Evaluation of the Amino Acid Profile and Haemoglobin Polymerization Inhibition Potential of Some Nigerian Legumes

The amino acid profile and the effects of the seed extracts of Sphenostylis sternocarpa, Monodora myristica and Mucuna sloanei were studied based on their ability to inhibit haemoglobin polymerization and improve the Fe2+/Fe3+ ratio of sickle cell erythrocytes. The samples were fractionated into crude aqueous extract (CAE), fat-soluble (FAS), butanol-soluble (BUS) and water-soluble (WAS) fractions. The CAEs of the samples ranked highest in amino acid content in the range of S. sternocarpa (7.12 ± 0.00 g/100g)>M. myristica (6.00 ± 0.15 g/100g)>M. sloanei (3.56 ± 0.21 g/100g). The amino acids identified in appreciable quantities in the seed samples included Phe, Leu, Val, Ile, His, Arg, Tyr, Met, among others. The extracts inhibited polymerization to varying degrees with CAE of both S. sternocarpa and M. myristica, as well as the WAS of M. myristica eliciting significantly (p<0.05) high percent inhibition of polymerization when compared with Phe standard. The extracts improved the Fe2+/Fe3+ ratio of HbSS blood from 1.36% for CAE of M. sloanei to 85.04% for CAE of S. sternocarpa; and from 11.03% for WAS of S. sternocarpa to 36.08% for WAS of M. sloanei. These legumes could, therefore, have immense nutritional and therapeutic importance in the management of sickle cell disease and other related diseases.