A comparative study on the effects of excess iodine and herbs with excess iodine on thyroid oxidative stress in iodine-deficient rats.

This study aimed to compare the effect of excess iodine and herbs with excess iodine on treating iodine deficiency-induced goiter from the perspective of oxidative stress and to measure selenium values in Chinese herbs. One hundred twenty 4-week-old Wistar rats were selected and randomly divided into four groups after inducing iodine-deficiency goiter: normal control group (NC), model control group (MC), iodine excess group (IE), and herbs with iodine excess group (HIE). The activities of oxidative enzymes and levels of oxidative products were measured using biochemical tests. The expression of 4-hydroxynonenal (4-HNE) in the thyroid was detected by immunohistochemistry and the expression of peroxiredoxin 5 (PRDX5) by the Western blot and immunohistochemistry. Selenium values in iodine-excessive herbs were measured by hydride generation-atomic fluorescence spectrometry. The herbs with iodine excess were tested to contain rich selenium. The activities of superoxide dismutase (SOD) and PRDX5 increased markedly, and the values of malondialdehyde (MDA) and 4-HNE decreased significantly in the HIE group. In conclusion, compared with excess iodine, herbs with excess iodine damaged thyroid follicular cells less, which may be related to the increase of antioxidant capacity and rich selenium values in iodine-excessive herbs.

[Study on mechanism of traditional Chinese medicines reducing phlegm and resolving masses in treatment of goiter].

OBJECTIVE: To discuss the mechanism of traditional Chinese medicines reducing phlegm and resolving masses in treatment of iodine deficiency-induced goiter by observing the expression of growth factors and the balance-regulating mechanism of proliferation and apoptosis. METHOD: 180 four-week-old Wistar rats were selected to establish the iodine deficiency model. After the modeling, the rats were randomly divided into six groups: the normal control group, the model control group, the iodine group, the phlegm compound group, the L-T4 group and the phlegm compound and L-T4 group. At the 21st day and 77th day after administration, 15 rats in each group were killed to collect specimens. Doses were calculated and adjusted according to body surface area and body weight. TT3, TT4 radioimmunoassay, TSH, immunoradiometric method were adopted. Fas, FasL and PCNA protein expressions are detected using immunohistochemical methods. RESULT: Compared with the normal group and the model group, the expressions of fas and FasL in the phlegm Group significantly increased, the expressions of fas and FasL in the phlegm and L-T4 group were also increased significantly. The expression of fas in the L-T4 Group was significantly lower than that of the L-T4 group and the phlegm compound and L-T4 group. Compared with the normal group, the expression of PCNA of the phlegm group and the phlegm and L-T4 group was significantly lower. Compared with the model group, the expression of PCNA of the iodine group, the phlegm groups and the phlegm and L-T4 group were significantly lower. Compared with the normal group, the expression of VEGF in the iodine group significantly decreased after treatment. Compared with the iodine group, the expression of VEGF in the phlegm group and the L-T4 group significantly reduced. Compared with the normal group, the expression of TGF-beta1 in the model group and the phlegm group significantly increased. Compared with model group, the expression of TGF-beta1 in the iodine group significantly reduced. Compared with the phlegm group, the expression of TGF-beta1 in the phlegm compound and L-T4 group was significantly reduced. CONCLUSION: Traditional Chinese medicines reducing phlegm and resolving masses can completely recover goiter by promoting apoptosis of thyroid cells, inhibiting their proliferation and the expression of growth factors and enhancing the expression of TGF-beta, without causing injury on thyroid cells.