Author(s): Dr Rambir Singh, SABZAR AHMAD DAR, Dr Poonam Sharma
The present study describes the antibacterial activity, phytochemical profile and toxicological evaluation of Urtica dioica. U. dioica leaves were subjected to solvent extraction by hexane, ethyl acetate, chloroform, methanol and water. All the extracts were tested for antibacterial activity against five clinical isolates of Gram positive and Gram negative bacteria by disc diffusion method. Hexane extract showed good antibacterial activity against all the five bacterial strains, hence it was further purified using silica column chromatography and MIC of the semi purified fraction-B (FB) of hexane extract was determined by serial tube dilution method. FB showed MIC value of 31.25, 250, 7.81, 31.25 and 125µg/ml against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi¬¬, Klebsiella pneumoniae and Shigella flexneri respectively. FB was subjected to GC-MS analysis in search of potent antibacterial compound(s). Neophytadiene (26.97%), butyl tetradecyl ester (9.53%), Dibutyl phthalate (7.45%), Bis(2-ethyl hexyl) maleate (8.80%) and 1,2- benzenedicarboxylic acid (9.89%) were the major constituents which may be responsible for the antibacterial activity of FB of U. dioica. Sub-acute oral toxicity of FB was carried out in wistar rats at doses of 100, 200, 400 and 800 mg/kg body weight (bw) to assess index of safety. Hematological and biochemical parametes showed that the FB was safe at tested concentrations.