Abstract
Due to the increase of microbial resistance to antibiotics and the occurrence of side effects, use of medicinal plants with anti-microbial properties seems to be rational. Hence, in this study, some plants of the Apiaceae, Asteraceae, Brassicaceae, and Cucurbitaceae families were evaluated for antimicrobial effects. The aerial parts of the plants were extracted by different solvents using a Soxhlet apparatus. Subsequently, the inhibitory effect of the extracts on different microbial species was assessed. Extracts with high growth inhibitory effect were fractionated and their MIC was determined. Furthermore, primary phytochemical and GC-MS analysis were used to identify the chemical compounds of potent samples of n-hexane extracts of Eryngium caerulum (E. caeruleum) and Eryngium thyrsoideum (E. thyrsoideum.) Both plants showed considerable antimicrobial activities against Staphylococcus epidermidis among the fractions, 40% and 60% VLC fractions of n-hex extract of E. caeruleum and 40% VLC fraction of n-hexane extract of E. thyrsoideum illustrated the most growth inhibitory effect. Moreover, the results of preliminary phytochemical and GC-MS analysis confirmed that steroids, fatty acids and terpenoids play an important role to show anti-microbial activity, respectively. Among all samples, the 40% VLC fraction of n-hexane extract of E. thyrsoideum for possessing high amounts of fatty acids and terpenoids indicated the most anti-microbial potency.