Phytochemical and in-vitro antibacterial activity of crude extracts of Xylopia aethiopica fruits (Dunal) A Rich (Annonaceae)

Abstract

Phytochemical screening of the aqueous and methanolic extracts of the fruit of Xylopia aethiopica (Annonaceae) confirmed the presence of saponin ,cardiac glycosides, tannin and volatile oil. Spectrophotometric analysis of the fruit of
X.aethiopica for trace metals, phosphorus and sulphur showed the plant contained Mn (0.037±0.002mg/100g), Zn (1.020 ± 0.001mg/100g), ,Cu (0.274±0.004mg/100g), Ni (1.099 ±0.001mg/100g), Fe (0.690 ±0.02mg/100g), P (30.62±0.002mg/100g) and
S (100.50±0.51mg/100g). Antibacterial activity of the crude aqueous, methanolic and petroleum-ether extracts were evaluated in- vitro against pathogenic bacteria (Staphylococcus aureus, Esherichia coli and Pseudomonas aeruginosa) using Agar diffusion method.
The aqueous and Petroleum-ether extract showed significant growth inhibitory effects on Staphylococcus aureus and Esherichia coli; with petroleum-ether extract being more active.
Esherichia coli was more susceptible to petroleum-ether extract with zone of inhibition diameter of 20mm, than Staphylococcus aureus 12mm.Pseudomonas aeruginosa was however resistant to all the plant extracts.
The minimum inhibitory concentration (MIC) of methanolic crude extract of Xylopia aethiopica fruits on Staphylococcus aureus and Esherichia coli were 12.50 and 6.25mg/ml respectively