Evaluation of inhibitory effect of chamomile alcoholic extract on the growth and production of certain factors of Staphylococcus aureus

Abstract

Investigation of the alcoholic extract of chamomile against growth and production of catalase, Dnase and haemolysin of Staphylococcus aureus (ATCC29213) were the aims of this study In this study, German chamomile was prepared from Tehran agricultural researches center. Extraction was performed by ethanol 85 (Maceration method) then solvent is removed by vacuum distillation system (concentrated extract). For initial screening of antibacterial property of the concentrated extract and determination of the mean diameter of growth inhibition zone of the MIC concentration, agar well diffusion assay were used. One ml of the concentrated extract was dried at 50°C within 24 hours. Its dried weight per ml was then measured. Dried extract powder is used for determination of Minimal Inhibitory Concentration (MIC) & Minimal Bactericidal Concentration (MBC) by using of the tube dilution method in broth media. In order to investigate the enzymatic activities, bacteria were treated by MIC (sub-inhibitory Concentrations, SIC) of extract for 24 hours as well as control tube (without extract). Catalase activity on 3% H2O2 by Iodometric & KMnO4 titration method, Dnase activity by culture of the treated bacteria and control tube on Dnase agar plate and comparison of nucleic acid precipitated zones and haemolysin activity in supernatant of the bacterial suspensions against sheep RBC for tests and control tube were performed and compared. All results were repeated three times and were analyzed by SPSS software. Our results were as follows: -Mean dry weight: 83.8±0.002 mg/ml -MIC: 2.615 mg/ml -MBC: 5.23 mg/ml -SIC: 1.35 mg/ml -SIC: 0.653 mg/ml -Inhibitory zone of MIC: 15±1.2 mm In concentration 1.35 mg/ml of extract 28-34% was decreased. Haemolysin activity: In concentration 0.653 mg/ml of extract 12-14% was decreased In concentration 1.35 mg/ml of extract 79-84% was decreased Catalase activity: In concentration 0.653 mg/ml of extract 34-38% was decreased In concentration 1.35 mg/ml of extract 71-74% was decreased Dnase activity: In concentration 0.653 mg/ml of extract 46-50% was decreased Although some of the concentrations of the chamomile alcoholic extract showed pronounced antibacterial activity on the Staphylococcus aureus; but its introduction as an antibacterial compound requires more information.