Black Seed OilvsL-Theanine

Thymoquinone is the primary bioactive, providing neuroprotection through multiple mechanisms: it scavenges reactive oxygen species (superoxide, hydroxyl radical, peroxynitrite) and upregulates Nrf2/ARE pathway, increasing glutathione (via GCLC, GSS), superoxide dismutase (SOD1/SOD2), and catalase. It inhibits NF-kB by preventing IkB-alpha degradation and blocking p65 nuclear translocation, reducing neuroinflammation and pro-inflammatory cytokine release. Thymoquinone inhibits acetylcholinesterase (AChE) at the peripheral anionic site, increasing synaptic acetylcholine. It modulates GABA-A receptors (positive allosteric modulation at benzodiazepine site), providing anxiolytic effects. Thymoquinone protects neurons from amyloid-beta toxicity by reducing oxidative stress and inhibiting beta-secretase (BACE1). It reduces tau hyperphosphorylation by inhibiting GSK-3beta and CDK5.

L-Theanine (gamma-glutamylethylamide) crosses the blood-brain barrier via the large neutral amino acid transporter (LAT1/SLC7A5) and exerts anxiolytic effects through multiple pathways. It increases GABA synthesis by serving as a substrate for glutamate decarboxylase (GAD), elevating inhibitory tone without directly binding GABA-A receptors — avoiding sedation. It modulates serotonin by increasing tryptophan hydroxylase (TPH2) activity and raises dopamine levels in the prefrontal cortex via inhibition of dopamine reuptake. L-Theanine antagonizes glutamate binding at AMPA and kainate receptor subtypes (GluA1-4, GluK1-5), reducing excitatory neurotransmission and excitotoxicity risk. This glutamate antagonism, combined with increased GABA, drives the characteristic increase in alpha brain wave power (8-14 Hz) in the posterior parietal and occipital cortex — the EEG signature of relaxed alertness. When co-administered with caffeine, L-theanine attenuates caffeine-induced increases in blood pressure and anxiety by modulating sympathetic nervous system activation through alpha-2 adrenergic receptor pathways, while caffeine's dopaminergic and adenosine-blocking effects on focus and attention are preserved.