The role of nitric oxide in anticonvulsant effects of lycopene supplementation on pentylenetetrazole-induced epileptic seizures in rats

Lycopene ameliorates locomotor activity and urinary frequency induced by pelvic venous congestion in rats

Decreased locomotor activity and altered urinary frequency are induced by bilateral common iliac vein ligation in rats. As a carotenoid, lycopene has a strong anti-oxidative function. This research investigated the function of lycopene in the pelvic venous congestion (PC) rat model and the underlying molecular mechanism. Lycopene and olive oil were administered intragastrically on a daily basis for 4 weeks after successful modeling. Locomotor activity, voiding behavior, and continuous cystometry were analyzed. The levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), nitrate and nitrite (NO _x ), and creatinine in the urine were measured. Gene expression in the bladder wall was analyzed by quantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blot. Locomotor activity, single voided volume, the interval between the bladder contractions, and urinary NO _x /cre ratio were all decreased in rats with PC, while the frequency of urination, urinary 8-OHdG/cre ratio, inflammatory responses, and nuclear factor-κB (NF-κB) signal activity were all increased. Lycopene treatment increased locomotor activity, decreased frequency of urination, elevated urinary NO _x level, and decreased urinary 8-OHdG level in the PC rat model. Lycopene also inhibited PC-enhanced pro-inflammatory mediator expression and NF-κB signaling pathway activity. In conclusion, lycopene treatment ameliorates PC-induced phenotypes and shows an anti-inflammatory effect in the PC rat model.

Esculetin alleviates pentylenetetrazole-induced seizures, cognitive impairment and pro-inflammatory cytokines and suppresses penicillin-induced epileptiform activity in rats

AIMS

To investigate the effects of different doses of esculetin on epileptiform activity, behavioral seizures, memory impairment, and cortical and hippocampal NF-κB, as a mediator of pro-inflammatory gene induction, and pro-inflammatory cytokines in penicillin- and pentylenetetrazole(PTZ)-induced seizure models in rats.

MAIN METHODS

Different doses of esculetin (5, 10, and 20 mg/kg), and diazepam (5 mg/kg) as a positive control, were tested in penicillin- and pentylenetetrazole(PTZ)-induced seizure models. In the PTZ model, cognitive function, behavioral seizures, and cortical and hippocampal pro-inflammatory biomarkers and survival factor was evaluated. In the penicillin model, the frequency and amplitude of electrophysiological epileptiform activity were assessed.

KEY FINDINGS

In the PTZ model, the 10 mg/kg esculetin displayed anticonvulsant effects by extending onset-times of myoclonic-jerk and generalized tonic-clonic seizure, and by diminishing seizure severity and duration of generalized tonic-clonic seizure. It also ameliorated PTZ-induced cognitive impairment, and cortical and hippocampal activin-A, IL-1β, IL-6 and NF-κB levels. In the penicillin model, the 10 mg/kg esculetin decreased the frequency of spikes without changing the amplitude of spikes. As a positive-control, diazepam reversed all changes induced by both PTZ and penicillin.

SIGNIFICANCE

Esculetin exhibits anticonvulsant and memory-improving effects by alleviating the behavioral and electrophysiological characteristics of epileptic seizures. Additionally, esculetin exerts anti-neuroinflammatory actions in the PTZ-induced seizures model. Thus, esculetin may be a multi-targeted promising agent with anticonvulsant and anti-neuroinflammatory effects in the treatment of epilepsy.

Endogenous and exogenous serotonin, but not sumatriptan, ameliorate seizures and neuroinflammation in the pentylenetetrazole-induced seizure model in rats

ABSTRACT Background: Epilepsy has neuropsychiatric comorbidities such as depression, bipolar disorder, and anxiety. Drugs that target epilepsy may also be useful for its neuropsychiatric comorbidities. Objective: To investigate the effects of serotonergic modulation on pro-inflammatory cytokines and the seizures in pentylenetetrazole (PTZ)-induced seizure model in rats. Methods: Male Wistar rats were injected intraperitoneally with serotonin, selective serotonin reuptake inhibitor fluoxetine, 5-HT1B/D receptor agonist sumatriptan, or saline 30 min prior to PTZ treatment. Behavioral seizures were assessed by the Racine's scale. Concentrations of IL-1β, IL-6, and TNF-α in serum and brain tissue were determined by ELISA. Results: Serotonin and fluoxetine, but not sumatriptan, alleviated PTZ-induced seizures by prolonging onset times of myoclonic-jerk and generalized tonic-clonic seizures. The anti-seizure effect of fluoxetine was greater than that of serotonin. Likewise, serotonin and fluoxetine, but not sumatriptan, reduced PTZ-induced increases in the levels of IL-1β and IL-6 in both serum and brain tissue. None of the administered drugs including PTZ affected TNF-α concentrations. Conclusions: Our findings suggest that endogenous and exogenous serotonin exhibits anticonvulsant effects by suppressing the neuroinflammation. It seems that 5-HT1B/D receptors do not mediate anticonvulsant and anti-neuroinflammatory effects of serotonin.