Underlying mechanism of regulatory actions of diclofenac, a nonsteroidal anti-inflammatory agent, on neuronal potassium channels and firing: an experimental and theoretical study.

Diclofenac (DIC), a nonsteroidal anti-inflammatory drug, is known to exert anti-nociceptive and anti-convulsant actions; however, its effects on ion currents, in neurons remain debatable. We aimed to investigate (1) potential effects of diclofenac on membrane potential and potassium currents in differentiated NSC-34 neuronal cells and dorsal root ganglion (DRG) neurons with whole-cell patch-clamp technology, and (2) firing of action potentials (APs), using a simulation model from hippocampal CA1 pyramidal neurons based on diclofenac's effects on potassium currents. In the NSC-34 cells, diclofenac exerted an inhibitory effect on delayed-rectifier K⁺ current (I(KDR)) with an IC50 value of 73 µM. Diclofenac not merely inhibited the I(KDR) amplitude in response to membrane depolarization, but also accelerated the process of current inactivation. The inhibition by diclofenac of IK(DR) was not reversed by subsequent application of either naloxone. Importantly, diclofenac (300 µM) increased the amplitude of M-type K⁺ current (I)(KM)), while flupirtine (10 µM) or meclofenamic acid (10 µM) enhanced it effectively. Consistently, diclofenac (100 µM) increased the amplitude of I(KM) and diminished the I(KDR) amplitude, with a shortening of inactivation time constant in DRG neurons. Furthermore, by using the simulation modeling, we demonstrated the potential electrophysiological mechanisms underlying changes in AP firing caused by diclofenac. During the exposure to diclofenac, the actions on both I(KM) and I(KDR) could be potential mechanism through which it influences the excitability of fast-spiking neurons. Caution needs to be made in attributing the effects of diclofenac primarily to those produced by the activation of I(KM).

Chronic valproate treatment enhances postischemic angiogenesis and promotes functional recovery in a rat model of ischemic stroke.

BACKGROUND AND PURPOSE: Enhanced angiogenesis facilitates neurovascular remodeling processes and promotes brain functional recovery after stroke. Previous studies from our laboratory demonstrated that valproate (VPA), a histone deacetylase inhibitor, protects against experimental brain ischemia. The present study investigated whether VPA could enhance angiogenesis and promote long-term functional recovery after ischemic stroke. METHODS: Male rats underwent middle cerebral artery occlusion for 60 minutes followed by reperfusion for up to 14 days. Assessed parameters were: locomotor function through the Rotarod test; infarct volume through T2-weighted MRI; microvessel density through immunohistochemistry; relative cerebral blood flow through perfusion-weighted imaging; protein levels of proangiogenic factors through Western blotting; and matrix metalloproteinase-2/9 activities through gelatin zymography. RESULTS: Postischemic VPA treatment robustly improved the Rotarod performance of middle cerebral artery occlusion rats on Days 7 and 14 after ischemia and significantly reduced brain infarction on Day 14. Concurrently, VPA markedly enhanced microvessel density, facilitated endothelial cell proliferation, and increased relative cerebral blood flow in the ipsilateral cortex. The transcription factor hypoxia-inducible factor-1α and its downstream proangiogenic factors, vascular endothelial growth factor and matrix metalloproteinase-2/9, were upregulated after middle cerebral artery occlusion and significantly potentiated by VPA in the ipsilateral cortex. Acetylation of histone-H3 and H4 was robustly increased by chronic VPA treatment. The beneficial effects of VPA on Rotarod performance and microvessel density were abolished by hypoxia-inducible factor-1α inhibition. CONCLUSIONS: Chronic VPA treatment enhances angiogenesis and promotes functional recovery after brain ischemia. These effects may involve histone deacetylase inhibition and upregulation of hypoxia-inducible factor-1α and its downstream proangiogenic factors vascular endothelial growth factor and matrix metalloproteinase-2/9.

Metabolic activation and inflammation reactions involved in carbamazepine-induced liver injury.

Drug-induced liver injury is a major safety concern in drug development and clinical pharmacotherapy; however, advances in the understanding of the mechanisms of drug-induced liver injury are hampered by the lack of animal models. Carbamazepine (CBZ) is a widely used antiepileptic agent. Although the drug is generally well tolerated, only a small number of patients prescribed CBZ develop severe hepatitis. In the present study, we developed a mouse model of CBZ-induced liver injury and elucidated the mechanisms accounting for the hepatotoxicity of CBZ. Male BALB/c mice were orally administered CBZ for 5 days. The plasma levels of alanine aminotransferase and aspartate aminotransferase were prominently increased, and severe liver damage was observed via histological evaluation. The analysis of the plasma concentration of CBZ and its metabolites demonstrated that 3-hydroxy CBZ may be relevant in CBZ-induced liver injury. The hepatic glutathione levels were significantly decreased, and oxidative stress markers were significantly altered. Mechanistic investigations found that hepatic mRNA levels of toll-like receptor 4, receptor for advanced glycation end products, and their ligands were significantly increased. Moreover, the plasma concentrations of proinflammatory cytokines were also increased. Prostaglandin E(1) administration ameliorated the hepatic injury caused by CBZ. In conclusion, metabolic activation followed by the stimulation of immune responses was demonstrated to be involved in CBZ-induced liver injury in mice.

Simultaneous folate intake may prevent adverse effect of valproic acid on neurulating nervous system.

PURPOSE: The aim of this study is to elucidate the preventive effect of folic acid (FA) on teratogenic effects of valporic acid (VA) in early stage chick embryos on neural tube development. MATERIALS AND METHODS: One hundred and fifty specific pathogen-free (SPF) chick eggs were used to investigate the neurulation in five groups. Group A was the control group. Group B was injected 0.02 ml of saline (0.9% NaCl) and was used for sham group. VA (0.72 mg) in 0.02 ml saline was injected in Group C, and 0.342 mcg of FA in 0.02 ml NaCl were administered to the embryos in Group D. VA (0.72 mg) + 0.342 mcg of FA in 0.02 ml saline were administered simultaneously to the eggs in Group E. At the end of 72 h, all embryos were extracted from eggs and were fixed, and for histological analyses hematoxylin and eosine was used, for detection of apoptotic cells terminal deoxyribonucleotide transferase-mediated dUTP-X nick end labeling (TUNEL) was used and for distribution of P53, bcl-2 and caspase-3, caspase-6, caspase-8 and caspase-9 immunoperoxidase techniques were used. RESULTS: While there were no neural tube defects in the embryos of groups A, B and D, eight embryos died in group C and there were 12 embryos with retarded embryological development. In contrast to that, no death was observed in group E, but only eight embryos were detected with maldevelopmental delay stage. CONCLUSION: These results suggested that VA may induce apoptotic mechanisms but not through the p53 pathway. In addition, FA effectively prevents the teratogenic influence of VA on chick embryo at neurulation stages by stopping cascade of apoptosis before caspase 3 expression.

Investigating paradoxical hysteresis effects in the mouse neocortical slice model.

Clinically, anesthetic drugs show hysteresis in the plasma drug concentrations at induction versus emergence from anesthesia induced unconsciousness. This is assumed to be the result of pharmacokinetic lag between the plasma and brain effect-site and vice versa. However, recent mathematical and experimental studies demonstrate that anesthetic hysteresis might be due in part to lag in the brain physiology, independent of drug transport delay - so-called "neural inertia". The aim of this study was to investigate neural inertia in the reduced neocortical mouse slice model. Seizure-like event (SLE) activity was generated by exposing cortical slices to no-magnesium artificial cerebrospinal fluid (aCSF). Concentration-effect loops were generated by manipulating SLE frequency, using the general anesthetic drug etomidate and by altering the aCSF magnesium concentration. The etomidate (24 µM) concentration-effect relationship showed a clear hysteresis, consistent with the slow diffusion of etomidate into slice tissue. Manipulation of tissue excitability, using either carbachol (50 µM) or elevated potassium (5mM vs 2.5mM) did not significantly alter the size of etomidate hysteresis loops. Hysteresis in the magnesium concentration-effect relationship was evident, but only when the starting condition was magnesium-containing "normal" aCSF. The in vitro cortical slice manifests pathway-dependent "neural inertia" and may be a valuable model for future investigations into the mechanisms of neural inertia in the cerebral cortex.

Multiple point action mechanism of valproic acid-teratogenicity alleviated by folic acid, vitamin C, and N-acetylcysteine in chicken embryo model.

The teratogenicity of antiepilepsy drug valproic acid (VPA) mostly is found in genetic and somatic levels, causing teratogenesis involving neurotubular defects (NTDs), anencephaly, lumbosacral meningomyelocele, and leg dysfunction due to spina bifida aperta. A diversity of nutraceutics have been tried to alleviate the risk of VPA-teratogenicity. The effect was varying. In order to promote the preventive prescription, to find out its action mechanism can be rather crucial. We used chicken embryo model to try the effect of folic acid (FA), ascorbic acid (AA), and N-acetyl cysteine (NAC). VPA at 30mM showed the higher malformation rate (66.7%) with the least mortality (22.2%). Pathological findings indicated that the cervical muscle was more susceptible to VPA injury than the ankle muscle. VPA downregulated levels of superoxide dismutase (SOD), glutathione (GSH), histone deacetylase (HDAC) and folate, and upregulated H(2)O(2) and homocysteine. FA, AA, and NAC significantly upregulated SOD, but only AA alone activated GSH. AA and NAC downregulated H(2)O(2), while FA was totally ineffective. All three nutraceutics comparably rescued HDAC with simultaneously suppressed homocysteine accumulation and folate re-elevation, although less effectively by NAC. Based on these data, we conclude VPA possesses "Multiple Point Action Mechanism". In addition to affecting the cited transcription and translation levels, we hypothesize that VPA competitively antagonize the glutamic acid to couple with pteroic acid in biosynthesis of dihydrofolic acid (DHFA). H(2)O(2) directly destroyed the NADPH reducing system at dihydrofolate reductase (DHFR) and methylene tetrahydrofolate reductase (MTHFR) levels, while completely restored by AA, an implication in preservation of intact apoenzymes. In addition, the GSH-GSSG system is sandwiched between the reducing systems NADPH/NADP and DHA-AA, its net balance is highly dependent on in situ in vivo Redox state, hence folic acid transformation is varying. To rescue the VPA-induced teratogenicity, simultaneous multiple prescriptions are suggested.

[Sedative, hypnotic and anticonvulsive effects of an adenosine analogue WS090501].

This study is to examine the sedative, hypnotic and anticonvulsive effects of an adenosine analogue, WS090501. The spontaneous locomotor activity was recorded by open field equipment, and the EEG of rats was recorded by polyphysiograph. Pentylenetetrazol (PTZ)-induced seizure model was used. The spontaneous locomotor activity was decreased by WS090501 at various doses (0.06, 0.13, and 0.25 mg x kg(-1)), and the decreasing rate was 28.4%, 47.1% and 61.2% respectively. Furthermore, the effect of WS090501 on spontaneous locomotor activity of mice can be antagonized by DPCPX, a selective adenosine A1R antagonist, but cannot be antagonized by SCH58261, a selective adenosine A2AR antagonist. The NREM sleep was significantly increased by WS090501 (0.05 and 0.2 mg x kg(-1)), and the increasing rate was 27.6% and 102.8%, respectively, at 6th hour after administration. The REM sleep decreased significantly at the higher dose. PTZ induced serious convulsion in mice. The latency of convulsion was prolonged, and the number of seizure and mortality decreased after administration of WS090501. These results show that WS090501 has potent sedative, hypnotic and anticonvulsive effects, which may be mediated through adenosine A1R.

Nicotine reversal of anticonvulsant action of topiramate in kainic acid-induced seizure model in mice.

INTRODUCTION: Tobacco smoking is a widespread phenomenon, and nicotine is the addictive component of tobacco. Nicotine acts through nicotinic cholinergic receptors and has been associated with different types of psychophysical disorders in human beings. The present study had explored the proconvulsive action of nicotine and its effect on the antiseizure efficacy of topiramate against kainic acid (KA)-induced seizures in mice. METHODS: The study had evaluated the dose-response curves for nicotine and KA and for KA in nicotine-pretreated mice and for topiramate against KA-induced seizures. Mecamylamine was used to antagonize the nicotinic receptor-mediated actions of nicotine. CD50 (convulsive dose in 50% of animals) for KA and nicotine and ED50 (effective dose in 50% of animals as anticonvulsant) for topiramate were determined. Brain lipid peroxidation studies were also undertaken in the treated mice. RESULTS: Nicotine significantly potentiated the convulsive action of KA acid and reduced the CD50 (95% confidence limits [CL]) value for KA from 2.6 mg/kg (2.3-3.1) to 1.4 mg/kg (0.9-2.1), intraperitoneally (i.p.). Topiramate pretreatment significantly inhibited KA-induced seizures and brain lipid peroxidation with ED50 (95% CL) value of 21.90 mg/kg (17.3-28.2), i.p. Nicotine pretreatment caused dose-dependent antagonism to the antiseizure and antilipid peroxidative actions of topiramate. Mecamylamine had antagonized the proconvulsant action of nicotine. CONCLUSION: The study highlights the fact that intake of nicotine, through agonism to nAChR, might predispose epileptic patients to lower seizure threshold and induce a state of refractoriness to the protective effects of the antiepileptic drugs, resulting in possible breakthrough seizure attacks.

Effects of phenytoin and Echinacea purpurea extract on proliferation and apoptosis of mouse embryonic palatal mesenchymal cells.

Cleft palate is one of the most common birth defects. Several environment factors are involved in the disorder, such as smoking, vitamin deficiency and teratogens. We investigated the teratogenic agent phenytoin and extract of the immunostimulant Echinacea purpurea in the etiology of cleft palate associated with the proliferation and apoptosis of mouse embryonic palatal mesenchymal (MEPM) cells. We measured the effects of phenytoin, E. purpurea extract, and the mixture of phenytoin and E. purpurea extract on the cell viability of MEPM cells by CCK-8 assay and on the proliferation and apoptosis of MEPM cells by BrdU labeling assay, flow cytometry, and TUNEL assay. Exposure to phenytoin for 24 h inhibited cell proliferation and increased cell apoptosis of MEPM cells, and E. purpurea extract had the reverse effect. Importantly, treatment with the mixture of phenytoin and E. purpurea extract increased the proliferation and decreased the apoptosis of MEPM cells as compared with treatment with phenytoin alone. The teratogenic effect of phenytoin on cleft palate is associated with the proliferation and apoptosis of MEPM cells, and E. purpurea extract may have a protective effect.

Prevention of sodium valproate-induced hepatotoxicity by curcumin, rosiglitazone and N-acetylcysteine in rats.

The present study was designed to examine the potential preventive effect of curcumin (CMN; CAS 458-37-7), rosiglitazone (RGN; CAS 155141-29-0), N-acetylcysteine (NAC; CAS 616-91-1), resveratrol (RSV; CAS 501-36-0), and losartan (LOS; CAS 114798-26-4) on sodium valproate-induced hepatotoxicity. Sodium valproate (SVP; CAS 1069-66-5) was given at a dose of 250 mg/kg i. p. 3 times daily for one week. The tested compounds were given simultaneously with SVP for one week. The results demonstrate that CMN, RGN and NAC treatment can confer protection from SVP-induced hepatotoxicity. The second part of the study includes an evaluation of the effect of CMN, RGN and NAC on the anticonvulsant activity of SVP against pentetrazole-induced seizures in mice. The results demonstrate that CMN, RGN and NAC do not affect the anticonvulsant activity of SVP. Combined administration of either of CMN, RGN and NAC with valproate appears to be beneficial in reducing valproate-induced hepatotoxicity.

[Effect of psychotropic drugs on activity of anticonvulsants in maximal electroshock test].

The effect ofpsychotropic drugs on the pharmacological properties of anticonvulsants was studied on white mice under maximal electroshock (ME) test conditions. Changes in the anticonvulsant effect of phenobarbital, diphenin, carbamazepine, hexamidine were traced upon their joint administration with psychotropic drugs, including piracetam, aminalon, amitriptyline, imizine, levomepromazine, and lithium oxybutyrate. An important result of research is the fact, that in no one of combinations the basic pharmacological effect of anticonvulsants was decreased. Based on the results of experiments, the most rational combinations of anticonvulsants with psychotropic preparations were revealed as manifested in the ME test. As criterion of rational combination was the increase in the activity of anticonvulsants and reduction of their toxicity in combination or at least invariance of this parameter. Rational combinations include (i) phenobarbital with piracetam, amitriptyline, levomepromazine, and lithium oxybutyrate; (ii) carbamazepine with piracetam; and (iii) hexamidine with amitriptyline, levomepromazine and imizine.

Functional effects of the KCNQ modulators retigabine and XE991 in the rat urinary bladder.

The anticonvulsant retigabine has previously been reported to inhibit bladder overactivity in rats in vivo but the mechanism and site of action are not known. In the present study we investigated the effect of retigabine in isolated rat bladder tissue. Bladders from Sprague-Dawley rats were cut transversally into rings and mounted on an isometric myograph. The average tension, the amplitude and frequency of bladder muscle twitches were measured. The bladder tissue was stimulated with carbachol, KCl (5, 10 and 60mM), and by electric field stimulation. Dose-response curves were obtained with increasing concentrations of the KCNQ((2-5)) selective positive modulator, retigabine or with the KCNQ((1-5)) negative modulator XE991. Retigabine experiments were repeated in the presence of 10 microM XE991. Retigabine reduced both the contractility and the overall tonus of bladder tissue independent of the mode of stimulation with EC(50) values ranging from 3.3 microM (20mM KCl) to 8.3 microM (0.2 microM carbachol). In support of a KCNQ-specific effect, retigabine had only weak effects after 60mM KCl pre treatment and all retigabine effects could be reversed by XE991. XE991 increased both the amplitude and mean tension of the bladder but was more potent at increasing the number rather than the size of the stimulated twitches. In conclusion, this study demonstrates an efficacious KCNQ dependent effect of retigabine and XE991 on rat bladder contractility.

Pharmacokinetics and tolerability of intranasal diazepam and midazolam in healthy adult volunteers.

OBJECTIVE: The purpose of this pilot study was to determine the pharmacokinetics and tolerability of an investigational diazepam (DZP) formulation and a parenteral midazolam (MDZ) formulation following intranasal (i.n.) administration for the efficient treatment of seizure emergencies. METHODS: Each subject received 5 mg of DZP and MDZ via both i.n. and intravenous routes in a four-way, randomized crossover trial. Blood samples were collected over 48 h. DZP and MDZ concentrations were measured using HPLC. Using analog scales, subjects rated tolerability (0 = no change from normal; 10 = maximum intolerability) and pain (0 = no pain; 4 = extreme pain) prior to and 0, 5, 15, 60 min, and 8 h after administration. RESULTS: The C(max) and T(max) values for i.n. DZP and MDZ were 179.2 ng/ml and 28.8 min vs 62.8 ng/ml and 21.6 min, respectively. Immediately following i.n. administration, subjects reported tolerability scores of 6.75 and 6.0, and identical pain scores, 3.2, for DZP and MDZ, respectively. CONCLUSION: Both formulations were rapidly absorbed following i.n. administration with transient discomfort. DZP had a longer half-life, which may result in an extended duration of action. Further studies in large patient populations to evaluate the safety after long term use, efficacy and pharmacokinetics of i.n. DZP are warranted.

Computational studies to discover a new NR2B/NMDA receptor antagonist and evaluation of pharmacological profile.

The ionotropic glutamate NMDA/NR2B receptor and its interaction with ifenprodil-like noncompetitive ligands were investigated by a combined ligand-based and target-based approach. First, we generated 3D pharmacophore hypotheses and identified common chemical features that are shared by a training set of well-known NR2B antagonists. The binding mode of the most representative ligand was also studied by molecular docking. Because the docking results and the suggested 3D pharmacophore model were in good agreement, we obtained new information about the NR2B ifenprodil site. The best pharmacophoric hypothesis was used as a query for in silico screening; this allowed the identification of new "hit". We synthesized "hit-compound" analogues, and some of the molecules showed significant activity both in binding and functional assay as well as in vivo anticonvulsant efficacy in DBA/2 mice. The most active derivatives also exhibited neuroprotective effects against glutamate-induced toxicity in HCN-1A cells.

Role of nitric oxide in the development of tolerance to diazepam-induced motor impairment in mice.

Chronic treatment with the benzodiazepines is well known to produce tolerance, which has been extensively documented to be attributed to modifications in the gamma-aminobutyric acid (GABA)ergic neurotransmission. However, literature data have also suggested the participation of different neurotransmitter systems, including glutamatergic, in benzodiazepine tolerance. The purpose of the present study was to determine the role of nitric oxide (NO) in the development of tolerance to the motor dysfunction induced by chronic administration of diazepam. The motor performance was assessed on the 1st and 10th day of experiment, using the rotarod and chimney tests in mice. Treatment of animals with both non-selective NO synthase (NOS) inhibitors: N(G)-nitro-L-arginine methyl ester (L-NAME), N(G)-nitro-L-arginine (L-NOARG) and selective NOS inhibitor: 7-nitroindazole was able to prevent the development of tolerance to the motor impairing effect of diazepam. Moreover, administration of L-arginine, a NO precursor, facilitated the development of diazepam-induced tolerance in rotarod test. These findings suggest that NO may be involved, at least in part, in the tolerance to the motor dysfunction, developed during the chronic administration of diazepam in mice.

The inhibitory effect of trimethylamine on the anticonvulsant activities of quinine in the pentylenetetrazole model in rats.

Quinine specifically blocks connexin 36 (Cx36), one of the proteins that form gap junction channels. Quinine suppressed ictal epileptiform activity in in vitro and in vivo studies without decreasing neuronal excitability. In this study, we considered the possible mechanism of anticonvulsant effects of quinine (1, 250, 500, 1000 and 2000 microM, i.c.v.) in the pentylenetetrazole (PTZ) model of seizure. Thus, we used trimethylamine (TMA) (0.05 microM, 5 microM, 50 microM), a gap junction channel opener, to examine whether it could reverse the effects of quinine in rats. Intracerebroventricular (i.c.v.) injection of quinine affected generalized tonic-clonic seizure (GTCS) induced by PTZ by increments in seizure onset and reducing seizure duration. Additionally, pretreatment with different doses of TMA (i.c.v.) attenuated the anticonvulsant effects of quinine on the latency and duration of GTCS. It can be concluded that quinine possesses anticonvulsant effects via modulation of gap junction channels, which could contribute to the control of GTCS.

First-line therapy for theophylline-associated seizures.

Theophylline-associated seizures (TAS) are considered a neurologic emergency, as they can sometimes be intractable and difficult to stop with standard treatments such as intravenous administration of diazepam. As a consequence, a proportion of patients who experience status epilepticus while receiving theophylline will require endotracheal intubation. The optimal first-line therapy for TAS has not yet been fully investigated. We compared 54 cases of TAS with 779 cases of non-TAS, that had presented at a single institution between 1991 and 2002. Among the 54 cases of TAS, 36 experienced generalized tonic-clonic seizures, with the remainder experiencing partial seizures. TAS occurred mainly in children under 3 years of age, and serum theophylline levels were within the therapeutic range in 78% of the cases. The duration of TAS tended to be longer than for non-TAS, and intravenous administration of diazepam was less effective in controlling TAS (45%), compared with non-TAS (68%). Many cases required repeated injections of diazepam, and 15 cases (27%) eventually required endotracheal intubation. Reports concerning the therapy for TAS were also reviewed. Theophylline is known to antagonize the effects of benzodiazepines, and this may explain why drugs such as diazepam are relatively ineffective in treating TAS. In TAS, the prompt use of barbiturates is recommended when diazepam is not effective, to avoid potential brain injury secondary to status epilepticus.

Effects of tianeptine on onset time of pentylenetetrazole-induced seizures in mice: possible role of adenosine A1 receptors.

Depression is a common psychiatric problem in epileptic patients. Thus, it is important that an antidepressant agent has anticonvulsant activity. This study was organized to investigate the effects of tianeptine, an atypical antidepressant, on pentylenetetrazole (PTZ)-induced seizure in mice. A possible contribution of adenosine receptors was also evaluated. Adult male Swiss-Webster mice (25-35 g) were subjects. PTZ (80 mg/kg, i.p.) was injected to mice 30 min after tianeptine (2.5-80 mg/kg, i.p.) or saline administration. The onset times of 'first myoclonic jerk' (FMJ) and 'generalized clonic seizures' (GCS) were recorded. Duration of 600 s was taken as a cutoff time in calculation of the onset time of the seizures. To evaluate the contribution of adenosine receptors in the effect of tianeptine, a nonspecific adenosine receptor antagonist caffeine, a specific A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), a specific A2A receptor antagonist 8-(3-chlorostyryl) caffeine (CSC) or their vehicles were administered to the mice 15 min before tianeptine (80 mg/kg) or saline treatments. Tianeptine (40 and 80 mg/kg) pretreatment significantly delayed the onset time of FMJ and GCS. Caffeine (10-60 mg/kg, i.p.) dose-dependently blocked the retarding effect of tianeptine (80 mg/kg) on the onset times of FMJ and GCS. DPCPX (20 mg/kg) but not CSC (1-8 mg/kg) blocked the effect of tianeptine (80 mg/kg) on FMJ. Our results suggest that tianeptine delayed the onset time of PTZ-induced seizures via adenosine A1 receptors in mice. Thus, this drug may be a useful choice for epileptic patients with depression.