Biological Activity of Some Medicinal Plants Sold in Turkish Health-Food Stores

ABSTRACT

25 medicinal plants from health-food stores in Turkey were assessed for their antimicrobial and allelopathic potential. Antibacterial activity was carried with six different species of bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Staphylococcus epidermidis) by using disc diffusion method. Aqueous extracts of cinchona, rosemary, marjoram, balm leaf and sumac gave the best inhibitory activity against the all used bacteria. Cinchona, rosemary, sumac and wormwood showed a broad-spectrum activity against both Gram-positive and Gram-negative bacteria. Allelopathic potential was determined with radish seed bioassay. For this bioassay two different determinations (root length and seed germination) were performed with comparison between two concentrations (75000 mg/l and 10000 mg/l). Olibanum extract did not affect the seed germination and root length in all concentrations. Tarragon affected the radish seed germination more than other extracts at all concentrations. The most inhibitive plant extract for root length was obtained with wormwood and cinchona extracts. Tarragon, wormwood and cinchona exhibited the most and olibanum exhibited the least allelopathic potential than other extracts.