Phytochemical and Antibacterial screening of Basil (Ocimum gratissium) leaf extract

Abstract

Leaf extract of Basil (Ocimum gratissimum) was screened for antibacterial activities. Agar diffusion method was used, and the result showed that Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli were all susceptible to the leaf extract of Basil {Ocimum gratissimum). The acetone extract of the plant leaf inhibited all the organisms. Pseudomonas aeruginosa was the most inhibited by the extract, while Escherichia coli was the least inhibited. The Minimum Inhibitory Concentration (MIC) and the Minimum Bacteriocidal Concentration (MBC) of extract ranged from lSSOpg/mL - 5000pg/mL respectively. The phytochemical screening of the extract revealed the presence of tannins, saponins, alkaloids, terpenes, steroids and flavonoids. Thin layer chromatography (TLC) of acetone and aqueous extracts of the leaf revealed two major spots while that of petroleum ether and methanol revealed three major spots respectively. The TLC purified fractions of the extract had no inhibitory activities on tested organisms. The efficacy of the leaf of Ocimum gratissimum in the treatment of diseases related to these pathogens was commendable as against the commercially available metronidozole used for similar disease related to these pathogens.