The Effects of Moringa oleifera Leaves Extracts on Sickle Cell Hemoglobin

Abstract

Sickle cell disease (SCD) caused by hemoglobin mutant called hemoglobin S or HbS, which originated from the replacement of a hydrophilic amino acid residue-glutamic acid by a hydrophobic moiety valine, at the sixth position of the β-chain of hemoglobin molecule. This loss of charge causes the erythrocytes to sickle under hypoxic conditions. The phytochemical, proximate and amino acid compositions of the leaves extracts of the plant Moringa oleifera were assayed to determine their antisickling effects on sickle cell hemoglobin. The proximate composition of the leaves showed the data:moisture (6.0±1.2mg/100g); crude protein (28.0±1.0mg/100g); carbohydrate (48.10±0.13mg/100g); crude fiber (10.05±0.01mg/100g); ash(9.30±0.01 mg/100g) ; pH 6.25 and crude fat (2.5±0.0 mg/100g). The different extracts including the crude aqueous extracts (CAE) revealed a preponderance of the following phytomedicines:-alkaloids (4.0±0,01mg/100g), flavonoids (0.4±0.0mg/100g), saponins (8.0mg/100g) and phenols (1.10±0.10mg/g. The antisickling effects of the different fractions of the leaves exhibited pronounced antisickling effectiveness by inhibiting sickle cell hemoglobin polymerization from 88.80% for the WAS(water-soluble) fraction to 98.35% for the FAS(fat-soluble) fraction. The BUS (butanol-soluble) fraction inhibited the process to 98.35%.The following antisickling amino acids were equally identified by TSM (technicon sequential multisample) amino acid analyzer at different concentrations: arginine (6g/100g); histidine(2.1g/100g);lysine (4.3/100g); tryptophan 1.9g/100g; phenylalanine 6.4g/100g. The total free amino acid concentration of the fractions (WAS, FAS, BUS) were high and expressed as follows: 13.57 mg/100g; 450.78 mg/100g and 49.76 mg/100g respectively. The total ascorbic (Vitamin C) acid concentration of the (crude aqueous extract) CAE was 4512 mg/100 g of sample. The Fe2+/Fe3+ ratio showed improvement from 5.48% for the WAS fraction to 18.89% for the FAS fraction. Based on the preponderance of phytonutients, the proximate composition of the leaves, the antisickling effectiveness of the fractions based on hemoglobin polymerization inhibition experiment, the presence of antisickling and essential amino acids; Moringa oleifera leaves extracts may present future therapeutic hope for the effective management of sickle cell disease and other related nutritional syndromes.