Antimicrobial activity of leaf extract of Ocimum sanctum on various clinical isolates

Abstract

Medicinal properties are present in different part s of Ocimum sps. like leaves flowers, root, stem etc. and have been used by traditional medical practitio ners. The aim of this study was to determine the antimicrobial activity of cold and hot water extrac t of leaves of Ocimum sanctum against clinical bacterial isolates by disc diffusion method. Cold a nd hot water extract of leaf of Ocimum sanctum were prepared at 250µg/ml, 500µg/ml, 1000µg/ml concentrations, impregnated into discs of 6mm diameter and tested on S.aureus , B.subtilis, E.coli , Proteus mirabilis , Shigella dysentriae , Salmonella typhimurium . There was no significant difference between the zo ne of inhibition of the test organisms to cold and hot water extracts. S. aureus and S. typhimurium had the zone size of 1.2 cm, 1.1 cm and 1.0 cm zone of inhibition for B. subtilis and Shigella dysentriae respectively. The inhibition was the greatest at concentration of 1000 µg/ml for both co ld and hot water extracts against all test organism s. The antimicrobial activity was the maximum for E. coli i.e. 1.4 cm in both cold and hot water extracts. The antimicrobial susceptibility pattern of leaf ex tract of Ocimum sanctum was found to be more or less active against all tested pathogenic strains f or both cold and hot water extracts; it may be due to the presence of tannins, essential oils, flavonoids , alkaloids and eugenol present in varying proportions. The plant contains important bio-activ e compounds and hence has found use as essential plant species in traditional medicine for treatment of various diseases.