Abstract

Infectious diseases remain a global health challenge as result of antimicrobial resistance. The use of natural products has revealed a potential source of alternative antimicrobial agents. The aim of this research was to evaluate the antibacterial activities and the phytoconstituents of Tragia brevipes against pathogenic bacteria. The crude extracts of leaves, roots and stems were obtained using polar and non-polar solvents and the antibacterial assay was performed using agar well diffusion and disc diffusion methods. The results showed that in the leaves and roots, flavonoids, saponins, glycosides, phenols, tannins and resins were present whereas in the stem, flavonoids, glycosides and resins were present. Only S. aureus ATCC43300, E. coli ATCC25922 did not show inhibition zone to all plant parts, P. aeruginosa ATTCC27853 showed the highest inhibition zone compared to other bacteria. It was observed that methanolic extract has a great potential antimicrobial activity, followed by distilled water extracts. The combination of plant extracts showed a marked synergic effect. The two way ANOVA showed a statistical difference in the mean zone of inhibition obtained among bacteria and leaves (f = 2.3478, p < 0.05), roots (f = 2.3478, p < 0.05) whereas stem extracts difference was between solvents and tested bacteria (f = 3.4923, p < 0.05). T. brevipes could be a potential candidate in bacterial infection treatment as a source of novel antimicrobial agents. Further studies are recommended to isolate the active ingredients and investigate pharmacological properties.

Key words: bioactive compounds; antimicrobial activity; Tragia brevipes; Rwanda