Evaluating the antibacterial, antioxidant and wound healing properties of the stem bark extract of Khaya grandifoliola (Welw) CDC (Meliaceae)(African mahogany)

Abstract

The study was conducted to evaluate the antibacterial, antioxidant, and wound healing properties of the stem bark of Khaya grandifoliola (Welw) CDC (Meliaceae). A preliminary phytochemical screening conducted showed the presence of tannins, alkaloids, saponins, reducing sugars, flavonoids, terpenoids, and phenols in the stem bark (KG) as well as its ethanol extract (KGE). The antibacterial activity of KGE was evaluated using agar well diffusion method against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae. In-vitro antioxidant activity of KGE was also evaluated using the total phenolic content, DPPH radical scavenging activity, and total antioxidant capacity assays. In the wound healing activity test, topical formulations of varying concentrations of KGE (1-15% w/w) with Emulsifying Ointment BP were used in an excision wound model involving Wistar albino rats. KGE demonstrated in-vitro antibacterial activity against all test microorganisms in a dose-dependent manner. It also showed good antioxidant effects, with a strong correlation between the antioxidant capacity and phenol content (r = 0.9898); indicating that the observed effects may be due to the phenolic compounds initially detected. KGE showed significant wound healing effects as compared to the untreated group (p < 0.05). Additionally, the observed wound healing effects from the adopted doses were showed to be comparable (p > 0.05). In effect, the smallest dose was as effective as the highest dose. These outcomes showed that KG was effective as an antibacterial and antioxidant agent, and a wound healing promoter, justifying its reported traditional uses for infections and wound management.