Assessment of antibacterial properties of Aspilia africana against Pseudomonas aeruginosa

Abstract

Aspilia africana, commonly known as wild sun flower, is prominently known for its wound healing properties and it is widely used as an herbal remedy for wounds in traditional societies of sub-Saharan Africa. A. africana is rich in secondary metabolites such as phenols, alkaloids, saponins and flavonoids. These phytochemicals are responsible for the antimicrobial activity of A. africana. However, there is limited information regarding the efficacy and efficiency of A. africana herbal products. Therefore, this study aimed at determining the antibacterial activity of A. africana extracts on Pseudomonas aeruginosa, a Gram-negative bacillus that is prominently known to cause nosocomial infections in humans, especially in patients with compromised immune systems. An experimental study was conducted using aqueous and ethanolic extracts from mature A. africana plants collected from Busia district, Buyimini East village. The extracts were found to have various quantities of phytochemicals including; phenols, tannins, alkaloids, flavonoids and saponins. The alkaline reagent was used for flavonoids, Mayer’s reagent for alkaloids and Iron (III) chloride was used for phenols. Agar well diffusion method was used for evaluation of the antibacterial activity of A. africana. Overall, the ethanol extract showed greater activity against P. aeruginosa than the aqueous extract. The minimum inhibitory concentration of P. aeruginosa for the ethanol extract (5X10-3 mg/ml) was lower than that of the aqueous extract (5X10-1 mg/ml). there were significant differences between the activity of A. africana ethanolic and aqueous extracts against P. aeruginosa (P<0.05). The A. africana ethanol extract was more effective than the aqueous extract. Therefore, A. africana is a promising candidate for the formulation of antipseudomonal drugs for treatment of nosocomial infections.