Antimicrobial Potential of Pelargonium citrosum and Rosmarinus officinalis Essential Oils
Njiema Gitaari *
Department of Chemistry, School of Physical Sciences, College of Pure and Applied Sciences, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200 Nairobi, Kenya.
Patrick Kareru
Department of Chemistry, School of Physical Sciences, College of Pure and Applied Sciences, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200 Nairobi, Kenya.
Mercy Githua
Department of Chemistry, School of Physical Sciences, College of Pure and Applied Sciences, Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000-00200 Nairobi, Kenya.
*Author to whom correspondence should be addressed.
Abstract
Essential oils derived from aromatic plants have exhibited biological properties and can be used to prevent and treat human diseases. The goal of this work was to investigate the antibacterial and antifungal potential of the essential oils extracted from R. officinalis and P. citrosum against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Pseudomonus aeruginosa, Escherichia coli) and fungus (Candida albicans). The antimicrobial activities of the R. officinalis and P. citrosum essential oils were carried out using the Disk diffusion method. The results indicated that the essential oils from P. citrosum had antimicrobial activity against Bacillus subtilis and Escherichia coli and Candida albicans at a low concentration of 0.5 % v/v and that the activity was concentration dependent. Essential oil from R. officinalis on the other hand showed effective antimicrobial activity against Escherichia coli, Staphylococcus aureus and Pseudomonus aeruginosa and Candida albicans. P. citrosum was found to be more effective than Nitrofuractoin and Gentamicin drugs against Staphylococcus aureus at a higher concentration of 6% v/v. R. officinalis oil extracts also demonstrated similar trends and were comparable to the positive controls against the tested microbes. It was therefore concluded that R. officinalis and P. citrosum plant extracts were effective against the tested antimicrobial agents and have potential to be used against the tested microbes.
Keywords: Essential oil, extract, chemical composition, antimicrobial activity, P. citrosum, R. officinalis.