COMPARATIVE ANTIMICROBIAL ACTIVITY OF VOLATILE AND NON-VOLATILE EXTRACTS OF CYMBOPOGON CITRATUS LEAVES

The present study, carried out on Cymbopogon citratus was interested in volatile and no-volatile extracts of the plant. It focused on the effect of two types of extracts on eleven strains of bacteria. Chemical analysis of the volatile extract obtained with a yield of 2.28% revealed the presence of 72.91% of citral and other minority compounds. The extraction yield of the ethanolic extract (no-volatile) is 10.8%. Chemical groups such as reducing compounds, alkaloids, flavonoids, phenolic compounds, leuco-anthocyanins, saponosides, coumarins, and finally, terpenoids have been identified in this extract. The Minimum Inhibitory Concentration (MIC) and Bactericidal (CMB) were determined by macro dilution method. The volatile extract showed the best inhibitory activities on more than 90% of the strains of bacteria studied. The lowest minimum inhibitory concentrations were obtained against Micrococcus luteus (0.3125 mg/ml), Staphylococcus epidermidis T22695 (0.625 mg/ml) and Proteus vulgaris A25015 (0.625 mg/ml). This extract also had the best inhibition diameters against most bacteria. The bactericidal activity of this extract was only obtained against Enterococcus faecalis (1.25 mg/ml). The no-volatile extract inhibited approximately 50% of the strains tested with values slightly higher than those noted in the case of the volatile extract. There was no bactericidal effect in all cases with this extract. In sum, the volatile extract of C. citratus is significantly more active than the non-volatile extract. Formulations of phyto-drugs based on the essential oil of C. citratus would therefore be more effective than those based on its non-volatile extract.