title: Neuroprotection of soyabean isoflavone co-administration with folic acid against beta-amyloid 1-40-induced neurotoxicity in rats.
abstract: Soya isoflavones (SIF) and folic acid (FA) both confer the biological properties of antioxidation; however, the mechanism of their antioxidant effect on nervous system development is unclear. Our purpose is to investigate the neuroprotective effects of SIF, FA or co-administration of SIF with FA against beta-amyloid 1-40 (Abeta1-40)-induced learning and memory impairment in rats. In the present study, the learning and memory ability of rats and the amount of amyloid-positive neurons in the cerebral cortex and hippocampal CA1 area were measured. The levels of total antioxidant capacity (T-AOC), glutathione (GSH) and glutathione peroxidase (GSH-Px) in serum and brain tissue were also measured. The results showed that intracerebroventricular administration of Abeta1-40 resulted in a dramatic prolongation of the escape latency; however, in the SIF, FA and SIF+FA treatment groups, the functional deficits of learning and memory were significantly improved. Moreover, after Abeta1-40 injection, the levels of T-AOC and GSH were profoundly decreased, suggesting a decline of antioxidant activity in the rats. However, intragastric pre-treatment with SIF, or FA, or SIF+FA resulted in a significant increase of antioxidative activity. SIF, or FA, or SIF+FA treatments also reversed the Abeta1-40-induced increase in the amount of amyloid-positive neurons. These results suggest that: (1) learning or memory impairment in experimental rats was caused by Abeta1-40, which is probably attributed to Abeta-induced oxidative damage and deposition of beta-amyloid peptides in the brain; (2) pre-administration of SIF and/or FA may prevent the pathological alterations caused by Abeta1-40 treatment and the neuroprotective effects of SIF and/or FA are indicated.
authors.affiliation: School of Public Health and Family Medicine, Capital Medical University, No. 10 Xitoutiao, You An Men, Beijing 100069, China.
authors.forename: Wei-wei
authors.initials: WW
authors.lastname: Ma
authors.forename: Li
authors.initials: L
authors.lastname: Xiang
authors.forename: Huan-Ling
authors.initials: HL
authors.lastname: Yu
authors.forename: Lin-Hong
authors.initials: LH
authors.lastname: Yuan
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Guo
authors.forename: Yi-Xiu
authors.initials: YX
authors.lastname: Xiao
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Rong
authors.initials: R
authors.lastname: Xiao
mesh_terms: D016229:Amyloid beta-Peptides / Q000032:analysis; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D002540:Cerebral Cortex / Q000737:chemistry; D005492:Folic Acid / Q000008:administration & dosage*; D006624:Hippocampus / Q000737:chemistry; D007529:Isoflavones / Q000008:administration & dosage*; D008297:Male; D018782:Maze Learning; D008568:Memory; D023421:Models, Animal; D019636:Neurodegenerative Diseases / Q000378:metabolism / Q000517:prevention & control*; D018696:Neuroprotective Agents / Q000008:administration & dosage*; D010446:Peptide Fragments / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013025:Glycine max
chemical_list: D016229:Amyloid beta-Peptides; D000975:Antioxidants; D007529:Isoflavones; D018696:Neuroprotective Agents; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); D005492:Folic Acid