Evaluation of the Antibacterial Activity and Phytochemical Screening of Nuxia congesta Leaf in Gondar, Northern Ethiopia

Abstract

This study aims to evaluate antibacterial properties of Nuxia congesta species and identify the biologically active compounds present in the extracts of Nuxia congesta. Organic solvents (methanol, and ethanol, and inorganic solvents (chloroform) were used for extraction of leaf of Nuxia congesta. Some bioactive compound found in this plant was screened in the Gondar microbiology laboratory and Identified bacterial strains were purchased from Ethiopia public health institute, Addis ababa Ethiopia and from national animal health diagnostic center Sebeta, Ethiopia (NAHDIC.). The antibacterial activity of the solvent extract was tested on seven bacterial species using agar disk diffusion method at the same concentrations (500 mg/ml) three times in the presence of positive control (tetracycline) and negative control (dimethyl sulphoxide). Test strains were E. coli, E. faecalis, S. aureus, P. aeruginosa, K. pneumonia, P. mirabilis and H. influenza. The antibacterial properties were quantitatively evaluated by the zone of inhibition and minimum inhibitory concentration. Ethanol and methanol extract showed positive response for alkaloid, flavonoid, tannin, terpenoid and polyphenol while chloroform extract showed positive respond for flavonoid, tannin, and terpenoid. Ethanol and methanol extraction revealed antibacterial activities against the growth of test bacterial strains with varying antibacterial spectrum where most tested strains were less sensitive to chloroform extraction. The average minimum inhibitory concentration value of the ethanol and methanol extracts ranged from 31.25 mg/ml to 208.33 mg/ml and from 41.75 mg/ml to 208.33 mg/ml, respectively. N. congesta leaf demonstrated significant antibiotic activity against the tested bacteria.