L-arginine enhances blood trace metals and reduces oxidative stress burden in sickle cell anaemia subjects in the steady state

Abstract

Background: It is not clear how arginine supplementation, which may be beneficial in the management of sickle cell anaemia, interplays with trace metals which are required as cofactors for antioxidant enzymes levels and activity.

Methods: We compared the effect of oral, low-dose (1 g/day), 6-week supplementation with L-arginine on some trace metals and antioxidant enzymes levels in 33 HbAA and 28 HbSS subjects. Ten (10) milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) levels and serum concentrations of Zn⁺⁺, Mn⁺⁺ and Cu⁺⁺.

Results: HbAA subjects had higher levels of Zn⁺⁺, Mn⁺⁺, [R], CAT, SOD and GPx but lower [MDA] (p < 0.05 in each case) than HbSS subjects. In both groups, L-arginine supplementation increased [R], SOD, GPx, CAT, Zn⁺⁺ and Cu⁺⁺ (p < 0.05 in each case and group) but decreased [MDA] (p < 0.001 in each group). Mn⁺⁺ level decreased in HbAA but, it increased in HbSS subjects (p < 0.001 in each case). The degree of change (%Δ) in all the measured parameters (except MDA) was higher in HbSS than in HbAA subjects. Correlation coefficients (r) calculated between changes (Δ) in trace metals levels and changes (Δ) in antioxidant levels were higher in HbSS subjects.

Conclusion: Study showed that L-arginine boosted plasma arginine, serum trace metals and antioxidant enzymes but decreased malondialdehyde in HbSS subjects in the steady state. Associations between changes in antioxidant enzymes and changes in trace metal levels were higher in HbSS than in HbAA subjects.

Keywords: L-arginine, sickle cell anaemia, antioxidant enzymes, trace metals, malondialdehyde