6533b873fe1ef96bd12d49c1

RESEARCH PRODUCT

L’usage de variétés de féveroles (Vicia faba L.) à faibles teneurs en vicine et convicine, réduit le risque du favisme chez l’homme hemizygote porteur d’une mutation de forte déficience en glucose-6-phosphate déshydrogénase (G6PD)

subject

description

Low vicine and convicine content in faba bean seeds is under oligogenic control and can be easily monitored by breeding. Aim of the study was to show that new faba beans (FB) genotypes with low content of vicine and convicine (low V/C FB) produced by selection, are non-toxic and non-hemolytic even when ingested in large amounts by highly susceptible glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. Evidence indicates that V/C, amino-pyrimidine derivatives present in high amounts in normal FB, are the causative agents of favism, ie severe oxidative damage and hemolysis occurring in G6PD-deficient subjects after FB ingestion. In vitro, micromolar V/C elicits oxidative damage in G6PDdeficient RBCs with decreased glutathione (GSH, main oxidant scavenger); aggregation of membrane proteins; increased lipoperoxidation; loss of deformability, binding of opsonins, and massive removal by phagocytosis. The present study was performed in severely G6PDdeficient volunteers fed with low V/C FB analyzing oxidation-sensitive parameters modified by V/C and causally connected with hemolytic anemia. 500 g fresh de-hulled FB seeds/70 kg body weight (10-fold a normal meal) of low V/C FB were administered to 7 hemizygous G6PD-deficient (Mediterranean variant) subjects. At hourly intervals RBC and blood plasma were isolated and a number of parameters of frank hemolysis (RBC numbers, Hb concentration, hematocrit, haptoglobin) and more subtle indicators of oxidant damage were measured in RBC or plasma/serum until 10 h, and 24-48 h after FB ingestion. No change in any parameter of frank hemolysis or in any indicator of oxidative damage in isolated RBC was observed in G6PD-deficient subjects after consumption of low V/C FB. Conclusions. In a sample of 7 hemizygous G6PD-deficient subjects with 1-3% residual enzyme activity, none of the parameters that accompany frank hemolysis or indicate more subtle oxidative RBC damages were modified in any of the deficient subjects either shortterm (1-8 h) or up to 48 h after ingestion of large amounts of raw FB seeds with low V/C content. Those data are the first evidence indicating that low V/C FB can be administered in large amounts even to severely deficient G6PD subjects without any risk of oxidative RBC damage or frank hemolysis and this result is supporting breeding developments in the direction of low V/C cultivars.