Glycyrrhizin regulates the HMGB1/P38MAPK signalling pathway in status epilepticus

Mol Med Rep. 2023 Feb;27(2):45. doi: 10.3892/mmr.2023.12932. Epub 2023 Jan 12.

Abstract

In recent decades, studies have reported that inflammation serves key roles in epilepsy and that high mobility group box protein‑1 (HMGB1) may be involved in status epilepticus. However, it has not been reported whether HMGB1 participates in the pathogenesis of status epilepticus through the regulation of the p38 mitogen‑activated protein kinase (p38MAPK) signalling pathway. In the present study, Sprague‑Dawley rats were randomly divided into four groups as follows: Control, status epilepticus (SE), dimethyl sulfoxide treatment (DMSO + SE), and glycyrrhizin treatment (GL + SE) groups. Behavioural changes were then evaluated using the Racine score. In the hippocampus, the protein expression levels of HMGB1 were assessed using western blotting, the neuronal damage was evaluated using haematoxylin and eosin staining and transmission electron microscopy, and the activation of microglia was assessed using immunochemistry and immunofluorescence. The results demonstrated that, in the hippocampal region, HMGB1 existed in neurons and astrocytes and the protein expression levels of HMGB1, p38MAPK and phosphorylated‑p38MAPK were significantly inhibited after treatment with GL. Furthermore, GL could alleviate neuronal injury in the CA1 region of the hippocampus and prevented HMGB1 translocation from the nucleus into the cytoplasm in these areas. These findings expand the understanding of how HMGB1 may participate in SE and lay a foundation for evaluation of HMGB1 as a drug target.

Keywords: Glycyrrhizin; high mobility group box protein‑1; p38 mitogen‑activated protein kinase; status epilepticus.

MeSH terms

  • Animals
  • Glycyrrhizic Acid* / pharmacology
  • Glycyrrhizic Acid* / therapeutic use
  • HMGB1 Protein* / metabolism
  • Hippocampus / drug effects
  • Hippocampus / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Status Epilepticus* / drug therapy
  • p38 Mitogen-Activated Protein Kinases* / metabolism

Substances

  • Glycyrrhizic Acid
  • HMGB1 Protein
  • p38 Mitogen-Activated Protein Kinases

Grants and funding

The present study was supported by The Zunyi City Science and Technology Foundation [grant no. (2018)64], The Zunyi Medical College Neurological Graduate Workstation (grant no. GZZ2017004), The Science and Technology Project in Guizhou Province [grant no. ZK (2022) General 656] and The Science and Technology Project of Guizhou Health Commission (grant no. gzwkj2021.017 and gzwjkj2020-1-010).