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

Abstract

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.

Effect of a plant origin drug on the biodistribution of 99mTc-DTPA in Wistar albino rats

“…Some studies have suggested that radiolabeling of blood constituents with just 99m Tc could be performed to evaluate the biological effects of medicinal plant extracts (Moreno et al, 2004;Benarroz et al, 2008;Gomes et al, 2001;Abreu et al, 2006;Silva et al, 2006). Particularly Goncalves studied 99m Tc sodium pertechnetate and unpeeled Passiflora flavicarpa extract, labeling of blood components.…”

Effect of a peel passion fruit flour (Passiflora edulis f. flavicarpa) extract on the labeling of blood constituents with technetium-99m and on the morphology of red blood cells

“…The radiolabeling of blood constituents has a great importance in nuclear medicine (Saha, 2004). Some authors have suggested that drugs could alter the radiolabeling of blood constituents (Moreno et al, 2002;Abreu et al, 2006;Silva et al, 2006), as well as, promote morphological alterations on the erythrocyte membrane Oliveira et al, 2002;Santos-Filho et al, 2004;Moreno et al, 2004). Other studies report that some natural products could not interfere on the radiolabeling of blood constituents Fernandez et al, 2005) and could not modify the morphology of the red blood cells (Fernandez et al, 2005).…”

Effect of an extract of Artemisia vulgaris L. (Mugwort) on the in vitro labeling of red blood cells and plasma proteins with technetium-99m

“…Some authors have been reported that natural and synthetic drugs could alter the labeling of blood constituents with 99mTc (Frydman et al, 2004;Abreu et al, 2006;Fonseca et al, 2007). The labeling of blood constituents would decrease due to the action of drugs that could (1) bind at the same sites of 99mTc on the blood constituents, (2) directly inhibit (chelating action) of the stannous and pertechnetate ions, (3) oxidize or generate free radicals that could oxidize the stannous ion, and (4) alter the plasma membrane structure or modify the transport systems of stannous and pertechnetate ions into cells.…”

“…Several factors can influence the labeling of blood constituents with 99mTc . Some investigators have reported that phytotherapeutic agents could alter the labeling of blood constituents with 99mTc (Oliveira et al, 2002;Santos-Filho et al, 2004;Abreu et al, 2006). The aim of this study was to evaluate the influence of mugwort extract on the labeling of blood constituents with 99mTc.…”