Antipsychotic-like effect of trimetazidine in a rodent model

Neuroprotective potential of trimetazidine against tramadol-induced neurotoxicity: role of PI3K/Akt/mTOR signaling pathways

Tramadol (TRA) causes neurotoxicity whereas trimetazidine (TMZ) is neuroprotective. The potential involvement of the PI3K/Akt/mTOR signaling pathway in the neuroprotection of TMZ against TRA-induced neurotoxicity was evaluated. Seventy male Wistar rats were divided into groups. Groups 1 and 2 received saline or TRA (50 mg/kg). Groups 3, 4, and 5 received TRA (50 mg/kg) and TMZ (40, 80, or 160 mg/kg) for 14 days. Group 6 received TMZ (160 mg/kg). Hippocampal neurodegenerative, mitochondrial quadruple complex enzymes, phosphatidylinositol-3-kinases (PI3Ks)/protein kinase B levels, oxidative stress, inflammatory, apoptosis, autophagy, and histopathology were evaluated. TMZ decreased anxiety and depressive-like behavior induced by TRA. TMZ in tramadol-treated animals inhibited lipid peroxidation, GSSG, TNF-α, and IL-1β while increasing GSH, SOD, GPx, GR, and mitochondrial quadruple complex enzymes in the hippocampus. TRA inhibited Glial fibrillary acidic protein expression and increased pyruvate dehydrogenase levels. TMZ reduced these changes. TRA decreased the level of JNK and increased Beclin-1 and Bax. TMZ decreased phosphorylated Bcl-2 while increasing the unphosphorylated form in tramadol-treated rats. TMZ activated phosphorylated PI3Ks, Akt, and mTOR proteins. TMZ inhibited tramadol-induced neurotoxicity by modulating the PI3K/Akt/mTOR signaling pathways and its downstream inflammatory, apoptosis, and autophagy-related cascades.

[Dopaminergic potential of domestic 3-hydroxypyridine and succinic acid derivatives and prospects for their therapeutic «retargeting»]

The review is devoted to the assessment of the pharmacological effects of 3-hydroxypyridine and succinic acid derivatives (emoxipin, reamberin and mexidol) from the standpoint of their dopaminergic activity. A systematic analysis of the data has been performed, allowing us to consider emoxipin, reamberin and mexidol as «normalizers of dopaminergic neurotransmission», the dopaminergic action of which in its phenotype corresponds to the effects of partial dopamine receptor agonists. The position that the dopaminergic effect, antioxidant and antidepressant potential of drugs containing 2-ethyl-6-methyl-3-oxypyridine (emoxipine and mexidol) are associated with their inhibitory effect on monoamine oxidase-A (MAO-A) has been substantiated. A direct relationship between the stimulating effect of succinate-containing drugs (reamberin and mexidol) on MAO-B, their prooxidant activity, insulin-potentiating and antidepressant effects was analyzed. A hypothesis has been put forward on the general pathological significance of dopaminergic regulation disorders, the correction of which with the 3-hydroxypyridine and succinic acid derivatives can be considered as a promising strategy for improving the complex therapy of socially significant and common human diseases.

Trimetazidine, an Anti-Ischemic Drug, Reduces the Antielectroshock Effects of Certain First-Generation Antiepileptic Drugs

Trimetazidine (TMZ), an anti-ischemic drug for improving cellular metabolism, is mostly administered to patients with poorly controlled ischemic heart disease (IHD). Since IHD is considered the most frequent causative factor of cardiac arrhythmias, and these often coexist with seizure disorders, we decided to investigate the effect of TMZ in the electroconvulsive threshold test (ECT) and its influence on the action of four first-generation antiepileptic drugs in the maximal electroshock test (MES) in mice. The TMZ (up to 120 mg/kg) did not affect the ECT, but applied at doses of 20–120 mg/kg it decreased the antielectroshock action of phenobarbital. The TMZ (50–120 mg/kg) reduced the effect of phenytoin, and, when administered at a dose of 120 mg/kg, it diminished the action of carbamazepine. All of these revealed interactions seem to be pharmacodynamic, since the TMZ did not affect the brain levels of antiepileptic drugs. Furthermore, the combination of TMZ with valproate (but not with other antiepileptic drugs) significantly impaired motor coordination, evaluated using the chimney test. Long-term memory, assessed with a passive-avoidance task, was not affected by either the TMZ or its combinations with antiepileptic drugs. The obtained results suggest that TMZ may not be beneficial as an add-on therapy in patients with IHD and epilepsy.

Preliminary assessment of proanthocyanidin isolates of Vitis vinifera seed on the central nervous system of male Albino mice

This study evaluated the potential neurobehavioral effects of proanthocyanidin-rich-fraction (PRF) obtained from Vitis vinifera seed in male Albino mice. Adult (2½- to 3-month old) male Albino mice were treated with PRF (200, 100, 50 mg/kg) and subjected to diverse behavioral models specially designed for the assessment of central nervous system-acting agents. One-shot intraperitoneal (i.p) injection of PRF (200 and 100 mg/kg) decreased the rectal temperature, exploratory activities (locomotion, rearing, and grooming), anxiety-like responses (% open-arm time, open-arm entries but decreased the total number of enclosed arm times). However, acute i.p administration of PRF decreased the total score of apomorphine-induced stereotyped behaviors, latency to hexobarbitone-induced sleep, and increased the total sleep duration. Moreover, indices of convulsion (tonic flexion, extension, clonic convulsion, stupor, and recovery time) were decreased in the PRF treatment groups, especially the PRF (50 mg/kg)-treated mice. Based on these present findings, it could therefore be inferred that systemic administration of PRF of V. vinifera seed origin induces diverse modification on the behaviors of the treated mice stemming from anxiolytic, anticonvulsant, sedative, and decrease in core temperature.

Event related potentials (ERPs) to assess the tinnitus complaint during drug treatment

INTRODUCTION

Previous studies have shown that the attention given to tinnitus can be a determinant of tinnitus severity. Some of these studies have shown changes in the amplitude and/or latency parameters of the event-related auditory potentials (ERPs). One of the tools previously employed to investigate an individual's attention is the Event Related Potential (ERP), which reflects the amount of attention from the patient to the provided auditory stimuli.

OBJECTIVE

To verify if the use of central and peripheral drugs tested for the treatment of tinnitus present changes in the measurable parameters of event-related potentials when compared to Tinnitus Handicap Inventory (THI) and Visual Analogue Scale (VAS).

METHOD

Eighty-eight tinnitus patients were randomly sorted into two drug groups: (1) drugs with a central action mechanism and (2) drug with peripheral action mechanism. Their effects upon the negative aspects caused by tinnitus symptoms were evaluated by the ERPs during three periods: Premedication (T1), at Termination of the drug treatment (T2), and following the Washout period (T3), and then compared with the results from the THI questionnaire and VAS.

RESULTS

ERP waves in both groups did not demonstrate significant differences during the three evaluated periods (P=0.53), despite the significant improvement seen through the evaluation by the THI questionnaire and VAS for tinnitus annoyance and intensity (P<0.0001).

CONCLUSION

The use of ERPs with patients of chronic tinnitus who have been submitted to treatment using drugs having actions on both the CNS and peripheral auditory system did not present changes in either latency or amplitude of the waves throughout the treatment when compared to the THI questionnaire and VAS. The ERPs cannot be considered as criterion to evaluate the evolution of drug treatment in patients complaining of tinnitus. The statistically significant reduction in THI and VAS scores among all drugs used occurred with dopamine antagonists. Considering the possible antipsychotic effects, we can conclude that the concomitance of a variety of psychopathological conditions such as obsessive-compulsive disorder may be associated with tinnitus in some patients and may be responsible for the severity of the symptom.

The Impact of Trimetazidine on Disease Severity and Quality of Life in Parkinson's Disease

Trimetazidine is contraindicated in movement disorders, however, a not negligible part of trimetazidine users is still patients with Parkinson’s disease (PD). The present study aimed to objectively determine the impact of trimetazidine on the severity of symptoms and the health-related quality of life of patients with PD by measuring changes after its withdrawal. A consecutive series of 42 patients with PD using trimetazidine underwent detailed neurological and neuropsychological assessments at baseline and three months after the discontinuation of trimetazidine. Clinically relevant improvements were achieved with discontinuation of trimetazidine according to changes in scores of each part of the Movement Disorder Society-sponsored Unified Parkinson’s Disease Rating Scale (Part I: −25.7%, p < 0.001; Part II: −23.8%, p < 0.001; Part III: −28.5%, p < 0.001; Part IV: −30.1%, p = 0.004) and total scores of the Non-Motor Symptoms Scale (−25.6%, p = 0.004) and the Montgomery-Asberg-Depression Rating Scale (−20.1%, p = 0.001). Benefits resulting from the withdrawal of the drug also manifested in the improvement of the health-related quality of life based on changes in the summary index of the 39-item Parkinson’s Disease Questionnaire (−18.2%, p = 0.031). Our results provide clinical rationale for strictly avoiding the use of trimetazidine in PD. Discontinuation of trimetazidin results in clinically relevant improvements in Parkinsonian symptoms.

Trimetazidine and parkinsonism: A prospective study

BACKGROUND

Although trimetazidine may induce parkinsonian symptoms in some patients, no systematic characterization has been reported on parkinsonism occurring during trimetazidine treatment since the first case reports.

OBJECTIVE

To systematically investigate parkinsonism occurring during trimetazidine use.

METHODS

Thirty-three consecutive patients on trimetazidine treatment with previously unrecognized parkinsonian symptoms were enrolled. Detailed neurological and neuropsychological examinations were performed at baseline and 1 and 12 months after trimetazidine withdrawal. In cases with persisting parkinsonian symptoms and suspected de novo Parkinson's disease, antiparkinsonian treatment was initiated. Twenty of the 33 patients underwent DaTSCAN imaging.

RESULTS

After trimetazidine withdrawal, parkinsonism was completely resolved in 11 cases. The comparison of baseline data of patients with reversible and persisting parkinsonism showed that trimetazidine-induced reversible parkinsonism was mainly characterized by akinesia, rigidity, postural instability and gait disturbances (PIGD; PIGD scores: 5.3 ± 3.8 vs. 2.0 ± 1.6 points, p = 0.006) rather than tremors (tremor scores: 1.5 ± 2.2 vs. 7.7 ± 4.6 points, p = 0.000). Trimetazidine-induced reversible parkinsonism was also more symmetrical (asymmetry index: 3.1 ± 3.6 vs. 40.1 ± 22.2, p = 0.000) and milder in severity (MDS-UPDRS Part III. scores: 10.5 ± 19. vs. 30.5 ± 11.3, p = 0.040) than nonreversible parkinsonism. DaTSCAN images were normal in all trimetazidine-induced reversible parkinsonism patients, while these images were abnormal in every patient with nonreversible parkinsonism. In cases of nonreversible parkinsonism, preexisting, incipient Parkinson's disease was suspected by clinical appearance and a good response to antiparkinsonian medication.

CONCLUSIONS

Mild and symmetrical appearance of parkinsonism with normal DaTSCAN results can indicate drug-induced parkinsonism. Trimetazidine discontinuation generally results in permanent remission in such cases.

Central Beneficial Effects of Trimetazidine on Psychomotor Performance in Normal Healthy Volunteers

Background:

Trimetazidine is a fatty oxidation inhibitor, leading to shifting of energy substrate from fatty acid oxidation toward glucose oxidation that leads to the reduction of oxygen requirement. The aims of the present study were to elucidate the effects of trimetazidine on psychomotor performance and vigilance on normal healthy volunteers.

Materials and Methods:

A total of 234 subjects (age 22–25 years) were recruited in this study. The volunteers were randomizing into two groups with 117 volunteers in each group. Group I received an inert starch capsule served as a control, and Group II received trimetazidine tablet 15 mg/day. The duration of therapy was 5 days. Test procedure was done at 9.00 a.m. on the psychomotor tester. Before the drug administration, prescore values were recorded and then after 5 days of therapy, the postscore values were recorded.

Results:

The placebo did not demonstrate a significant effect on all psychomotor performances and flicker-fusion elements (P > 0.05). Trimetazidine therapy produced a highly significant effect on all components of psychomotor performances and flicker-fusion parameters (P < 0.001) compared with pretreatment era.

Conclusion:

We conclude that trimetazidine improves psychomotor performance and vigilance in normal healthy volunteers through advancing total reaction time and critical flicker-fusion frequency.

Anxiolytic Properties of Trimetazidine in Experimental Models of Increased Anxiety

Effect of trimetazidine (20 and 30 mg/kg) on elevated plus maze behavior of rodents was assessed in the genetic and pharmacological anxiety models. Single intraperitoneal injection of trimetazidine in a dose of 20 mg/kg prevented anxiety development in highly emotional male BALB/c mice and increased the time spent in open arms of the maze. In outbred male rats receiving 10% ethanol solution for 20 weeks, trimetazidine administered intraperitoneally in a dose of 20 mg/kg for 28 days abolished ethanol withdrawal-induced anxiogenesis developed against the background of 4-week alcohol deprivation: it increased the time spent in open arms, the number of entries into open arms, and total locomotor activity in the maze. Anxiolytic properties of trimetazidine were not inferior to those of the non-benzodiazepine anxiolytic Afobazole (fabomotizole) in acute and chronic administration.

The Antipsychotic Effects of Omega-3 Fatty Acids in Rats

BACKGROUND

In humans, omega-3 fatty acids are necessary for cell membranes, brain function and nerve transmission continuation. When animals are exposed to a new environment-or as a result of an apomorphine application that creates an agonistic effect on D1 and D2 receptors-they display behavioral reactions like rearing and stereotypy. This study aims to reveal the possible antipsychotic and oxidative effects of omega-3 fatty acids by comparing with chlorpromazine, a conventional antipsychotic drug, through evaluating the novelty-induced rearing and apomorphine-induced stereotypic behaviors, as well as malondialdehyde and glutathione levels in rats.

METHODS

Twenty-eight, adult, male, Wistar rats were used in the study. Briefly, 4 groups of rats (n = 7) were administered docosahexaenoic acid (DHA) + eicosapentaenoic acid (EPA) (300 mg/kg; DHA: 120 mg/kg + EPA: 180 mg/kg intraperitoneally [IP]), DHA + EPA (150 mg/kg; DHA: 60 mg/kg + EPA: 90 mg/kg IP), chlorpromazine (1 mg/kg, IP) and isotonic saline (1 mL/kg, IP). One hour later, apomorphine (2 mg/kg, subcutaneously) was administered to each rat. After the apomorphine administration, rats were observed for stereotypic behavior.

RESULTS

This study shows that omega-3 fatty acids, "similar to antipsychotics," reversed the psychotic like effects, increase of oxidants and decrease of antioxidants that are composed experimentally in rats.

CONCLUSIONS

The application of omega-3 fatty acids has antipsychotic effects and causes an oxidative imbalance. This study adds new evidence to the current literature regarding the possible antipsychotic effects of omega-3 fatty acids.