Antimicrobial Potency of Hydro, acetone and Ethanolic extracts of <i>Treculia africana</i> Decne Root and Stem Bark

Abstract

Treculia africana is a plant that is used in traditional medicine for the treatment of diverse ailments. To investigate the scientific basis for the use of the plant, the antimicrobial activities/potency of the root and stem bark extracts were evaluated against common gram negative and gram positive bacteria as well as yeast. The chemical constituents of the plant in addition to the effect of temperature and pH on its antimicrobial potencies were investigated. The phytochemical constituents of the dried powdered plant parts were extracted using aqueous and organic solvents (acetone and ethanol). The antimicrobial activity of the concentrated extracts was evaluated by determining the diameter of zone of inhibition against both gram negative and gram positive bacteria and yeast, using the disc diffusion technique. Phytochemical studies revealed the presence of glycosides, anthraquinone, free aglycone, saponin, steroids and polyphenols. The extracts were active against both gram positive and gram negative bacteria. The activities of the plant extracts were not affected at varied temperatures (4^oC, 30^oC, 60^oC and 100^oC), but decreased at alkaline pH. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extracts on the test organisms revealed lowest MIC and MBC against Salmonella paratyphi, Salmonella typhi and Bacillus subtilis with highest MIC and MBC exhibited against Staphylococcus aureus. Generally, there was significant difference (p<0.05) in the antimicrobial activities of the test extracts and control antibiotics, with the control antibiotics exerting broader antimicrobial activity. Treculia africana demonstrated broad spectrum antibacterial activity and a potential source of new classes of antibiotics that could be useful for infectious disease chemotherapy and control.

Keywords: Treculia africana, Underutilized plant, Antimicrobial potency, MIC, MBC, Phytochemicals