{"id":1003,"date":"2024-11-23T08:19:01","date_gmt":"2024-11-23T08:19:01","guid":{"rendered":"https:\/\/one-peptides.com\/product\/semax-50mg\/"},"modified":"2026-10-05T13:49:43","modified_gmt":"2026-10-05T13:49:43","slug":"semax-50mg","status":"publish","type":"product","link":"https:\/\/one-peptides.com\/de\/produkt\/semax-50mg\/","title":{"rendered":"SEMAX 50 mg"},"content":{"rendered":"
\n

Semax 50 mg – chemical reagent | One-Peptides<\/h2>\n

Semax (CAS: 80714-61-0) is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP), classified as a chemical reagent intended for research purposes only (Research Use Only – RUO<\/strong>). This substance is not a medicinal product within the meaning of Art. 2 point 32 of the Pharmaceutical Law, does not constitute a dietary supplement in accordance with the provisions on food and nutrition safety, nor is it subject to the marketing authorization procedure by the Office for Registration of Medicinal Products. Distribution takes place in accordance with Art. 3a of the Pharmaceutical Law – the product is intended for laboratory use, in vitro tests and experiments on animal models conducted by authorized research entities.<\/p>\n

Semax was developed in the 1980s at the Institute of Molecular Genetics of the Russian Academy of Sciences – the same research team that created Selank. However, while Selank is structurally derived from tuftsin (a fragment of immunoglobulin G), Semax is a derivative of a completely different parent molecule: a fragment of ACTH(4-7), i.e. the tetrapeptide sequence Met-Glu-His-Phe cut from the adrenocorticotropic hormone. This different structural origin determines a fundamentally different pharmacodynamic profile – Semax affects primarily neurotrophic pathways, while Selank focuses its activity on the immunomodulatory axis.<\/p>\n

General description<\/h2>\n

In laboratory practice, this reagent is often compared with\u00a0SELANK 10 mg<\/a> and DSIP 5 mg<\/a>to assess differences in action profile across consistent study protocols.<\/p>\n

Semax belongs to the group of synthetic low molecular weight melanocortin peptides. Adrenocorticotropic hormone (ACTH) is a 39-amino acid peptide secreted by the pituitary gland, fragments of which – especially the ACTH(4-10) sequence – have long aroused research interest due to their activity beyond the classic steroidogenic effect. The ACTH(4-7) fragment retains the ability to interact with melanocortin receptors (MC3R, MC4R), but is devoid of the steroidogenic activity typical of full-length ACTH.<\/p>\n

The modification introduced by Russian researchers consisted in extending the C-end of the ACTH(4-7) sequence with the Pro-Gly-Pro tripeptide, which – analogous to the strategy used in Selank – was aimed at increasing the enzymatic resistance of the molecule. The presence of C-terminal proline protects the peptide against degradation by carboxypeptidases, while the internal Gly-Pro bond introduces additional conformational rigidity limiting the access of endopeptidases to sensitive peptide bonds.<\/p>\n

Scientific interest in Semax focuses on its neurotrophic potential – the ability to modulate the expression of nerve growth factors (BDNF, NGF) in neuronal cultures and the effect on the dopaminergic and serotonergic systems in brain tissue preparations.<\/p>\n

\"Semax<\/p>\n

What is Semax?<\/h2>\n

Semax is a synthetic heptapeptide with the molecular formula C37H51N7O10S<\/strong> and molecular weight 813.97 g\/mol<\/strong> (a form of free base). Biochemically, it is a derivative of the ACTH(4-7) fragment, i.e. the Met-Glu-His-Phe sequence, which in the full-length adrenocorticotropic hormone corresponds to positions 4\u20137. This fragment – referred to in the literature as the “melanocortin core” – has biological activity independent of the steroidogenic function of ACTH, which was first described by de Wied in studies on the effects of ACTH fragments on rodent behavior in the 1960s.<\/p>\n

The addition of the tripeptide Pro-Gly-Pro to the C-terminus of ACTH(4-7) creates a seven-element MEHFPGP sequence in which a methionine residue (Met1) with a thioether group provides redox reactivity, a glutamate residue (Glu2) introduces a negative charge at physiological pH, histidine (His3) acts as a proton buffer (imidazole pKa ~6.0), and phenylalanine (Phe4) with the aromatic ring is responsible for hydrophobic interactions with the binding pockets of melanocortin receptors.<\/p>\n

The classification of Semax in the scientific literature places it among neurotrophic peptides – molecules capable of modulating the expression and activity of nerve growth factors. This distinguishes Semax from Selank, which is classified primarily as an immunomodulatory peptide, even though both compounds exhibit some degree of pleiotropicity.<\/p>\n

Structure and physicochemical properties<\/h2>\n

Sequence and characteristics of amino acid residues<\/h3>\n

The Semax peptide chain contains seven amino acid residues connected by peptide bonds in the trans configuration. Unlike Selank, which contains two prolines, Semax has three proline residues (Pro5, Pro7 and a proline in the internal position Gly6-Pro7), which gives the molecule particularly high conformational stiffness. The presence of methionine at the N-terminus introduces a sulfur atom into the structure – this residue can be oxidized to methionine sulfoxide (Met(O)), which is an important degradation factor under storage conditions.<\/p>\n

Stability and degradation<\/h3>\n

Semax lyophilisate is stable at -20 \u00b0C for up to 24 months. The main chemical degradation pathway is the oxidation of the Met1 residue, which is accelerated by exposure to light, increased temperature and the presence of transition metal ions (Cu2+, Fe3+) in the solution. For this reason, after reconstitution, it is recommended to store at 2-8 \u00b0C in an inert gas atmosphere (argon, nitrogen) and use within 14 days.<\/p>\n

The enzymatic stability of Semax – similarly to Selank – is significantly higher than that of the parent molecule. The ACTH(4-7) fragment is rapidly degraded by blood serum aminopeptidases (t1\/2 of the order of minutes), while Semax with the C-terminal tripeptide Pro-Gly-Pro has a half-life several times longer under analogous incubation conditions.<\/p>\n

Solubility<\/h3>\n

Semax dissolves well in distilled water and aqueous buffers (PBS, Tris-HCl) at the working concentrations used in in vitro experiments (1\u2013100 \u00b5M). The presence of hydrophilic (Glu, His) and hydrophobic (Phe, Met) residues gives the molecule an amphiphilic character, which affects its behavior in two-phase systems and interactions with lipid membranes. The isoelectric point (pI) of Semax is approximately 6.7 – a value close to neutral pH – which means that under physiological conditions the molecule exists in a mixture of ionized forms.<\/p>\n

Trading figure<\/h3>\n

One-Peptides Semax 50 mg is supplied as a lyophilized powder in a sterile vial. The increased amount of the substance (50 mg compared to the standard amounts of 5-10 mg) meets the needs of laboratories conducting experiments requiring multiple applications to cell or animal models within one research series.<\/p>\n

Mechanism of action at the molecular level<\/h2>\n

BDNF\/TrkB pathway<\/h3>\n

Brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor TrkB constitute a signaling axis of fundamental importance for the processes of neuroplasticity, neuronal survival and synaptogenesis. In rat cortical neuron cultures, it was shown that exposure to Semax (10 \u00b5M, 24 h) led to a significant increase in the level of BDNF mRNA measured by RT-qPCR and to increased phosphorylation of the TrkB receptor (pTrkB-Y816) in Western blot analysis. TrkB activation triggers MAPK\/ERK and PI3K\/Akt signaling cascades, which in in vitro models correlates with increased survival of neurons subjected to oxidative stress.<\/p>\n

An important difference between Semax and Selank in the context of the BDNF pathway is the strength and consistency of the effect: while both peptides increase the expression of BDNF, Semax additionally modulates the expression of NGF (nerve growth factor) and NT-3 (neurotrophin-3), which suggests a broader neurotrophic profile.<\/p>\n

Modulation of NGF expression<\/h3>\n

Nerve growth factor (NGF) is a neurotrophin that plays a central role in the differentiation and survival of cholinergic neurons. In hippocampal astrocyte cultures from C57BL\/6 mice, exposure to Semax (1\u201310 \u00b5M) led to an increase in NGF secretion into the culture medium, measured by ELISA. This effect was dependent on the activation of the MC4R receptor (melanocortin type 4 receptor), which was confirmed in experiments with the selective antagonist HS024 – preincubation with the antagonist abolished the Semax-induced increase in NGF.<\/p>\n

Interactions with the dopaminergic and serotonergic systems<\/h3>\n

In brain slice preparations of rat brain sections including the nucleus accumbens (nucleus accumbens) and the prefrontal cortex, Semax was shown to modulate the release of dopamine and serotonin in a concentration-dependent manner. In vivo microdialysis in the striatum of Wistar rats showed increased dopamine turnover (increase in DOPAC\/DA and HVA\/DA ratio) after Semax administration. At the same time, modulation of the serotonin transporter (SERT) was observed in synaptosome preparations, suggesting an effect on 5-HT reuptake. These observations indicate potential interactions of Semax with monoaminergic neurotransmission pathways, requiring further characterization.<\/p>\n

Neuroprotection in the oxygen-glucose deprivation (OGD) model<\/h3>\n

The OGD (oxygen-glucose deprivation) model is an established in vitro paradigm for studying neuronal ischemic damage. In cortical neuron cultures subjected to 2-hour oxygen-glucose deprivation followed by 24-hour reperfusion, preincubation with Semax (100 nM) significantly reduced the percentage of cells showing signs of apoptosis (Annexin V\/PI staining, flow cytometry). The neuroprotective effect correlated with activation of the PI3K\/Akt pathway and inhibition of cytochrome c translocation from mitochondria to the cytoplasm, suggesting a mechanism of action at the level of the intrinsic apoptotic pathway.<\/p>\n

Cerebral flow studies – MCAO model<\/h3>\n

In animal models of middle cerebral artery occlusion (MCAO) in Wistar rats, studies were conducted on the effect of Semax on cerebral blood flow and the size of the ischemic focus. Using laser Doppler flowmetry (LDF), modulation of regional cerebral flow in the penumbra was observed after intranasal administration of Semax. The size of the ischemic focus was assessed by TTC (2,3,5-triphenyltetrazolium chloride) staining on brain sections 24 h after reperfusion. These data are preliminary and require confirmation in independent laboratories using blinded evaluation protocols.<\/p>\n

Applications in scientific research<\/h2>\n

In vitro neurotrophic studies<\/h3>\n

Semax is a research tool in experiments related to the regulation of neurotrophin expression. Cultures of cortical neurons, hippocampal astrocytes and mixed glia-neuron cultures exposed to Semax allow for the study of transcriptional mechanisms underlying BDNF and NGF induction. The use of reporter techniques (BDNF promoter-luciferase constructs) allows the identification of promoter regions responsible for the response to the peptide. Knock-down experiments (siRNA against MC4R) allow verification of the involvement of melanocortin receptors in the observed effects.<\/p>\n

Models of central nervous system ischemia<\/h3>\n

The MCAO model in rats and the in vitro OGD model are the main experimental paradigms in which the neuroprotective potential of Semax is investigated. In the animal model, the parameters assessed include: the size of the ischemic focus (TTC staining), neurological deficit (point scales: Bederson, mNSS), cerebral flow (LDF, perfusion MRI) and the expression of apoptosis and inflammation markers in the brain tissue (immunohistochemistry, Western blot).<\/p>\n

Studies on monoaminergic interactions<\/h3>\n

In vivo microdialysis combined with HPLC with electrochemical detection (HPLC-ED) allows for the measurement of the concentrations of monoamine neurotransmitters (dopamine, serotonin, norepinephrine) and their metabolites in selected brain structures after Semax administration. These studies are conducted on Wistar rats with microdialysis probes implanted in the striatum, prefrontal cortex or nucleus accumbens. The results provide data on the effect of the peptide on monoamine turnover, which is a starting point for further receptor analyses.<\/p>\n

Comparative analysis of ACTH-derived peptides<\/h3>\n

Semax, as one of the best characterized analogues of the ACTH(4-7) fragment, serves as a reference molecule in comparative studies of other modifications of this motif. Comparisons include Semax vs. ACTH(4-10), Semax vs. ORG 2766 (another synthetic ACTH analogue) and Semax vs. N-acetyl-Semax, which allows for the analysis of structure-activity relationships (SAR) within the melanocortin peptide family.<\/p>\n

Summary<\/h2>\n

Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide derived from the ACTH(4-7) fragment, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. Its pharmacodynamic profile distinguishes it from the “sister” Selank peptide – while Selank focuses its activity on the immunomodulatory axis (a derivative of tuftsin), Semax exhibits primarily neurotrophic properties: modulation of BDNF and NGF expression, interactions with the dopaminergic and serotonergic systems, and a neuroprotective effect in models of oxygen-glucose deprivation. These data come from in vitro studies and experiments on animal models (Wistar rats, C57BL\/6 mice).<\/p>\n

The One-Peptides Semax 50 mg product is a RUO class chemical reagent intended only for laboratory use. All experiments using this substance should be conducted by qualified research personnel, in compliance with applicable safety procedures and ethical standards regarding animal research.<\/p>\n