion: Aqueous, ethanolic, and methanolic extracts showed different levels of antibacterial properties in a concentration-dependent method. Therefore, the inhibitory effects against each bacterium can probably be attributed to the activity of the active ingredients of the plant, the extraction method, and the properties of the solvent used.

Keywords

• escherichia coli
• salmonella typhimurium
• bacillus subtilis
• staphylococcus aureus
• physalis alkekengi