Comparison of oxidative stresses in thyroid gland between excessive iodine intake and iodine-rich herbs in rats with iodine deficiency / 中华内分泌代谢杂志

ABSTRACT

One-hundred and twenty 4-week-old Wistar rats were selected.After making the model of goiter by iodine deficiency,the rats were divided into 4 groupsnormal control group (NC),model control group (MC),excessive iodine group(IE) and herbs rich in iodine group (HIE).The rats were killed 0 week and 8 weeks after different treatments.The activity of rat serum glutathione peroxidase (GSH-Px),xanthineoxidase (XOD),and superoxide dismutase (SOD),as well as the levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2),were measured by biochemical methods.The expression of 4-hydroxynonenal (4-HNE) in the rat thyroid was detected by immunohistochemistry method.The expression of peroxiredoxin5 (PRDX5) in the rat thyroid was detected by the Western blotting and immunohistochemistry.After 8 weeks of different treatments,the SOD activities in IE group decreased significantly compared with HIE group(P＜0.05).While the GSH-Px activities in IE group and HIE group decreased significantly compared with MC group (both P ＜ 0.01),the values of H2O2 in IE group increased significantly compared with NC group (P＜0.05).The values of MDA in IE group increased markedly compared with HIE group (P＜0.05).The XOD activities in IE group and HIE group were significantly higher than NC group.(both P＜0.01).The expression of thyroid 4-HNE in IE group was significantly higher than HIE group(P＜0.05).The expression of thyroid PRDX5 in HIE group was markedly higher than that in the other groups,as shown by both immunohistochemistry and Western blotting methods (all P＜0.05).Compared with excessive iodine intake,herbs rich in iodine may cause less damage to thyroid follicular cells and make iodine deficiency induced goiter recover more completely,suggesting that this improved result may be related to the enhanced antioxidant capacity,owing to administering iodine-rich herbs.