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

Antioxidant extract counteracts the effects of aging on cortical spreading depression and oxidative stress in the brain cortex

“…Interestingly, a well-known antioxidant molecule, ascorbic acid, has demonstrated similar biphasic effects in distinct models of experimental seizures 21 . In addition, Mendesda-Silva et al 10 found that ascorbic acid administered in low doses (30 mg/kg/d) acted as an antioxidant in the brain and decelerated CSD propagation, whereas at the doses of 60 mg/kg/d and 120 mg/kg/d, it accelerated CSD and had a pro-oxidant effect. Evidence indicates that antioxidant compounds, such as ascorbic acid, carotenoids and polyphenols can produce reactive radical species when they are in high concentrations or in the presence of transition metal ions in the brain 22 .…”

“…Researchers have suggested this is due to an increase in free radicals in the cortical tissue. However, treatment with antioxidants has different effects depending of dosage 10 or the type of stress imposed to the brain. This work aimed to investigate the effects of two doses of murici extract on CSD and on the oxidative status of the cortex brain both in adult or aged rats.…”

Alpha‐Tocopherol Counteracts the Effect of Ethanol on Cortical Spreading Depression in Rats of Various Ages, With and Without Ethanol Abstinence

“…However, as the antioxidants astaxanthin (Abadie‐Guedes et al., ) and α ‐tocopherol (present study) both effectively minimize the effects of EtOH on CSD, we suggest that ROS scavenging may underlie the action of α ‐tocopherol (Abadie‐Guedes et al., ), which is plausible because ROS production in nervous tissue can modulate CSD (El‐Bachá et al., ). Future analyses of brain ROS levels, as our group recently carried out for the antioxidant ascorbic acid (Mendes‐da‐Silva et al., ), will be necessary to explore this possibility.…”

“…For example, the photoactivation of the rose Bengal dye applied to the chicken retina (Netto and Martins‐Ferreira, ), or the yellow‐colored neutral dye riboflavin applied to the rat cortex (El‐Bachá et al., ) can elicit the spreading depression phenomenon in those neural structures. Recently, we have shown that the brain levels of malondialdehyde, which is the final product of lipid peroxidation and generates free radicals, are directly correlated with the CSD velocity of propagation (Mendes‐da‐Silva et al., ). Furthermore, recent data from others have suggested that excessive accumulation of ROS might be the primary trigger of CSD (Malkov et al., ).…”

The Effect of Antioxidants on Ischemia-Reperfusion Injury in Flap Surgery

“…On the other hand, it has been shown that it has a prooxidant act in humans even at a dose of 500 mg/day [74]. Moreover, according to Mendes-da-Silva et al [75], ascorbic acid was served as an antioxidant on rats at 30/mg/kg/day but they were discovered opposite effects at 60/ mg/kg/day. In light of these findings, since the use of antioxidants is like a doubleedged sword, careful dose adjustment is required for use in I/R injury.…”