Ascorbic acid: a putative biochemical marker of irreversible neurologic functional loss following spinal cord injury

The Role of Vitamins in Spinal Cord Injury: Mechanisms and Benefits

Spinal cord injury (SCI) is a common neurological disease worldwide, often resulting in a substantial decrease in quality of life, disability, and in severe cases, even death. Unfortunately, there is currently no effective treatment for this disease. Nevertheless, current basic and clinical evidence suggests that vitamins, with their antioxidant properties and biological functions, may play a valuable role in improving the quality of life for individuals with SCI. They can promote overall health and facilitate the healing process. In this review, we discuss the mechanisms and therapeutic potential of vitamins in the treatment of SCI.

Plasma vitamin C levels are decreased and correlated with brain damage in patients with intracranial hemorrhage or head trauma

BACKGROUND AND PURPOSE

Free radical hyperproduction may play an important role in brain hemorrhage and ischemia/reperfusion injury. The aims of this study were to assess whether antioxidant depletion occurs after intracranial hemorrhage (ICH) and head trauma (HT) and to evaluate the relation between the diameter of the brain lesion, the degree of the neurological impairment, and any observed antioxidant changes.

METHODS

We measured plasma levels of vitamin C (ascorbic acid, AA), uric acid (UA), vitamin E (alpha-tocopherol), and ubiquinol-10 in 13 patients with ICH and 15 patients with HT on the day of the brain injury and subsequently every other day up to 1 week. Patients were compared with 40 healthy control subjects.

RESULTS

ICH and HT patients had significantly lower plasma levels of AA compared with healthy subjects, in contrast to plasma levels of UA, alpha-tocopherol, and ubiquinol-10. AA levels were significantly inversely correlated with the severity of the neurological impairment as assessed by the Glasgow Coma Scale and the National Institutes of Health Stroke Scale. AA levels were also significantly inversely correlated with the major diameter of the lesion. In addition, mean plasma AA levels were lower in jugular compared with peripheral blood samples obtained from 5 patients.

CONCLUSIONS

These findings suggest that a condition of oxidative stress occurs in patients with head trauma and hemorrhagic stroke of recent onset. The consequences of early vitamin C depletion on brain injury as well as the effects of vitamin C supplementation in ICH and HT patients remain to be addressed in further studies.

Ascorbic acid in cerebrospinal fluid — a possible protection against free radicals in the brain

The function of ascorbic acid in living organisms is complex. Previous studies emphasize its protective role against harmful effect of free radicals, and its presence is necessary for the function of numerous enzymes. Ascorbic acid is a powerful reducing agent due to its dienol molecular structure, which is not present in the oxidized form, dehydroascorbic acid. The ratio of ascorbic acid and dehydroascorbic acid might be a marker of oxidative-reductive processes. We measured and compared the level of ascorbic acid and dehydroascorbic acid in the plasma of healthy persons and those of senile dementia patients, who represent pathological aging of the brain. In senile dementia patients, ascorbic acid and dehydroascorbic acid levels were also measured in the cerebrospinal fluid. Concentrations were determined by high performance liquid chromatography with electrochemical detection. In the plasma of senile dementia patients, very low ascorbic acid levels were found (ca. 30% of the healthy control). In lumbar cerebrospinal fluid, the concentration of ascorbic acid is 2.7 times higher compared to that of the plasma level. After intravenous infusion of ascorbic acid, a slow but marked increase of the concentration in the cerebrospinal fluid was measured. Our results support an active transport process for ascorbic acid through the blood-CSF barrier. Ascorbic acid level might be an important factor representing the protection of the central nervous system against free radicals.