Influence of antipyretic drugs on the labeling of blood elements with technetium-99m

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

Background:

Natural products might alter the labeling of blood constituents with technetium-99m (^99mTc) 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).

Materials and Methods:

To study the effect of the CE on the labeling of blood constituents with ^99mTc, 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^99mTcO₄) in Wistar rats, these animals were treated or not with a CE. Na^99mTcO₄ was injected, the rats were sacrificed, the organs were removed, weighted and percentage of radioactivity/gram calculated.

Result:

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^99mTcO₄ was observed in stomach after in vivo treatment.

Conclusion:

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.

Assessment of effects of a Cordia salicifolia extract on the radiolabeling of blood constituents and on the morphology of red blood cells

Effects of a Cordia salicifolia (porangaba) extract on the labeling of blood cells (BCs) with technetium-99m ((99m)Tc) and on the morphology of red BCs were evaluated. Labeling of cellular and molecular structures with (99m)Tc depends on a reducing agent. Some physical characteristics, as visible absorbance spectrum, electric conductivity, and refractive index of this porangaba extract, were also determined. Blood samples from Wistar rats were incubated with porangaba extract or with 0.9% NaCl (control). Labeling of blood constituents with (99m)Tc was performed. Plasma (P) and BCs, both soluble (SF-P and SF-BC) and insoluble (IF-P and IF-BC) fractions, were separated. The radioactivity in each fraction was counted, and the percentage of radioactivity incorporated (%ATI) was calculated. Blood smears were prepared, fixed, and stained, and the morphology of the red BCs was evaluated. Data showed an absorbance peak at 480 nm and electric conductibility and refractive index concentration-dependent. Porangaba extract decreased significantly (P < .05) the BC, IF-P, and IF-BC %ATI, and no modifications were verified on the shape of red BCs. Analysis of the results reveals that some physical parameters could be useful to aid in characterizing the extract studied. Moreover, it is possible that chemical compounds of this extract could have chelating/redox actions or be capable of binding to plasma and/or cellular proteins.

Evaluation of the in vitro effect of a Lantana camara extract on the labeling of blood constituents of rats with technetium-99m

Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures and drugs are capable to interfere on this labeling. Lantana camara (lantana) has medicinal properties and it has been used in folk medicine. The aim is to verify the effect of a lantana extract on the labeling of blood constituents with 99mTc. Blood of rats was incubated with extract, stannous chloride and 99mTc, as sodium pertechnetate. Plasma (P) and blood cells (BC) were isolated, also precipitated with trichloroacetic acid and soluble (SF) and insoluble fractions (IF) were separated. The % of radioactivity (%ATI) in these samples was calculated. Samples of labeled BC were washed and the %ATI maintained (%ATI-M) in the BC was determined. The results showed that lantana extract decreased significantly (p < 0.05) in the IF-P from 70.24 +/- 2.59 to 11.95 +/- 3.07. This effect was not observed in the BC and IF-BC. The BC-%ATI-M was significantly (p < 0.05) decreased in all concentrations tested when the BC was washed. This fact was not observed in the control. Substances present on the extract should have redoxi action decreasing the concentration of the stannous ion and this condition could justify the effect on the IF-P. The results about the BC-%ATI-M should indicate a possible effect on the transport of ions through the erythrocyte membrane.

Cinnamomum zeylanicum extract on the radiolabelling of blood constituents and the morphometry of red blood cells: in vitro assay

Effects of Cinnamomum zeylanicum (cinnamon) on the labelling of blood constituents with technetium-99m(99mTc) and on the morphology of red blood cells were studied. Blood samples from Wistar rats were incubated with cinnamon extract for 1 hour or with 0.9% NaCl, as control. Labelling of blood constituents with 99mTc was performed. Plasma (P) and blood cells (BC), soluble (SF-P and SF-BC) and insoluble (IF-P and IF-BC) fractions were separated. The radioactivity in each fraction was counted and the percentage of radioactivity incorporated (%ATI) was calculated. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphological analysis of the red blood cells was evaluated. The data showed that the cinnamon extract decreased significantly (p<0.05) the %ATI on BC, IF-P and IF-BC. No modifications were verified on shape of red blood cells. Cinnamon extracts could alter the labelling of blood constituents with 99mTc, and although our results were obtained with animals, precaution is suggested in interpretations of nuclear medicine examinations involving the labelling of blood constituents in patients who are using cinnamon.

Acetylsalicylic acid decreases the labeling of blood constituents with technetium-99M

Acetylsalicylic acid is the most widely used drug as antipyretic, analgesic, anti-inflammatory agent and for secondary prevention of thrombotic phenomena in the heart, brain and peripheral circulation. Drugs can modify the labeling of blood constituents with technetium-99m (99mTc). This work has evaluated the effect of in vivo treatment with acetylsalicylic acid on the in vitro labeling of the blood constituents with 99mTc. Wistar rats were treated with different doses (1.5, 3.0 and 6.0 mg/kg) of acetylsalicylic acid during 1 hour. At higher dose used (6.0 mg/kg) animals were treated during different period of time (0.25, 1.0 and 4.0 hours). Animals treated with physiologic saline solution were used as control. After the labeled process; plasma (P), blood cells (BC), insoluble (IF-P, IF-BC) and soluble (SF-P, SF-BC) fractions were separated. Afterwards, the percentage of radioactivity (%ATI) in each fraction was calculated. The treatment during 1 hour with acetylsalicylic acid at higher dose has significantly (p < 0.05) modified the fixation of 99mTc on blood cells. Considering the results, we suggest that acetylsalicylic acid used at therapeutic doses may interfere with the nuclear medicine procedures related to these blood constituents.

Effect of a commercial extract of Paullinia cupana (guarana) on the binding of 99mTc-DMSA on blood constituents: An in vivo study

We studied the influence of a commercial extract of Paullinia cupana (guarana) on the binding of technetium-99m-dimercaptosuccinic acid ((99m)Tc-DMSA) on blood constituents. Plasma (P) and blood cells (BC) from Wistar rats (control and treated) were separated. P and BC were precipitated with trichloroacetic acid (TCA) or ammonium sulphate (AS) and soluble (SF) and insoluble fractions (IF) isolated. The percentage of incorporated radioactivity (%ATI) in each fraction was determined. The treatment influenced the %ATI in IF-P and in IF-BC isolated by TCA precipitation.

Guava extract (Psidium guajava) alters the labelling of blood constituents with technetium-99m

Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with technetium-99m ((99m)Tc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with (99m)Tc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with (99m)Tc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with (99m)Tc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with (99m)Tc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.

A propolis extract and the labeling of blood constituents with technetium-99m

Since ancient times propolis has been employed for many human purposes because to their favourable properties. Blood constituents labeled with technetium-99m (99mTc) have been used in nuclear medicine procedures. Some authors have reported that synthetic or natural drugs can interfere with the labeling of blood constituents with 99mTc. The aim of this work was to evaluate the action of a propolis extract on the labeling of blood elements with 99mTc. Samples of whole blood of male Wistar rats were incubated in sequence with an aqueous propolis extract at different concentrations, stannous chloride and 99mTc, as sodium pertechnetate. Blood samples were centrifuged to separate plasma and blood cells, soluble and insoluble fractions of plasma and blood cells were also separated after precipitation in trichloroacetic acid solution and centrifugation. The radioactivity was counted and the percentage of incorporated radioactivity (%ATI) for each fraction was calculated. The data obtained showed that the aqueous propolis extract used decreased significantly the %ATI in plasma proteins at higher concentration studied. Results suggest that at high concentration the constituents of this extract could alter the labeling of plasma proteins competing with same binding sites of the 99mTc on the plasma proteins or acting as antioxidant compounds.