Elaine A. C. Lima

Effect of an extract of cauliflower (leaf) on the labeling of blood elements with technetium-99m and on the survival of Escherichia coli AB1157 submitted to the treatment with stannous chloride

The labeling of red blood cells (RBC) with technetium-99m (99mTc) depends on a reducing agent and stannous chloride (SnCl(2)) and is widely utilized. This labeling may also be altered by drugs, and SnCl(2) reduces the survival of Escherichia coli cultures. Cauliflower (Brassica oleracea L. var. botrytis) is used in folk medicine and we evaluated its influence on (i) the labeling of blood elements with 99mTc, and (ii) on the survival of an E. coli strain. Blood was withdrawn from rats that drank the extract of cauliflower (15 days). Blood was incubated with SnCl(2) and with 99mTc, as sodium pertechnetate, centrifuged and plasma (P) and RBC were isolated. Samples of P and RBC were also precipitated, centrifuged and soluble and insoluble fractions isolated. E. coli culture was treated with SnCl(2) in the presence of cauliflower. The extract of cauliflower did not alter the fixation of 99mTc on blood fractions; however, it abolished the lethal effect of SnCl(2) on the E. coli culture. We suggest that the substances present in the extract of cauliflower probably, would have redox property with different mechanisms of action. The oxidant action of the substances of the extract would not be strong enough to oxidise the stannous ions altering the 99mTc-labeling. However, the referred substances could oxidise these ions sufficiently to protect the E. coli culture against the lethal effect of the stannous ion.

Influence of biflorin on the labelling of red blood cells, plasma protein, cell protein, and lymphocytes with technetium-99m: in vitro study

In this paper we report the results of an in vitro study involving the influence of biflorin (an o-quinone isolated from Capraria biflora L. that has potent antimicrobial activity) on the Tc-99m labeling of red blood cells, plasma protein, cells protein, and lymphocytes. Blood was withdrawn from Wistar rats and incubated with various concentrations of biflorin, and solutions of stannous chloride and Tc-99m were added. Plasma (P) and red blood cells (RBC) were isolated, precipitated, and centrifuged, and soluble (SF) and insoluble (IF) fractions were isolated. The results show that the highest concentration (100%) of biflorin is able to reduce the uptake of Tc-99m (%ATI) on RBC and the fixation on IF-P. To study the influence of biflorin on 99mTc lymphocyte labeling, human blood was submitted to a technique with Ficoll-Hypac and centrifuged, and white cells were isolated. Lymphocytes (2.5 mL; 1.0 x 106 cells/mL) were obtained and a 0.2 mL solution was incubated with biflorin (0.1 mL). Solutions of stannous chloride and 99mTc were added. Lymphocytes were separated and the %ATI bound in these cells was evaluated. A reduction in %ATI (from 97.85 ± 0.99 to 88.86 ± 5) was observed for RBC and for IF-P (73.24 ± 5.51 to 20.72 ± 6.95). In this case the results showed no decrease in %ATI for the lymphocytes with biflorin.

Assessment of a fruit extract (Sechium edule) on the labeling of blood elements with technetium-99m

Natural products have been widely used by human beings. However, sometimes the biological effects of these products are not fully known. Chayotte ( Sechium edule ) is a vegetable used in the folk medicine. Red blood cells (RBC) labeled with technetium-99m (99mTc) have several clinical applications. The aim of this work was to evaluate the influence of an extract of chayotte on the labeling of blood elements with 99mTc using stannous chloride (SnCl 2 ) in the concentrations like to 1.2, 0.006, 0.0005 and 0.0006 μg/ml. The extract of chayote was incubated in various concentrations for 1hour with blood which was withdrawn from Wistar rats. After that SnCl 2 was added and the incubation continued for more 1 h. Elapsed this time 99mTc as sodium pertechnetate (NaTcO 4 ) was toted. The blood was centrifuged and plasma (P) and RBC were isolated, also precipitated with trichloroacetic acid (TCA, 5%) and soluble (S) and insoluble (I) fractions (F) of plasma and cells (C) were determined. The radioactivity (ATI%) was rated in RBC, IF-P and IF-C. The results have showed that extract was able to reduce the radiolabeling using SnCl 2 (0.006, 0.0005 and 0.0006μg/ml). We can speculate that this effect may be on account of the products with oxidant proprieties. Key Words: chayote, red blood cells, plasma proteins, technetium-99m, radiopharmacy. African Journal of Biotechnology Vol.3(9) 2004: 484-488