New insights into the effects of vinpocetine against neurobehavioral comorbidities in a rat model of temporal lobe epilepsy via the downregulation of the hippocampal PI3K/mTOR signalling pathway

J Pharm Pharmacol. 2021 Mar 27;73(5):626-640. doi: 10.1093/jpp/rgab011.

Abstract

Objectives: As one of the most frequent worldwide neurological disorders, epilepsy is an alteration of the central nervous system (CNS) characterized by abnormal increases in neuronal electrical activity. The mammalian target of rapamycin (mTOR) signalling pathway has been investigated as an interesting objective in epilepsy research. Vinpocetine (VNP), a synthesized derivative of the apovincamine alkaloid, has been used in different cerebrovascular disorders. This study aimed to examine the modulatory effects of VNP on neurobehavioral comorbidities via the mTOR signalling pathway in a lithium-pilocarpine (Li-Pil) rat model of seizures.

Methods: In male Wistar rats, seizures were induced with a single administration of pilocarpine (60 mg/kg; i.p.) 20 hours after the delivery of a single dose of lithium (3 mEq/kg; i.p.). VNP (10 mg/kg; i.p.) was administered daily for 14 consecutive days before Li-Pil administration.

Key findings: VNP had a protective effect against Li-Pil-induced seizures. VNP improved both the locomotor and cognitive abilities, moreover, VNP exerted a neuroprotective action, as verified histologically and by its inhibitory effects on hippocampal glutamate excitotoxicity, mTOR pathway, and inflammatory and apoptotic parameters.

Conclusions: VNP is a valuable candidate for epilepsy therapy via its modulation of the mechanisms underlying epileptogenesis with emphasis on its modulatory effect on mTOR signalling pathway.

Keywords: epilepsy; lithium–pilocarpine; mTOR; vinpocetine.

MeSH terms

  • Animals
  • Anticonvulsants / pharmacology*
  • Apoptosis / drug effects
  • Epilepsy, Temporal Lobe / drug therapy*
  • Epilepsy, Temporal Lobe / metabolism*
  • Epilepsy, Temporal Lobe / pathology
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Hippocampus / pathology
  • Male
  • Memory / drug effects
  • Motor Activity / drug effects
  • Neurons / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Rats
  • Rats, Wistar
  • Seizures / drug therapy
  • Seizures / metabolism
  • Seizures / pathology
  • Signal Transduction / drug effects
  • TOR Serine-Threonine Kinases / metabolism*
  • Vinca Alkaloids / pharmacology*

Substances

  • Anticonvulsants
  • Vinca Alkaloids
  • vinpocetine
  • mTOR protein, rat
  • TOR Serine-Threonine Kinases