Devi Ahilya University, Indore, India.
Pharmacol Rep. 2014 Dec;66(6):1092-9. doi: 10.1016/j.pharep.2014.07.002. Epub 2014 Aug 2.
Investigations are meager on the ameliorative role of plant based active compounds in regulating hyperthyroidism. We have now explored the possible role of three flavonoids in the regulation of L-thyroxine (l-T4)-induced hyperthyroidism in rats. This investigation attempts to reveal whether rutin, naringin and hesperidin supplementation exhibit antithyroid effects in L-T4-induced hyperthyroid rats and to work out the possible involvement of free radicals in their mode of action.
Either rutin or naringin or hesperidin (50mg/kg each) was administered to L-T4-induced hyperthyroid rats for two weeks and their effects were evaluated on the alterations in levels of thyroid hormones, 5'-deiodinase I (5'DI) activity, hepatic lipid peroxidation as well as in antioxidants.
l-T4 administration significantly enhanced the serum concentrations of thyroxine and triiodothyronine; the activities of hepatic 5'DI, serum lactate dehydrogenase and serum glutamate pyruvate transaminase along with an increase in content of malondialdehyde in hepatic tissues, but depleted the cellular antioxidants. However, on administration of the test flavonoids, these effects were more or less normalized. Electro paramagnetic resonance (EPR) spectra also indicated the suppression of the hydroxyl radicals (OH) in the hepatic tissues.
Rutin, naringin and hesperidin have the potential to inhibit thyroid functions without hepatotoxicity and the effects are possibly mediated through their free radical scavenging action as evidenced by EPR study. From the comparative analyses of the results, rutin appeared to be the most effective one suggesting its better antithyroid and antioxidative potential over other two.
关于植物活性化合物在调节甲状腺功能亢进方面的改善作用的研究还很少。我们现在已经探讨了三种类黄酮在调节甲状腺素（L-T4）诱导的大鼠甲状腺功能亢进中的可能作用。本研究试图揭示芦丁、柚皮苷和橙皮苷补充剂是否在 L-T4 诱导的甲状腺功能亢进大鼠中表现出抗甲状腺作用，并探讨自由基在其作用模式中的可能参与。
将芦丁或柚皮苷或橙皮苷（各 50mg/kg）给予 L-T4 诱导的甲状腺功能亢进大鼠两周，并评估它们对甲状腺激素水平、5'-脱碘酶 I（5'DI）活性、肝脂质过氧化以及抗氧化剂的改变的影响。
L-T4 给药显著增加了血清甲状腺素和三碘甲状腺原氨酸的浓度；肝 5'DI、血清乳酸脱氢酶和血清谷氨酸丙酮酸转氨酶的活性以及肝组织丙二醛含量增加，但耗尽了细胞抗氧化剂。然而，给予测试的类黄酮后，这些作用或多或少得到了正常化。电子顺磁共振（EPR）谱也表明抑制了肝组织中的羟基自由基（OH）。
芦丁、柚皮苷和橙皮苷具有抑制甲状腺功能而无肝毒性的潜力，其作用可能通过 EPR 研究证实的自由基清除作用介导。从结果的比较分析来看，芦丁似乎是最有效的一种，表明其在抗甲状腺和抗氧化方面的潜力优于其他两种。
