in vitro study on interfering effects of carum copticum essential oil, propolis extract, and silver nanoparticles on gram-negative bacteria

Propolis or bee glue is considered to be one of the most useful products of the hive. it is a colloidal and resinous matter that its structural composition composed of various components such as aromatic acids and their esters, flavonoids and terpenoids. escherichia coli, salmonella typhimurium and pseudomonas aeruginosa as gram-negative bacteria are among important causes of bacterial infections. the aim of this study was to determine the interfering effects of ethanolic extract of propolis, carum copticum essential oil and silver nanoparticles on gram-negative bacteria. the ajowan oil (carum copticum essential oil) and propolis extract prepaird in the microbiology lab. the silver nanoparticle was prepaird from nanomaterials company, usa. the in vitro study was done for determining of mic for each treatment by using broth microdilution method. gentamicin used as a positive control in this study. the results for minimum inhibitory concentration (mic) of propolis extract with ajowan essential oil on escherichia coli and salmonella typhimurium was 250 and 125µg/ml respectively. these agents had no deterrent effect on pseudomonas aeruginosa. the mic of propolis with silver nanoparticles on escherichia coli and salmonella typhimurium was respectively 500 and 50 µg/ml and on pseudomonas aeruginosa was respectively 250 and 25 µg/ml. the results of mic for ajowan essential oil with silver nanoparticles on escherichia coli and salmonella typhimurium was respectively 125 and 25 µg/ml and on pseudomonas aeruginosa 62/5 and 12/5 µg/ml was respectively. due to synergistic anti-bacterial properties of ethanolic extract of propolis, ajowan essential oil and silver nanoparticles, it can be concluded that these materials are able to have several usage in pharmaceuticals. therefore, an ethanolic extract of propolis, ajowan essential oil and silver nanoparticles can be appropriate replacements for chemical agents.