title: Prooxidant versus antioxidant brain action of ascorbic acid in well-nourished and malnourished rats as a function of dose: a cortical spreading depression and malondialdehyde analysis.
abstract: Although ascorbic acid (AA) is an antioxidant, under certain conditions it can facilitate oxidation, which may underlie the opposite actions of AA on brain excitability in distinct seizure models. Here, we investigated whether chronic AA administration during brain development alters cortical excitability as a function of AA dose, as indexed by cortical spreading depression (CSD) and by the levels of lipid peroxidation-induced malondialdehyde. Well-nourished and early-malnourished rats received per gavage 30, 60, or 120 mg/kg/d of AA, saline, or no gavage treatment (naïve group) at postnatal days 7-28. CSD propagation and malondialdehyde levels were analyzed at 30-40 days. Confirming previous observations, CSD velocities were significantly higher in the early-malnourished groups than in the well-nourished groups. AA dose was important: 30 mg/kg/d AA decelerated CSD and reduced malondialdehyde levels, whereas 60 mg/kg/d and 120 mg/kg/d accelerated CSD and augmented malondialdehyde levels compared with the corresponding saline and naïve groups. Our findings reinforce previous suggestion that AA acts as an antioxidant in the brain when administered at low doses, but as a prooxidant at high doses, as indicated by CSD propagation and malondialdehyde levels.
authors.affiliation: Departamento de Nutrição, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.
authors.forename: Rosângela Figueiredo
authors.initials: RF
authors.lastname: Mendes-da-Silva
authors.affiliation: Departamento de Nutrição, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.
authors.forename: Andréia Albuquerque Cunha
authors.initials: AA
authors.lastname: Lopes-de-Morais
authors.affiliation: Departamento de Nutrição, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.
authors.forename: Maria Eduarda
authors.initials: ME
authors.lastname: Bandim-da-Silva
authors.affiliation: Departamento de Nutrição, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.
authors.forename: Gabriela de Araujo
authors.initials: Gde A
authors.lastname: Cavalcanti
authors.affiliation: Departamento de Nutrição, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil.
authors.forename: Ana Rafaela Oliveira
authors.initials: AR
authors.lastname: Rodrigues
authors.affiliation: Departmento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, 50670901, Recife, Brazil.
authors.forename: Belmira Lara da Silveira
authors.initials: BL
authors.lastname: Andrade-da-Costa
authors.affiliation: Departamento de Nutrição, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil. Electronic address: guedes.rca@gmail.com.
authors.forename: Rubem Carlos Araújo
authors.initials: RC
authors.lastname: Guedes
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000187:drug effects* / Q000254:growth & development / Q000503:physiopathology*; D013181:Cortical Spreading Depression / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology; D044342:Malnutrition / Q000503:physiopathology*; D008315:Malondialdehyde / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology*; D011897:Random Allocation; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D016877:Oxidants; D008315:Malondialdehyde; D001205:Ascorbic Acid
keywords: Antioxidant molecules; Ascorbic acid; Brain development; Cortical spreading depression; Malnutrition; Prooxidant molecules