Acute and chronic tianeptine treatments attenuate ethanol withdrawal syndrome in rats

Interactions of antiepileptic drugs with drugs approved for the treatment of indications other than epilepsy

Introduction: Comorbidities of epilepsy may significantly interfere with its treatment as diseases in the general population are also encountered in epilepsy patients and some of them even more frequently (for instance, depression, anxiety, or heart disease). Obviously, some drugs approved for other than epilepsy indications can modify the anticonvulsant activity of antiepileptics. Areas covered: This review highlights the drug-drug interactions between antiepileptics and aminophylline, some antidepressant, antiarrhythmic (class I-IV), selected antihypertensive drugs and non-barbiturate injectable anesthetics (ketamine, propofol, etomidate, and alphaxalone). The data were reviewed mainly from experimental models of seizures. Whenever possible, clinical data were provided. PUBMED data base was the main search source.Expert opinion: Aminophylline generally reduced the protective activity of antiepileptics, which, to a certain degree, was consistent with scarce clinical data on methylxanthine derivatives and worse seizure control. The only antiarrhythmic with this profile of action was mexiletine when co-administered with VPA. Among antidepressants and non-barbiturate injectable anesthetics, trazodone, mianserin and etomidate or alphaxalone, respectively, negatively affected the anticonvulsant action of some antiepileptic drugs. Clinical data indicate that only amoxapine, bupropion, clomipramine and maprotiline should be used with caution. Possibly, drugs reducing the anticonvulsant potential of antiepileptics should be avoided in epilepsy patients.

Resource, chemical structure and activity of natural polysaccharides against alcoholic liver damages

Many natural polysaccharides from bio-resources hold advantages of multi-functions, high efficiency, non-toxicity or low side effect, and have strong potentials in protection against alcoholic liver damages. This review summarized the bio-resources, chemical and structural characteristics of natural polysaccharides with potentials in inhibition against alcoholic liver damages, and also emphasized knowledge on correlations between their chemical structure and function. Approximately 95 species were confirmed in generation of hepatoprotective polysaccharides. Products as crude polysaccharides originated from 17 species were sum up despite the indetermination of their accurate structure. Additional four polysaccharides were described for their known chemical structures. Possible roles of hepatoprotective polysaccharides were provided with evidence on antioxidant promotion, lipids regulation, apoptosis inhibition and anti-inflammation, as well as confirmations in immune enhancement, iron removal and anti-fibrosis when currently treated against the alcoholic liver damages. To sum up, this overview could serve to guide development and utilization of natural hepatoprotective polysaccharides.

Pharmacokinetic study of tianeptine and its active metabolite MC5 in rats following different routes of administration using a novel liquid chromatography tandem mass spectrometry analytical method

Tianeptine is an atypical antidepressant with a unique mechanism of action and recently it has been also reported that its major metabolite, compound MC5, possesses pharmacological activity similar to that of the parent drug. The current study aims to investigate the pharmacokinetics (PK) of both tianeptine and MC5 after intravenous or intraperitoneal administration of the parent drug as well as the metabolic ratio of MC5 in rats. To achieve these goals an LC-MS/MS method using the small sample volume for the quantitation of tianeptine and its active metabolite MC5 in rat plasma and liver perfusate has been developed and validated. Following an intravenous administration of tianeptine pharmacokinetic parameters were calculated by non-compartmental analysis. The average tianeptine volume of distribution at steady state was 2.03 L/kg and the systemic clearance equaled 1.84 L/h/kg. The mean elimination half-lives of tianeptine and MC5 metabolite were 1.16 and 7.53 h, respectively. The hepatic clearance of tianeptine determined in the isolated rat liver perfusion studies was similar to the perfusate flow rate despite the low metabolic ratio of MC5. Mass spectrometric analysis of rat bile indicated that tianeptine and MC5 metabolite are eliminated with bile as glucuronide and glutamine conjugates. Bioavailability of tianeptine after its intraperitoneal administration was 69%. The PK model with a metabolite compartment developed in this study for both tianeptine and MC5 metabolite after two routes of administration may facilitate tianeptine dosage selection for the prospective pharmacological experiments.

Pharmacokinetic/pharmacodynamic considerations for epilepsy - depression comorbidities

INTRODUCTION

Epilepsy may be frequently associated with psychiatric disorders and its co-existence with depression usually results in the reduced quality of life of patients with epilepsy. Also, the efficacy of antiepileptic treatment in depressed patients with epilepsy may be significantly reduced.

AREAS COVERED

Results of experimental studies indicate that antidepressants co-administered with antiepileptic drugs may either increase their anticonvulsant activity, remain neutral or decrease the protective action of antiepileptic drugs in models of seizures. Apart from purely pharmacodynamic interactions, pharmacokinetic mechanisms have been proven to contribute to the final outcome. We report on clinical data regarding the pharmacokinetic interactions of enzyme-inducing antiepileptic drugs with various antidepressants, whose plasma concentration may be significantly reduced. On the other hand, antidepressants (especially selective serotonin reuptake inhibitors) may influence the metabolism of antiepileptics, in many cases resulting in the elevation of plasma concentration of antiepileptic drugs.

EXPERT OPINION

The preclinical data may provide valuable clues on how to combine these two groups of drugs - antidepressant drugs neutral or potentiating the anticonvulsant action of antiepileptics are recommended in this regard. Avoidance of antidepressants clearly decreasing the convulsive threshold or decreasing the anticonvulsant efficacy of antiepileptic drugs (f.e. bupropion or mianserin) in patients with epilepsy is recommended.

CaMKIIα-GluA1 Activity Underlies Vulnerability to Adolescent Binge Alcohol Drinking

BACKGROUND

Binge drinking during adolescence is associated with increased risk for developing alcohol use disorders; however, the neural mechanisms underlying this liability are unclear. In this study, we sought to determine whether binge drinking alters expression or phosphorylation of 2 molecular mechanisms of neuroplasticity, calcium/calmodulin-dependent kinase II alpha (CaMKIIα) and the GluA1 subunit of AMPA receptors (AMPARs) in addiction-associated brain regions. We also asked whether activation of CaMKIIα-dependent AMPAR activity escalates binge-like drinking.

METHODS

To address these questions, CaMKIIαT286 and GluA1S831 protein phosphorylation and expression were assessed in the amygdala and striatum of adolescent and adult male C57BL/6J mice immediately after voluntary binge-like alcohol drinking (blood alcohol >80 mg/dl). In separate mice, effects of the CaMKIIα-dependent GluA1S831 phosphorylation (pGluA1S831 )-enhancing drug tianeptine were tested on binge-like alcohol consumption in both age groups.

RESULTS

Binge-like drinking decreased CaMKIIαT286 phosphorylation (pCaMKIIαT286 ) selectively in adolescent amygdala with no effect in adults. Alcohol also produced a trend for reduced pGluA1S831 expression in adolescent amygdala but differentially increased pGluA1S831 in adult amygdala. No effects were observed in the nucleus accumbens or dorsal striatum. Tianeptine increased binge-like alcohol consumption in adolescents but decreased alcohol consumption in adults. Sucrose consumption was similarly decreased by tianeptine pretreatment in both ages.

CONCLUSIONS

These data show that the adolescent and adult amygdalae are differentially sensitive to effects of binge-like alcohol drinking on plasticity-linked glutamate signaling molecules. Tianeptine-induced increases in binge-like drinking only in adolescents suggest that differential CaMKIIα-dependent AMPAR activation may underlie age-related escalation of binge drinking.

Improved Serotonergic Tone Contributes to the Mechanism of Action of St John’s Wort in Nicotine Withdrawn Mice

Present study aims to investigate the acute effects of St John’s Wort (SJW) on nicotine withdrawal syndrome and serotonergic hypo activity in mice. Adult male Albino mice weighing 20-25g were housed 6 per cage under light and dark conditions at 22±3oC and maintained on lab chow and water ad libitum under standard housing conditions. Nicotine was administered at the concentrations of 3.08mg (1mg of free base) in 100 ml of drinking water for 4 weeks. Nicotine withdrawal was achieved by substituting nicotine containing water with drinking water. Nicotine withdrawn (NW) mice were evaluated for locomotor activity and abstinence signs at 72 h. Whole brain tryptophan (TRP). 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were measured using high performance liquid chromatography connected to fluorescence detector. St John’s Wort (SJW) (500mg/kg) was given intraperitonially 3 h prior to completion of 72 h of nicotine withdrawal period. Behavioral analysis in SJW administered NW mice showed attenuation in nicotine abstinence signs (shaking, scratching, chewing and facial tremors) and locomotor activity when compared with respective controls. NW mice showed decrease in plasma TRP, brain TRP and 5-HT concentrations while increase in 5-HT turnover and corticosterone concentrations as compared to respective controls. SJW administrated NW mice showed decrease in corticosterone levels and 5-HT turnover while plasma TRP, brain TRP and 5-HT synthesis were increased when compared with similarly treated saline injected group. Our findings warrant SJW’s therapeutic efficacy to alleviate nicotine withdrawal associated depression by virtue of its ability to improve serotonergic activity by increasing brain TRP, 5-HT concentrations and decreased turnover.

Consumption of Coprinus comatus polysaccharide extract causes recovery of alcoholic liver damage in rats

CONTEXT

Excess use of alcohol is known to be associated with liver diseases such as fatty liver, alcoholic hepatitis, and cirrhosis. Various practices may be applied to prevent or treat the damage caused by chronic alcoholism. Coprinus comatus (O.F. Müll.) Pers. (Agaricaceae) is a macrofungus that has been reported to aid the recovery of murine livers damaged by benzopyrene.

OBJECTIVE

In this study, the possible therapeutic effects of three different doses (50, 100, and 150 mg/kg) of C. comatus polysaccharide (PS) extract were studied in rats subjected to an alcoholic diet. The histological and biochemical results were compared between the control and experimental groups.

MATERIALS AND METHODS

Modified Lieber-Decarli's calorie-adjusted liquid alcohol diet was given orally for 60 d. In addition to histopathology, alanine transaminase (ALT), aspartate transaminase (AST), mitochondrial membrane integrity, total cytochrome-c oxidase activity (TotalStCox), total mitochondrial cytochrome-c oxidase activity (TotalMtStCox), and caspase-3 values were used as liver parameters, and liver sections from all experimental groups were examined by electron microscopy.

RESULTS

Using histopathological assessment, it was observed that there was a decline in liver hepatocyte vacuolization in the treatment group fed 50 mg PS/kg. The TotalStCox and TotalMtStCox values of this group differed from the EtOH control group (p < 0.05).

DISCUSSION AND CONCLUSION

Daily administration of 50 mg/kg of C. comatus PS extract considerably reduced the negative effects of alcohol on liver structure and function.

Effect of acute and chronic tianeptine on the action of classical antiepileptics in the mouse maximal electroshock model

BACKGROUND

The aim of the study was to analyze the influence of acute and chronic treatment with tianeptine, an antidepressant selectively accelerating presynaptic serotonin reuptake, on the protective activity of classical antiepileptic drugs in the maximal electroshock test in mice.

METHODS

Electroconvulsions were produced by means of an alternating current (50 Hz, 25 mA, 0.2 s) delivered via ear-clip electrodes. Motor impairment and long-term memory deficits in animals were quantified in the chimney test and in the passive-avoidance task, respectively. Brain concentrations of antiepileptic drugs were measured by fluorescence polarization immunoassay.

RESULTS

Acute and chronic treatment with tianeptine (25-50 mg/kg) did not affect the electroconvulsive threshold. Furthermore, tianeptine applied in both acute and chronic protocols enhanced the anticonvulsant action of valproate and carbamazepine, but not that of phenytoin. Neither acute nor chronic tianeptine changed the brain concentrations of valproate, carbamazepine or phenytoin. On the other hand, both single and chronic administration of tianeptine diminished the brain concentration of phenobarbital. In spite of this pharmacokinetic interaction, the antidepressant enhanced the antielectroshock action of phenobarbital. In terms of adverse effects, acute/chronic tianeptine (50 mg/kg) and its combinations with classic antiepileptic drugs did not impair motor performance or long-term memory in mice.

CONCLUSION

The obtained results justify the conclusion that tianeptine may be beneficial in the treatment of depressive disorders in the course of epilepsy.

The antinociceptive effects of intravenous tianeptine in colorectal distension-induced visceral pain in rats: the role of 5-HT₃ receptors

Tianeptine is an unusual tricyclic antidepressant drug. In this study, we aimed to investigate the antinociceptive effect of tianeptine on visceral pain in rats and to determine whether possible antinociceptive effect of tianeptine is mediated by serotonergic (5-HT(2,3)) and noradrenergic (α(1,2)) receptor subtypes. Male Sprague Dawley rats (250-300 g) were supplied with a venous catheter, for drug administrations, and enameled nichrome electrodes, for electromyography, at external oblique musculature. Colorectal distension (CRD) was employed as the noxious visceral stimulus and the visceromotor response (VMR) to CRD was quantified electromyographically before and 5, 15, 30, 60, 90 and 120 min after tianeptine administration. Antagonists were administered 10 min before tianeptine for their ability to change tianeptine antinociception. Intravenous administration of tianeptine (2.5-20 mg/kg) produced a dose-dependent reduction in VMR. Administration of 5-HT(3) receptor antagonist ondansetron (0.5, 1 and 2 mg/kg), but not 5-HT(2) receptor antagonist ketanserine (0.5, 1 and 2 mg/kg), reduced the antinociceptive effect of tianeptine (10mg/kg). In addition, administration of α(1)-adrenoceptor antagonist prazosin (1 mg/kg) or α(2)-adrenoceptor antagonist yohimbine (1 mg/kg) did not cause any significant effect on the tianeptine-induced antinociception. Our data indicate that intravenous tianeptine exerts a pronounced antinociception against CRD-induced visceral pain in rats, and suggests that the antinociceptive effect of tianeptine appears to be mediated in part by 5-HT(3) receptors, but does not involve 5-HT(2) receptors or α-adrenoceptors.

Beneficial Effects of Tianeptine on Hippocampus-Dependent Long-Term Memory and Stress-Induced Alterations of Brain Structure and Function

Tianeptine is a well-described antidepressant which has been shown to prevent stress from producing deleterious effects on brain structure and function. Preclinical studies have shown that tianeptine blocks stress-induced alterations of neuronal morphology and synaptic plasticity. Moreover, tianeptine prevents stress from impairing learning and memory, and, importantly, demonstrates memory-enhancing properties in the absence of stress. Recent research has indicated that tianeptine works by normalizing glutamatergic neurotransmission, a mechanism of action that may underlie its effectiveness as an antidepressant. These findings emphasize the value in focusing on the mechanisms of action of tianeptine, and specifically, the glutamatergic system, in the development of novel pharmacotherapeutic strategies in the treatment of depression.

Tianeptine: potential influences on neuroplasticity and novel pharmacological effects

Tianeptine is an atypical antidepressant drug. In contrast to tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs), it has been suggested that tianeptine decreases serotonin's activity and amount in serotonergic synapses of the central nervous system by increasing serotonin reuptake. Tianeptine, which has a mechanism of action opposite to that of SSRIs, necessitated a re-evaluation of the biochemical basis of depression and revealed that it cannot be explained by the monoamine hypothesis only. Recent studies by tianeptine have been focused on neuroplasticity. Neuroplasticity hypothesis of depression has the potential to make important contributions to the diagnosis, as well as it may be helpful in the explanation of the drug effects, which cannot be explained by neurochemical mechanisms. In addition, recent interesting results indicating anticonvulsant and analgesic activity of tianeptine and its possible interaction with adenosine A(1) receptors were obtained. In this review, novel central actions of tianeptine and the relationship between stress, neuroplasticity and drug effects were evaluated in the light of the current literature.

Attenuation of ethanol withdrawal syndrome by extract of Hypericum perforatum in Wistar rats

The effects of Hypericum perforatum (St John's wort) on ethanol withdrawal syndrome have been investigated in ethanol-dependent rats. Adult male Wistar rats were subjects. Ethanol (7.2% v/v) was given to rats by a liquid diet for 15 days. Hypericum perforatum extract (HPE) (25-200 mg/kg) and saline were injected to rats intraperitoneally just before ethanol withdrawal. After second, fourth and sixth hour of ethanol withdrawal, rats were observed for 5 min, and withdrawal signs that included locomotor hyperactivity, stereotyped behavior and tremors were recorded or rated. A second series of injections was given at 6 h after the first one, and subjects were then tested for audiogenic seizures. HPE (25-200 mg/kg) produced some dose-dependent and significant inhibitory effects on locomotor hyperactivity at second and sixth hour of ethanol withdrawal. In addition, it significantly reduced the number of stereotyped behaviors at the same dose range. HPE (50 and 100 mg/kg) produced some significant inhibitory effects on tremor and audiogenic seizures during withdrawal period. These results suggest that HPE has some beneficial effects on ethanol withdrawal syndrome in rats.

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.