Alterations of erythrocyte antioxidant mechanisms: Antioxidant enzymes, lipid peroxidation and serum trace elements associated with anemia in bovine tropical theileriosis

In order to investigate the alterations of erythrocyte protective antioxidant mechanisms, lipid peroxidation and trace elements associated with anemia in bovine tropical theileriosis, an infected group comprised of 50 crossbred Holstein cattle, about 1-2 years old, naturally infected with Theileria annulata, were divided into 4 subgroups according to their parasitemia rates (<1%, 1-3%, 3-5%, >5%) and also 10 healthy cattle as control were selected. Blood samples were taken and hematological parameters, the activities of antioxidant enzymes including superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase and serum concentrations of some antioxidant trace elements (copper, iron, zinc, manganese and selenium) were measured. As an index of lipid peroxidation, the level of Malondialdehyde (MDA) was also determined. The results showed a conspicuous decrease in the activities of SOD, GPX and catalase (P < 0.01), and a significant decrease in the serum concentrations of Cu, Zn, Mn and Se in cattle with higher than 1% parasitemia (P < 0.05) compared to the control. In addition, remarkable elevations in the MDA level (P < 0.01) and serum concentration of iron (P < 0.05) were observed in the infected animals. These findings pointed to the occurrence of exacerbating oxidative injuries to erythrocytes during parasitemia. Furthermore, it can be concluded that infection with T. annulata can interfere with protective antioxidant mechanisms of RBCs against oxidative damages, which promote the development of anemia.