Evidence that l-Carnitine and Selenium Supplementation Reduces Oxidative Stress in Phenylketonuric Patients
- 370 Downloads
It is well established that the involvement of reactive species in the pathophysiology of several neurological diseases, including phenylketonuria (PKU), a metabolic genetic disorder biochemically characterized by elevated levels of phenylalanine (Phe). In previous studies, we verified that PKU patients (treated with a protein-restricted diet supplemented with a special formula not containing l-carnitine and selenium) presented high lipid and protein oxidative damage as well as a reduction of antioxidants when compared to the healthy individuals. Our goal in the present study was to evaluate the effect of Phe-restricted diet supplemented with l-carnitine and selenium, two well-known antioxidant compounds, on oxidative damage in PKU patients. We investigated various oxidative stress parameters in blood of 18 treated PKU patients before and after 6 months of supplementation with a special formula containing l-carnitine and selenium. It was verified that treatment with l-carnitine and selenium was capable of reverting the lipid peroxidation, measured by thiobarbituric acid-reactive species, and the protein oxidative damage, measured by sulfhydryl oxidation, to the levels of controls. Additionally, the reduced activity of glutathione peroxidase was normalized by the antioxidant supplementation. It was also verified a significant inverse correlation between lipid peroxidation and l-carnitine blood levels as well as a significant positive correlation between glutathione peroxidase activity and blood selenium concentration. In conclusion, our results suggest that supplementation of l-carnitine and selenium is important for PKU patients since it could help to correct the oxidative stress process which possibly contributes, at least in part, to the neurological symptoms found in phenylketonuric patients.
KeywordsPhenylketonuria Oxidative stress l-Carnitine Selenium
This work was supported in part by grants from FAPERGS, CNPq, and FIPE/HCPA-Brazil.
- Deon M, Sitta A, Barschak AG, Coelho DM, Pigatto M, Schmitt GO, Jardim LB, Giugliani R, Wajner M, Vargas CR (2007) Induction of lipid peroxidation and decrease of antioxidant defenses in symptomatic and asymptomatic patients with X-linked adrenoleukodystrophy. Int J Dev Neurosci 25:441–447CrossRefPubMedGoogle Scholar
- German B (1999) Free radical and antioxidant protocols. Humana Press, TotowaGoogle Scholar
- Hagen MEK, Pederzolli CD, Sgaravatti AM, Bridi R, Wajner M, Wanmacher CMD, Wyse ATS, Dutra-Filho CS (2002) Experimental hyperphenylalaninemia provokes oxidative stress in rat brain. Biochim Biophys Acta 1586:344–352Google Scholar
- Halliwell B, Gutteridge JMC (2007) Oxidative stress: adaptation, damage, repair and death. In: Halliwell B, Gutteridge JMC (eds) Free radicals in biology and medicine. Oxford University Press, Oxford, pp 246–350Google Scholar
- Rajasekar P, Kaviarasan S, Anuradha CV (2005) l-carnitine administration prevents oxidative stress in high fructose-fed insulin resistant rats. Diab Croat 34:21–28Google Scholar
- Ribas GS, Manfredini V, de Mari JF, Wayhs CY, Vanzin CS, Biancini GB, Sitta A, Deon M, Wajner M, Vargas CR (2010) Reduction of lipid and protein damage in patients with disorders of propionate metabolism under treatment: a possible protective role of l-carnitine supplementation. Int J Dev Neurosci 28:127–132CrossRefPubMedGoogle Scholar
- Scriver CR, Kaufman S (2001) Hyperphenylalaninemia: phenylalanine hydroxylase deficiency. In: Scriver CR, Beaudet AL, Sly WS, Valle D (eds) The metabolic and molecular bases of inherited disease. McGraw-Hill, New York, pp 1667–1724Google Scholar
- van Backel MME, Printzen G, Wermuth B, Wiesmann UN (2000) Antioxidant and thyroid hormone status in selenium-deficient phenylketonuric and hyperphenylalaninemic patients. Am J Clin Nutr 72:976–981Google Scholar