Oral supplementation with melon superoxide dismutase extract promotes antioxidant defences in the brain and prevents stress-induced impairment of spatial memory

• Published in: Behavioural brain research 2009-06, Vol.200 (1), p.15-21
• Main Authors: Nakajima, Sanae, Ohsawa, Ikuroh, Nagata, Kazufumi, Ohta, Shigeo, Ohno, Makoto, Ijichi, Tetsuo, Mikami, Toshio
• Format: Article
• Language: English
• Subjects: Administration, Oral; Aldehydes - metabolism; Animals; Antioxidant; Antioxidants - administration & dosage; Behavioral psychophysiology; Biological and medical sciences; Cucurbitaceae - chemistry; Fundamental and applied biological sciences. Psychology; GliSODin; Hippocampus; Hippocampus - metabolism; Hippocampus - pathology; Ki-67 Antigen - metabolism; Male; Maze Learning - drug effects; Maze Learning - physiology; Memory; Memory Disorders - etiology; Memory Disorders - pathology; Memory Disorders - prevention & control; Mice; Mice, Inbred C57BL; Neurogenesis; Neurogenesis - drug effects; Neurogenesis - physiology; Neurons - metabolism; Nutritional Support - methods; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Reaction Time - drug effects; Reaction Time - physiology; Restraint, Physical - methods; Stress; Stress, Psychological - complications; Superoxide Dismutase - administration & dosage; Superoxide Dismutase - metabolism; Tocopherols - administration & dosage; Tocopherols - metabolism
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2008.12.038

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.