Abstract:
Polygonum barbatum, known as atalari (in Tamil) or ratu kimbulwenna (in Sinhala), are perennial herbs of the family polygonaceae have been widely used anciently to treat various ailments including infections, fever, pain and tumor. In this study bioassays were carried out to analyse antibacterial activity by using leaves of Polygonum barbatum. Crude extracts were prepared from leaves by sequential extraction method, first by dichloro methane (DCM) then by ethyl acetate (EA) and finally by ethanol (EtOH). These were tested against gram positive bacteria Bacillus subtilis, Staphylococcus aureus and gram negative bacteria Escherichia coli, Pseudomonas aeruginosa by agar well diffusion method. Ethanolic extracts showed a higher inhibition zones for all tested pathogens when compared with other extracts DCM and EA. Antibiotic streptomycin was used as a control for this analysis. The results revealed that the antibacterial activities of ethanolic extract of this plant was comparable to those of selected chemical antibiotic and suggesting its potential as alternative to the commercially available antibiotics in the treatment of infections caused by these microorganisms.
