Phytochemical Composition and Antibacterial Activities of the Ethyl Acetate Leaf Extract of Ocimum basilicum
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Date
2020
Authors
Rapando, Japheth Wambani
Ngugi, Mathew Piero
Muturi, Margaret
Ogutu, James Opiyo
Journal Title
Journal ISSN
Volume Title
Publisher
Research square
Abstract
Introduction
Antibiotic resistance is a serious threat to humankind. There is need for the development of new
therapeutic options. Ocimum basilicum has been used traditionally as a medicinal herb against
infectious diseases and as a food additive.
Objective
This study aimed at evaluating the phytochemical composition and in vitro antibacterial activities of the
ethyl acetate leaf extract of Ocimum basilicum.
Methods
Ocimum basilicum leaves were collected from Mbeere, Embu County, Kenya and ethyl acetate extraction
done at Kenyatta University. Phytochemical composition was evaluated by Gas chromatograph mass
spectrophotometry while antibacterial activities were evaluated by disc diffusion and broth microdilution
methods. The test microorganisms were methicillin resistant S. aureus, S. aureus, P. aeruginosa and E.
coli.
Results
The extract exhibited a broad spectrum antibacterial activity. The gram negative bacteria showed more
susceptibility to the organic extract compared to the gram positive bacteria. Pseudomonas aeruginosa
had the highest zone of inhibition (27.00 ± 2.00 mm), while the S. aureus isolate had the lowest zone of
inhibition (24.00 ± 1.00 mm). Escherichia coli, S. aureus and MRSA species had an MIC of 62.5 mg/ml
compared to P. aeruginosa with an MIC of 125mg/ml when exposed to the leaf extract. The antibacterial
activity could be attributed to the synergistic effects of phytochemicals such as terpenoids, alkaloids,
essential oils, fatty acids, avonoids and aldehydes that have been known to have antimicrobial
properties. A total of 30 phytochemical compounds were eluted from the extract of O. basilicum.
Nootkatone, a sesquiterpenoid had the highest concentration at 20.86mg/g. The compound 1,3-Dimethyl5-isobutylcyclohexane, a fatty acid had the lowest concentration at 0.10mg/g.
Conclusion
O. basilicum has antibacterial activities on the tested pathogens and can be used to treat infections.
Phytochemicals with antibacterial effects in the herb can be used as lead molecules in developing new
antibacterial drugs.
Description
A preprint published in Research Square
Keywords
Ethyl Acetate Leaf Extract, Ocimum basilicum
Citation
Rapando, J. W., Ngugi, M. P., Muturi, M., & Ogutu, J. O. (2020). Phytochemical Composition and Antibacterial Activities of the Ethyl Acetate Leaf Extract of Ocimum basilicum.