Phytochemical screening and antimicrobial activity of flowers of Terminalia brownii

Abstract

Terminalia brownii is traditionally used in treatment and management of human illness such as arthritis, hepatitis, diabetes, stomach ulcers, abdominal pain and yellow fever. The objective of this study aimed at determining phytochemical, antibacterial and antifungal activity of Terminalia brownii flower extracts. Extraction was performed using n-hexane, dichloromethane, dichloromethane: methanol (1:1), methanol and water. The extracts were screened for the presences of phytochemicals namely alkaloids, flavonoids, tannin, terpenoids, saponins, steroids, phenols and glycosides. Antibacterial activity test of n-hexane, dichloromethane, dichloromethane: methanol (1:1), methanol and water. Crude extracts of Terminalia brownii flowers were tested against Escherichia coli, Pseudomonas aeroginosa, Staphylococcus Aureus and antifungal activity against Candida albicans. Phytochemical screening of dichloromethane: methanol (1:1) and methanol flower extract of Terminalia brownii the study revealed the presence of alkaloids, tannin, saponins, phenols and absence of flavonoids and steroids in both dichloromethane: methanol (1:1) and methanol extracts. Glycoside and terpenoids were only found in methanol extract. Antibacterial activity test of n-hexane, dichloromethane, dichloromethane: methanol (1:1), methanol and water crude extract of Terminalia brownii flowers against E. coli, P. aeroginosa and S. Aureus showed that all extracts except n-hexane extract exhibited good antibacterial activity against E. coli, S. Aureus, and P. Aeroginosa with zone of inhibition ranging between 8.0 ±0.71 and 17.3 ±0.42 mm. Dichloromethane: methanol (1:1) flower extract exhibited the highest inhibitory activity against E. coli and P. Aeroginosa with zone of inhibition of 17.3±0.42 and 16.0±0.71 respectively. Only Methanol extract exhibited antifungal activity against Candida albicans with zone of inhibition of 7.6±0.84 mm. Dichloromethane: methanol flower extract was the most active with minimum inhibitory concentration (MIC) for E. coli and P. aeruginosa decreasing with decreasing concentration of crude extract starting from 9.25±1.34 and 7.50±0.42 mm for E. coli and P. aeruginosa respectively. The MIC values were higher in E. coli (1.25±0.07 mm). The present study concluded that phytochemicals in dichloromethane: methanol (1:1) and methanol flower extract are almost similar with those identified in the previous studies of roots, stem bark and leaves of Terminalia brownii.