RESUMO
BACKGROUND: Evidence suggests that selenium supplementation could be useful in the treatment of Hashimoto thyroiditis (HT), but the available trials are heterogeneous. This study investigates clinically relevant effects of selenium supplementation in patients with HT. METHODS: A systematic search was performed in PubMed, Web of Science, EMBASE, Scopus, and the Cochrane Library. The latest update was performed on December 3, 2022. We investigated the changes in thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb) after selenium supplementation. The effect sizes were expressed as weighted mean difference (WMD) with 95% confidence intervals (CIs). RESULTS: After screening and full-text assessment, 7 controlled trials comprising 342 patients were included in the systematic review. The results showed that there was no significant change in TPOAb levels (WMD = -124.28 [95% CI: -631.08 to 382.52], P = .631, I2 = 94.5%) after 3 months of treatment. But there was a significant decrease in TPOAb levels (WMD = -284.00 [95% CI: -553.41 to -14.60], P < .05, I2 = 93.9%) and TgAb levels (WMD = -159.86 [95% CI: -293.48 to -26.24], P < .05, I2 = 85.3%) after 6 months of treatment. CONCLUSIONS: Selenium supplementation reduces serum TPOAb and TgAb levels after 6 months of treatment in patients with HT, but future studies are warranted to evaluate health-related quality or disease progression.
Assuntos
Doença de Hashimoto , Selênio , Humanos , Selênio/administração & dosagem , Selênio/uso terapêutico , Suplementos Nutricionais , Doença de Hashimoto/tratamento farmacológico , Iodeto Peroxidase/sangue , Iodeto Peroxidase/efeitos dos fármacos , Tireoglobulina/sangue , Tireoglobulina/efeitos dos fármacosRESUMO
Di-(2-ethylhexyl)phthalate (DEHP) was a widely used chemical with human toxicity. Recent in vivo and in vitro studies suggested that DEHP-exposure may be associated with altered serum thyroid hormones (THs) levels, but the underlying molecular mechanisms were largely unknown. To explore the possible molecular mechanisms, 128 Wistar rats were dosed with DEHP by gavage at 0, 150, 300, and 600 mg/kg/day for 3 months (M) and 6 M, respectively. After exposure, expression of genes and proteins in the thyroid, pituitary, and hypothalamus tissues of rats were analyzed by Q-PCR and western blot, while the sera and urine samples were assayed by radioimmunoassay and ELISA. Results showed that serum THs levels were suppressed by DEHP on the whole. DEHP treatment influenced the levels of rats' thyrotropin releasing hormone receptor (TRHr), Deiodinases 1 (D1), thyroid stimulating hormone beta (TSHß), sodium iodide symporter (NIS), thyroid stimulating hormone receptor (TSHr), thyroperoxidase (TPO), thyroid transcription factor 1 (TTF-1), and thyroglobulin (TG) mRNA/protein expression in the hypothalamus-pituitary-thyroid (HPT) axis and decreased urine iodine. Taken together, observed findings indicate that DEHP could reduce thyroid hormones via disturbing the HPT axis, and the activated TSH/TSHR pathway is required to regulate thyroid function via altering TRHr, TSHß, NIS, TSHr, TPO, TTF-1 and TG mRNA/protein expression of the HPT axis.
Assuntos
Dietilexilftalato/farmacologia , Hipotálamo/efeitos dos fármacos , Hipófise/efeitos dos fármacos , Glândula Tireoide/efeitos dos fármacos , Hormônios Tireóideos/metabolismo , Animais , Autoantígenos/efeitos dos fármacos , Relação Dose-Resposta a Droga , Iodeto Peroxidase/efeitos dos fármacos , Proteínas de Ligação ao Ferro/efeitos dos fármacos , Proteínas Nucleares/efeitos dos fármacos , Hormônios Hipofisários/metabolismo , Ratos , Ratos Wistar , Fator Nuclear 1 de Tireoide , Tireotropina/metabolismo , Fatores de Transcrição/efeitos dos fármacosRESUMO
The hypothalamic-pituitary-thyroid axis is governed by hypophysiotropic TRH-synthesizing neurons located in the hypothalamic paraventricular nucleus under control of the negative feedback of thyroid hormones. The mechanisms underlying the ontogeny of this phenomenon are poorly understood. We aimed to determine the onset of thyroid hormone-mediated hypothalamic-negative feedback and studied how local hypothalamic metabolism of thyroid hormones could contribute to this process in developing chicken. In situ hybridization revealed that whereas exogenous T4 did not induce a statistically significant inhibition of TRH expression in the paraventricular nucleus at embryonic day (E)19, T4 treatment was effective at 2 days after hatching (P2). In contrast, TRH expression responded to T3 treatment in both age groups. TSHß mRNA expression in the pituitary responded to T4 in a similar age-dependent manner. Type 2 deiodinase (D2) was expressed from E13 in tanycytes of the mediobasal hypothalamus, and its activity increased between E15 and P2 both in the mediobasal hypothalamus and in tanycyte-lacking hypothalamic regions. Nkx2.1 was coexpressed with D2 in E13 and P2 tanycytes and transcription of the cdio2 gene responded to Nkx2.1 in U87 glioma cells, indicating its potential role in the developmental regulation of D2 activity. The T3-degrading D3 enzyme was also detected in tanycytes, but its level was not markedly changed before and after the period of negative feedback acquisition. These findings suggest that increasing the D2-mediated T3 generation during E18-P2 could provide the sufficient local T3 concentration required for the onset of T3-dependent negative feedback in the developing chicken hypothalamus.
Assuntos
Retroalimentação Fisiológica/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Sistema Hipotálamo-Hipofisário/metabolismo , Iodeto Peroxidase/metabolismo , Neurônios/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , RNA Mensageiro/metabolismo , Glândula Tireoide/metabolismo , Hormônio Liberador de Tireotropina/metabolismo , Tiroxina/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/metabolismo , Linhagem Celular Tumoral , Embrião de Galinha , Células Ependimogliais/efeitos dos fármacos , Células Ependimogliais/metabolismo , Retroalimentação Fisiológica/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Humanos , Sistema Hipotálamo-Hipofisário/embriologia , Hipotálamo/efeitos dos fármacos , Hipotálamo/embriologia , Hipotálamo/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Iodeto Peroxidase/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Proteínas Nucleares/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Núcleo Hipotalâmico Paraventricular/embriologia , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , RNA Mensageiro/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator Nuclear 1 de Tireoide , Tireotropina Subunidade beta/genética , Tiroxina/farmacologia , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/metabolismo , Tri-Iodotironina/efeitos dos fármacos , Tri-Iodotironina/metabolismo , Iodotironina Desiodinase Tipo IIRESUMO
The effects of supplemental Se in rodent models may depend upon composition of the basal diet to which it is added. Wild-type male littermates of Transgenic Adenocarcinoma of Mouse Prostate mice were fed until 18 wk of age 1 of 2 Se-adequate stock diets high in soy (HS) or low in phytoestrogens (LP) or the same diets supplemented with 3.0 mg Se/kg diet as seleno-methylselenocysteine. Body and abdominal fat pad weights were lower (P < 0.01) in mice fed the HS diet. Supplemental Se reduced fat pad weights in mice receiving the LP diet but increased body and fat pad weights in mice consuming the HS formulation (P-interaction < 0.005). Serum free triiodothyronine concentrations were unaffected by supplemental Se in mice fed the LP diet but were decreased by Se supplementation of mice given the HS feed (P-interaction < 0.02). Free thyroxine concentrations were higher in mice consuming the HS diet regardless of Se intake (P < 0.001). Hepatic mRNA for iodothyronine deiodinase I was lower (P < 0.001) in mice fed the HS diet. Supplementation of Se increased this mRNA (P < 0.001) in both diet groups. Results from this study show a significant interaction between the composition of basal diets and the effects of supplemental Se with respect to body composition. These findings have important implications for future studies in rodent models of the effects of supplemental Se on heart disease, cancer, diabetes, and other conditions related to body weight and composition.
Assuntos
Dieta , Suplementos Nutricionais , Glycine max , Selênio/sangue , Tecido Adiposo/metabolismo , Animais , Composição Corporal/efeitos dos fármacos , Peso Corporal , Iodeto Peroxidase/efeitos dos fármacos , Iodeto Peroxidase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fitoestrógenos/administração & dosagem , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Selênio/administração & dosagem , Selênio/farmacologia , Tiroxina/sangue , Tri-Iodotironina/sangueRESUMO
OBJECTIVE: To investigate the effects of Nano-Selenium on learning memory capability and activity of two kinds of Se-protein in brain and liver of mice, Na, SeO3 as the controls. METHODS: The mice were administred two kinds of origin (doses of 1 microgSe/d, 2 microgSe/d, 4 microgSe/d) Se by intra-gastric injection respectively. The learning memory ability of the mice was measured by Y-type maze test. Activities of glutathione peroxidase (GSH-Px) and iodothyronine deiodinase (ID) in brain and liver were also measured. RESULTS: In comparison with the control groups of Na2 Se03, learning memory abilities were improved and activities of ID and GSH-Px (P < 0.01 or P < 0.05) of brain and liver were increased in Nano-Se treatment groups. CONCLUSION: Nano-Se could improve learning memory ability of mice, and enhance ID and GSH-Px activities of brain and liver in mice.
Assuntos
Glutationa Peroxidase/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Nanopartículas Metálicas , Selênio/farmacologia , Animais , Encéfalo/enzimologia , Feminino , Glutationa Peroxidase/efeitos dos fármacos , Iodeto Peroxidase/efeitos dos fármacos , Iodeto Peroxidase/metabolismo , Fígado/enzimologia , Masculino , Camundongos , Distribuição Aleatória , Selênio/administração & dosagemRESUMO
We recently conducted a prospective, placebo-controlled clinical study, where we could demonstrate, that a substitution of 200 microg sodium selenite for three months in patients with autoimmune thyroiditis reduced thyroid peroxidase antibody (TPO-Ab) concentrations significantly. Forty-seven patients from the initially 70 patients agreed to participate in a follow-up cross-over study for further six months. One group (n = 13), which initially received selenium continued to take 200 microg sodium selenite (Se-Se), one group stopped taking selenium (Se-0) ( n = 9), another group which received placebo started to take 200 microg selenium (n = 14) (Plac-Se) and the last group was without selenium substitution (Plac-0) (n = 11). TPO-Ab concentrations were measured at beginning and the end of the study. In the Se-Se group, the TPO-Ab concentrations further significantly p = 0.004) decreased from 625 +/- 470 U/ml to 354 +/- 321 U/ml, in the Se-0 group the TPO-Ab concentrations increased significantly p = 0.017) from 450 +/- 335 to 708 +/- 313 U/ml. In the placebo group, the TPO-Ab concentrations in those patients who were followed without selenium substitution were unchanged (1351 +/- 940 vs. 1724 +/- 1112 U/ml, p = 0.555). In contrast, the patients who received 200 microg sodium selenite after placebo, the TPO-Ab concentrations decreased significantly (p = 0.029) from 1182 +/- 723 to 643 +/- 477 U/ml.
Assuntos
Antioxidantes/uso terapêutico , Selênio/uso terapêutico , Tireoidite Autoimune/tratamento farmacológico , Adulto , Autoanticorpos/sangue , Estudos Cross-Over , Feminino , Seguimentos , Humanos , Iodeto Peroxidase/sangue , Iodeto Peroxidase/efeitos dos fármacos , Pessoa de Meia-Idade , Estudos Prospectivos , Tireoidite Autoimune/sangue , Tireoidite Autoimune/imunologiaRESUMO
We previously reported that garlic cultivated with selenium fertilization is superior to regular garlic in mammary cancer prevention in the rat 7,12-dimethylbenz[a]anthracene (DMBA) model (Nutr. Cancer, 17, 279-286, 1992). A new crop of high-selenium garlic was harvested in 1992 and was used in a dose-response study to confirm the reproducibility of the product and the bioassay. Supplementation of 1 or 2 p.p.m. Se in the diet from the high-selenium garlic produced a 56% or 75% reduction respectively in the total tumor yield. Since both garlic and onion belong to the same allium family of vegetables, we were also interested in finding out whether our experience with garlic could be similarly applied to onion. A high-selenium onion crop was grown in the same season and location and with the same schedule of selenium fertilization. Two distinct differences were noted with the high-selenium onion regarding its capacity to accumulate selenium and its efficacy in cancer prevention. First, the selenium concentration in onion was considerably lower (28 p.p.m. Se dry wt) as compared to that found in garlic (110-150 p.p.m. Se). Second, given the same levels of selenium supplementation, the high-selenium onion was apparently not as powerful as the high-selenium garlic in mammary cancer inhibition. Thus different plants, even those of the same genus, may respond in their unique way to selenium fertilization and the biological benefits of selenium enrichment may vary depending on the species. Additional information from our study indicated that the high-selenium garlic/onion might provide an ideal system for delivering selenium-substituted analogs in a food form for cancer prevention: (i) they expressed a good range of anticancer activity and could be easily adapted for human consumption on a regular basis; (ii) their ingestion did not result in an excessive accumulation of tissue selenium, a concern that is associated with the standard selenium compounds such as selenite and selenomethionine; (iii) no perturbation in the maintenance of functional selenoenzymes were observed even at high levels of supplementation.