Effect of heat and filter sterilization on the efficiency of coleus aromaticus as an antibacterial agent against diabetic wound pathogens

Abstract

Objective: The purpose of the present study is to evaluate the effect of sterilization on the efficiency of Coleus aromaticus on eradicating diabetic wound pathogens.Methods: The investigation was explored by deploying disc diffusion, Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and time kill studies on Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa and Proteus mirabilis.Results: Zone of inhibition was 17.5-27.0 mm for unsterilized extract, 11.0-20.0 mm for heat sterilized extract and 6.0-12.0 mm for filter sterilized extract. MIC ranged from 1.02-2.60 mg/ml for unsterilized extract, 2.60-5.21 mg/ml for heat sterilized extract and 8.33-18.75 mg/ml for filter sterilized extract. MBC ranged from 2.60-8.33 mg/ml for unsterilized extract and much higher values were noted with heat and filter sterilized extract. Time kill assay showed log reduction of more than 3 in 2 x MIC unsterilized extract on microorganisms tested. Both heat and filter sterilized extract didn�t show 3 log or more reduction even at 2 x MIC. However, better log reduction was observed in heat sterilized extract compared to filter sterilized extract.Conclusion: C. aromaticus is a potent antibacterial agent and heat sterilization could be used to prepare this agent pharmaceutically. The evaluation on the effect of other sterilization methods on its efficiency as an antimicrobial wound remedy is highly suggested. 2014, International Journal of Pharmacy and Pharmaceutical Science. All rights reserved.