Cardarin effect on the formation of histopathological and behavioral abnormalities in the lithium-pilocarpine model of temporal lobe epilepsy in rats

Abstract

Epilepsy is a severe neuropsychological disease accompanied by the development of spontaneous recurrent seizures (SRS) and associated behavioral disorders that are difficult to treat. In recent years, the neuroprotective properties of agonists of peroxisome proliferator-activated receptors (PPAR α, β/δ, γ), nuclear transcription factors involved in the regulation of lipid and carbohydrate metabolism, as well as inflammatory signaling pathways involved in the pathogenesis of epilepsy, have been actively investigated. The neuroprotective properties of PPARγ agonists have been repeatedly described in models of epilepsy; the effects of PPARβ/δ agonists in these models have not been sufficiently investigated. The aim of this work was to study the effects of administering the PPARβ/δ agonist cardarin on the formation of histopathological and behavioral abnormalities in the lithium-pilocarpine model of temporal lobe epilepsy (TLE). The lithium-pilocarpine model is one of the best experimental models of chronic temporal lobe epilepsy. In this study, epilepsy was induced by administration of pilocarpine to male Wistar rats at the age of 7 weeks one day after LiCl injection. Cardarin (2.5 mg/kg) was administered daily for 7 days after pilocarpine, with the first injection one day after pilocarpine injection. Behavioral testing was performed 2‒3 months after induction of the model in the following tests: Open Field, Resident Stranger, New Object Exploration, Y Maze Spontaneous Alternation and Morris Water Maze. Brain sampling for histological studies (assessment of neuronal death, Nissl staining) was performed after the end of behavioral experiments, 95 days after TLE induction. It was shown that untreated rats with TLE exhibited significant hippocampal neuron death and behavioral disorders: increased motor activity, anxiety, memory disorders, research and communicative behavior. Caradrin did not affect the survival rate of hippocampal neurons, but reduced the manifestation of almost all the above-mentioned behavioral disorders, except for hyperactivity. Thus, this study demonstrated the promising use of PPARβ/δ agonists to attenuate the development of behavioral disorders characteristic of epilepsy.