en عمومى General پژوهشي Research <span style="font-family:Tahoma;"><span style="font-size:12px;"><span lang="EN">The present study was carried out to identify potential effects of dexamethasone (DEX) on antioxidant parameters of <i>Acanthopagrus arabicus</i>, <i>in vitro</i>. </span>Cultured hepatocytes from <i>A. arabicus</i><span lang="EN"> were exposed to </span>3, 3&times;10, 3&times;10² and 3&times;10³&micro;g/ ml of <span lang="EN">DEX for 48 h. </span><span lang="EN">Then, </span>the toxic effects of DEX on the total antioxidant capacity (TAC), <em><span style="font-style:normal">glutathione</span></em><i> </i>enzyme activity (GSH), lipid peroxidation (LPO), alanine aminotransferase (ALT), aspartate aminotransferase (AST),&nbsp; and alkaline phosphatase (ALP) were<span lang="EN"> measured </span>at 12, 24 and 48h of the experiment<span lang="EN">. The results indicated that </span>the sensitivity of cultivated liver cells to DEX increased in a dose-dependent manner. The levels of TAC and GSH activity increased significantly in cells exposed to 3 and 3&times;10 &micro;g/ml of DEX after 48 h of experiment. <span lang="EN">In contrast, higher concentrations of DEX (</span>3&times;10² and 3&times;10³ &micro;g/ml<span lang="EN">) induced a significant decrease in TAC value and </span>GSH activity<span lang="EN"> in treated hepatocytes throughout the experiment.</span> The LPO, <span lang="EN">AST, ALT, and ALP</span> activities increased dose and time-dependently in cultivated hepatocytes exposed to 3&times;10² and 3&times;10³ &micro;g/ml and reached their peak following 48 h of exposure. In conclusion, DEX can suppress the antioxidant defense system, as evidenced by the significant increase in lipid peroxides and decrease in antioxidant factors in the liver. <span lang="FA" dir="RTL" style="font-size:8.0pt"></span></span></span><br> &nbsp; Acanthopagrus arabicus, Dexamethasone, Glutathione, Liver enzymes, Total antioxidant capacity 130 138 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-1476-1&slc_lang=en&sid=1 ahmad Gabari ahmad.J@gmail.com 100319475328460019332 100319475328460019332 No Department of Marine Biology, Faculty of Marine Science and oceanography, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran. Negin Salamat salamatnegin@yahoo.com 100319475328460019333 100319475328460019333 Yes Department of Marine Biology, Faculty of Marine Science and oceanography, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran. Asma Mohammadi as.mohamadi@yahoo.com 100319475328460019334 100319475328460019334 No Department of Basic Sciences, Abadan University of Medical Sciences, Abadan, Iran.