Baicalin Inhibits NLRP3 Inflammasome Activity Via the AMPK Signaling Pathway to Alleviate Cerebral Ischemia-Reperfusion Injury

Inflammation. 2021 Oct;44(5):2091-2105. doi: 10.1007/s10753-021-01486-z. Epub 2021 Jun 2.

Abstract

Baicalin has been reported to have ameliorative effects on nerve-induced hypoxic ischemia injury; however, its role in the NLRP3 inflammasome-dependent inflammatory response during cerebral ischemia-reperfusion remains unclear. To investigate the molecular mechanisms involved in baicalin alleviating cerebral ischemia-reperfusion injury, we investigated the AMPK signaling pathway which regulates NLRP3 inflammasome activity. SD rats were treated with baicalin at doses of 100 mg/kg and 200 mg/kg, respectively, after middle cerebral artery occlusion at 2 h and reperfusion for 24 h (MCAO/R). MCAO/R treatment significantly increased cerebral infarct volume, changed the ultrastructure of nerve cells, and activated the NLRP3 inflammasome, manifesting as significantly increased expression of NLRP3, ASC, cleaved caspase-1, IL-1β, and IL-18. Our results demonstrated that baicalin treatment effectively reversed these phenomena in a dose-dependent manner. Additionally, inhibition of NLRP3 expression was found to promote the neuroprotective effects of baicalin on cortical neurons. Furthermore, baicalin remarkably increased the expression of p-AMPK following oxygen glucose deprivation/reperfusion (OGD/R). The expression of the NLRP3 inflammasome was also increased when the AMPK pathway was blocked by compound C. Taken together, our findings reveal that baicalin reduces the activity of the NLRP3 inflammasome and consequently inhibits cerebral ischemia-reperfusion injury through activation of the AMPK signaling pathway.

Keywords: AMPK signaling pathway; NLRP3 inflammasome; baicalin; cerebral ischemia-reperfusion.

MeSH terms

  • AMP-Activated Protein Kinase Kinases / antagonists & inhibitors*
  • AMP-Activated Protein Kinase Kinases / metabolism
  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology
  • Anti-Inflammatory Agents, Non-Steroidal / therapeutic use*
  • Brain Ischemia / drug therapy
  • Brain Ischemia / metabolism*
  • Cells, Cultured
  • Flavonoids / pharmacology
  • Flavonoids / therapeutic use*
  • NLR Family, Pyrin Domain-Containing 3 Protein / antagonists & inhibitors*
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Neurons / drug effects
  • Neurons / metabolism
  • Pyroptosis / drug effects
  • Pyroptosis / physiology
  • Rats
  • Rats, Sprague-Dawley
  • Reperfusion Injury / drug therapy
  • Reperfusion Injury / metabolism*
  • Signal Transduction / drug effects
  • Signal Transduction / physiology

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Flavonoids
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, rat
  • baicalin
  • AMP-Activated Protein Kinase Kinases