PHYTOCHEMICAL, ANTIMICROBIAL AND TOXICITY STUDIES OF Ocimum gratissimum LEAF (SCENT LEAF)

Abstract

The present study investigated the phytochemical, antimicrobial and toxicity studies of Ocimum
gratissimum leaf. The leaves were extracted using n-hexane, ethyl acetate and methanol. Phytochemical screening was carried out on the three extracts to check for the presence of plant
metabolites. Antimicrobial activity of the methanolic leaf extract was carried out using disk
diffusion method and the toxicity of the leaves extracts was carried out using Drosoplila assay. The results showed the plant leaves contains secondary metabolites such as tannins, saponins, flavonoids, alkaloids, glycosides and steroids/terpenes among others. The in vitro antimicrobial
screening of the plant extracts showed that they are potential antimicrobial agents against the
tested microorganisms with S. pneumonia showing highest zone of inhibition of 16 mm at
concentration of 240 mg/cm3
. Toxicity using Drosophila melanogaster flies showed the plant
extracts are safe for oral consumption up to concentration of 320 mg/10g diet. The presence of
these secondary metabolites suggests great potentials of the plants as a source of useful
phytomedicine. Keywords: Antimicrobial activity, Drosophila melanogaster, Ocimum gratissimum, Phytomedicine