Riboflavin and pyridoxine restore dopamine levels and reduce oxidative stress in brain of rats

BACKGROUND: Neurological disorders suggest that the excitotoxicity involves a drastic increase in intracellular Ca(2+) concentrations and the formation of reactive oxygen species. The presence of these free radicals may also affect the dopaminergic system. The aim of this work was to determine if riboflavin (B(2)) and pyridoxine (B(6)) provide protection to the brain against free radicals generated by 3-nitropropionic acid (3-NPA) by measuring the levels of dopamine (DA) and selected oxidative stress markers. METHODS: Male Fisher rats were grouped (n = 6) and treated as follows: group 1, control (NaCl 0.9%); group 2, 3-NPA (20 mg/kg); group 3, B(2) (10 mg/kg); group 4, B(2) (10 mg/kg) + 3-NPA (20 mg/kg); group 5, B(6) (10 mg/kg) and group 6, B(6) + 3-NPA. All treatments were administered every 24 h for 5 days by intraperitoneal route. After sacrifice, the brain was obtained to measure DA, GSH, and lipid peroxidation, Ca(2+), Mg(2+), ATPase and H(2)O(2). MAIN FINDINGS: Levels of dopamine increased in cortex, striatum and cerebellum/medulla oblongata of animals that received 3-NPA alone. The lipid peroxidation increased in cortex, striatum, and cerebellum/medulla oblongata, of animals treated with B(2) vitamin alone. ATPase dependent on Ca(+2), Mg(+2) and H(2)O(2) increased in all regions of animals that received 3-NPA alone. CONCLUSION: The results confirm the capacity of 3-NPA to generate oxidative stress. Besides, the study suggests that B(2) or B(6) vitamins restored the levels of DA and reduced oxidative stress in brain of rats. We believe that these results would help in the study of neurodegenerative diseases.