Comparison of Methods of Extraction and Antimicrobial Activity of Six Ocimum Species against Human Pathogens

Abstract

Extracts from plants continue to be a vital source of medicines, Ocimum, (family Labiatae) is well known for treatment of a wide range of human illnesses. This study evaluates the extraction methods best suited for the determination of the antimicrobial potential of basil. The methanolic extract of O. gratissimum species had the highest yield (1.48±1.48%), while the essential oil of O. tenuiflorum had the lowest (0.19±0.30%). Comparison of methanolic extracts of different accessions, O.tenuiflorum (MSR1), O.basilicum (PI 172996) showed a growth reduction of 74%, for S. pyogenes, 91% for E. coli respectively; while essential oils of O. basilicum (PI 358472) had a growth reduction of 57% for S. pyogenes, 72% for E. coli. The chloroform extracts exhibited little or no inhibitory effects. In conclusion, the methanolic extracts, and essential oils were equally effective against the tested bacteria. Ocimum species may be used as an alternative source in the search for agents to treat bacteria.