phytochemical screening of methanolic extract of nauclea latifolia leaves



The present study is aimed to investigate the potential effects of Nauclea latifolia leaves extracts on seven sh pathogens: Escherichia coli, Staphylococcus aureus, Streptococcus iniae, Bacillus subtilis, Pseudomonas aeruginosa, Samonella typhi and Aeromonas hydrophila using agar well diffusion assay. The phytochemical screening and minimum inhibitory concentration of ethanolic and methanolic extracts of N. latifolia were determined using standard methods. Data were analyzed using ANOVA at P=0.05. Ethanolic and methanolic extracts of N. latifolia leaves exhibited antibacterial activity against all the pathogens investigated. Ethanolic extracts of N. latifolia had better antibacterial activity when compared to the methanolic extracts. No antibacterial activity was recorded in the negative control (distilled water) while antibacterial activity was recorded in the positive control (chloramphenicol). Agar well diffusion assay for antibacterial activity yielded the inhibitory zone of 9.18±0.04mm to 27.50±0.25 mm diameter for ethanolic and methanolic extracts of N. latifolia leaves respectively. The phytochemical screening for metabolites indicated the presence of saponins, alkaloids, avonoids, glucosinolates and protein and amino acids while phenol and tannin were not detected. The minimum inhibitory concentration of methanolic and ethanolic extracts of N. latifolia leaves were 450μg/ml and 900μg/ml respectively. The results indicated that leaves extracts of N. latifolia express better antibacterial effect against multi – drug resistant bacteria and it can be used as a potential source for various biomedical applications. Keywords: Fish pathogens, Nauclea latifolia, Antibacterial, Phytochemical screening, Clarias gariepinus