Antimicrobial Potential of Root, Stalk and Leaves Extracts of

Plants, as sources of medicinal compounds have continued to play a dominant role in the maintenance of human health since ancient times. Rheum ribesis from Polygonaceae family which is endemic to Iran and a few neighboring countries. In this investigation, antimicrobial effects of root, stalk and leaves methanol extracts of R. ribesagainstStaphylococcusaureus, Escherichia coli, Klebsiella-pneumoniae, Pseudomonas aeruginosa, Shigellaflexneri were studied, using well diffusion method. Methanol extracts obtained from root, stalk and leaves of R. ribes exhibited antimicrobial activity against test micro-organisms. R. ribes extracts were found to be more active against S. flexneri and K. pneumonia withinhibitory, 13.75 and 13.5 mm. The results suggested that extracts of R. ribes could be effectively used against diseases caused by selected human pathogens