Evaluation of antibacterial activities of urtica dioica against some pathogenic bacterial strains

In view of the fact that ancient time, plants have been a tremendous source of medicine. The knowledge of traditional medicine and medicinal plants and their study of scientific chemical principles may lead to the discovery of newer and cheaper drugs.Fresh Leaves of Urtica dioica was collected from different sites from Diyala , Iraq.the leaves were dried and chopped into small pieces, pulverized into fine powder in a grinder .Methanol extract :25 g of air dried powder of plant leaves extracted successively with 300 ml of methanol using a Soxhlet extractor for 72 hours. The methanol was concentrated to near dryness under reduced pressure below 40 oC..Aqueous extract : 25 g of dried of leaves powder was filled in a beaker extracted successively with 400 ml of distil water using heat magnetic stirrer at 50 oC for 24 hours.then the extract was filtered over what – man No.1 paper. The aqueous was concentrated to near dryness under reduced pressure below 40 oC, after complete solvent evaporation. 1 g of solvent residue from aqueous and methanol extract was dissolved 10%dimethylsulfoxide (DMSO) solution was used as the test extract for antibacterial activity assay. The concentrations depended in both aqueous and methanol extracts.were, 50, 100, and 200 mg/ ml. The antibacterial activity of aqueous and methanol extract of Urtica dioica was evaluated via growth inhibitory zone assay using well and disc diffusion methods, against isolated pathogenic bacterial strains of Pseudomonas aeruginosa, E. coli, Staphylococcus aureus, Bacillus subtilis, Proteus and Klebsiella. All extract established significant antibacterial activity against tested bacteria.In aqueous extract in well method Proteus was the most sensitive at the three concentration, followed by the other tested bacteria in used as they were sensitive at 200 mg / ml only . While in disc method aqueous extract exhibit inhibition to Pseudomonas, then Proteus only. While the other tested bacteria showed no significant difference in their sensitivity. when compared aqueous extract according methods( Well with disc) Bacillus was sensitive at significant level at 100 and 200 mg / ml, then Staphylococcus and Proteus at 200 mg / ml. Methanol extract of U. Dioica in well method only showed inhibition at significant level to Pseudomonas aeruginosa. other tested bacteria were not sensitive at significant difference.in disc method methanol extract exhibit sensitivity to Proteus, E. Coli, Staphylococcus and Klebsiella respectively. in comparison the inhibition of methanol extract only Klebsiella showed significant difference other test bacteria did not showed significant difference. In comparison methanol extract with aqueous extract in well method only Klebsiella and Proteus showed a significant difference and the methanol extract was more inhibited. While in disc method there were significant difference between methanol and aqueous extract to E. Coli, Bacillus and Staphylococcus to side of methanol extract. at the three in used concentration.