en pharmacology pharmacology Original Article Original Article <span style="font-size:14px;"><span style="font-family:times new roman;"><span style="color:#0000FF;"><strong><em>Background</em></strong><em>:</em></span> Propolis as a natural product has shown beneficial effects on human health. This study was aimed to investigate the chemical compositions and biological activity of three different extracts of propolis from two distinct geographic areas in Iran.<br> <span style="color:#0000FF;"><strong><em>Methods</em></strong><em>:</em> </span>The chemical composition of Iranian propolis extracts that were collected in the Spring of 2016 from two provinces in northern Iran: Ardabil and Polur in Mazandaran Province were measured through gas chromatography-mass spectrometry (GC-MS) methods. In addition, antimicrobial activity and cytotoxicity effect on HN5 and LNCaP cell lines were evaluated. The data were analyzed using one-way ANOVA and p<0.05 was considered as significant.<br> <span style="color:#0000FF;"><strong><em>Results: </em></strong></span>The GC-MS analysis identified the presence of compounds that belonged to the different groups such as aromatics acids and their related esters, flavonoid and flavonoid derivatives and terpenes. Flavanone was the most dominant compound of flavonoids. The maximum growth inhibition was observed against <em>S. aureus</em> of ethanolic extract of propolis (p<0.05). Moreover, cytotoxicity showed that ethanolic and dichloromethane extracts had more inhibitory effects on cell lines than the water extract.<br> <span style="color:#0000FF;"><strong><em>Conclusion</em></strong><em>:</em></span> The results determined that extracts had the highest percentage of flavonoids. Therefore, it is expected that the synergistic effect of the main components of propolis is related to the increase of biological activity of propolis.</span></span> Cytotoxicity, Flavonoids, Gas chromatography-mass spectrometry, Propolis, 191 198 http://caspjim.com/browse.php?a_code=A-10-143-2&slc_lang=en&sid=1 Fariba Asgharpour f_asgharpour@yahoo.com 100319475328460021767 100319475328460021767 No Dental Materials Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Ali Akbar Moghadamnia moghadamnia@gmail.com 100319475328460021768 100319475328460021768 No Neuroscience Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Sohrab Kazemi kazemi.msm@gmail.com 100319475328460021769 100319475328460021769 No Neuroscience Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Hamid Reza Nouri nourihr851@gmail.com 100319475328460021770 100319475328460021770 No Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Mina Motallebnejad mmotallebnejad@yahoo.com 100319475328460021771 100319475328460021771 Yes Oral Health Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran