Scientific Reference
Semax
Evidence profile: Predominantly preclinical
Semax is a seven-residue synthetic peptide, Met-Glu-His-Phe-Pro-Gly-Pro, derived from a short piece of adrenocorticotropic hormone (ACTH). Its first four residues correspond to positions 4 to 7 of ACTH, while the Pro-Gly-Pro tail has no counterpart there and is reported to slow breakdown by peptidases. Short ACTH fragments like this are described as lacking the steroid-releasing action of the full hormone. Semax was developed in Russia, and most of what has been published comes from Russian groups using rats and cell cultures. Controlled human studies are few, many appear only in Russian, and independent replication elsewhere is limited.
Mechanism of Action
No specific receptor for Semax has been identified. Rat studies have reported increased hippocampal expression of brain-derived neurotrophic factor (BDNF) and its receptor TrkB, and other work has examined dopamine and serotonin turnover in the striatum. Transcriptome studies in rat models of cerebral ischaemia describe changes in genes linked to immune and vascular processes. Because its core derives from ACTH, an interaction with melanocortin receptors has been proposed, but direct binding evidence is limited. How these separate observations fit together has not been worked out.
Molecular Information
- Type: Synthetic ACTH analog (heptapeptide)
- Molecular weight: 813.9 g/mol
- Molecular formula: C37H51N9O10S
- CAS: 80714-61-0