Mice fed the antioxidant supplement experienced lower levels of oxidative stress and performed better in a maze test after supplementation with the SOD supplement, according to results published in the journal Behavioural Brain Research.
Animals fed vitamin E also experienced lower levels of oxidative stress caused by stress, as measured by levels of lipid peroxidation, but no beneficial effects were observed in terms of the vitamin E-supplemented animals’ spatial learning, according to researchers led by Sanae Nakajima from the Nippon Medical School in Kawasaki.
SOD has a different mode of action to vitamins. Dubbed 'the enzyme of life' when first discovered in 1968, it is the first antioxidant mobilised by the cell for defence. It is thought to be more powerful than antioxidant vitamins as it activates the body's production of its own antioxidants, including catalase and glutathione peroxidase.
GliSODin, the combination of SOD extracted from cantaloupe melon and wheat gliadin, is patented and trademarked by Paris-based Isocell. In North America PL Thomas distributes the ingredient.
Study details
Nakajima and co-workers divided male C57BL/6 mice divided into four groups, the first group acted as the control, and were fed a normal diet and housed in normal cages. The second group was fed the normal diet, but restrained in a case to induce stress. The third and fourth groups were restrained and had their diets supplemented with vitamin E (alpha-tocopherol acetate at 88mg per 100 g of diet) and GliSODin (125mg 100 per 100 g of diet), respectively.
After five weeks, the researchers report that both the vitamin E and SOD groups had lower blood levels of a compound called 4-hydroxy-2-noneral (4-HNE), a marker of lipid peroxidation, and therefore oxidative stress.
Mice supplemented with SOD showed greater spatial learning memory, added the researchers.
Looking at the brain physiology and biochemistry, the researchers noted that the SOD group had a lower loss of certain cells linked to better brain function. This is related to the development of new neurons in the hippocampal region of the brain, they added.
“These finding suggests that GliSODin prevents stress-induced impairment of cognitive function and maintains neurogenesis in the hippocampus through antioxidant activity,” concluded the researchers.
Source: Behavioural Brain ResearchPublished online ahead of print, doi: 10.1016/j.bbr.2008.12.038“Oral supplementation with melon superoxide dismutase extract promotes antioxidant defences in the brain and prevents stress-induced impairment of spatial memory”Authors: S. Nakajima, I. Ohsawa, K. Nagata, S. Ohta, M. Ohno, T. Ijichi, T. Mikami