2. Academic Validation
  3. Inflammatory mechanism of cerebral ischemia-reperfusion injury with treatment of stepharine in rats

Inflammatory mechanism of cerebral ischemia-reperfusion injury with treatment of stepharine in rats

  • Phytomedicine. 2020 Dec;79:153353. doi: 10.1016/j.phymed.2020.153353.
Tingyu Hao 1,  Yanqiu Yang 1,  Ning Li 2,  Yan Mi 1,  Guijie Zhang 3,  Junyu Song 2,  Yusheng Liang 4,  Jiao Xiao 2,  Di Zhou 2,  Dakuo He 5,  Yue Hou 6
Affiliations

Affiliations

  • 1 College of Life and Health Sciences, Northeastern University, Shenyang, China; Key Laboratory of Data Analytics and Optimization for Smart Industry, Northeastern University, Ministry of Education, Shenyang, China.
  • 2 School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Shenyang, China.
  • 3 College of Pharmacy, Guilin Medical University, Guilin, China.
  • 4 College of Life and Health Sciences, Northeastern University, Shenyang, China.
  • 5 College of Information Science and Engineering, Northeastern University, Shenyang, China; State Key Laboratory of Synthetical Automation for Process Industries, Northeastern University, Shenyang, China. Electronic address: [email protected].
  • 6 College of Life and Health Sciences, Northeastern University, Shenyang, China; Key Laboratory of Data Analytics and Optimization for Smart Industry, Northeastern University, Ministry of Education, Shenyang, China. Electronic address: [email protected].
PMID: 33007731 DOI: 10.1016/j.phymed.2020.153353
Abstract

Background: Increasing evidence has shown that microglia-induced neuroinflammation is involved in the pathogenesis of ischemic stroke. Stepharine, one of the Alkaloids extracted from Stephania japonica (Thunb.) Miers, exhibited strong inhibitory effect on microglial overactivation. However, it is not known whether it has the potential to prevent ischemic stroke.

Methods: The neuroprotective and anti-neuroinflammatory effects of stepharine were investigated in vivo and in vitro, using a rat model of middle cerebral artery occlusion (MCAO) and lipopolysaccharide (LPS)-stimulated BV-2 cells, respectively.

Results: In vivo, stepharine (500 μg/kg) suppressed neurological deficits scores, brain water content and cerebral infarct volume induced by MCAO. Moreover, stepharine (500 μg/kg) inhibited NeuN+ cells loss and Iba-1+ cells increase in the MCAO ischemic cortex. In vitro, stepharine (10, 30 μM) substantially inhibited nitric oxide release as well as the mRNA and protein expression of pro-inflammatory mediators [inducible nitric oxide synthase, interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-1β] in LPS-activated BV-2 cells. LPS-induced increase of TLR4 expression, IκBα phosphorylation, and NF-κB p65 nuclear translocation was inhibited by stepharine (10, 30 μM). Molecular docking analysis showed that stepharine directly interacted with TLR4. SPR assay further confirmed that stepharine could bind to the TLR4/MD2 complex. Meanwhile, stepharine exhibited neuroprotective effects on SH-SY5Y cells cultured with LPS-treated conditioned medium.

Conclusion: Our study demonstrated for the first time that stepharine improved the outcomes in MCAO rats, reduced neuronal loss, and suppressed microglial overactivation via the inhibition of TLR4/NF-κB pathway. These results suggest that stepharine might be a potential therapeutic agent for the treatment of ischemic stroke.

Keywords

Ischemic stroke; Microglia; NF-κB; Stepharine; TLR4.

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