title: s-Allyl cysteine, s-ethyl cysteine, and s-propyl cysteine alleviate β-amyloid, glycative, and oxidative injury in brain of mice treated by D-galactose.
abstract: The neuroprotective effects of s-allyl cysteine, s-ethyl cysteine, and s-propyl cysteine in D-galactose (DG)-treated mice were examined. DG treatment increased the formation of Aβ(1-40) and Aβ(1-42), enhanced mRNA expression of β-amyloid precursor protein (APP) and β-site APP cleavage enzyme 1 (BACE1), and reduced neprilysin expression in brain (P < 0.05); however, the intake of three test compounds significantly decreased the production of Aβ(1-40) and Aβ(1-42) and suppressed the expression of APP and BACE1 (P < 0.05). DG treatments declined brain protein kinase C (PKC) activity and mRNA expression (P < 0.05). Intake of test compounds significantly retained PKC activity, and the expression of PKC-α and PKC-γ (P < 0.05). DG treatments elevated brain activity and mRNA expression of aldose reductase (AR) and sorbitol dehydrogenase as well as increased brain levels of carboxymethyllysine (CML), pentosidine, sorbitol, and fructose (P < 0.05). Test compounds significantly lowered AR activity, AR expression, and CML and pentosidine levels (P < 0.05). DG treatments also significantly increased the formation of reactive oxygen species (ROS) and protein carbonyl and decreased the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (P < 0.05); however, the intake of test compounds in DG-treated mice significantly decreased ROS and protein carbonyl levels and restored brain GPX, SOD, and catalase activities (P < 0.05). These findings support that these compounds via their anti-Aβ, antiglycative, and antioxidative effects were potent agents against the progression of neurodegenerative disorders such as Alzheimer's disease.
authors.affiliation: School of Medicine, Chung Shan Medical University, Taichung City, Taiwan.
authors.forename: Shih-Jei
authors.initials: SJ
authors.lastname: Tsai
authors.forename: C Perry
authors.initials: CP
authors.lastname: Chiu
authors.forename: Hui-Ting
authors.initials: HT
authors.lastname: Yang
authors.forename: Mei-Chin
authors.initials: MC
authors.lastname: Yin
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D003545:Cysteine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004195:Disease Models, Animal; D005690:Galactose / Q000009:adverse effects; D006031:Glycosylation / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D016564:Amyloid beta-Protein Precursor; C031752:ethyl cysteine; C028742:S-propylcysteine; C065299:S-allylcysteine; D003545:Cysteine; D005690:Galactose