George Chaves Jimenez

Testicular development evaluation in rats exposed to 60 Hz and 1 mT electromagnetic field

Society has been increasingly exposed to low‐frequency electromagnetic fields (EMF), mainly from electricity distribution networks and electro‐electronic devices. Aiming to clarify the extension of possible interactions between EMF and testicular development, this study evaluated the effects of exposure to 60 Hz and 1 mT EMF in the maturation of testicular components. Wistar rats were exposed to EMF three times per day for 30 min, between the 13th day of gestation and the 21st postnatal day. Results showed a decrease in the following parameters: tubular diameter and seminiferous tubules area; seminiferous epithelium height; total volume of seminiferous tubule; tubular lumen; seminiferous epithelium; and Leydig cells. On the other hand, an increase was observed in connective tissue cells and blood vessels volume. Plasma testosterone, Sertoli cells population, tubular length and gonadosomatic index did not change when exposed to EMF. Histomorphometric analysis showed that exposure to EMF can promote a delay in testicular development. Copyright

Evaluation of testicular degeneration induced by low-frequency electromagnetic fields

The population exposure to electromagnetic fields (EMF) has been growing in recent decades. The generation, distribution and use of electric energy can generate low‐frequency electromagnetic fields. The present study investigates the effects of EMF (60 Hz and 1 mT) on spermatogenesis of rats during different periods of maturation. Wistar rats were exposed to EMF from day 13 of gestation to postnatal day 21 or 90 in three daily applications of 30 min. Plasma testosterone concentration was not changed by EMF exposure; however, histopathological and histomorphometrical analyses of the testes showed testicular degeneration in a subset of animals exposed to EMF. The magnitude of the degenerative process varied between those individuals affected, indicating different individual sensitivity to EMF. The main alterations observed through transmission electron microscopy were highly electron‐dense mitochondria with loss of their organization and cristae. Exposure to 60 Hz and 1 mT EMF can disturb spermatogenesis and may produce subfertility or infertility. Copyright

Evaluation of Antioxidant and Antiangiogenic Properties of Caesalpinia Echinata Extracts

Natural products contain important combinations of ingredients, which may to some extent help to modulate the effects produced by oxidation substrates in biological systems. It is known that substances capable of modulating the action of these oxidants on tissue may be important allies in the control of neovascularization in pathological processes. The aim of this study was to evaluate the antioxidant and antiangiogenic properties of an ethanol extract of Caesalpinia echinata. The evaluation of antioxidant properties was tested using two methods (DPPH inhibition and sequestration of nitric oxide). The antiangiogenic properties were evaluated using the inflammatory angiogenesis model in the corneas of rats. The extract of C. echinata demonstrated a high capacity to inhibit free radicals, with IC50 equal to 42.404 µg/mL for the DPPH test and 234.2 µg/mL for nitric oxide. Moreover, it showed itself capable of inhibiting the inflammatory angiogenic response by 77.49%. These data suggest that biochemical components belonging to the extract of C. echinata interfere in mechanisms that control the angiogenic process, mediated by substrates belonging to the arachidonic acid cascade, although the data described above also suggest that the NO buffer may contribute to some extent to the reduction in the angiogenic response.

Avaliação da ação da macroalga marinha Ulva lactuca em animais de experimentação

Ulva lactuca e uma macroalga verde marinha comum em ambientes de temperatura elevada e com grandes variacoes de salinidade. A flora ficologica marinha vem sendo objeto de estudo por apresentar propriedades farmacoterapeuticas sobre o metabolismo animal, alem de oferecer uma alternativa viavel no tratamento de patologias que acometem o ser humano e afeta a sua qualidade de vida, ela e bastante utilizada na culinaria, como iogurte, sushi. Objetivando avaliar a toxicidade aguda da Ulva lactuca foram utilizados camundongos albinos Swiss (Mus musculus), durante os estudos foi evidenciado que a alga tem efeitos estimulante do sistema nervoso central e periferico, e que em doses elevadas como 2000 a 3750 mg/kg/ip podem causar alteracoes na morfologia dos orgao comprometendo seu funcionamento,ja que foram observado na analise macroscopica dos orgaos que os vasos do trato gastrointestinal estavam dilatados, os rins hipertrofiados,o figado isquemico , pulmoes hemorragicos,e a bexiga cheia.

Análise fitoquímica e o poder sequestrador de peróxido de hidrogênio da macroalga Dyctiota dichotoma

As algas pardas que pertencem ao Filo Phaeophyta, amplamente distribuidos em habitats marinhos temperados ate regioes subtropicais. As especies do genero Dictyota apresentam grande variabilidade morfologica e a sua composicao diterpenica tem auxiliado no estabelecimento de seus limites taxonomicos. Diversos estudos tem comprovado a existencia da atividade antioxidante em extratos de algas pardas. O objetivo deste estudo foi avaliar poder sequestrador de peroxido de hidrogenio bem como identificar a presenca de metabolitos secundarios da Dyctiota dichotoma. A determinacao da habilidade do sequestro de peroxido de hidrogenio foi seguida. Para a identificacao de monoterpenoides, sesqueterpenoides, diterpenoides e saponina foi usado como revelador a vanilina sulfurica; para a identificacao de triterpenoides e esteroides o reagente Liberman/Buchard e para flavonoides o revelador utilizado foi Os resultados referentes a avaliacao fitoquimica de D. dichotoma, nao foram encontrados flavonoides, esteroides. Contudo, em relacao a saponina, esta nao foi identificada em quantidade significante, mas, nesta avaliacao foi evidenciada a presenca diterpenos. Em relacao a atividade antioxidante foi capaz de sequestrar 92,85% de peroxido de hidrogenio. Os dados fitoquimicos estao de acordo com as literaturas citadas, no entanto, acreditamos que sera necessario dar continuacao da pesquisa, com o intuito de melhor caracterizar fitoquimicamente, assim como, estudar o potencial oxidante da referida alga.