en عمومى General پژوهشي Research <strong>Background:</strong> The aim of this study was to evaluate and compare the hepatotoxicity as well as antioxidants activities of hydromethanolic extract of six common traditional species (<em>Origanum vulgar</em>, <em>Pterocarya fraxinifolia</em>, <em>Ferula assafoetida</em>, <em>Artemisia dracunculus</em>, <em>Rosmarinus officinalis</em>, and <em>Valerian officinalis</em>) in order to find a safe antioxidant source.<br> <strong>Methods:</strong> This research project was performed at Toxicology and Animal Poisoning Research Center, University of Tehran (Tehran, Iran), in 2016. The HepG2 cells viability was examined by LDH and MTT techniques following treatment with different concentrations of selected herbal hydroethanolic extracts for 72 h. Furthermore, assessment of antioxidative properties of the extracts was carried out by various scavenging models including DPPH and FRAP.<br> <strong>Results:</strong> The highest cytotoxicity was displayed by <em>F. asafoetida </em>extract (IC50= 67.3 &micro;g/ml). <em>R. Officinalis </em>and <em>A. dracunculus</em> extracts were noted as non-toxic due to the high effective dose. Interestingly, <em>V. officinalis</em> extract indicated stimulating effects on cell growth/ proliferation with ED50 values of 20.9 &micro;/ml. The highest and lowest antioxidant capacities refer to <em>R. officinalis </em>and <em>V. officials</em>. In DPPH assay, the IC50 value of <em>R. officinalis </em>and <em>V. officinalis</em> extracts was found to be 39.82 and 371.77 &micro;g/ml, respectively. FRAP values of <em>R. officinalis </em>and <em>V. officials</em> were 2754.07 and 561.14 &micro;M/g, respectively.<br> <strong>Conclusion:</strong> This study identified <em>R. officinalis </em>extract as a natural non-toxic agent with remarkable antioxidant potential in phytomedicine. Antioxidant Activity, Cell Viability, Hepg2 Cells, Hydromethanolic Extracts, Medicinal Herbs 13 20 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-447-1&slc_lang=en&sid=1 Ali Bashiri Dezfouli 10031947532846006619 10031947532846006619 No PhD of Toxicology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Jamileh Salar-Amoli jsalar@ut.ac.ir 10031947532846006620 10031947532846006620 No DVSc of Clinical Pathology, Toxicology and Animal Poisoning Research Center, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Mina Yazdi 10031947532846006621 10031947532846006621 Yes DVM, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Tahereh Ali-Esfahani 10031947532846006622 10031947532846006622 No MSc Student of Mycology, Toxicology and Animal Poisoning Research Center, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Abbas Barin 10031947532846006623 10031947532846006623 No PhD of Pathobiology, Toxicology and Animal Poisoning Research Center, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.