ABSTRACT. The radioisotope iodine-131 [131 I] can damage DNA. One way to prevent this is to increase the amount of antioxidants via dietary consumption. The goal of this study was to evaluate the radioprotective effect of fresh acerola pulp and synthetic beta-carotene in Rattus norvegicus hepatoma cells (HTC)

ABSTRACT. Radioactive iodine-131 (131I) is used in the treatment and diagnosis of thyroid gland injuries. However, because it emits ionizing radiation, it causes harmful effects to cells. Given that betacarotene (BC) has antioxidant and antigenotoxic properties, this study aimed to investigate its radioprotective and antimutagenic activity in relation to 131I at the dose that is used to treat hyperthyroidism using a test system of bone marrow cells from Wistar rats (Rattus norvegicus). The doses were 0.2 mL of 8 mg BC/mL corn oil and 25 μCi 131I per 100 g body weight, and they were given via gavage in acute and subchronic treatments. Treatment groups included simultaneous, pre-treatment, post-treatment, and continuous treatment types. In all antimutagenic acute treatments, BC had a significant antimutagenic/radioprotective activity in relation to 131I. In subchronic antimutagenic treatments, BC reduced the damage that was caused by the radioisotope; however, this reduction was not statistically significant because of the relatively low percentage of chromosomal abnormalities that were observed with only 131I compared to the acute treatment. These results demonstrate the radioprotective and antimutagenic activity of BC, indicating its use by the population, which inevitably is exposed to mutagenic agents, as a means of health protection.

Iodine-131 ((131)I) is a radioisotope used for the diagnosis and treatment of thyroidal disorders such as hyperthyroidism and cancer. During its decay, (131)I emits beta particles and gamma rays; its physical half-life is 8 days, and it is accumulated preferentially in the thyroid tissue. This study aimed to evaluate the cytotoxicity and mutagenicity of diagnostic and therapeutic doses of (131)I using bone marrow cells of rats treated in vivo in a test system with a single dose by gavage. Concentrations of 5, 25, 50 and 250 μCi in 1 ml of water were used, and after 24 h, the animals were killed. Also, a concentration of 25 μCi/ml of water was used, and the animals were killed after 5 days. The results showed that no concentration of (131)I was cytotoxic and that all concentrations were mutagenic. As a result, there was no statistically significant difference detected by the χ(2) test in the induction of chromosomal aberrations between the different doses. Thus, the present study demonstrated a significant increase in chromosomal aberration in bone marrow cells exposed to (131)I regardless of the dose or the treatment time.

BackgroundThe increasing consumption of fruits and vegetables has contributed to the improvement of populational health, due in part, to the abundance of antioxidants in these foods. Antioxidants reduce the level of oxidative damage to DNA caused by free radicals and ionizing radiation, including the radioisotope iodine-131 (131I). This isotope is used for the diagnosis and treatment of thyroid injuries, such as hyperthyroidism and cancer.MethodsThis study aimed to evaluate the radioprotective and cytotoxic activity of acute and subchronic treatments with Barbados Cherry (BC) (Malpighia glabra L.) fruit juice (5 mg), which is rich in potent antioxidants such as vitamin C, phenols, carotenoids, anthocyanins and yellow flavonoids and its activity against the mutagenic activity of the therapeutic dose of 25 μCi of radioiodine for hyperthyroidism. The test system used was the bone marrow cells of Wistar rats (Rattus norvegicus) that were treated in vivo by gavage.ResultsBC showed radioprotective activity in acute treatments, which is most likely due to the joint action of its antioxidant components. In subchronic treatments, the continuous treatment presented an effective radioprotective activity, which was significantly different from treatment with the radiopharmaceutical only. Treatment with BC prior to (PRE) and simultaneous with (SIM) ionizing radiation decreased the number of induced chromosomal alterations, while post-treatment produced no protective effect. In addition, BC exhibited no cytotoxic activity.ConclusionsThese data serve as evidence that BC can be used as a preventive health measure to improve public health quality by countering the action of inevitable exposure to mutagens, such as 131I.

Neste trabalho desenvolvemos um software que calcula os valores das doses externas numa instalação radioativa, e os apresenta graficamente em curvas de nível de doses (isodoses), utilizando o método geométrico. Ele foi criado para auxiliar as aulas sobre radioproteção, mas pode ser utilizado para análise de planos de radioproteção. O software foi escrito para a versão 6.0 do aplicativo Mathematica ® da Wolfram Research para o cálculo algébrico e numérico, mas pode ser facilmente traduzido para Maple ® , Matlab ® ou mesmo Delphi ® . Para demonstrar sua aplicação, este softwareé utilizado para elaborar o plano de radioproteção de um laboratório que utiliza um laser de gás isotópico ( 14 CO 2 ). Palavras-chave: plano de radioproteção, física médica, mathematica, laser.In this work we developed a software that calculates the external doses in a plant radioactive, and presented graphically in contour dose (isodoses) using the geometric method. It was created to help the lessons of radioprotection, but can be used to review plans for radioprotection. The software was written for version 6.0 of the application Mathematica ® from Wolfram Research for the algebraic and numerical calculation, but can be easily translated into Maple ® , Matlab ® or Delphi ® . To demonstrate its application, this software is used to prepare the plan for radioprotection of a laboratory that uses a gas isotopic laser ( 14 CO 2 ).