Oxiracetam is nootropic agent of the racetam family, a cyclic derivative of γ-aminobutyric acid (GABA) the chief inhibitory neurotransmitter in mammals. It has been shown to improve memory and learning in mouse models. In pharma, it is used as a racemic mixture of (S)-oxiracetam and (R)-oxiracetam, the pharmacological activity is mainly associated with one enantiomer, (S)-oxiracetam. Oxiracetam is slightly soluble in water and DMSO but is practically insoluble in ethanol.
|Mechanism of Action||The mechanism of action of Oxirectam is not yet known, but it may modulate glutamatergic neurotransmission. In mice, it interacts with the glutamatergic NMDA receptor system, forestalling the impairment of retrieval of long-term memory.|
|Eukaryotic Cell Culture Applications||Oxiracetam enhanced α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA)‐stimulated 45Ca2+ influx in primary cultures of cerebellar granule cells. The nootropic agent increased the maximal density of the specific binding sites for [3H]AMPA in synaptic membranes from rat cerebral cortex. Results support the view that Oxiracetam and other nootropic agents act as positive modulators of AMPA‐sensitive glutamate receptors in neurons (Copani et al, 1992).
In the two-vessel occlusion model, a rat model of chronic cerebral hypoperfusion (2-VO), researchers found that it was (S)-Oxiracetam that alleviated impairments in learning and memory. It is thought that vascular dementia is associated with chronic cerebral hypoperfusion. (S)-Oxiracetam caused a reduction in the abnormal accumulation of glucose and citric acid in the brain and increased ATP metabolism. A novel finding was that it induced the Glutamate-glutamine cycle, malate-aspartate shuttle, and pool of antioxidants and maintained homeostasis of Na+ and K+ in the rat cortex (Li et al, 2017).
Copani A et al (1992) Nootropic drugs positively modulate alpha‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid‐sensitive glutamate receptors in neuronal cultures. J. Neurochem. 58(4):1199-1204 PMID 1372342
Fordyce DE, Clark VJ, Paylor R, Wehner JM. Enhancement of hippocampally-mediated learning and protein kinase C activity by Oxiracetam in learning-impaired DBA/2 mice. Brain Res. 1995;672(1-2):170‐176
Li W et al (2017) (S)-Oxiracetam is the active ingredient in Oxiracetam that alleviates the cognitive impairment induced by chronic cerebral hypoperfusion in rats. Sci. Rep. 7(1):10052 PMID 28855592