Antimicrobial compounds and Antimicrobial Activity of Extracts of Thespesia garckeana F. Hoffm. on Candida albicans, Staphylococcus aureus and Escherichia coli

Abstract

Herbal medicines form a significant role in African ethnomedicine. Thespesia garckeana F. Hoffm. is an important herbal medicinal plant used to treat or manage human diseases and ailments. However, its antimicrobial compounds and activity analysis has not been evaluated. This study aimed at evaluating the phytochemical and antimicrobial activities of compounds in Thespesia garckeana leaves and bark extracts on growth of C. albicans, S. aureus and E. coli.  Plant  materials were collected from Mwingi, Kenya.  Crude plant extraction was done using soxhlet method with methanol and water solvents. Thin layer chromatography was used to purify the extracts and Phytochemical screening was done using standard methods. Thin layer chromatography plate surface was coated with silica gel, and n-Hexane and Ethyl acetate used as solvent systems in the ratio 2:3 and 3:7 respectively. Antimicrobial activity was performed on test microorganisms using plant extracts; 0 (distilled water), 90, 180, 270 and 360 mg/ml of the extract using paper disc method. Diameter of inhibition zones was dmeasured. The data on growth inhibition was subjected to analysis of variance (ANOVA). The extracts of Thespesia garckean revealed the presence of Tannins, Saponins, Cardiac glycosides, and Alkaloids. TLC using n-Hexane and Ethyl acetate ratio of 2:3 methanol leaves extracts produced 9 spots and The bark extracts produced 4 spots. Leaf methanol extracts using n-Hexane and Ethyl acetate in the ratio of 3:7 produced 8 spots and Bark methanol extracts produced 2 spots.  Increase in extracts concentration of the leaves and bark of Thespesia garckeana, significantly inhibited the growth of Candida albicans, Staphylococcus aureus and E. coli.  Methanol leaf and bark extracts had more inhibitory activity compared to the water extracts. The results from this study confirm the use of Thespesia garckeana  in herbal medicine by traditional herbalists.