Assessment of the effect of Maytenus ilicifolia (espinheira santa) extracton the labeling of red blood cells and plasma proteins with technetium-99m

We are trying to develop a model to assess properties of products utilized in popular medicine. Maytenus ilicifolia is used in herbal medicine. Red bl ood cells (RBC) labeled with technetium-99m (99mTc) are employed in nuclear medicine. This labeling procedure depends on a reducing agent and stannous chloride is used. There is evidence that this labeling may be altered by d rugs. We have investigated the possibility of M. ilicifolia extract being c apable to alter the labeling of blood elements with 99mTc. Blood was incuba ted with M. ilicifolia extract. Stannous chloride solution and Tc-99m were added. Blood was centrifuged and plasma (P) and blood cells (C) were isolat ed. Samples of P or C were also precipitated, centrifuged and insoluble (IF ) and soluble (SF) were separated. The percentages of radioactivity (%ATI) in C, IF-P and IF-C was calculated. The %ATI decreased on C from 93.6 +/- 2 .3 to 29.0 +/- 2.7 on IF-P from 77.6 +/- 1.2 to 7.5 +/- 1.0 and on IF-C fro m 80.0 +/- 3.4 to 12.6 +/- 4.8. Once in RBC labeling procedure with 99mTc d epends on the presence of stannous (+ 2) ions, the substances of the M. ili cifolia extract could increase the valence these ions to stannic (+ 4). Thi s fact would decrease the %ATI on blood elements and indicate the presence of oxidant agents in the M. ilicifolia extract. (C) 2000 Elsevier Science I reland Ltd. All rights reserved.