ABSTRACT
The chemical composition of the essential oil isolated from the aerial parts of Melampodium divaricatum (Rich.) DC. (Asteraceae) was characterized by GC-FID and GC/MS analyses. (E)-Caryophyllene (56.0%), germacrene D (12.7%), and bicyclogermacrene (9.2%) were identified as the major oil components. The antimicrobial activity of the oil against seven standard strains of oral pathogens from the American Type Culture Collection (ATCC) was evaluated by determining minimum inhibitory concentrations (MICs) using the microdilution method. MIC Values below 100â µg/ml were obtained against Streptococcus sobrinus (90â µg/ml), Lactobacillus casei (30â µg/ml), S. mutans (20â µg/ml), and S. mitis (18â µg/ml). In contrast, the MIC values of the major oil compound (E)-caryophyllene were higher than 400â µg/ml against all pathogens, suggesting that the activity of the oil might depend on minor oil components and/or on synergistic effects. The M. divaricatum essential oil is a promising agent to include in anticariogenic oral rinse formulations for the control of oral pathogens.
