S. SATISH, D.C. MOHANA, M.P. RAGHAVENDRA, SHAFEER BABU AND K.A. RAVEESHA
Abstract
The aqueous and different solvent extracts of seven higher medicinal plants viz., Althea officinalis L.(Malvaceae), Origanum vulgare Oregano (Lamiaceae), Plantago lanceolata L. (Plantaginaceae), Polygonum bistorta L. (Polygonaceae), Satureja hortensis L. (Lamiaceae), Solanum dulcamara L. (Solanaceae) and Quercus robur L. (Fagaceae), were screened in vitro for anti-bacterial activity by cup diffusion method against fourteen human pathogenic bacteria. All the plants recorded antibacterial activity against all the test bacteria. Among the seven plants tested methanol extract of Origanum vulgare and Althea officinalis recorded highly significant antibacterial activity against all the human pathogenic bacteria. The antibacterial activity was more significant in solvent extracts compared to aqueous extract in all the plants indicating that the active principle responsible for antibacterial activity is more soluble in organic solvents. Comparison of the inhibitory activity of the extracts with the antibiotics gentamicin and streptocycline revealed that methanol extracts of Origanum vulgare and Althea officinalis were significantly higher than that of the antibiotics tested. The results suggest that Origanum vulgare and Althea officinalis are potential candidate plants for isolation and characterization of the active principle for further exploitation in medical microbiology.