Comparison of urinary amino acids and trace elements (copper, zinc and manganese) of recent neurolathyrism patients and healthy controls from Ethiopia

Objective: The irreversibly crippling disease neurolathyrism is caused by prolonged over-consumption of Lathyrus sativus seed. The molecular mechanism of toxicity is unclear and more biochemical information is needed. Methods: The urinary amino acids from 5 recent patients and 9 healthy subjects in Ethiopia were analysed by HPLC after PITC (phenyl isothiocyanate) derivatisation. The trace elements Cu, Zn and Mn of urine and seeds were determined by atomic absorption spectroscopy. Results: The free amino acids aspartic acid, glycine, β-aminoisobutyric acid, arginine, α-aminoadipic acid and phenylalanine were statistically higher (p < 0.05) in urine from patients than in urine from control subjects. The trace element Cu was also statistically higher (p < 0.05) in patient urine. Conclusion: The amino acid metabolism of the neurolathyrism patients is disturbed by over-consumption of grass pea seeds. The high concentrations of Cu found in the patient urine might indicate the involvement of trace elements in the aetiology of neurolathyrism.