Abstract
Plants are rich source of antibacterial agents because they produce wide array of bioactive molecules, most of which probably evolved as chemical defense against predation or infection. A major part of the total population in developing countries still uses traditional folk medicine obtained from plant resources With an estimation of WHO that as many as 80% of world population living in rural areas rely on herbal traditional medicines as their primary health care, the study on properties and uses of medicinal plants are getting growing interests. In recent years this interest to evaluate plants possessing antibacterial activity for various diseases is growing. Different solvent extracts (aqueous, alcohol and ethanol) of leaves, flower and seed of various plants selected based on an ethnobotanical survey from India were subjected to in vitro antibacterial activity assay against Gram-positive and Gram-negative bacteria employing different diffusion method. Based on local use of common diseases and Ethnobotanical knowledge, an attempt has been made to assess the antibacterial properties of selected medicinal plants viz. Argemone mexicana (Shialkanta), Aster lanceolatus (White panicle), Capparis thonningii and Capparis tomentosa (Woolly caper bush), Cardiospermum halicacabum (Balloonvine), Cassia alata (Herpetic alata), Centaurea sclerolepis, Cinnamomum zeylanicum (Cinnamon), Curcuma longa (Turmeric), Cymbopogon nervatus, Ficus religiosa (Peepal), Indigofera aspalathoides (Ajara), Marrubium vulgare (Horehound), Medicago Spp.(Medick, Burclover), Morus alba (Mulberry), Ocimum sanctum (Tulsi), Origanum marjorana (Marjoram), Oxalis corniculata (Amli), Piper nigrum (Kala mirch), Plectranthus amboinicus (Indian borage, Patharchur), Plumeria acutifolia (Kachuchi), Salvadora persica (Piludi), Salvia repens and Syzygium aromaticum (Clove) for potential antibacterial activity against some important bacterial strains, namely Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas spp, Proteus spp, Salmonella Typhi, Escherichia coli, Shigella dysentriae, Klebsiella pneumoniae. The plant extracts were more active against Gram-positive bacteria than against Gram-negative bacteria.

Key words: Antibacterial plants, herbs, plant extract