Chemical composition and antimicrobial activities of leaves of sweet basil (Ocimum basilicum L.) herb

Abstract

Background: Leaves and flowering parts of Ocimum basilicum are believed to be rich of different phytochemicals and are traditionally used as antispasmodic, aromatic, carminative, digestive, galactogogue, stomachic, and tonic agents. Hence , the study was designed to evaluate the phytochemical constituents and antimicrobial activities of the leaves of sweet basil ( O. basilicum ) herb. Methods: The leaf extract was used for screening of phytochemicals. A small amount of the powdered leaves of the plant was subjected to hydrodistillation to extract the essential oil, and the components of the essential oil were evaluated by gas chromatography-mass spectroscopy instrument. The extract was tested in vitro for its antibacterial activity against two bacteria; Escherichia coli and Staphylococcus aureus and antifungal activity against two fungi; Aspergillus niger and Rhizoctonia bataticola by paper disc diffusion method. Results: Results revealed the presence of many phytochemicals such as alkaloids, tannins, flavonoids, cholesterol, terpernoids, glycosides, phenols, cardiac glycosides, carbohydrates, and phlobatannins. The essential oil extracted from the leaves of O. basilicum was found to have estragole (38.22%) as a major constituent followed by 1-isopropyl-4-methylenecyclohex-1-ene (11.10%). Tests of antimicrobial activity showed that the hydrodistilled oil was effective against all the tested bacterial and fungal strains. However, the crude extract was found not to have antimicrobial activity toward the tested bacteria and fungi. Conclusion: So, the study has showed that the observed antimicrobial effect of O. basilicum essential oil on the bacterial and fungal isolate, though in vitro appear interesting and promising. So, emphasize have to made on the antimicrobial activities of the plant during the time of drug extraction.