Genistein as a neuroprotective antioxidant attenuates redox imbalance induced by beta-amyloid peptides 25-35 in PC12 cells.
OBJECTIVE
Genistein (GEN), a principal component of soybean isoflavones, might possess the neuroprotective role through its antioxidant activity. However, the detailed mechanisms are unknown yet. The purpose of this study was to investigate whether GEN could alleviate oxidative damage induced by beta-amyloid peptides 25-35 (Abeta25-35) in PC12 cells.


METHODS
The PC12 cells were pre-incubated with or without GEN for 2h following incubation with Abeta25-35 for another 24h. MTT was used to assess the cell viability. Hoechst 33342 staining was applied to determine the apoptotic cells. Confocal laser scanning microscopy was implemented to examine the reactive oxygen species (ROS) levels. Mitochondrial membrane potential (MMP) was measured by flow cytometry. Reduced and oxidized glutathione (GSH/GSSG) ratio was analyzed by using assay kits. Western blot analysis was performed to assess the proteins expression of NF-E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and gamma-glutamylcysteine synthetase (gamma-GCS).


RESULTS
GEN attenuated the cytotoxicity and partially prevented apoptosis induced by Abeta25-35. GEN dramatically attenuated ROS levels induced by Abeta25-35 in PC12 cells. In addition, GEN significantly reversed the reduction of MMP caused by Abeta25-35 to maintain the normal levels of the cells. The GSH/GSSG ratio in GEN pretreated groups significantly increased compared to the groups without GEN pretreatment. GEN reversed Abeta25-35 induced down regulation of the protein expression of gamma-GCS, Nrf2 and HO-1.


CONCLUSIONS
GEN could alleviate the oxidative stress caused by Abeta25-35 treatment and maintain redox balance in PC12 cells, which might be associated with the regulation of Nrf2/HO-1 signal pathway.
Ma
Weiwei
W
Department of Nutrition and Food Hygiene, School of Public Health and Family Medicine, Capital Medical University, No. 10 Xitoutiao, YouAnMen, Beijing 100069, China. weiweizibeike@yahoo.com.cn
Yuan
Linhong
L
Yu
Huanling
H
Ding
Bingjie
B
Xi
Yuandi
Y
Feng
Jinfang
J
Xiao
Rong
R
D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D019833:Genistein / Q000494:pharmacology*; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects*; D016716:PC12 Cells; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism
D016229:Amyloid beta-Peptides; D000975:Antioxidants; D051267:NF-E2-Related Factor 2; D018696:Neuroprotective Agents; D010446:Peptide Fragments; D017382:Reactive Oxygen Species; C074636:amyloid beta-protein (25-35); D019833:Genistein; D051547:Heme Oxygenase-1; D005721:Glutamate-Cysteine Ligase