Abstract

The aim of the present study was to assess the effect of the oral ingestion of an extract of the Arctium lappa (burdock) on the bio-distribution of the radio-pharmaceutical (radio-biocomplex) sodium pertechnetate (Na^99mTcO₄) in rats. Male Wistar rats (3 to 4 months of age, 329 ± 16 g) were treated with a burdock extract (1 ml, 20 mg/ml, n = 5) or 0.9% NaCl solution (control: n = 5) for 7 days. After this period of time, Na^99mTcO₄ (3.7 MBq, 0.3 ml) was injected through the ocular plexus. After 10 min, the rats were sacrificed, the organs isolated and counted in an automatic gamma counter. The percentage of radioactivity was calculated per gram of tissue (%ATI/g) or per whole organ (% ATI/organ). Alteration in Na^99mTcO₄ uptake was observed in liver from 1.72 ± 0.38 to 0.27 ± 0.07 (% ATI/organ, p < 0.05) and % ATI/g in lung (from 0.45 ± 0.40 to 1.02 ± 0.15 % ATI/g), in testis (from 0.12 ± 0.01 to 0.18 ± 0.02 % ATI/g), in tooth (from 0.24 ± 0.08 to 0.06 ± 0.13 % ATI/g), in tongue (from 0.38 ± 0.06 to 0.08 ± 0.16 % ATI/g) and in liver (from 1.07 ± 0.06 to 0.56 ± 0.15) after treatment with burdock. These findings could result from the interaction between components of the A. lappa extract and the radio-biocomplex which may influence the uptake of Na^99mTcO₄ in some organs of rats. Therefore, precautions are suggested in the interpretation of nuclear medicine results in patients using burdock.

Key words: Arctium lappa (Burdock), biodistribution, sodium pertechnetate, radiobiocomplex.

Abbreviation

AcOE, Ethyl acetate fraction; Na^99mTcO₄, sodium perthecnetate; MBq, mega becquerel; NaCl, sodium chloride; A. Lappa, Arctium lappa; Tc-99m, technetium-99m