Cytotoxicity and antibacterial activity of fruits extracts of Xylopia aethiopica against some selected beta-lactamase producing bacteria

Abstract

Xylopia aethiopica commonly known as the West African pepper tree is consumed as food condiment and also used traditionally in the treatment of cough, bronchitis, dysentery and female sterility. Air-dried and ground fruits of Xylopia aethiopica were extracted using ethanol and the recovered extract was partitioned to give chloroform, water, methanol and n-hexane fractions. The five extracts were screened for antibacterial activity against strains of β-lactamase producing bacteria: Escherichia coli, Proteus sp., and Klebsiella pneumonia as well as cytotoxicity against brine shrimp larvae. The result of the antibacterial screening showed that all the extracts exhibited selective activity against Proteus sp., the interface-2 demonstrated the highest activity with diameter of zone of inhibition of 14mm at 1000μg/disc. On the other hand, methanolic extract showed high cytotoxic activity in the brine shrimp lethality bioassay with LC₅₀ value of 3.4μg/mland moderate antibacterial activity with diameter of zone of inhibition of 12mm at 1000μg/ml.

Keywords: Xylopiaaethiopica; Extracts; antibacterial activity; β-lactamase producing bacteria; cytotoxicity; brine shrimp lethality bioassay