Biomarkers of oxidative stress in schizophrenic and bipolar patients during manic episode

  • PhD Keila Ceresér, Hospital de Clínicas de Porto Alegre, INCT Translational Medicine, Brazil
  • Nut Karine Zortéa, Federal University of Rio Grande do Sul, Brazil
  • Pharm Lenise Francesconi, Federal University of Rio Grande do Sul, Brazil
  • PhD Ângelo Cunha, Federal University of Santa Maria, Brazil
  • PhD Clarissa Gama, Hospital de Clínicas de Porto Alegre, INCT Translational Medicine, Brazil
  • Biol Matheus Pasquali, Federal University of Rio Grande do Sul, Brazil
  • Biol Carlos Schnorr, Federal University of Rio Grande do Sul, Brazil
  • PhD José Moreira, Federal University of Rio Grande do Sul INCT Translational Medicine, Brazil

Objective
Oxidative stress may contribute to the pathophysiology of schizophrenia and bipolar disorder. The aim of our study was to evaluate biomarkers of oxidative stress in patients with schizophrenia (SZ) and bipolar disorder (BD) compared to healthy subjects.
Methods
This study evaluated serum levels of the lipid peroxidation product, thiobarbituric acid reactive substances (TBARS), protein oxidative damage (carbonyl) and total non-enzymatic antioxidant potential (TRAP) in 20 subjects with BD in manic episode, 55 with SZ and 80 healthy volunteers. The diagnosis was in accordance to DMS-IV criteria.
Results
Serum TBARS and carbonyl levels were significantly higher in schizophrenic (p<0,001) and manic (p<0,001) patients than in controls, they are also significantly increased in schizophrenic when compared to manic patients (respectively p<0,001 and p=0,026). Serum levels of TRAP were significantly lower in schizophrenic patients than in manic (p=0,028) and in controls (p<0,001), but difference between TRAP levels in manic compared to controls was not found.
Conclusion
Oxidative stress can result from diminished levels of antioxidants or increased production of reactive species from oxygen or nitric oxide. The central nervous system is extremely vulnerable to peroxidative damage. Since CNS is rich in oxidizable substrates; it has a high oxygen tension and a relatively low antioxidant capacity. Our results are in line with literature about SZ and BD concerning an initial deterioration in SZ and, an episode-dependant pattern of deterioration in BD. Although our results show increased oxidative stress in both BD and SZ, protein damage is increased in SZ.