Effects of sub-inhibitory concentrations of German chamomile (Matricaria recotita) extracts on the activity of catalase enzyme of S. aureus

Background: German chamomile (Matricaria recotita) as a medicinal plant has several therapeutic effects. Since the extract of this plant contains a high amount of α-bisabolol (Terpenoid) its antibacterial properties can be considered. Staphylococcus aureus as a pathogenic bacterium is important in clinical situations and food hygiene. So, investigation of effects of antibacterial compounds against this bacterium is important. Catalase as decomposing enzyme of hydrogen peroxide has important roles in physiology, identification and pathogenesis of many bacteria such as S. aureus. We evaluated the effect of sub-inhibitory concentrations of German chamomile alcoholic extract on the activity of S. aureus catalase. Materials and methods: German chamomile was prepared from the Agricultural Research Center of Tehran. Extraction was performed by ethanol 85°. Minimum inhibitory concentration and minimum bactericidal concentration of the extract against the standard strain of S. aureus was determined by tube dilution method in broth media. Effect of sub-inhibitory concentrations of the extract on catalase activity of the given bacteria was determined by titration method using KMnO4. Findings: The extract showed growth inhibitory effect at dilution of and at dilution of showed bactericidal effect on standard strain. Dilutions of and as sub-inhibitory concentrations, decreased catalase activity prominently. Conclusion: Significant decrease of catalase activity at sub-inhibitory concentrations of this extract shows that this extract affects the production of catalase at different levels such as transcription, translation or transport and etc. Therefore, it is necessary to further study this extract. This enzyme can be a new target for production of novel antimicrobial agents.