Amprolium is a thiamine analog and antiprotozoal agent that interferes with thiamine metabolism and inhibits carbohydrate synthesis.1,2,3,4 It competitively inhibits thiamine uptake by E. tenella schizonts and by chick host intestinal cells (Kis = 7.6 and 326 μM, respectively).1 It also inhibits hexose formation and pentose utilization ex vivo in isolated lysed rat erythrocytes and in liver, kidney, heart, and intestinal tissue homogenates following dietary administration.2 Amprolium (1,000 ppm in feed) inhibits oocyst output and sporulation of Eimeria maxima, E. brunetti, and E. acervulina in infected chicks.3 It also decreases lesion and oocyst scores and mortality of E. tenella-infected chicks following dietary administration of a 125 ppm dose.4 Amprolium (100 μM) induces apoptosis in PC12 rat adrenal cells and increases the level of cleaved caspase-3.5 Formulations containing amprolium have been used as coccidiostats in poultry processing.
1.James, S.Thiamine uptake in isolated schizonts of Eimeria tenella and the inhibitory effects of amproliumParasitology80(2)313-322(1980) 2.Brin, M.The antithiamine effects of amprolium in rats on tissue transketolase activityToxicol. Appl. Pharmacol.6(4)454-458(1964) 3.Joyner, L.P., and Norton, C.C.The anticoccidial effects of amprolium, dinitolmide and monensin against Eimeria maxima, E. brunetti and E. acervulina with particular reference to oocyst sporulationParasitology75(2)155-164(1977) 4.Abbas, R.I., Manzoor, Z., Munawar, S.H., et al.Anticoccidial activity of hydrochloric acid (HCl) against Eimeria tenella in broiler chickensPesq. Vet. Bras.31(5)425-429(2011) 5.Chornyy, S., Parkhomenko, J., and Chorna, N.Thiamine deficiency caused by thiamine antagonists triggers upregulation of apoptosis inducing factor gene expression and leads to caspase 3-mediated apoptosis in neuronally differentiated rat PC-12 cellsActa. Biochim. Pol.54(2)315-322(2007)