Selank

Selank (TKPRPGP) is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences as an analog of the endogenous immunopeptide tuftsin (Thr-Lys-Pro-Arg). The additional Pro-Gly-Pro extension confers metabolic stability, resistance to peptidase degradation, and a significantly longer half-life than the parent molecule. Selank's primary anxiolytic mechanism involves inhibition of enkephalin-degrading enzymes (enkephalinases), prolonging the synaptic availability of endogenous enkephalins and enhancing opioidergic tone. Biochemical studies demonstrate dose-dependent inhibition of enkephalin hydrolysis with an IC50 of approximately 15 μM, exceeding the potency of conventional peptidase inhibitors. Selank also modulates GABAergic neurotransmission by enhancing GABA-A receptor sensitivity and increasing chloride ion influx, producing anxiolytic effects comparable to benzodiazepines but without sedation, tolerance development, or physical dependence. Additionally, Selank upregulates brain-derived neurotrophic factor (BDNF) expression in the hippocampus and prefrontal cortex, contributing to its nootropic effects on memory consolidation, learning, and synaptic plasticity. Metabolomic studies show normalization of monoamine neurotransmitter ratios (serotonin, dopamine, norepinephrine) in stress models. Clinical research in Russia and Ukraine has investigated Selank for generalized anxiety disorder, phobias, and stress-related cognitive impairment, demonstrating anxiolytic and attention-enhancing effects without the sedative side effects of traditional anxiolytics. Research applications include anxiety neurobiology, cognitive enhancement, BDNF-mediated neuroprotection, and peptide-based neuropsychiatric therapeutics. Selank is administered intranasally in research settings, achieving rapid CNS delivery.