Tangeretin alters neuronal apoptosis and ameliorates the severity of seizures in experimental epilepsy-induced rats by modulating apoptotic protein expressions, regulating matrix metalloproteinases, and activating the PI3K/Akt cell survival pathway

Adv Med Sci. 2017 Sep;62(2):246-253. doi: 10.1016/j.advms.2016.11.011. Epub 2017 May 11.

Abstract

Purpose: Epilepsy is complex neural disarray categorized by recurring seizures. Despite recent advances in pharmacotherapies for epilepsy, its treatment remains a challenge due to the contrary effects of the drugs. As a result, the identification of novel anti-epileptic drugs (AEDs) with neuroprotective properties and few side effects is of great value. Thus, the present study assessed the treatment effects of tangeretin using a rat model of pilocarpine-induced epilepsy.

Materials and methods: Separate groups of male Wistar rats received oral administrations of tangeretin at 50, 100, or 200mg/kg for 10 days and then, on the 10th day, they received an intraperitoneal injection of pilocarpine (30mg/kg). Subsequently, neuronal degeneration and apoptosis were assessed using Nissl staining and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay procedures. Additionally, the expressions of phosphatidylinositol-3-kinase (PI3K/Akt) pathway proteins, cleaved caspase-3, Bad, Bcl-2, Bcl-xL, and Bax were determined using Western blot analyses.

Results: Tangeretin reduced the seizure scores and latency to first seizure of the rats and effectively activated the pilocarpine-induced suppression of PI3K/Akt signaling. Additionally, tangeretin effectively regulated the levels of apoptosis-inducing factor (AIF) in mitochondria as well as the expressions of apoptotic pathway proteins. Seizure-induced elevations in the activities and expressions of matrix metalloproteinases (MMPs)-2 and -9 were also modulated.

Conclusion: The present results indicate that tangeretin exerted potent neuroprotective effects against pilocarpine-induced seizures via the activation of PI3K/Akt signaling and the regulation of MMPs.

Keywords: Epilepsy; Matrix metalloproteinases; PI3K/Akt signaling; Pilocarpine; Tangeretin.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis Regulatory Proteins / metabolism*
  • Cells, Cultured
  • Epilepsy / chemically induced
  • Epilepsy / complications
  • Epilepsy / physiopathology*
  • Flavones / pharmacology*
  • Male
  • Matrix Metalloproteinase 2 / metabolism*
  • Matrix Metalloproteinase 9 / metabolism*
  • Muscarinic Agonists / toxicity
  • Neurons / drug effects
  • Neurons / pathology*
  • Neuroprotective Agents / pharmacology
  • Phosphatidylinositol 3-Kinases / metabolism
  • Pilocarpine / toxicity
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats
  • Rats, Wistar
  • Seizures / drug therapy*
  • Seizures / etiology
  • Seizures / metabolism
  • Seizures / pathology
  • Severity of Illness Index
  • Signal Transduction*

Substances

  • Apoptosis Regulatory Proteins
  • Flavones
  • Muscarinic Agonists
  • Neuroprotective Agents
  • Pilocarpine
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • Matrix Metalloproteinase 2
  • Mmp2 protein, rat
  • Matrix Metalloproteinase 9
  • Mmp9 protein, rat
  • tangeretin