Resistance to Malaria in Riboflavin Deficiency

The biochemiced basis of this resistemce to malMia in riboflavin deficiency is not known, but a number of mechemisms have been proposed, including the following  

The mtdMial parasites may have a particularly high requirement for riboflavin. A number of flavin rmalogs have antimtdMicd action. 

The impairment of glutathione reductase activity may result in lower availahility of glutathione in erythrocytes and hence a more oxidizing environment, which is hostile to the parasites. 

As a result of impaired antioxidtmt activity in erythrocytes, there may be incretised fragility of erythrocyte membremes or reduced membrane fluidity. As in sickle cell treiit, which edso protects ageiinst malaria, this may result in  

In vitro, high concentrations of riboflavin also impair parasite growth, apparently as a result of increased reduction of methemoglobin. The peuasites can only hydrolyze methemoglobin, not native hemoglobin. 

A number of studies have noted that, in areas where malaria is endemic, riboflavin-deficient subjects are relatively resistant and have a lower parasite burden than adequately nourished subjects. Dietary deficiency of riboflavin, hypothyroidism, which induces functional riboflavin deficiency by lowering the synthesis of flavokinase (Section 7.2.4), or the administration of chlor-promazine, which inhibits flavokinase and can cause functional riboflavin deficiency (Section 7.4.4), all inhibit the growth of malarial parasites in experimental animals. However, although parasitemia is less in riboflavin deficiency, the course of the disease may be more severe (Dutta et al., 1985 Dutta, 1991 Akompong et al., 2000a, 2000b Shankar, 2000). 

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A number of studies have noted that in areas where malaria is endemic riboflavin-deficient subjects are relatively resistant and have a lower parasite burden than adequately nourished subjects. The biochemical basis of this resistance to malaria in riboflavin deficiency is not known, but two possible mechanisms have been proposed ... 

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