Antibacterial activity of aqueous extract of three plants of medicinal use in Ivory Coast, Olax subscorpiodea, Guiera senegalensis and Psorospermum guineense

Abstract

The aim of this study was to evaluate the antibacterial effects of aqueous extracts of Olax subscorpioidea and Guiera senegalensis leaves and Psorospermum guineense stem bark, three taxa used in Korhogo (Côte d'Ivoire) to treat skin infections. Muller-Hinton diffusion and dilution methods were used to assess the antibacterial activity of the aqueous extracts. All the clinical strains tested were resistant to the aqueous extract of Olax subscorpioidea leaves, with the exception of the ATCC reference strains. However, they are sensitive to aqueous extracts from Guiera senegalensis leaves and Psorospermum guineense stem bark. All three plants gave MIC values ranging from 1.56 mg/mL to 50 mg/mL, and BMC values from 6.25 mg/mL to 50 mg/mL for clinical strains. In all tests, only the aqueous extracts of Guiera senegalensis and Psorospermum guineense were bactericidal on the clinical strain of Pseudomonas aeruginosa. The phyto-constituents assay quantified various chemical compounds present in the different aqueous extracts of Olax subscorpiodea, Guiera senegalensis and Psorospermum guineense. These are alkaloids, terpenoids, saponins, polyphenols and tannins. Polyphenols are the main phyto-constituents (7.26 mg/mL), followed by saponins (3.98 mg/mL). Aqueous extracts of Guiera senegalensis and Psorospermum guineense could constitute a good alternative in the treatment of infectious diseases.

Keywords: aqueous extract, antibacterial activity, bactericide, Korhogo