Fernanda Sbaraini Gravina

Experimental Hypothyroidism Inhibits δ-Aminolevulinate Dehydratase Activity in Neonatal Rat Blood and Liver:

The aim of this study was to investigate the potential relationship between hypothyroidism and δ-aminolevulinate dehydratase (δ-ALA-D) activity in rat blood and liver. Experimental hypothyroidism was induced in weanling rats by exposing their mothers to propylthiouracil (PTU) diluted in tap water (0.05% w/ v), ad libitum, during the lactational period (PTU group). Control (euthyroid) group included weanling rats whose mothers received just tap water, ad libitum, during the lactational period. Reverted-hypothyroid group (PTU + 3,3′,5-triiodo-L-thyronine [T3]) included weanling rats whose mothers were exposed to PTU similarly to those in the hypothyroid group, but pups received daily subcutaneous injections of T3 (20 μg/kg, from Postnatal Days 2–20). After the treatment, serum T3 levels were drastically decreased (around 70%) in the PTU group, and this phenomenon was almost reverted by exogenous T3. PTU decreased blood δ-ALA-D activity by 75%, and T3 treatment prevented such phenomena. Erythrocytes and hemoglobin levels were increased by 10% in PTU-treated animals and higher increments (around 25%) were observed in these parameters when exogenous T3 was coadministered. Dithiothreitol did not change blood δ-ALA-D activity of PTU-exposed animals when present in the reaction medium, suggesting no involvement of the enzyme’s essential thiol groups in PTU-induced δ-ALA-D inhibition. PTU did not affect blood δ-ALA-D activity in vitro. These results are the first to show a correlation between hypothyroidism and decreased δ-ALA-D activity and point to this enzyme as a potential molecule involved with hypothyroidism-related hematological changes.

Polyphenol-rich food general and on pregnancy effects: a review.

Abstract This review aimed to investigate possible protective or deleterious effects of polyphenol-rich foods (PRF) on chronic diseases, e.g. cardiovascular, and in pregnant women, along with their antioxidant and anti-inflammatory action. A great variety of foods and beverages, such as herbal teas, grape and orange derivatives, dark chocolate, and many others contain high concentrations of flavonoids and are freely consumed by the general population. In humans, PRF consumption reduces lipid peroxidation, and several studies have shown a positive correlation between an increased consumption of PRF and a decrease in the incidence of cardiovascular disease. On the other hand, current studies have suggested that maternal ingestion of PRF, especially during the third trimester of pregnancy, could be associated to fetal ductal constriction (DC). Fetuses exposed to this type of diet show higher ductal velocities and lower pulsatility indexes, as well as larger right ventricles than those exposed to minimal amounts of these substances. The underlying mechanism involved in these conditions has not been entirely elucidated, but it seems to be a result of the antioxidant and anti-inflammatory effects of polyphenols by some pathway. Furthermore, taking into account the deleterious effect in late-pregnancy against the numerous positive effects associated to polyphenols, this dual behavior deserves attention particularly to control the dietary ingestion of PRF during gestation. In this line, same PRF, natural constituents of human diet, may represent risk to fetal in late pregnancy compared to the use of nonsteroidal anti-inflammatory drugs.