Abstract

Antimicrobial activity of alcoholic and aqueous extracts from Rosa damascena was evaluated against 10 pathogenic microorganisms. Minimum inhibition concentration (MIC), Minimum bactericidal concentration (MBC) and  the diameter of inhibition zone (DIZ) were determined by in vitro bioassays using hole-plate diffusion method and broth micro-dilution method (BMD) against Staphylococcus aureus ATCC 25923, Staphylococcus aureus, Pseudomonas aeruginosa ATCC 27853, Psuedomonas aeruginosa, Escherichia coli ATCC 25922, E. coli, Streptococcus pneumoniae ATCC 55143, Acinetobacter calcaoceuticus, Salmonella enteritidis and Aspergillus niger ATCC 16404. While hexane extracts showed very low activity against the test microorganisms, ethanol, methanol and water extracts significantly exhibited antimicrobial activity and inhibited the growth of Gram-positive and Gram-negative bacteria as well as A. niger at all tested concentrations. The most active antimicrobial effect was recorded for ethanol extract of R. damascena against P. aeruginosa ATCC 27853 at MIC and MBC of 62.5 µg/ml (DIZ = 34 mm), E. coli ATCC25922 at MIC and MBC of 62.5 µg/ml (DIZ = 30 mm).  MIC and MBC data obtained from the antimicrobial studies were analyzed for significant difference at p<0.05 using one way analysis of variance (ANOVA). The extracted oil of Damascus rose petals were characterized by GC/MS; analysis reported that 30 compounds were present. The predominant components were citronellol (14.8- 29.0%), geraniol (11.3-16.2%) and nerol (11.6%) while the phenyl ethyl alcohol was 1.2%.  This study sheds the light on the efficacy of plant extracts to combat pathogens which will help as natural antimicrobial agents.

Key words: Rosa damascena, antimacrobial activity, gas chromatography-mass spectrometry (GC/MS), Rose oil extracts.