Oral supplementation with melon superoxide dismutase extract promotes antioxidant defences in the brain and prevents stress-induced impairment of spatial memory.
The purpose of this study was to investigate the effect of antioxidant ingestion on stress-induced impairment of cognitive memory. Male C57BL/6 mice were divided into four groups as follows: (1) control mice (C mice) fed in a normal cage without immobilization; (2) restraint-stressed (RS mice) fed in a small cage; (3) vitamin E mice (VE mice), mice were fed in a small cage with a diet supplemented with vitamin E; (4) GliSODin mice (GS mice) fed in a small cage with a diet supplemented with GliSODin. RS, VE and GS mice were exposed to 12 h of immobilization daily. Five weeks later, spatial learning was measured using the Morris Water Maze (MWM) test. After water maze testing, we performed immunohistochemical analysis using 4-hydroxy-2-noneral (4-HNE) and an anti-Ki67 antibody. 4-HNE is a marker of lipid peroxidation. RS mice showed impaired spatial learning performance and an increased number of 4-HNE-positive cells in the granule cell layer (GCL) of the hippocampal dentate gyrus when compared to C mice. Moreover, RS mice showed a decreased number of Ki67-positive cells in the subgranular zone (SGZ). GS mice showed better spatial learning memory than RS mice. The number of 4-HNE-positive cells in the GCL of GS mice was significantly less than that of RS mice. The number of Ki67-positive cells in the SGZ of GS mice was significantly greater than that of RS mice. These finding suggests that GliSODin prevents stress-induced impairment of cognitive function and maintains neurogenesis in the hippocampus through antioxidant activity.
Department of Biochemistry and Cell Biology, Institute of Gerontology, Nippon Medical School, Kawasaki, Kanagawa 211-8533, Japan.
Sanae
S
Nakajima
Ikuroh
I
Ohsawa
Kazufumi
K
Nagata
Shigeo
S
Ohta
Makoto
M
Ohno
Tetsuo
T
Ijichi
Toshio
T
Mikami
D000284:Administration, Oral; D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D019662:Cucurbitaceae / Q000737:chemistry*; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008569:Memory Disorders / Q000209:etiology / Q000473:pathology* / Q000517:prevention & control*; D051379:Mice; D008810:Mice, Inbred C57BL; D055495:Neurogenesis / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D018529:Nutritional Support / Q000379:methods; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012149:Restraint, Physical / Q000379:methods; D013315:Stress, Psychological / Q000150:complications; D013482:Superoxide Dismutase / Q000008:administration & dosage* / Q000378:metabolism; D024505:Tocopherols / Q000008:administration & dosage / Q000378:metabolism
D000447:Aldehydes; D000975:Antioxidants; D019394:Ki-67 Antigen; D013482:Superoxide Dismutase; C027576:4-hydroxy-2-nonenal; D024505:Tocopherols