An Evaluation of the Antioxidant Status and Antimicrobial Activity of the Methanol Extract of Ocimum Gratissimum

Abstract

Herbal drug therapy is regarded as an important alternative for the treatment of chronic and infectious disease. Ocimum gratissimum has been used extensively in traditional medicine in many countries. The aim of this study was to evaluate antioxidant status and antimicrobial activity of the methanol extract of Ocimum gratissimum (MEOG) and to establish that the antimicrobial activity is due to its antioxidant potentials. The total antioxidant status was evaluated using DPPH and ABTS assays and the Folin-Ciocalteu reagent method to determine total phenolic content of the MEOG. The antimicrobial effect was determined by agar diffusion and broth dilution method against different ATCC strains of pathogenic bacteria. Zones of inhibition, minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) were determined.  The results indicate that the antioxidant potential and antimicrobial activity of MEOG is mainly due to its total phenolic content and bioactive ingredients like  tannins, flavonoids, saponins, phenols, quinones and terpenoids. The MEOG was found microbicidal against all tested gram positive and negative organisms and against the fungus, Candida albicans. The MIC for gram positive organisms ranged between 0.117 – 7.5mg/ml and for gram negative organisms the range were between 0.469 – 3.75 mg/ml. The MBC for the gram positive bacteria ranged from 0.117mg/ml – 15 mg/ml and for gram negative bacteria from 3.75 mg/ml- 15 mg/ml. In conclusion, MEOG can be used in the treatment of skin infections due to bacteria and fungus and also in the respiratory and gastro intestinal infections due to its antioxidant properties.