Radioprotective effect of the Barbados Cherry (Malpighia glabra L.) against radiopharmaceutical iodine-131 in Wistar rats in vivo.

BACKGROUND: The 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. METHODS: This 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. RESULTS: BC 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. CONCLUSIONS: These 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.

Evaluation of the cytotoxicity, mutagenicity and antimutagenicity of a natural antidepressant, Hypericum perforatum L. (St. John's wort), on vegetal and animal test systems.

BACKGROUND: St. John's wort (Hypericum perforatum L.) is an herbaceous plant that is native to Europe, West Asia and North Africa and that is recognized and used worldwide for the treatment of mild and moderate depression. It also has been shown to be therapeutic for the treatment of burns, bruises and swelling and can be used for its wound healing, antiviral, antimicrobial, antioxidant, analgesic, hepato-protective and anxiolytic properties. The aim of this study was to evaluate the potential cytotoxic, mutagenic and antimutagenic action of H. Perforatum. METHODS: Meristematic cells were used as the test system for Allium cepa L., and bone marrow cells from Rattus norvegicus, ex vivo, were used to calculate the mitotic index and the percentage of chromosomal aberration. Statistical analysis was performed using the chi-square test. RESULTS: This medicinal plant had no cytotoxic potential in the vegetal test system evaluated. In the animal test system, none of the acute treatments, including intraperitoneal gavage and subchronic gavage, were cytotoxic or mutagenic. Moreover, this plant presented antimutagenic activity against the clastogenic action of cyclophosphamide, as confirmed in pre-treatment (76% reduction in damage), simultaneous treatment (95%) and post-treatment (97%). CONCLUSIONS: Thus, the results of this study suggest that the administration of H. perforatum, especially by gavage similar to oral consumption used by humans, is safe and with beneficial antimutagenic potential.

Cytotoxic potential of waters of the streams Mandacaru, Maringá, Miosótis and Nazareth in the urban area of Maringá, Paraná State, Brazil / Investigação do potencial citotóxico das águas dos ribeirões Mandacaru, Maringá, Miosótis e Nazareth, localizados na área urbana de Maringá, Estado do Paraná, Brasil

Streams Mandacaru, Maringá, Miosótis and Nazareth in the urban area of Maringá, Estado do Paraná, Brazil are affected by the local population's polluting practices. Meristemic cells of Allium cepa L. roots were used as test system to evaluate the cytotoxic effects of the streams' water. Onion roots were prepared by Feulgen reaction and stained with Schiff's reagent. Statistical analysis of the mitotic index was undertaken with the chi-square test. Results did not show significant cytotoxic effect of water samples. Results may dependent on climate variations, concentration of harmful substances, and on the time and samples sites evaluated. A deeper awareness of the population should be underscored for the proper use, preservation and maintenance of soil and water, with particular emphasis to this region.

Os Ribeirões Mandacaru, Maringá, Miosótis e Nazareth estão localizados na zona urbana da cidade de Maringá, Estado do Paraná, e por isso, recebem influência das práticas poluentes da população local. Com o objetivo de avaliar os efeitos citotóxicos das águas desses ribeirões, foi utilizado como sistema-teste de células meristemáticas de raízes de Allium cepa L. As raízes de cebola foram preparadas pela reação de Feulgen e coradas com o reativo de Schiff. Os índices mitóticos foram analisados estatisticamente utilizando o teste do Qui-quadrado. Os resultados obtidos não mostram efeito citotóxico significativo das águas amostradas avaliadas. Os resultados obtidos podem ser dependentes das variações climáticas, da concentração das substâncias nocivas, e da época e local das amostragens avaliadas. Além disso, vale destacar a necessidade de ser realizada, principalmente na área de estudo, conscientização da população em geral, no sentido de uso, preservação e manutenção do solo e das águas.

Mutagenicity of diagnostic and therapeutical doses of radiopharmaceutical iodine-131 in Wistar rats.

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.