Phytochemical screening

O.O. Ayepola, G.I. Olasehinde, O.A. Adedeji, O.O. Adeyemi, O.A. Onile-Ere

Abstract

Diospyros species in folklore medicine are used as anti-inflammatory, antibacterial, antioxidant, anticancer and antiviral agents. The in vitroantimicrobial activity of crude extracts of the leaves of Diospyros monbuttensis were evaluated against three bacterial species (Staphylococcus aureus, Escherichia coli and Micrococcus luteus ) and fungal strain (Aspergillus niger). Extraction was carried out using both polar and non-polar solvents (ethanol and water). The leaves were screened for phytochemical constituents and preliminary screening for antimicrobial activity carried out using the agar well diffusion method. The minimum inhibitory concentration (MIC) was determined using the agar well dilution method. The phytochemical screening revealed the presence of saponins, tannins, glycosides and alkaloids in the plant. The ethanolic leaf extract of D. monbuttensis had no activity against the test organisms, but antimicrobial activity was observed for the aqueous extract against S. aureus and E. coli at all concentrations tested. The MIC of the aqueous extract of D. monbuttensis on S. aureus and E. coli was 0.78 mg/ml. The results of this study indicate that Diospyros monbuttensis leaves may be used for treatment of infections caused by S. aureus and E. coli.

Keywords: Diospyros monbuttensis, Antimicrobial activity, phytochemical screening

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In-vitro antimicrobial activity of crude extracts of Diospyros monbuttensis

J Mushore, M Matuvhunye

Abstract

Antibacterial activity of Mangifera indica stem bark extracts was determined using disk diffusion, agar and broth dilution methods. In disk diffusion method, inhibition zone sizes were used to determine the susceptibility of S. aureus to the extracts. The results showed that the stem-bark extracts of M. indica have antimicrobial activity against S. aureus. Methanol extracts showed the highest inhibition zone diameter of 25 mm, followed by ethyl acetate, water and hexane extracts with inhibition zone diameter of 22 mm, 14 mm and 10 mm, respectively. The antibacterial activities of different extracts were found to be concentration dependent, in agar and broth dilution methods. The plant extracts were shown to have a MIC range of 0.62 mg/ml to 4.17 mg/ml, in agar dilution method. Results from the broth dilution method had a MIC range of 0.16 mg/ml to 1.25 mg/ml. The control (ampicillin) was however, more effective than plant extracts since only a concentration of 0.03 mg/ml in agar dilution and 0.001 mg/ml in broth dilution method were effective to inhibit the growth of S. aureus. The extracts were shown to be bacteriostatic at low concentrations. Phytochemical screening of the extracts revealed the presence of phyto-compounds such as alkaloids and tannins which are known to inhibit bacterial growth by different mechanisms from those of synthetic drugs. These phyto-constituents may be responsible for the M. indica antibacterial
activity.

Keywords: Staphylococcus aureus, antimicrobial activity, MIC, Phytochemical screening, MBC.

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Antibacterial properties of Mangifera indica on Staphylococcus aureus