The Effects of Ciglitazone on Enzyme Activities of Carbonic Anhydrase II and Glucose-6- Phosphate Dehydrogenase

Ciglitazone is a compound belonging to the thiazolidinedione (TZD) class and has hypoglycemic effects. Although ciglitazone is not used as a drug, it has been used as a template for the development of other TZD group drugs. Like many TZD group drugs, ciglitazone causes anemia. In this study, the effects of ciglitazone on the enzyme activities of Glucose-6- Phosphate Dehydrogenase (G6PD) and Carbonic Anhydrase II (CA II), which have important functions in maintaining erythrocyte functions and integrity, were investigated in vitro. Pure human erythrocyte CA II and G6PD enzymes were used for activity measurements. Both esterase and hydratase activities were measured for CA II. The result of activity measurements, it was observed that ciglitazone inhibited CA II (IC50 =0.0063 mM for hydratase activity, and IC50 =0.047 mM for esterase activity) and G6PD (IC50 = 0.067 mM) activities. As a result, it was concluded that these enzyme inhibitions may be important in the anemia-causing mechanisms of cigitazone.