Avaliação dos efeitos do extrato etanolico de Curatella americana sobre a marcação de elementos sanguineos com tecnecio 99M e na sobrevivencia de cultura bacteriana

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Technetium 99m (Tc-99m), as sodium pertechnetate (Na99m,-c04), is a radionuclide employed in nuclear medicine clinical evaluations. Curatella americana is a plant from the Brazilian "cerrado" and its bark is used as antiulcerogenic. It has been described that the interaction of drugs alters the biodistribution of radionuclides, as well as its binding to blood elements or to other molecules, what may alter an examination. 50, to contribute with this study, we have studied how other substances interfere on the labeling of Tc-99m and also to elucidate the biological effects in vitro the interference of C. americana in this process was studied too. The results obtained through the in vitro labeling of blood elements showed that there was a significant decrease (p<0,001) in the fixation of Tc-99m in red blood cells between the control group (97.0 :t 2.0) and the treated groups 100%; 50%; 25%; 12.5%,6.2%,3.1%,1.6%,0.8% (49.3:t 6,7; 48.9:t 5.2; 44.2:t 9.9; 48.1 :t 4.7; 35.3:t 7.1; 37.3 t 10.2; 34.1 t 3.8; 41.2 t 2.1; respectively), where 100% corresponds to the maximum concentration used equal to 5 mg/mL, and 50%; 25%; 12.5%,6.2%,3.1%,1.6%, 0.8% correspond to 100% subsequent dilutions. Regarding the fixation of Tc-99m in cellular protein, there was, also, a decrease in the control group (79.6 t 2.9) with regard to the following treated groups 100%; 50%; 25%; 12.5%, 6.2%, 3.1 % (41.5 :t 8.8; 39.6 t 16.6; 44.1 t 12.1; 43.9 t 12.7; 42.7 t 8.7; 44.5 :f: 1.7; respectively). No significative alterations were observed on the labeling of plasma proteins with Tc-99m. Among animais treated with the extract it was verified an increase in the bond ot Tc-99m on lungs (from 0.3 t 0.07 to 0.5 t 0.2), duodenum (from 0.3 t 0.2 to 0.5 :t 0.1) and muscle (trom 0.09 t 0.02 to 0.1 :t 0.04) control and treated groups, respectively (p<0.05); pancreas (from 0.1 :t 0.03 to 0.26 t 0.07) control and treated groups, respectively (p<0.01). Morphological alterations were observed in red blood cells treated in vitro with the extract even under low concentrations, altering the shape of red blood cells significantly and so that, decreasing the perimeter/area relation from 0.9 :t 0.2 (control) to 0.7 :t 0.03; 0.7 :t 0.05; 0.7 :t 0.02; 0.6:t 0.05; 0.7 :t 0.03 (6.2%; 12.5%; 25%, 50%, 100%, respectively). These results could explain the decrease in the fixation of Tc-99m on red blood cells. After the incubation of the extract with cultures of Escherichia coli AS 1157 there was a decrease in thesurvival fraction of this microorganism. This decrease indicated a relatively low citotoxicity of the extract considering that the most significant drop occurred due to the time and concentration of the extract.

ASSUNTO(S)

medicina nuclear plantas medicinais escherichia coli radioisotopos em biologia

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