the antibacterial activity of methanolic anacyclus pyrethrum and pistacia lentiscus l. extract on escherichia coli

background and objectives: antibiotic therapy is the main choice in treatment of escherichia coli induced infections. using herbal medication is an alternative choice in treatment of diseases. the aim of this study was to determine the antibacterial activity of two traditionally used herbs in iranian medicine, anacyclus pyrethrum and pistacia lentiscus l., on escherichia coli. materials and methods: the antibacterial effect of methanolic extract of anacyclus pyrethrum and pistacia lentiscus l. were examined in disk diffusion and skipped wells methods by measuring the diameter of inhibition zones around wells containing different concentrations of extracts from (10-1000 mg/ml) using standard broth macrodilution, method the mic and mbc were defined. results: the methanolic extract of anacyclus pyrethrum from 300 to 1000 mg/ml and the methanolic extract of pistacia lentiscus l. from 30 to 1000 mg/ml showed antibacterial activity on escherichia coli. the mic of anacyclus pyrethrum and pistacia lentiscus l. methanolic based extract were 800 and 1000 mg/ml, respectively. the mbc was achieved at 800 mg/ ml for methanolic extract of anacyclus pyrethrum and pistacia lentiscus l. conclusion: the methanolic extract of anacyclus pyrethrum and pistacia lentiscus l. have antibacterial effect on escherichia coli bacteria. this activity is dose-dependent. keywords: antibacterial activity, anacyclus pyrethrum , pistacia lentiscus l ., escherichia coli