Antibacterial, antioxidant and fibroblast growth stimulation activity of crude extracts of Bridelia ferruginea leaf, a wound-healing plant of Nigeria

Abstract

Aim of the study: Determination of pharmacological activity relevant to wound healing of Bridelia ferruginea leaf, a traditional medicine used to treat wounds in rural Nigeria.

Materials and methods: Aqueous and ethanolic leaf extracts were tested against bacterial species of relevance to wound infections: Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ethanolic extracts were assessed for their ability to stimulate the growth of human dermal fibroblasts (FS5) and protect against damage induced by hydrogen peroxide. Antioxidant activity was also assessed using the DPPH assay.

Results: Both aqueous and ethanolic extracts had weak antibacterial activity (MIC>470 μg/ml). A significant effect (p<0.001) on the growth of FS5 fibroblasts was observed only at a concentration of 5 μg/ml (28% increase), above which the extracts appeared toxic to the cells. The ethanolic extract offered the highest protection against H(2)O(2) damage to FS5 cells, comparable with catalase (82% at 250 μg/ml). The DPPH assay revealed antioxidant activity of the ethanolic leaf extract with IC(50) 12.5±0.3 μg/ml comparable to l-ascorbic acid (7.3±0.1 μg/ml).

Conclusion: The antibacterial, modest fibroblast stimulation activity and relatively strong antioxidant activity lend some support to the topical use of Bridelia ferruginea leaf for wound-healing in the traditional medicine of South-western Nigeria.