Antioxidant and Antibacterial Activities of
Ocimum gratissimum

Omodamiro O.D; Jimoh. M.A

Abstract

Antioxidant and Antibacterial Activities of Ocimum gratissimum

Aim: The study was planned to investigate the efficiency of ethanol extract of Ocimum gratissimum on pathogens obtained from clinical samples using standard microbiological procedures and also determined the antioxidant capacity of the plant extract.
Study design: Ocimum gratissimum was harvested and air dried for 6-7days. The plant material was milled into fine powdered. Ethanol served as extraction solvent, and after extraction, the obtained plant extract was weighed and preserved under anti-microbial condition. DPPH radical scavenging activity, anti-lipid peroxidation activity and nitric oxide scavenging activity served as marker for determination of antioxidant capacity. For anti-bacterial activity, clinical strains of microorganism used for the anti-microbial study includes Proteus mirabilis, Streptococcus pneumonia, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Salmonella species. The disc agar method was used and zone of inhibition recorded also minimum inhibitory concentration was determined.
Place and duration of study: the study was conducted at Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria, College of Natural Sciences, Department of Biochemistry. The study lasted for 3weeks, which began November 2013 and ended December 2013.
Result: The IC50 for nitric oxide yielded 56.91 0.33 at 800 g/ml, for anti-lipid peroxidation it yielded 54.76 1.35 at 400 g/ml but for DPPH, the results were less when compared with the standard agent Ascorbic Acid. For its antibacterial activity, the results at different graded concentrations (500, 250,125, 62.25, 31mg/ml) of the ethanol extract containing 500mg/ml showed he highest mean SD zones of inhibition against the clinical pathogens while the discs containing 31mg/ml revealed least inhibitory zones for Escherichia coli, Staphylococcus aureus, Salmonella spp., Proteus mirabilis and 62.25mg/ml for Pseudomonas aeruginosa and Streptococcus pneumonia.
Conclusion: The results obtained from this study implies that the ethanol extracts of Ocimum gratissimum could be useful in the treatment of infections and for scavenging free radicals and its effectiveness increases with increasing concentration.