A Study of the Phytochemical Properties and Synergistic Antibacterial Activity of Annona comosus (LINN) Merr. Peel and Citrus senensis Peel Extracts on Aeromonas hydrophila and Salmonella species.

Abstract

In Nigerian traditional medicine, the combination of A. comosus and C. senensis peels has antibacterial effect against typhoid fever and diarrhoea due to Aeromonas hydrophila. A. comosus and C. senensis peels were extracted using percolation method and ethanol solvent. The antibacterial potential of ethanolic extract of A. comosus and C. senensis peels were investigated by disc diffusion and broth dilution techniques. The extracts were subjected to phytochemical screening using standard procedures. This study was aimed at verifying the synergistic effects of the two plant extracts against some clinical isolates: six Salmonella paratyphi B, one S. typhi and three A. hydrophila. The antibacterial activity of the combined extracts was 7-12mm and from 15- 42mm for the standard antibiotic disc. The minimum inhibitory concentration (MIC) of the combined extracts was 0.25-12.50mg/ml while the minimum bactericidal concentration (MBC) was 0.50-50.00mg/ml. Phytochemical investigation of the extracts revealed the presence secondary metabolites like alkaloids, flavonoids, saponins, tannins, steroids, triterpenoids and phytosterols in C. senensis peels while alkaloids, flavonoids, saponins, tannins, triterpenoids and phytosterols were found in A. comosus peels. In-vitro antibacterial potential was confirmed and no synergism was demonstrated at a combination ratio of 1:1 of the extracts tested (P = 0.05).

Keywords: - Anti-bacterial, Annona comosus, Citrus senensis, synergism, Extracts