In-vitro assessment of antibacterial activity of methanol extract of Brassica oleracae against selected bacterias

Objective: to evaluate in-vitro antibacterial activity of methanol extract of brassica oleracae study against selected bacterias. design: the study was conducted in the department of pharmacology,faculty of pharmacy,university of karachi,pakistan. method: the agar diffusion method was used to measure zones of inhibition in millimeter (mm) against organisms staphylococcus aureus,staphylococcus epidermidis,streptococcus,escherichia coli and proteus. values of growth inhibitory zones are expressed as mean ± sd (standard deviation) of three triplicates i.e n=3. results: the methanol extract of brassica oleracae exhibited distinct zones of inhibition at all the concentrations i.e 10mg/ml,20mg/ml,40mg/ml,and 100mg/ml towards all bacterial strains under study i.e staphylococcus aureus,staphylococcus epidermidis,streptococcus,escherichia coli and proteus against the methanol control which did not show any growth inhibitory zone. methanol extract of brassica oleracae showed widest inhibitory zone toward e.coli (16.98±0.00) followed by proteus (13.10±0.55),streptococcus (12.00±0.00),staph epidermidis (11.10±1.3) and staph aureus (11.02±0.67) at the concentration of 100mg/ml of extract,in comparison to methanol control which did not manifest any growth inhibitory zone (0.00). the diameters of zones of inhibition were found to increase in size with increase in concentration of extract. however,the antibacterial activity against streptococci was almost same at 20mg/ml and 40mg/ml of concentration of extract (9.33±0.17 and 9.10±0.00 respectively). results were also compared with the standard antibacterial agent against chloramphenicol at a concentration of 100 ug /ml. conclusion: these results suggest that of brassica oleracae may be use as anti-bacterial agent,thus providing ailing mankind a wonderful gift from nature.