In-vitro antimicrobial activity of crude extracts of Diospyros monbuttensis

Abstract

Diospyros species in folklore medicine are used as anti-inflammatory,  antibacterial, antioxidant, anticancer and antiviral agents. The in vitro antimicrobial 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