Evaluation of the Antibacterial Activity of Commonly used Plants for Wound Treatment in Southwestern Nigeria

Aims: Infection of wounds by microorganisms can prolong wound healing process and result in wound associated complications. Therefore, wound treatment entails the use of antimicrobial agents usually administered directly on the wound where possible to prevent microbial colonization. Traditionally, various plants have been used in wound treatment in different regions of the world. This study evaluated the contribution of the antibacterial activity of four plants commonly use in the treatment of wound in southwestern Nigeria to their ethnobotanically acclaimed wound healing property. Methodology: The antibacterial activity of aqueous and ethanolic extracts of the selected plants (Chromolaena odorata, Sida acuta, Ageratum conyzoides and Carica papaya) was evaluated using the agar well diffusion assay. Wound isolates of Pseudomonas aeruginosa and Staphylococcus aureus, two commonly isolated Gram negative and Gram-positive bacteria from wounds were used for this study. Antibacterial activity was inferred for plant extracts that achieved zone of inhibition ≥ 7 mm in diameter (size of the well inclusive). Results: Generally, the ethanolic extracts of the selected plants showed better extraction yield and antibacterial activity compared to the aqueous extracts. The ethanolic extracts of the four selected plants demonstrated antibacterial activity against the test organisms used while only the aqueous extracts of Chromolaena odorata and Sida acuta showed activity against both test organisms. The aqueous extracts of Ageratum conyzoides and Carica papaya only showed antibacterial activity against S. aureus. Conclusion: Results from this study demonstrated that the antibacterial activity of the selected plants contributes to their acclaimed wound healing property. Although there is need to investigate the role of other non-antibacterial properties of the plants that may be associated with wound healing to fully understand the usefulness of the plants in wound treatment.