Antimicrobial activities of the leaf extracts of two Moroccan Cistus L. species.

We used the standard M27-T technique to study organic and aqueous leaf extracts of two Moroccan Cistus L. species: Cistus villosus L. and Cistus monspeliensis L. (Cistaceae L.) used in traditional medicine, for their antimicrobial properties against microorganisms, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, Candida krusei, Candida glabrata and Aspergillus fumigatus. The broth dilution method M27-T, standardized by the National Committee for Clinical Laboratory Standards (NCCLS) allowed to determine the minimum inhibitory concentrations (MICs) of different extracts. Results showed that the different extracts differed clearly in their antimicrobial activities. Cistus villosus extracts exhibited more interesting activity than Cistus monspeliensis extracts when used on Staphylococcus aureus (MIC=0.78 mg/ml) and Candida glabrata (MIC=0.19 mg/ml), which are the most susceptible microorganisms. On the other hand, Candida krusei and Aspergillus fumigatus were the least susceptible microorganisms to all Cistus extracts. Comparison results were carried out using chloramphenicol, amoxicillin and amphotericin B as standard antibiotics.