Applying GC-MS analysis to identify chemical composition of Iranian propolis prepared with different solvent and evaluation of its biological activity

Background 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. Methods 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. Results 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 S. aureus 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. Conclusion 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.