Effect of dietary iron supplementation on the course of Plasmodium chabaudi malaria in weanling mice

Abstract

The hypothesis that iron repletion may enhance parasite multiplication and aggravate malaria infection in iron-deficient hosts was tested in a murine model of dietary iron deficiency and iron supplementation. Weanling C57Bl/6J mice were fed diets containing either 15mg iron/kg diet (Group D, n=20) or 50 mg iron/kg diet (Group N, n=12). After 30 days, when hemoglobin levels (Hb in g/100ml; Mean ± SD) were significantly lower in Group D (13.7 ± 1.2) than in from Group N (15.4 ± 2.0), 16 mice from Group D and 8 mice from Group N were inoculated intraperitoneally with 10 4 intraerythrocytic Plasmodium chabaudi (AS strain) malaria parasites. Four animals from each group remained as non-infected controls. At the time of inoculation, 8 mice from Group D (thereafter Group DS) and all animals from Group N (thereafter Group NS) were transferred to a diet containing 140 mg iron/kg, whereas 8 mice from Group D were maintained on the original iron-deficient diet. At the peak of parasitemias (day 10–11 post-infection), anemia was less severe in mice from Group DS if compared to those from Group D (Hb: 4.5 ± 1.1 vs. 3.4 ± 1.0), but more severe than in those from Group NS (5.6 ± 1.8). However, the time course of parasitemias was similar in all groups. Mortality was higher among mice from Groups D and DS (87.5%) than in those from Group NS (37.5%; Fisher's exact test, p = 0.0104). These data indicate that neither iron deficiency suppressed nor iron repletion enhanced P. chabaudi multiplication in weanling mice. Moreover, dietary iron supplementation induced hemoglobin response in iron-deficient mice but did not increase their ability to resist severe malarial anemia.