Cognitive enhancer (Nootropic) that potentiates AMPA receptor mediated ion conductance and potentiates mGluR activity; also demonstrates anxiolytic activity.
Biochemical Activity
In rats, post administration plasma levels have been determined by HPLC method. Aniracetam has an overall bioavailability of around 8.6-11.4%, when taken up by the gut. In human studies, plasma levels of Aniracetam were determined using sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Cmax was found to be 8.75+/-7.82 and 8.65+/-8.7ng/mL over two testing periods, with corresponding Tmax times of 0.4+/-0.1 hour.
Human studies have shown the key metabolite to be N-Anisoyl-GABA (4,p-Anisaminobutyric acid, ABA), with roughly 70% of ingested Aniracetam being transformed into ABA through the liver. Alternate metabolites include P-Anisic Acid and 2-pyrrolidinone.
Aniracetam is a potent agonist for AMPA receptors in the glutaminergic system. At a concentration range of 1-5mM, Aniracetam binds to AMPA receptors and potentiates receptor activity, especially in the presence of positive stimuli (as indicated in Xenopus oocytes and in human hippocampus pyramidal cells). Tang et al. showed that Aniracetam reversibly and selectively slows the desensitization kinetics of non-NMDA receptors while simultaneously modulating fast EPSC.
Further studies have shown that Aniracetam increases peak amplitude of EPSCs, as well as the amplitude and duration of signals from IPSCs, resulting in a decrease in ESPC/ISPC charge ratio and representing a shift in the excitation-inhibition balance, towards inhibition. D Ling and L Bernardo have postulated that this may be due to Aniracetam’s additional modulation of the GABAergic system.
Studies on hippocampal cells have shown that 100mM of Aniracetam is capable of improving norepinephrine release from NMDA receptors. To further illustrate the point, Pittaluga et al. showed that Aniracetam reduces kynurenic acid antagonism of norepinephrine release by NMDA receptors, as well as modulating the inhibitory effects of the AMDA antagonist NBQX.
At an extremely low concentration of 0.1 nM, Aniracetam is capable of potentiating nicotinic α4β2 receptor transmission by 200-300%, through coupling mechanisms with G(s) proteins. Since Aniracetam acts on AMPA receptors, it can be consider an Ampakine. Studies have shown that these kinds of compounds (including Piracetam and Oxiracetam) also have the ability to upregulate Brain-derived Neurotrophic factor (BDNF) expression, for extended periods that exceed the AUC of the Ampakine.