Ginsenoside Rg1 attenuates cerebral ischemia-reperfusion injury due to inhibition of NOX2-mediated calcium homeostasis dysregulation in mice

J Ginseng Res. 2022 Jul;46(4):515-525. doi: 10.1016/j.jgr.2021.08.001. Epub 2021 Aug 10.

Abstract

Background: The incidence of ischemic cerebrovascular disease is increasing in recent years and has been one of the leading causes of neurological dysfunction and death. Ginsenoside Rg1 has been found to protect against neuronal damage in many neurodegenerative diseases. However, the effect and mechanism by which Rg1 protects against cerebral ischemia-reperfusion injury (CIRI) are not fully understood. Here, we report the neuroprotective effects of Rg1 treatment on CIRI and its possible mechanisms in mice.

Methods: A bilateral common carotid artery ligation was used to establish a chronic CIRI model in mice. HT22 cells were treated with Rg1 after OGD/R to study its effect on [Ca2+]i. The open-field test and pole-climbing experiment were used to detect behavioral injury. The laser speckle blood flowmeter was used to measure brain blood flow. The Nissl and H&E staining were used to examine the neuronal damage. The Western blotting was used to examine MAP2, PSD95, Tau, p-Tau, NOX2, PLC, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging was used to test the level of [Ca2+]i.

Results: Rg1 treatment significantly improved cerebral blood flow, locomotion, and limb coordination, reduced ROS production, increased MAP2 and PSD95 expression, and decreased p-Tau, NOX2, p-PLC, CN, NFAT1, and NLRP1 expression. Calcium imaging results showed that Rg1 could inhibit calcium overload and resist the imbalance of calcium homeostasis after OGD/R in HT22 cells.

Conclusion: Rg1 plays a neuroprotective role in attenuating CIRI by inhibiting oxidative stress, calcium overload, and neuroinflammation.

Keywords: ANOVA, One-way analysis of variance; ASC, Apoptosis-associated speck-like protein containing a CARD; CBF, cerebral blood flow; CIRI, cerebral ischemia/reperfusion injury; CN, Calcineurin; Calcium overload; Cerebral ischemia-reperfusion injury (CIRI); DHE, Dihydroethidium; FBS, fetal bovine serum; Ginsenoside Rg1; I/R, ischemia reperfusion; IL-1β, Interleukin-1β; IPP, Image-Pro Plus; MAP2, microtubule-associated protein 2; NADPH oxidase 2; NFAT1, nuclear factor of activated T-cells 1; NLRP1 inflammasome; NLRP1, Nucleotide-binding oligomerization domain like receptor protein 1; NMDA, N-methyl-d-aspartate; NOD, nucleotide-binding oligomerization domain; NOX, Nicotinamide adenine dinucleotide phosphate oxidase; OFT, Open field test; OGD/R, oxygen glucose deprivation/reperfusion; PCT, Pole-climbing test; PIP2, phosphatidyl-inositol bisphosphate; PLC, phospholipase C; PSD95, postsynaptic density protein 95; ROS, reactive oxygen species; Rg1, Ginsenoside Rg1; SCII, Spinal cord ischemia-reperfusion injury; TBST, Tris buffered saline Tween; caspase-1, Cysteinyl aspartate-specific protease-1.