Phytochemical and antibacterial studies of methanolic extract and fractions of <i>Guiera senegalensis</i> leaves

Abstract

The aim of the research study was to carry out phytochemical and antibacterial studies of methanolic leaves extract and its fractions of Guiera senegalensis. The plant material was collected, identified, shed dried and pulverized to fine powder using pestle and mortar. The powdered plant material was subjected to maceration using methanol to obtained crude methanol leaf extract which was then partitioned using n-hexane, chloroform ethyl acetate and n-butanol. The extract and the fractions obtained were subjected to phytochemical screening using standard procedure, to detect the presence of secondary metabolites. The antibacterial assay of the extract and its fractions against S. aureus, B. subtilus, P.mirabilis and S. typhyrium were investigated using agar well diffusion method at different concentration (100 – 12.5 mg/mL). The phytochemical screening revealed the presence of various secondary metabolites which varies in the extract and fractions. The extract and its fractions showed significant (p< 0.05) antibacterial activities against all the test isolates with the methanol extract having the highest mean zone of inhibition ranging from 2.00±1.00d-24.00±1.00* mm then followed by ethyl acetate fraction with the mean zone of inhibitions from 4.00±1.00d-22.00±1.00* mm the n-butanol fraction and the chloroform fraction had mean zone from 4.00±1.00d-18.50±1.00* mm and 4.00±1.00d-17.60±1.00d mm respectively while n-hexane fraction recorded lower mean zone of inhibition from 4.00±1.00a-15.00±1.00* The standard drug Ciprofloxacin had mean zone of inhibition from 16.20±0.00-39.0±0.00 mm. The most sensitive organism was S. aureus, while the least sensitive organism was S. typhyrium. The study has validated the ethnomedicinal claim for the use of this plant in treatment of antibacterial infections.