Antimicrobial and Free Radical Scavenging Activities of Basil (Ocimum basilicum) Essential Oil Isolated from Five Plant Varieties Growing in Greece

The antimicrobial activity and DPPH free radical scavenging capacity of six essential oils isolated from the leaves (in all cases) and flowers (in one case) of five basil varieties (Ocimum basilicum) growing in Greece were examined. The antimicrobial activity was probed via disc diffusion and minimum inhibitory concentration and tested against 16 Gram-positive and 17 Gram-negative ATCC bacterial strains. The essential oils from three basil varieties exhibited statistically significant increased antimicrobial activity towards Gram-positive relative to Gram-negative bacteria. Both antimicrobial and free radical scavenging activities showed significant dependence on basil variety as well as on plant part.