Antimicrobial Effects of Ocimum basilicum (Labiatae) Extract

Ethanol, methanol, and hexane extracts from Ocimum basilicum Labiatae (sweet basil) were investigated for their invitro antimicrobial properties. A total of 146 microbial organisms belonging to 55 bacteria, and four fungi, and a yeast species were studied using a disk-diffusion and minimal inhibition concentration (MIC) method. The result showed that none of the three extracts tested have antifungal activities, but anticandidal and antibacterial effects. Both the hexane and methanol extracts, but not the ethanol extracts, inhibited three isolates out of 23 strains of Candida albicans studied. All three extract of O. basilicum were differentin terms of their antibacterial activities. The hexane extract showed a stronger and broader spectrum of antibacterial activity,followed by the methanol and ethanol extracts, which inhibited 10, 9 and 6% of the 146 bacterial strains tested, respectively. The minimal inhibition zones (MIC) of the hexane, methanol, and ethanol extracts ranged from 125 to 250 µl/ml, 62.50 to 500 µl/ml,and 125 to 250 µl/ml, respectively.