Pharmacokinetics of aniracetam and its metabolites in rat brain

Aniracetam does not improve working memory in neurologically healthy pigeons

Understanding the effects of cognitive enhancing drugs is an important area of research. Much of the research, however, has focused on restoring memory following some sort of disruption to the brain, such as damage or injections of scopolamine. Aniracetam is a positive AMPA-receptor modulator that has shown promise for improving memory under conditions when the brain has been damaged, but its effectiveness in improving memory in neurologically healthy subjects is unclear. The aim of the present study was to examine the effects of aniracetam (100mg/kg and 200 mg/kg) on short-term memory in "neurologically healthy" pigeons. Pigeons were administered aniracetam via either intramuscular injection or orally, either 30 or 60 minutes prior to testing on a delayed matching-to-sample task. Aniracetam had no effect on the pigeons' memory performance, nor did it affect response latency. These findings add to the growing evidence that, while effective at improving memory function in models of impaired memory, aniracetam has no effect in improving memory in healthy organisms.

Oral aniracetam treatment in C57BL/6J mice without pre-existing cognitive dysfunction reveals no changes in learning, memory, anxiety or stereotypy

Background: The piracetam analog, aniracetam, has recently received attention for its cognition enhancing potential, with minimal reported side effects.  Previous studies report the drug to be effective in both human and non-human models with pre-existing cognitive dysfunction, but few studies have evaluated its efficacy in healthy subjects. A previous study performed in our laboratory found no cognitive enhancing effects of oral aniracetam administration 1-hour prior to behavioral testing in naïve C57BL/6J mice. Methods: The current study aims to further evaluate this drug by administration of aniracetam 30 minutes prior to testing in order to optimize any cognitive enhancing effects. In this study, all naïve C57BL/6J mice were tested in tasks of delayed fear conditioning, novel object recognition, rotarod, open field, elevated plus maze, and marble burying. Results: Across all tasks, animals in the treatment group failed to show enhanced learning when compared to controls. Conclusions: These results provide further evidence suggesting that aniracetam conveys no therapeutic benefit to subjects without pre-existing cognitive dysfunction.

Oral aniracetam treatment in C57BL/6J mice without pre-existing cognitive dysfunction reveals no changes in learning, memory, anxiety or stereotypy

Background: The piracetam analog, aniracetam, has recently received attention for its cognition enhancing potential, with minimal reported side effects.  Previous studies report the drug to be effective in both human and non-human models with pre-existing cognitive dysfunction, but few studies have evaluated its efficacy in healthy subjects. A previous study performed in our laboratory found no cognitive enhancing effects of oral aniracetam administration 1-hour prior to behavioral testing in naïve C57BL/6J mice. Methods: The current study aims to further evaluate this drug by administration of aniracetam 30 minutes prior to testing in order to optimize any cognitive enhancing effects. In this study, all naïve C57BL/6J mice were tested in tasks of delayed fear conditioning, novel object recognition, rotarod, open field, elevated plus maze, and marble burying. Results: Across all tasks, animals in the treatment group failed to show enhanced learning when compared to controls. Conclusions: These results provide further evidence suggesting that aniracetam conveys no therapeutic benefit to subjects without pre-existing cognitive dysfunction.

Study of oral aniracetam in C57BL/6J mice without pre-existing cognitive impairments

BACKGROUND

The piracetam analog, aniracetam, has recently received attention for its cognition enhancing potential, with minimal reported side effects.  Previous studies report the drug to be effective in both human and non-human models with pre-existing cognitive dysfunction, but few studies have evaluated its efficacy in healthy subjects. A previous study performed in our laboratory found no cognitive enhancing effects of oral aniracetam administration 1-hour prior to behavioral testing in naïve C57BL/6J mice.

METHODS

The current study aims to further evaluate this drug by administration of aniracetam 30 minutes prior to testing in order to optimize any cognitive enhancing effects. In this study, all naïve C57BL/6J mice were tested in tasks of delayed fear conditioning, novel object recognition, rotarod, open field, elevated plus maze, and marble burying.

RESULTS

Across all tasks, animals in the treatment group failed to show enhanced learning when compared to controls.

CONCLUSIONS

These results provide further evidence suggesting that aniracetam conveys no therapeutic benefit to subjects without pre-existing cognitive dysfunction.

Development and validation of a liquid chromatographic method for the simultaneous determination of aniracetam and its related substances in the bulk drug and a tablet formulation

Simultaneous determination of aniracetam and its related impurities (2-pyrrolidinone, p-anisic acid, 4-p-anisamidobutyric acid and (p-anisoyl)-4-methyl-2-pyrrolidinone) was accomplished in the bulk drug and in a tablet formulation using a high performance liquid chromatographic method with UV detection. Separation was achieved on a Hypersil BDS-CN column (150 mm × 4.0 mm, 5 μm) using a gradient elution program with solvent A composed of phosphate buffer (pH 4.0; 0.010 M) and solvent B of acetonitrile-phosphate buffer (pH 4.0; 0.010 M) (90:10, v/v). The flow rate of the mobile phase was 1.0 mL min(-1) and the total elution time, including the column re-equilibration, was approximately 20 min. The UV detection wavelength was varied appropriately among 210, 250 and 280 nm. Injection volume was 20 μL and experiments were conducted at ambient temperature. The developed method was validated in terms of system suitability, selectivity, linearity, range, precision, accuracy, limits of detection and quantification for the impurities, short term and long term stability of the analytes in the prepared solutions and robustness, following the ICH guidelines. Therefore, the proposed method was suitable for the simultaneous determination of aniracetam and its studied related impurities.

Content determination of aniracetam in aniracetam inclusion complex by HPLC

We established a HPLC method for content determination of aniracetam in aniracetam inclusion complex. The chromato column was Agilent ODS (4.6mm x 150mm, 5 microm), the mobile phase was methanol-0.01 mol/L Potassium dihydrogen phosphate buffer solution (25:75, pH 3.0), with the flow rate of 1.0 ml/min, column temperature of 30 degrees and the detection wave at 280 nm, the sample size was 20microL. A good linear relationship was obtained between the peak areas and the concentrations of aniracetam in the range from 5- 80microg/ml (r=0.9998), the mean recovery was 100.1% (n=15), RSD=0.19%. This method is convenient, rapid, accurate, and brings about good recovery; it can be used for content determination of aniracetam in aniracetam inclusion complex.

Aniracetam: its novel therapeutic potential in cerebral dysfunctional disorders based on recent pharmacological discoveries

Aniracetam is a pyrrolidinone-type cognition enhancer that has been clinically used in the treatment of behavioral and psychological symptoms of dementia following stroke and in Alzheimer's disease. New discoveries in the behavioral pharmacology, biochemistry and pharmacokinetics of aniracetam provided new indications for this drug in the treatment of various CNS disorders or disease states. This article reviews these new findings and describes the effects of aniracetam in various rodent models of mental function impairment or cerebral dysfunction. Also, several metabolites of aniracetam have been reported to affect learning and memory in animals. It is, therefore, conceivable that major metabolites of aniracetam contribute to its pharmacological effects. The animal models, used in pharmacological evaluation of aniracetam included models of hypoattention, hypovigilance-arousal, impulsiveness, hyperactivity, fear and anxiety, depression, impaired rapid-eye movement sleep, disturbed temporal regulation, behavioral performance, and bladder hyperactivity. These are models of clinical disorders or symptoms that may include personality disorders, anxiety, depression, posttraumatic stress disorder, attention-deficit/hyperactivity disorder, autism, negative symptoms of schizophrenia, and sleep disorders. At present, there is no convincing evidence that promising effects of aniracetam in the animal models will guarantee its clinical efficacy. It is conceivable, however, that clinical trials will demonstrate beneficial effects of aniracetam in the above listed disease states. New findings regarding the mechanism of action of aniracetam, its central target sites, and its effects on signal transduction are also discussed in this review article.

Pyrrolidone derivatives

The pyrrolidone (2-oxopyrrolidine) family of chemicals has been the subject of research for more than three decades. Experimental and clinical work first focused on their so-called nootropic effects; later came the possibilities for neuroprotection after stroke and use as antiepileptic agents. Piracetam, the first of the class, was developed by pioneering research by C Giurgea in the late 1960s, and it was he who coined the term "nootropic", to mean enhancement of learning and memory. The term is sometimes extended to include other actions such as neuroprotection. These properties, together with the lack of other generally adverse psychopharmacological actions (eg, sedation, analgesia, or motor or behavioural changes), distinguish the pyrrolidones from other psychoactive drug classes. The mechanisms of action of these drugs are still not fully established; indeed, different compounds in this class may have different modes of action. Interest in this drug class has recently been reawakened by the licensing of levetiracetam as a potentially major new antiepileptic drug and of piracetam for its antimyoclonic action and effects after stroke and in mild cognitive impairment. Other drugs in this class are currently at an advanced stage of development, and the renewal of interest in this therapeutic area is likely to mean not only that more pyrrolidones will enter clinical practice in the next few years but also that the clinical indications of drugs already licensed will widen.

Aniracetam enhances cortical dopamine and serotonin release via cholinergic and glutamatergic mechanisms in SHRSP

Aniracetam, a cognition enhancer, has been recently found to preferentially increase extracellular levels of dopamine (DA) and serotonin (5-HT) in the prefrontal cortex (PFC), basolateral amygdala and dorsal hippocampus of the mesocorticolimbic system in stroke-prone spontaneously hypertensive rats. In the present study, we aimed to identify actually active substances among aniracetam and its major metabolites and to clarify the mode of action in DA and 5-HT release in the PFC. Local perfusion of mecamylamine, a nicotinic acetylcholine (nACh) and N-methyl-D-aspartate (NMDA) receptor antagonist, into the ventral tegmental area (VTA) and dorsal raphe nucleus (DRN) completely blocked DA and 5-HT release, respectively, in the PFC elicited by orally administered aniracetam. The effects of aniracetam were mimicked by local perfusion of N-anisoyl-gamma-aminobutyric acid [corrected] (N-anisoyl-GABA), one of the major metabolites of aniracetam, into the VTA and DRN. The cortical DA release induced by N-anisoyl-GABA applied to the VTA was also completely abolished by co-perfusion of mecamylamine. Additionally, when p-anisic acid, another metabolite of aniracetam, and N-anisoyl-GABA were locally perfused into the PFC, they induced DA and 5-HT release in the same region, respectively. These results indicate that aniracetam enhances DA and 5-HT release by mainly mediating the action of N-anisoyl-GABA that targets not only somatodendritic nACh and NMDA receptors but also presynaptic nACh receptors.