Diospyros lotus L. fruit extract protects G6PD-deficient erythrocytes from hemolytic injury in vitro and in vivo: prevention of favism disorder.

OBJECTIVE: The aim of this study was to evaluate the protective effect of Diospyros lotus L. fruit extract against the hemolytic damage induced by Vicia faba beans extract in both G6PD enzyme-deficient human and rat erythrocyte in vitro and in vivo. MATERIALS AND METHODS: In the former model, venous blood samples were obtained from five subjects with known G6PD deficiency and erythrocyte hemolysis induced by Vicia faba L. bean extract was asessed spectrophotometrically in the presence and absence of Diospyros lotus L. fruits extract. In the in vivo model, G6PD-deficient rats (induced by intraperitoneal injection of dehydroepiandrosterone for 35 days) pre-treated with different doses of Diospyros lotus L. (500, 750, 1000, and 1500 mg/kg, p.o for 7 days) were challenged with Vicia faba beans extract and the protective effect of the fruit extract against hemolysis was evaluated as above. RESULTS AND CONCLUSIONS: The results have shown that Diospyros lotus L. fruits extract has antioxidant activity that may protect against hemolytic damage induced by Vicia faba bean extract in both G6PD-deficient human and rat erythrocytes. The study gives a scientific basis for the efficacy of the fruit extract as used in Iran. The fact that this was shown in human erythrocytes in vitro is significant and provides a rationale for further testing in vivo in G6PD-deficient human populations.

Acute massive haemolysis in children with glucose-6-phosphate dehydrogenase deficiency.

We report seven consecutive episodes of acute massive haemolysis accompanied by symptomatic anaemia and gross haemoglobinuria in six boys with glucose-6-phosphate dehydrogenase deficiency seen in a regional hospital during a 12-year period. They presented at a mean age of 5.5 years (range, 1.5-11.3 years) with trough haemoglobin levels between 35 and 84 g/L. Two children developed transient renal impairment. Five children required erythrocyte transfusion, of whom one underwent exchange transfusion during the oliguric phase. Three patients required intensive care but all recovered from the haemolysis. The probable precipitating factors included consumption of fava beans (n=2), exposure to mothballs (n=1), treatment with herbal medicine or intramuscular injection of unknown nature (n=3), and upper respiratory tract infection (n=1). Although uncommon, acute massive haemolysis remains a life-threatening complication in children with glucose-6-phosphate dehydrogenase deficiency. Improvement in patient education and public health measures is suggested.

Hydrolysis of vicine and convicine from fababeans by microbial beta-glucosidase enzymes.

The toxic glycosides vicine and convicine which are present in fababeans have been implicated in favism, an anaemic disease of humans. Vicine and convicine concentrations are reduced by growth of Lactobacillus plantarum on fababean suspensions. The glycosides are eliminated from the fababean substrate by the growth of the filamentous fungus Fusarium graminearum. Incubation of fababean suspension with concentrated culture filtrate of Aspergillus oryzae, induced for extracellular beta-glucosidase production, results in complete degradation of the glycosides. This study suggests a potential use of micro-organisms or microbial enzymes for detoxification of fababeans.

Marked decline of favism after neonatal glucose-6-phosphate dehydrogenase screening and health education: the northern Sardinian experience.

Favism is a potentially fatal manifestation of glucose-6-phosphate dehydrogenase (G6PD) deficiency, and it is therefore a public health problem in areas where this genetic abnormality is common. In the district of Sassari (northern Sardinia), the frequency of G6PD male hemizygotes is approximately 7.5%, and therefore all newborns since 1971 have been screened for G6PD deficiency. We have analyzed the incidence of favism in this community in two 10-year periods: (1) 1961-1970; and (2) 1981-1990. In period 1, there were 508 cases of favism, of which 76% occurred in boys. In period (2) there were 144 cases of favism, of which only 52% in boys. Thus, between the two periods there was an overall decrease in the incidence of favism of 75%, whereas the proportion of girls affected has approximately doubled. These data suggest that neonatal screening and health education programs can produce a substantial decrease in the number of cases of favism, and that the relative increase in favism in girls is possibly due to failure of the screening method used to detect all the heterozygotes for G6PD deficiency.