Antimicrobial activity of Hypericum annulatum moris and Hypericum elegans stephan ex willd. essential oils from Serbia

The in vitro antimicrobial activity of Hypericum annulatum and Hypericum elegans essential oils was evaluated against a panel of standardized bacteria and fungi using broth microdilution assay. Both essential oils showed antimicrobial activity against all the tested microorganisms. Hypericum annulatum essential oil showed better antibacterial than antifungal activity, being more effective against Pseudomonas aeruginosa and Escherichia coli while H. elegans essential oil showed no significant difference between antibacterial and antifungal activity. Antimicrobial testing of α-pinene, β-pinene and β-myrcene compounds was also performed. All the compounds were active against all the tested microorganisms, however, based on the MIC, MBC and MFC values, none of these compounds could be thought of as the main bearer of the oils’ antimicrobial activity. This is the first report regarding the antimicrobial activity of the essential oils of the two Hypericum species.