Pharmacokinetics and hematotoxicity of a novel copper-based anticancer agent: casiopeina III-Ea, after a single intravenous dose in rats

Casiopeina III-Ea is a mixed chelate copper (II) complex that has shown cytotoxic and antitumor activity <i>in vitro</i> and <i>in vivo</i>. The aim of this study was to investigate the pharmacokinetics of total copper derived from casiopeina III-Ea administered by intravenous bolus injection to Wistar rats. Other objective was to evaluate the hematotoxicity produced by this compound in those animals. Wistar rats received a single intravenous dose of 4 mg/kg of casiopeina III-Ea. Blood samples were taken and pharmacokinetics evaluated. Furthermore, erythrocyte copper levels were determined to identify a potential target and Zn levels were analyzed to determine a possible change. For the evaluation of hematotoxicity, both blood and urine samples were collected for hematological and biochemical analyses; moreover, Fe determination was performed. Blood copper and zinc levels, red blood cell copper levels as well as copper, zinc, and iron amounts excreted into urine were analyzed by ICP-MS. The blood concentration–time profile of copper derived from casiopeina III-Ea was fitted to a two-compartment model with a zero-order input. Cumulative amounts of Cu, Zn, and Fe excreted into rat urine after administration of casiopeina III-Ea were different with respect to control. Hematological and biochemical data indicated a hemolytic toxicity. Pharmacokinetic analysis of total copper derived from casiopeina III-Ea provided a general knowledge about distribution and elimination process of this compound. Additionally, the systemic exposure of the copper derived from casiopeina III-Ea accounts for the hematotoxicity of this complex at test dose.