Published online Mar 19, 2022. doi: 10.5498/wjp.v12.i3.410
Peer-review started: October 11, 2021
First decision: November 17, 2021
Revised: December 15, 2021
Accepted: March 6, 2022
Article in press: March 6, 2022
Published online: March 19, 2022
Processing time: 158 Days and 1.8 Hours
Oxidative stress results in the production of excess reactive oxygen species (ROS) and triggers hippocampal neuronal damage as well as occupies a key role in the pathological mechanisms of neurodegenerative disorders such as Alzheimer’s disease (AD). A recent study confirmed that magnesium had an inhibitory effect against oxidative stress-related malondialdehyde in vitro. However, whether Magnesium-L-threonate (MgT) is capable of suppressing oxidative stress damage in amyloid β (Aβ)25-35-treated HT22 cells and the AD mouse model still remains to be investigated.
To explore the neuroprotective effect of MgT against oxidative stress injury in vitro and in vivo, and investigate the mechanism.
Aβ25-35-induced HT22 cells were preconditioned with MgT for 12 h. APPswe/PS1dE9 (APP/PS1) mice were orally administered with MgT daily for 3 mo. After MgT treatment, the viability of Aβ25-35-treated HT22 cells was determined via conducting cell counting kit-8 test and the cognition of APP/PS1 mice was measured through the Morris Water Maze. Flow cytometry experiments were applied to assess the ROS levels of HT22 cells and measure the apoptosis rate of HT22 cells or hippocampal neurons. Expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), hypoxia-inducible factor (HIF)-1α, NADPH oxidase (NOX) 4, Aβ1-42 and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway proteins was quantified by Western blot.
In vitro data confirmed that Aβ25–35-induced HT22 cells had a significantly lower cell viability, higher ROS level and higher apoptosis rates compared with those of control cells (all P < 0.001). MgT prevented the Aβ25-35-triggered oxidative stress damage by elevating viability and decreasing ROS formation and apoptosis of HT22 cells (all P < 0.001). APP/PS1 mice exhibited worse cognitive performance and higher apoptosis rate of hippocampal neurons than wild-type (WT) mice (all P < 0.01). Meanwhile, significant higher expression of Aβ1-42 and NOX4 proteins was detected in APP/PS1 mice than those of WT mice (both P < 0.01). MgT also ameliorated the cognitive deficit, suppressed the apoptosis of hippocampal neuron and downregulated the expression of Aβ1-42 and NOX4 proteins in APP/PS1 mouse (all P < 0.05). Moreover, MgT intervention significantly downregulated HIF-1α and Bax, upregulated Bcl-2 and activated the PI3K/Akt pathway both in vitro and in vivo (all P < 0.05).
MgT exhibits neuroprotective effects against oxidative stress and hippocampal neuronal apoptosis in Aβ25-35-treated HT22 cells and APP/PS1 mice.
Core Tip: The dysfunction of oxidative stress is considered to stimulate the production of reactive oxygen species and induce hippocampal neuron damage which are the significant hallmarks of neurodegenerative diseases such as Alzheimer’s disease. Recent studies have explored the in vitro anti-malondialdehyde effect of magnesium. However, the potential neuroprotective effect of Magnesium-L-threonate (MgT) against oxidative stress remains to be explored. Our study demonstrated that MgT exhibited neuroprotective effects on suppressing oxidative stress and hippocampal neuronal apoptosis in vitro and in vivo, suggesting the promising therapeutic potential of MgT in oxidative stress-associated neurodegenerative disorders.