Cassia angustifolia Vahl (senna) is a natural product that contains sennosides, which are active components that affect the intestinal tract and induce diarrhea. Authors have shown that senna produces DNA (deoxyribonucleic acid) lesions in Escherichia coli cultures and can act as an antifungal agent. Natural drugs can alter the labeling of blood constituents with technetium-99m (99mTc) and can affect the biodistribution of radiopharmaceuticals. In this work, we have evaluated the influence of a senna extract on the radiolabeling of blood constituents and on the biodistribution of the radiopharmaceutical sodium pertechnetate (Na99mTcO4)in Wistar rats. Twelve animals were treated with senna extract for 7 days. Blood samples were withdrawn from the animals and the radiolabeling procedure was carried out. The senna extract did not modify the radiolabeling of the blood constituents. A biodistributional assay was performed by administering Na99mTcO4 and determining its activity in different organs and in blood. The senna extract altered the biodistribution of Na99mTcO4 in the thyroid, liver, pancreas, lungs and blood. These results are associated with properties of the chemical substances present in the aqueous senna extract. Although these assays were performed in animals, our findings suggest that caution should be exercised when nuclear medicine examinations using Na99mTcO4 are conducted in patients who are using senna extract.

O objetivo desse trabalho foi estudar a influência de um extrato de nogueira (Juglans regia) no crescimento de Escherichia coli (E. coli) AB1157, na topologia do DNA plasmidial e na marcação de constituintes sanguíneos com tecnécio-99m (99mTc). Uma cultura de E. coli AB1157, em fase estacionária, foi incubada com nogueira e o crescimento da cultura foi avaliado por densidade óptica a 600nm por 7 horas. Amostras de DNA plasmidial foram incubadas com SnCl2 na presença ou ausência de nogueira por 40 minutos, a eletroforese em agarose 0.8% foi realizada, o gel foi corado e as formas topológicas do plasmídio foram visualizadas. Amostras de sangue de ratos Wistar foram incubadas com extrato de nogueira e um ensaio de marcação de constituintes sanguíneos com tecnécio-99m (99mTc) foi realizado. Células sanguíneas e plasma foram separadas. A radioatividade em cada fração foi contada e a percentagem de radioatividade incorporada (%ATI) foi determinada. Os resultados apresentaram uma ação inibitória do crescimento da cultura de E. coli AB1157, nenhuma ação protetora do extrato de nogueira em DNA plasmidial tratado com SnCl2. Além disso, na nogueira também não foi capaz de induzir modificações na mobilidade do DNA em gel de agarose, mas a nogueira foi capaz de diminuir a distribuição de 99mTc no compartimento sanguíneo celular. Concluindo, nosso resultado experimental sugere que no extrato de nogueira existem substâncias com um efeito no crescimento de cultura de E. coli, uma ação capaz de aumentar o efeito do SnCl2 no DNA plasmidial e também ser capaz de alterar a distribuição de 99mTc no compartimento sanguíneo celular provavelmente devido a propriedades redoxi.

The aim of this work was to study the influence of a walnut (Juglans regia) extract on the growth of Escherichia coli (E. coli) AB1157, on the plasmid DNA topology and on the labeling of blood constituents with technetium-99m (99mTc). An E. coli AB1157 culture, in stationary phase, was incubated with walnut and the growth of the culture was evaluated by optical density at 600 nm for 7 hours. Plasmid DNA samples were incubated with SnCl2 in presence or absence of walnut for 40 minutes, 0.8% agarose gel electrophoresis was performed, the gel was stained and the plasmid topological forms were visualized. Blood samples from Wistar rats were incubated with walnut extract and an assay of labeling of blood constituents with technetium-99m (99mTc) was performed. Blood cells and plasma were separated. The radioactivity in each fraction was counted and percentage of incorporated radioactivity (%ATI) was determined. The results presented an inhibitory action of the growth of the E. coli AB1157 culture, no protective action of the walnut extract in plasmid DNA treated with SnCl2. Moreover, walnut was also not capable to induce modifications in the DNA mobility in agarose gel but walnut was capable to decrease the distribution of 99mTc on the blood cell compartment. In conclusion, our experimental data suggest that in the walnut extract has substances with an effect on the growth of E. coli culture, a potential action to increase the SnCl2 effect on plasmid DNA and also is capable to alter the distribution of 99mTc on the blood cell compartment probably due to redoxi properties.

Este estudo avalia o efeito do tratamento agudo com extrato de Centella asiatica (CA) na biodistribuição do radiofármaco Na99mTcO4 e na fixação do tecnécio-99m pelos constituintes sanguíneos. Ratos Wistar foram tratados com extrato de CA e, 1 hora após, Na99mTcO4 foi administrado, órgãos e tecidos foram retirados e pesados. A radioatividade foi contada para calcular a porcentagem de atividade por grama (%ATI/g). Amostras de sangue foram retiradas, plasma (P), células sanguíneas, frações insolúveis (FI) e solúveis de P e C foram isoladas e a radioatividade foi contada para calcular a porcentagem de atividade (%ATI). Os dados revelam que o tratamento agudo com o extrato de CA alterou significativamente (p<0,05) a %ATI/g em diversos órgãos e tecidos (baço, coração, duodeno, estômago, fígado, músculo, rim, testículo e sangue) e a %ATI de constituintes sanguíneos (P, CS, FI-P e FI-CS). Esses resultados indicam que substâncias ou metabólitos do extrato de CA poderiam alterar a biodistribuição do Na99mTcO4 e a fixação do tecnécio-99m nos constituintes sanguíneos em um tratamento agudo.

This study evaluates the effects of an acute treatment with a Centella asiatica (CA) extract on the biodistribution of the radiopharmaceutical Na99mTcO4 and on the fixation of technetium-99m on blood constituents. Wistar rats were treated with CA extract and, 1 hour after, Na99mTcO4 was administered; organs/tissues were withdrawn and weighted. The radioactivity was counted to calculate the percentage of activity per gram (%ATI/g). Also, blood samples were withdrawn, plasma (P), blood cells (BC), insoluble fraction (IF) and soluble fractions of P and BC were isolated and the radioactivity was counted to calculate the percentage of activity (%ATI). Data indicated that the acute treatment with CA extract changed significantly (p<0.05) the %ATI/g in several organs/tissues (spleen, heart, duodenum, stomach, liver, muscle, kidney, testis and blood) and the %ATI on the blood constituents (P, BC, IF-P and IF-BC). These results indicate that the substances or metabolites of the CA extract would change the biodistribution of Na99mTcO4 and the fixation of the technetium-99m on blood constituents in an acute treatment.