Rodent malaria in rats exacerbated by milk protein, attenuated by low‐protein vegetable diet

Abstract

Young male Wistar rats were fed a purified, vegetable, low-protein diet containing 6% protein from maize gluten and 2% from soy protein isolate, or comparable diets in which maize gluten was replaced partly or completely by the equivalent amount of a milk protein concentrate. Diets with adequate protein level (16% or 22%) served as a control. At 21 or 31 days of age, the rats were infected with 3000 or 100000 erythrocytes parasitized with Plasmodium berghei. Results reported include body weight, mortality, paralysis and parasitaemia. Dietary replacement of part of the maize gluten protein by milk protein increased weight gain, but aggravated the malaria, as shown by increases in parasitaemia, paralysis and mortality. The aggravating effect of milk protein was dose-dependent. With only 4% milk protein in an 8% total protein diet, the disease symptoms were nearly as severe as with diets adequate in protein level. With a vegetable-only 8% protein diet symptoms were considerably less severe.

Nutritional Modulation of Malaria Morbidity and Mortality

“…Subsequent studies in rats and mice confirmed that low-protein diets suppressed parasitemia [77][78][79][80][81] and inhibited cellmediated immunity [77] and that effects were reversible by addition of para-amino benzoic acid [78]. Effects on mortality were less consistent.…”

“…Others observed no effect on mortality in moderately malnourished mice but noted increased deaths in severely malnourished animals [83]. Protein-deficient diets were, however, consistently protective for rodent cerebral malaria [80,81,84].…”

Effects of dietary protein types on immune responses and levels of infection with Eimeria vermiformis in mice

“…Although the effects of supplementing or restricting the intake of dietary protein on immunity and protection against parasites have been studied extensively, little attention has been given to the effects of the quality of proteins on parasitic infections and their interaction with the immune system. In this regard, while van Doorne et al 12 have reported that milk proteins can exacerbate the clinical condition of rats infected with malaria, others have found that lactoferrin, derived from milk, protects against infections with microorganisms such as Toxoplasma gondii , Giardia lamblia and Helicobacter pylori 13 , 14 , 15 . In the current study, we investigated the effects of dietary protein type on the immune and parasitological responses in mice infected with Eimeria vermiformis .…”