Physicochemical Properties, Antioxidant and Antimicrobial Activities of Ethiopian Sweet Basil (Ocimum basilicum L.) Leaf and Flower Oil Extracts

Background: The occurrence of multidrug resistant pathogenic microbes has initiated the development of natural antimicrobial agents from plants. Oils from herbal sources have drawn scientific interest due to their potential source of bioactive compounds. Objective: This study was aimed to examine the physicochemical and biological activities including antioxidant and antimicrobial potential of the oil extracted from basil leaves and flowers. Methods: The physicochemical properties of the oil extracts were measured based on oil yield, specific gravity, acid value, free fatty acids and peroxide values whilst the antioxidant activities were assessed by ascorbic acid, DPPH (2, 2- diphenyl-1-picrylhydrazyl), and hydrogen peroxide free radical scavenging activities. The antimicrobial experiment was conducted based on disc diffusion and broth dilution methods. Results: The result of antioxidant activity of Ocimum basilicum indicated significantly higher DPPH (86.45%) for leaf oil extract. The strongest antibacterial activity with maximum zone of inhibition (15.47 mm), minimum inhibitory concentration MIC (0.09 μg/ml), and corresponding minimum bactericidal concentration MBC (0.19 μg/ml) was exhibited by the flower oil extract against Staphylococcus aureus ATCC-25923. The strongest antifungal activity with maximum zone of inhibition (15.90 mm), MIC (0.125 μg/ml, the least value), and minimum fungicidal concentration MFC (0.09 μg/ml) were recorded for leaf oil against Candida albicans. Conclusion: It can be concluded from the present study that the sweet basil flower and leaf oil extracts can be potential antioxidant, antibacterial, and antifungal agents.