Mutagenic bioassay of certain pharmacological drugs. I. Thiabendazole (TBZ).

This report describes the chromosomal damage produced by 2-(4'-thiazolyl)benzimidazole or thiabendazole (TBZ) evaluated by "in vivo" and "in vitro" cytogenetic tests. The doses assayed in adult mice by the sister-chromatid exchange (SCE) and micronucleus tests were: 50, 100 and 200 mg/kg body weight; these are within the range of those used in human antihelminthic treatments. SCE frequency was increased only in the last dose (p less than 0.05). A significant increase of micronucleated cells was shown in the 3 doses assayed (p less than 0.001). A marked increase in abnormal anaphase-telophase cells was only detected with the two highest concentrations assayed (0.60-0.24 microgram/ml) p less than 0.01 and p less than 0.05 respectively. The observed genotoxic effects of this compound indicate that TBZ itself is a mutagenic agent.