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The protective effects of melatonin from oxidative damage induced by amyloid beta‐peptide 25–35 in middle‐aged rats
Author(s) -
Shen Y. X.,
Xu S. Y.,
Wei W.,
Sun X. X.,
Liu L. H.,
Yang J.,
Dong C.
Publication year - 2002
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1034/j.1600-079x.2002.1819.x
Subject(s) - melatonin , morris water navigation task , lipid peroxidation , superoxide dismutase , endocrinology , medicine , amyloid beta , glutathione peroxidase , chemistry , oxidative stress , antioxidant , pharmacology , biochemistry , hippocampus , peptide
This work investigated the ability of melatonin to prevent oxidative damage in brain tissue induced by injection of beta‐amyloid peptide 25–35 (A β 25–35 ) in middle‐aged rats. The Morris water maze was used to evaluate the cognitive function of the rats. Thiobarbituric acid‐reactive substances and antioxidative enzymes (superoxide dismutase and glutathione peroxidase) activities were measured. It was found that injection of (A β 25–35 ) (20 μ g) into the rat hippocampus caused an increase in the latency (the time to find the platform), the total swimming distance to the platform, and the starting angles in (A β 25–35 )‐treated rats. Furthermore, a significant rise in lipid peroxidation and decrease in antioxidative enzyme activities in brain tissue were found. Melatonin (0.1, 1, and 10 mg/kg, i.g. × 10 days) improved the spatial resolution of amnesic rats in the Morris water maze test. Meanwhile, melatonin antagonized the lipid peroxidation in both the mitochondria ( P < 0.01) at the doses of 0.1, 1.0, and 10 mg/kg and in the cytoplasm at the doses of 0.1 and 1.0 mg/kg. Also in the amnesic rats, melatonin (0.1, 1.0, and 10 mg/kg, i.g. × 10 days) stimulated the antioxidative enzyme activities. The results show that melatonin effectively reduced lipid peroxidation and enhanced the antioxidative enzyme activities in A β 25–35 ‐treated rats, which may contribute to the improvement of rats' learning and memory impaired by A β 25–35 .