Selank: The Tuftsin-Derived Peptide for GABAergic and Immune Regulation
Selank is a synthetic heptapeptide that acts as a mild anxiolytic, cognitive enhancer, and immune modulator.49
Structural Parameters of Selank
| Property | Value and Specification | References |
|---|---|---|
| CAS Number | 129954-34-3 | 52 |
| Molecular Formula | C33H57N11O9 | 52 |
| Molecular Weight | 751.87 g/mol | 52 |
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-P ro (Tuftsin-PGP) | 49 |
| Mode of Action | Indirect GABAA receptor modulator | 49 |
Origin, History, and Research Stage
Selank was developed in the 1990s by the Institute of Molecular Genetics of the Russian Academy of Sciences in collaboration with the V.V. Zakusov Institute of Pharmacology . Researchers sought to stabilize tuftsin, an endogenous immunomodulatory peptide, to create an effective neuropsychiatric treatment.49 Selank was approved in Russia in the late 2000s for the treatment of Generalized Anxiety Disorder (GAD) and asthenic conditions . It has been utilized in clinical settings across Eastern Europe, though it is not approved by the US FDA or EMA.55
Mechanism of Action and Pharmacokinetics
Selank is a heptapeptide containing the sequence of the human tetrapeptide tuftsin (Thr-Lys-Pro-Arg), stabilized at its C-terminus by the addition of three amino acids (Pro-Gly-Pro).49 This PGP sequence prevents enzymatic degradation, extending its half-life in human plasma.49 Unlike benzodiazepines, Selank does not bind directly to the benzodiazepine site of the receptor.49 Instead, it upregulates the mRNA expression of the alpha2, alpha3, and gamma2 subunits of the GABAA receptor in the hippocampus . This indirect modulation restores inhibitory tone under stress.49 Additionally, Selank inhibits enkephalin-degrading enzymes, such as aminopeptidase N (APN) and dipeptidyl peptidase IV (DPP-IV), raising plasma levels of endogenous enkephalins.49 It also balances monoamines (serotonin and dopamine) and suppresses the elevated interleukin-6 (IL-6) gene expression observed in patients with anxiety.49
Scientific and Clinical Effects
In clinical trials, intranasal Selank (400 mcg, 3x daily) reduced scores on the Hamilton Anxiety Scale (HAM-A) by day 7 without causing sedation, memory impairment, or physical dependence.49 It acts as a stress-protector, neutralizing stress-induced BDNF depletion.49 Furthermore, due to its tuftsin lineage, Selank enhances immune resilience by stimulating phagocytosis, NK cell activity, and IFN-gamma expression.49
