Inhibition of malate dehydrogenase enzymes by benzimidazole anthelmintics.

Determinations were made of the inhibitory activities of four benzimidazole anthelmintics (Albendazole, Parbendazole, Mebendazole and Thiabendazole) on purified extracts of cytoplasmic and mitochondrial malate dehydrogenase obtained from Ascaris suum, Fasciola hepatica and Moniezia expansa. The highest percentage inhibitions were exhibited by Mebendazole. The results confirm that cytoplasmic MDH and mitochondrial MDH regulator enzymes of glycogen synthesis are the sites of mebendazole inhibitory activity, but the activity sites of the other anthelmintics in the study remain unclear.