Proceedings of The Physiological Society

Physiology 2016 (Dublin, Ireland) (2016) Proc Physiol Soc 37, PCB233

Poster Communications

Nesfatin-1 and phenytoin have synergistic effects in improving seizure-induced neuronal damage and memory dysfunction in rats

T. Koyuncuoglu1, S. ARABACI-TAMER1, A. Karagoz2, D. Akakin2, C. Erzik4, M. Yuksel3, B. C. Yegen1

1. Physiology, Marmara University, School of Medicine, Istanbul, Turkey. 2. Histology and Embryology, Marmara University, School of Medicine, Istanbul, Turkey. 3. Vocational School of Health Related Services, Marmara University, Istanbul, Turkey. 4. Medical Biology, Marmara University, School of Medicine, Istanbul, Turkey.

Nesfatin-1 (NES) has anti-inflammatory and anti-apoptotic effects in several inflammatory models. Epilepsy is characterized by seizures resulting in oxidative injury and cognitive impairment. We aimed to investigate neuroprotective effects of nesfatin-1 in seizure-induced neuronal injury. Following an initial passive avoidance test (PAT), male Wistar albino rats were divided into control (n=12) and pentylenetetrazole (PTZ)-induced seizure (n=72) groups. Thirty minutes prior to PTZ (45 mg/kg; intraperitoneal, i.p.) injection, NES (0.3, 1 or 3 µg/kg/day), phenytoin (PH, 40 mg/kg/day), PH + NES (0.3 µg/kg/day) or saline was injected i.p, and seizures were scored by using Racine's scale. Treatments were repeated at 24th and 48th h of seizures. At 72nd hour of seizure induction, second PAT was carried out to evaluate memory function, and then rats were decapitated. Brain levels of malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) and lucigenin-enhanced chemiluminescence (CL) were determined. Four rats in each group were perfused with paraformaldehyde, paraffin blocks were stained with hematoxylene and eosin. BDNF expression was detected by immune blotting, and immunohistochemical study was done using glial fibrillary acidic protein (GFAP) antibody, while apoptotic cells were determined by TUNEL. Statistical analysis was performed by ANOVA and Student's t tests. Among PTZ groups, high percentage of rats with tonic-clonic seizures and their high average seizure-scores were reduced only in PH+NES-treated group (p<0.05). Control rats avoided entrance to dark-chamber in 5 min (cut-off) where they have received non-painful electrical shock, while rats in PTZ groups entered in shorter times, indicating memory dysfunction. NES (3 µg/kg/day) increased the delay in entrance (p<0.05). Seizure-induced elevations in MDA, NO and CL levels were depressed by NES- (0.3 µg/kg), and PH+NES-treated groups, while all doses of NES, but not PH, elevated depleted GSH level (p<0.001). BDNF levels were lower in NES-treated PTZ group, but the differences were not significant. Neuronal cell degeneration in cerebral cortex, hippocampal CA3 and dentate gyrus of saline-treated PTZ group (p<0.001) was reduced in NES- (0.3 µg/kg), PH- and PH+NES-treated rats. Increased TUNEL-positive (apoptotic) cells were determined in the cortices of PTZ-administered rats compared to control rats, but no significant difference was observed among treatments. Increased GFAP immunolabelling determined in the hippocampal CA3 fields and cortices of PTZ-administered group was reduced in NES- (0.3 µg/kg)-treated and PH+NES-treated groups (p<0.05). Nesfatin-1 appears to have a synergistic effect with phenytoin, potentiating its anti-seizure effect along with an additional neuroprotection on seizure-induced oxidative brain injury.

Where applicable, experiments conform with Society ethical requirements