Study of the chemical composition, antimicrobial activity of the essen- al oil of Cistus salviifolius from Tissemsilt National Park (Algeria) and influence of the drying period in the shade on the yield of this oil

Abstract

The genera Cistus present groups of about twenty species of shrubs belon- ging to the Cistaceae family are very common throughout the Mediterranean region. Cistus salviifolius, known as Melliya is a species of this genus that occurs in the forest region of Mount Ouarsenis (northwest Algeria), exactly in Thniet El Had Na onal Park in the Wilaya of Tissemsilt. This study was un- dertaken to evaluate the an bacterial effects of C. salviifolius and its chemical composition in addition the effect of shade drying me on essen al oil yield in order to op mize this parameter which is most o en not controlled for producers. The op mal yield recorded is about 0.07± 0.02%. Its characte- riza on by gas chromatography coupled with mass spectrometry shows a dominance of hydrocarbon compounds. The minimum inhibitory concentration (MIC) is established using 6 strains of Gram-positive and negative bacteria. The antibiotic susceptibility test is performed using the giliose- environment diffusion method, a bacterial suspension is prepared and subsequently well homogenized. Opacity must be adjusted to 0.5 McF (McFarland), from a young exponen al culture (18 to 24 hours). The an mi- crobial ac vity of C. salviifolius EO was tested against three Gram-posi ve and three Gram-nega ve bacteria. In fact, a strong inhibitory and bactericidal effect has been demonstrated against all Gram-positive and Gram- negative bacteria tested. It appears from this study that the EO of C. salviifo- lius has a very high antimicrobial activity, it shows a wide spectrum covering Gram positive and Gram negative bacteria. Taking into account the results of this study, new an bacterial agents could be developed and the use of C.salviifolius should be encouraged in the pharmaceutical and perfumery industries.