S. H. Riwom Essama^1,, M. A. Nyegue¹, C. Ndoye Foe^{1, 2}, K. Kamga Silihe¹, S. P. Bouopda Tamo¹, F. X. Etoa¹

The purpose of this study was to evaluate the in-vitro antibacterial activity of hydro-ethanol extracts of stems, barks and leaves of Annona muricata against Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabillis and Bacillus cereus, followed by the evaluation of their antioxidant activities. The sensitivity of the bacteria to extracts was evaluated by the well diffusion method and the inhibition parameters of the bacterial growth were determined by the micro-dilution assay. The Minimum Bactericidal concentrations (MBC) obtained were between 6.25 and 25.00 mg/ml. Pseudomonas aeruginosa was the most sensitive strain with a MBC value of 6.25 mg/ml obtained from leaves extract. The antioxidant activity was evaluated using1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and ferric reducing antioxidant power (FRAP) assay. Hydro-ethanol extract of barks exhibited the highest DPPH scavenging activity of 0.010 ± 0.004 g/mg and the highest reducing power with ascorbic acid equivalence of 49.45 ± 0.067 mg EAA/gw. This extract has presented only the highest phenolic content 25.00 ± 1.070 mg EAA/gw. The phytochemical screening revealed that the plant contain bioactive compounds such as steroids, triterpenes and alkaloids. These results confirm the use of this plant in traditional medicine for the treatment of bacterial infections and diseases associated to oxidative stress such as diabetes.

Annona muricata, Antibacterial susceptibility, Antioxidant activity, Bioactive compounds