Selank

About Selank

Selank is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences.

It is based on tuftsin (Thr-Lys-Pro-Arg), a fragment of immunoglobulin G with immunomodulatory activity, to which the Pro-Gly-Pro sequence was added to increase its stability. It has been studied for its anxiolytic activity and its effects on the expression of genes related to neurotransmission and inflammation. It is registered in Russia as an intranasal anxiolytic.

Quick guide · 5 key points

Selank and anxiety research

Selank is a synthetic heptapeptide derived from tuftsin, studied mainly for its anti-anxiety activity. Here are five things the research shows.

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1
A tuftsin analogue that acts on the GABA system
Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic analogue of tuftsin, an immunomodulatory peptide. In brain membranes it has been shown to act as a positive allosteric modulator of GABA binding. In the frontal cortex of rats, it was associated with changes in the expression of neurotransmission genes.^1,2,3

GABAThe system Selank modulates allosterically in lab studies
2
Anti-anxiety effect similar to a benzodiazepine
In 62 patients with generalized anxiety disorder and neurasthenia, Selank (30 patients) showed an anti-anxiety effect similar to medazepam (32 patients), with additional anti-asthenic (anti-fatigue) and psychostimulant effects.⁴

62patients in the comparison with medazepam
3
Compared and combined with phenazepam
In 60 patients with anxiety disorders, Selank was associated with a marked anti-anxiety effect that lasted a week after the last dose. In another study of 70 patients, adding it to phenazepam was associated with fewer side effects from the benzodiazepine.^5,6

1 weekof anti-anxiety effect after the last dose in that study
4
Enkephalins and immunity
In vitro, Selank has been shown to inhibit the human serum enzymes that break down enkephalins (IC50 20 µM). In anxiety patients who received it for 14 days, shifts in the Th1/Th2 cytokine balance were observed.^7,8

20 µMSelank's IC50 against enkephalin-degrading enzymes
5
Limited evidence outside Russia
Published clinical studies are small (60–70 patients) and come from Russia. A 2021 U.S. review described Selank as poorly studied. In plasma, the peptide is broken down into shorter fragments.^4,5,6,9,10

References

Slominsky PA, et al. Peptides semax and selank affect the behavior of rats with 6-OHDA induced PD-like parkinsonism. Dokl Biol Sci. 2017;474(1):106-109. PMID 28702721
Vyunova TV, et al. Peptide-based anxiolytics: the molecular aspects of heptapeptide Selank biological activity. Protein Pept Lett. 2018;25(10):914-923. PMID 30255741
Volkova A, et al. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Front Pharmacol. 2016;7:31. PMID 26924987
Zozulia AA, et al. Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(4):38-48. PMID 18454096
Medvedev VE, et al. A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2014;114(7):17-22. PMID 25176261
Medvedev VE, et al. Optimization of the treatment of anxiety disorders with selank. Zh Nevrol Psikhiatr Im S S Korsakova. 2015;115(6):33-40. PMID 26356395
Kost NV, et al. Semax and selank inhibit the enkephalin-degrading enzymes from human serum. Bioorg Khim. 2001;27(3):180-3. PMID 11443939
Uchakina ON, et al. Immunomodulatory effects of selank in patients with anxiety-asthenic disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(5):71-5. PMID 18577961
Doyno CR, White CM. Sedative-hypnotic agents that impact gamma-aminobutyric acid receptors: focus on flunitrazepam, gamma-hydroxybutyric acid, phenibut, and selank. J Clin Pharmacol. 2021;61 Suppl 2:S114-S128. PMID 34396551
Zolotarev IuA, et al. Evenly tritium-labeled peptides and their in vivo and in vitro biodegradation. Bioorg Khim. 2006;32(2):183-91. PMID 16637290

Structure and sequence

2D structure generated from PubChem CID 11765600

Sequence

ThrLysProArgProGlyPro (TKPRPGP)

Five findings from studies

Summary of results reported in the scientific literature. Each finding describes what was observed in the cited study, in its specific population and conditions; it does not constitute a therapeutic indication.

Clinical study
In 62 patients with generalized anxiety disorder and neurasthenia, Selank has shown an anxiolytic effect similar to that of medazepam, with additional antiasthenic and psychostimulant effects.
Zozulia AA et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108:38-48 · PMID 18454096
Preclinical
In studies in rat frontal cortex, Selank has been associated with changes in the expression of genes involved in GABAergic neurotransmission.
Volkova A et al. Front Pharmacol. 2016;7:31 · PMID 26924987
Preclinical
In rats subjected to chronic unpredictable mild stress, Selank has reduced anxiety indicators and has potentiated the anxiolytic effect of diazepam.
Kasian A et al. Behav Neurol. 2017;2017:5091027 · PMID 28280289
Clinical study
In patients with generalized anxiety disorder and neurasthenia treated for 14 days, Selank has been associated with changes in the serum Th1/Th2 cytokine balance; in vitro, it altered IL-6 expression in patients' blood cells.
Uchakina ON et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108:71-75 · PMID 18577961
In vitro
In in vitro studies, Selank has been observed to inhibit, in a dose-dependent manner, the human serum enzymes that degrade enkephalins.
Kost NV et al. Bioorg Khim. 2001;27:180-183 · PMID 11443939