Lipid peroxidation associated with anemia in rats experimentally infected with Trypanosoma evansi

This study aimed to assess the plasma lipid peroxidation and the susceptibility of erythrocytes to in vitro peroxidation as indicators of oxidative damage in erythrocytes and their roles in the pathogenesis of anemia during the early acute phase of Trypanosoma evansi infection in rats. Fifty male Wistar rats were randomly distributed into seven groups: three trypanosome-infected groups (T2, T4 and T6; n = 10 animals per group) and four uninfected controls (C0, C2, C4 and C6; n = 5 animals per group). Animals from trypanosome-infected groups were inoculated intraperitoneally with 106 trypanosomes. Blood samples were collected by cardiac puncture before infection (day 0; group C0) or on the 2nd (C2 and T2), 4th (C4 and T4) and 6th (C6 and T6) day post-infection (dpi). Samples were analyzed for red blood cell (RBC) count, hemoglobin (Hb) concentration, packed cell volume (PCV), plasma malondialdehyde (MDA) and in vitro peroxidation of erythrocytes. The mean values of the hematological indices gradually decreased in the infected rats compared with the control. MDA was significantly increased (P < 0.001) on the 6th dpi in infected versus control animals and was negatively correlated with PCV (P < 0.001; R2 = 0.372). The values for erythrocyte in vitro peroxidation were higher for groups T4 and T6 than for the control rats (P < 0.01). A positive correlation between erythrocyte peroxidation and MDA (P < 0.001; R2 = 0.414) was observed. The results of this study indicate that T. evansi infection in rats is associated with oxidative stress, indicated by lipid peroxidation and oxidative damage in erythrocyte membranes, as demonstrated by in vitro peroxidation. This may be one of the causes of anemia in acute trypanosomosis.