The aim of present study was conducted to evaluate the inhibitory activity of ethanolic and chloroformic extracts of some medicinal plants{ pomegranate peel (Punicagranatum) , oak trunks (Quercusacuta),thyme fruit(Thymus vulgaris )andCinnamon tree cortex (Cinnamomumzeylanicum)}at different concentrations (50, 100, 200 and 400 mg/ml) against Escherichia coli and Salmonella Typhimurium isolated from fecal samples of domestic chickens (suffering from signs of enteritis infection) and compared their activity with effectiveness of standard reference antibiotics used in this study and by measuring the zones of inhibition produced around the holes after incubation on Muller-Hinton agar.
The results exhibited variable susceptibility of tested microorganisms for different concentration of extracts. In present study, the activity of most these medicinal plants extracts was associated with high concentrations. The results showed ethanolic and chloroformic extracts of thyme and Cinnamon as well as,ethanolic extracts of pomegranate peel, oak exhibited significant effectiveness against E.coli isolates while, same isolates werethe more resistant bacteria for chloroformic extracts of pomegranate peel and oak.
The ethanolic and chloroformic extracts of oak andCinnamon showed good antibacterial activity against salmonella Typhimuriumisolates, except ethanolic extract of oak at concentration 50 mg/mldid not show any antibacterial activity againstSalmonella Typhimurium isolates.Ethanolic and chloroformic extracts of thyme as well as, ethanolic extracts of pomegranate peel showed moderate antibacterial activity against Salmonella Typhimuriumisolates while;chloroformic extracts of pomegranate peel did not show any antibacterial activity against same isolates. In this study, the standard antibiotics (nalidixic acid, lincomycin, rifampin, chloramphenicol, streptomycin, amoxicillin/clavulanic acid and novobiocin) showed low effective in inhibition the growth of E.coli andSalmonella typhimurium isolates while,cephalothin showed no effect in inhibition against the growth of the tested organisms.