title: In vitro and in vivo studies of an aqueous extract of Matricaria recutita (German chamomile) on the radiolabeling of blood constituents, on the morphology of red blood cells and on the biodistribution of the radiopharmaceutical sodium pertechnetate.
abstract: BACKGROUND
  Natural products might alter the labeling of blood constituents with technetium-99m ((99m)Tc) and these results may be correlated with modifications of the shape of the red blood cells (RBC). The biodistribution of radiopharmaceuticals can be also altered.
  
  
  OBJECTIVE
  This investigation aimed to determine biological effects of an aqueous extract of chamomile (CE).
  
  
  METHODS
  To study the effect of the CE on the labeling of blood constituents with (99m)Tc, in vitro and in vivo assays were performed. The effect of the CE on the morphology of RBC was observed under light microscope. The images were acquired, processed, and the perimeter/area ratio of the RBC determined. To analyze the effect of the CE on biodistribution of the sodium pertechnetate (Na(99m)TcO4) in Wistar rats, these animals were treated or not with a CE. Na(99m)TcO4 was injected, the rats were sacrificed, the organs were removed, weighted and percentage of radioactivity/gram calculated.
  
  
  RESULTS
  In the in vitro experiment, the radioactivity on blood cells compartment and on insoluble fractions of plasma was diminished. The shape and the perimeter/area ratio of the RBC were altered in in vitro assays. An increase of the percentage of radioactivity of Na(99m)TcO4 was observed in stomach after in vivo treatment.
  
  
  CONCLUSIONS
  These results could be due to substances of the CE or by the products of the metabolism of this extract in the animal organism. These findings are examples of drug interaction with a radiopharmaceutical, which could lead to misdiagnosis in clinical practice with unexpected consequences.
authors.affiliation: Laboratório de Radiofarmácia Experimental, Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, RJ, Brasil ; Programa de Pós-Graduação em Biologia Humana e Experimental, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, RJ, Brasil.
authors.forename: Angélica B
authors.initials: AB
authors.lastname: Garcia-Pinto
authors.forename: Sebastião D
authors.initials: SD
authors.lastname: Santos-Filho
authors.forename: Jorge J
authors.initials: JJ
authors.lastname: Carvalho
authors.forename: Mário J S
authors.initials: MJ
authors.lastname: Pereira
authors.forename: Adenilson S
authors.initials: AS
authors.lastname: Fonseca
authors.forename: Mário
authors.initials: M
authors.lastname: Bernardo-Filho
keywords: Biodistribution; Matricaria recutita; radiolabeling; red blood cells; sodium pertechnetate; technetium-99m