Semax is a synthetic peptide — a short chain of amino acids — made from a piece of ACTH, a hormone your body releases under stress, with a small added tail that helps it survive longer in the body. It has been sold as a prescription nasal-drop medicine in Russia since the 1990s, mainly to help people recover after an ischemic stroke, and it's also used off-label there as a so-called 'nootropic' for focus and memory. Most of what's known about how it actually works comes from rat and lab research; the human evidence is real but comes from a handful of small studies, not the large randomized trials used to approve drugs in the US or Europe.
How strong is the evidence?
About 40 papers were gathered for this review, but a handful are off-target hits that only mention 'Semax' — or the unrelated statistics term 'Emax' — in passing rather than studying the peptide. Among the genuine Semax studies, only 3 involved real people, and none were large randomized drug trials in the Western sense: one Russian study followed 110 stroke patients using Semax alongside standard rehab, and two studied brain-scan changes in a combined 76 healthy volunteers. The remaining studies are animal research (mostly rats and mice, largely from a small number of Russian labs studying stroke and brain injury), chemistry-lab experiments on how Semax binds copper and zinc, and general review articles. That means the core biology is well mapped in rodents and cells, but confirmation in people is still early and thin.
Uses
What people use it for
Stroke recovery support
Some human dataIn Russia, Semax nasal drops are used alongside standard rehabilitation after an ischemic stroke, with the goal of helping people regain movement and daily function faster.
Nootropic for focus, memory, and stress resilience
Some human dataOutside the clinic, people use it off-label as a 'smart drug.' This use is built mostly on rat memory experiments and a couple of brain-scan studies in healthy volunteers that showed changed activity in networks tied to attention and emotion — not on measured improvements in real-world focus or memory in people.
Early-stage research into other brain conditions
Animal / labLab and animal studies are exploring Semax for spinal cord injury recovery and as a possible protective agent against the kind of brain changes seen in Alzheimer's disease, but none of this has reached human testing yet.
Potential benefits
What it may help with
May speed recovery after a stroke
Some human dataIn a study of 110 stroke patients, those given Semax alongside rehab had higher blood levels of BDNF (a protein the brain uses to repair and rewire itself) and better scores for movement and daily function than expected from rehab timing alone.
Studies:29798983Raises BDNF and NGF, the brain's own repair chemicals
TheoryIn rats, a single nasal dose of Semax increased BDNF in brain regions tied to memory within a few hours, and NGF and BDNF gene activity rose in the hippocampus. The human stroke study above saw a similar rise in BDNF in blood, but the mechanism itself is mapped mainly in rodents.
Calms brain inflammation after injury, in animal studies
Animal / labIn rat stroke models, Semax repeatedly turned down a cluster of inflammation genes that normally spike after a stroke, while turning up genes involved in healthy nerve signaling. This pattern showed up across multiple independent experiments from the same group.
Changes brain activity patterns linked to focus and emotion
Some human dataBrain scans of healthy volunteers showed that a nasal dose of Semax altered the brain's resting 'default mode network' and shifted connections between the amygdala (the brain's threat-detection center) and areas involved in processing emotion, within 20 minutes.
Protects memory from toxins and stress, in animal and lab studies
Animal / labIn rats, Semax blocked the memory-impairing effects of heavy metals and improved learning speed on a maze task. In lab dishes, it also helped a type of brain cell (cholinergic neurons, the kind lost in Alzheimer's) survive longer.
Early lab interest for Alzheimer's-related brain buildup
Animal / labIn test-tube experiments, Semax grabbed onto copper in a way that reduced toxic buildup and clumping of amyloid-beta, the protein linked to Alzheimer's disease. This is chemistry-lab evidence only — nobody has tested whether it slows Alzheimer's in animals or people.
What to watch for
Side effects & risks
- Moderate
Long-term safety hasn't been studied
Every study in this file lasted days to a few weeks at most. Nobody has published data on what happens with months or years of regular use.
- Moderate
Not tested in pregnancy, children, or alongside other drugs
None of the human studies included pregnant people or children, and none tested Semax combined with other medications or supplements. There's simply no safety data for those situations.
- Mild
Nasal irritation is plausible but not actually documented
Because Semax is given as nasal drops, mild nose or throat irritation is a reasonable everyday concern, but none of the studies reviewed here actually tracked or reported side effects at all — so this is a guess based on the delivery method, not a finding.
Dosing
Dosing — what studies used
There's no dose approved for use outside Russia, and even the Russian literature mostly describes research protocols rather than one fixed prescription. The single real human dosing schedule in this file comes from a stroke-rehab study: 6,000 micrograms (6 mg) per day, given intranasally, for 10 days, repeated as a second 10-day course after a 20-day break. Two other human studies used a 1% Semax nasal solution as a single one-time dose to look at brain-scan changes, but didn't report the exact microgram amount. Everything else — the detailed dose-response work — comes from rats and mice, and those doses don't translate directly to a safe human amount.
Post-stroke rehabilitation
Human trial6,000 mcg (6 mg) per day
Once daily (6,000 mcg/day total) · 10 days, then a second 10-day course after a 20-day break · Intranasal
The only full human dosing regimen reported in this literature. The paper doesn't restate the delivery route, but intranasal is the standard method used for Semax in every other human study reviewed here.
Brain-scan (fMRI/connectivity) studies in healthy adults
Human trial1% Semax solution; exact microgram dose not stated in the abstracts
Single one-time dose · Brain effects measured 5 and 20 minutes after dosing · Intranasal
Used to study brain-network changes, not a treatment protocol.
Rat neuroprotection and memory research
Animal studyRoughly 50 to 250 micrograms per kilogram of body weight
Single dose or a short daily course, depending on the study · Hours to a few weeks · Intranasal or intraperitoneal, depending on the study
Animal research doses only. These are not a guide for human use and don't scale directly to a human dose.
Not reported in the studies reviewed. Dosing above reflects what was studied, not a recommendation — Semax is unregulated outside Russia, so anyone considering it should get medical guidance first.
These figures describe what researchers used in studies. They are not a recommendation or a prescription.
Mechanism
How it works
Semax is a small piece of ACTH, a hormone your body makes during stress, with an extra three-amino-acid tail stitched on so it lasts longer before breaking down. Unlike full ACTH, it doesn't trigger your adrenal glands or raise cortisol — its effects are mostly in the brain. In animal studies, it boosts BDNF and NGF, two natural 'brain fertilizer' chemicals that help nerve cells survive and form new connections, and it turns down inflammation genes that flare up after a stroke while turning up genes involved in normal brain-cell communication. It also nudges the brain's serotonin and dopamine messenger systems and affects GABA, a calming brain chemical. Separately, in test-tube chemistry experiments, it binds tightly to copper, which is why some researchers are studying whether it can interfere with the toxic copper-amyloid clumps involved in Alzheimer's disease.
Who should avoid it
- Pregnant or breastfeeding people — no human studies included this group.
- Children — none of the studies enrolled children.
- Anyone using it as a substitute for regulated stroke or psychiatric treatment outside Russia — it isn't an approved medicine in the US, UK, EU, Canada, or Australia.
- Anyone with a hormone-sensitive condition — Semax comes from a stress-hormone fragment and affects immune-gene activity in animal studies, and this population hasn't been studied.
Interactions to know
- No published studies test Semax alongside prescription medications, supplements, or other peptides in people, so interactions are largely unknown.
- In one rat study, Semax made the stimulant amphetamine's effects on dopamine release and movement much stronger, which hints it could amplify other stimulants or nootropics — but this hasn't been tested in people.
- Because it's derived from a stress-hormone fragment, it could in theory interact with corticosteroid or other hormone-based treatments, but this isn't tested anywhere in the literature reviewed.
The papers that matter most
Key studies
Semax added to stroke rehab raised BDNF levels and was linked to better motor recovery and daily-function scores, especially with early rehab.
The efficacy of semax in the treatment of patients at different stages of ischemic stroke
A single intranasal dose changed activity in a key resting-state brain network within 20 minutes, the clearest direct human evidence that Semax reaches and affects the brain quickly.
Effects of Semax on the Default Mode Network of the Brain
Semax changed connections between the amygdala and emotion-processing brain regions, supporting a role in stress and mood circuits, though effects on real-world anxiety weren't measured.
Functional Connectomic Approach to Studying Selank and Semax Effects
Identified specific binding sites for Semax in the brain and showed it raises BDNF protein levels, a core piece of the mechanism story.
Semax...binds specifically and increases levels of brain-derived neurotrophic factor protein in rat basal forebrain
Large-scale gene analysis showing Semax's main effect after stroke is reshaping immune and blood-vessel gene activity, the leading theory for how it protects the brain.
The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis
Recent test-tube evidence that Semax can grab copper and reduce toxic amyloid-beta damage to cells, opening early interest in Alzheimer's-related research.
Semax, a Copper Chelator Peptide, Decreases the Cu(II)-Catalyzed ROS Production and Cytotoxicity of Abeta
Bottom line
Semax has genuine human evidence behind its stroke-recovery use in Russia, backed by a large and consistent body of animal research explaining why it might help the brain repair itself and calm inflammation after injury. But its reputation as a 'smart drug' for everyday focus rests mostly on small brain-scan studies and rat experiments, not proof that it improves memory or mood in healthy people. Treat it as a promising, early-stage compound rather than a proven cognitive enhancer.
Research papers
Studies we have on file for Semax. Tap a title to open it on PubMed. Labels like “animal” or “human trial” are rough guides.
40 papers
Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.
Therapeutic peptides are emerging as promising adjuncts in the management of orthopaedic injuries, grounded in their ability to modulate molecular signaling networks central to cellular medicine. By acting on key pathways such as PI3K/Akt, mTOR, MAPK, TGF-β, and AMPK, peptides exert influence over tissue regeneration, inflammation resolution, and neuromuscular recovery. Wound-healing peptides such as BPC-157, TB-500, and GHK-Cu promote angiogenesis, integrin-mediated extracellular matrix remodeling, and fibroblast activation, whereas growth hormone secretagogues like ipamorelin, CJC-1295, tesamorelin, sermorelin, and AOD-9604 activate IGF-1 signaling and satellite cell repair. Recovery-enhancing agents such as epithalon, delta sleep-inducing peptide, and pinealon target circadian and mitochondrial regulators, and neuroactive peptides like selank, semax, and dihexa enhance brain-derived neurotrophic factor and HGF/c-Met pathways critical to neuroplasticity. Although preclinical studies are promising, there is a current lack of clinical trials. This review integrates current mechanistic insights with orthopaedic relevance, emphasizing safety, efficacy, and future directions for responsible integration into musculoskeletal care.
Pharmacological Aspects of Neuro-Immune Interactions.
The use of systematic approach for the analysis of mechanism of action of drugs at different levels of biological organization of organisms is an important task in experimental and clinical pharmacology for drug designing and increasing the efficacy and safety of drugs. The analysis of published data on pharmacological effects of psychotropic drugs possessing immunomodulatory and/or antiviral properties have shown a correlation between central effects of examined drugs associated with the impact on the processes of neurogenesis of adult brain and survival of neurons, and their ability to alter levels of key proinflammatory cytokines. The changes that occur as a result of the influence of pharmacological agents at one of the systems should inevitably lead to the functional reorganization at another. Integrative mechanisms underlying the neuro-immune interactions may explain the "pleiotropic" pharmacological effects of some antiviral and immunomodulatory drugs. Amantadine, which was originally considered as an antiviral agent, was approved as anti-parkinsonic drug after its wide medical use. The prolonged administration of interferon alpha caused depression in 30-45% of patients, thus limiting its clinical use. The antiviral drug "Oseltamivir" may provoke the development of central side effects, including abnormal behavior, delirium, impaired perception and suicides. Anti-herpethetical drug "Panavir" shows pronounced neuroprotective properties. The purpose of this review is to analyze the experimental and clinical data related to central effects of drugs with antiviral or/and immunotropic activity, and to discover the relationship of these effects with changes in reactivity of immune system and proinflammatory response.
Semax peptide targets the μ opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice.
Lysosomal membrane permeabilization (LMP) is exacerbated following spinal cord injury (SCI), leading to increased neuronal cell death. Ubiquitination may affect LMP by regulating the stability and functionality of lysosomal membranes. Semax, a synthetic heptapeptide, comprising the ACTH (4-7) fragment and a C-terminal Pro-Gly-Pro tripeptide, exhibits neuroprotective properties and improves cognitive function. Given the key roles of LMP and ubiquitination in SCI pathophysiology, this study investigated how Semax could modulate these pathways to affect functional recovery following SCI. An SCI mouse model was generated by impacting the spinal cord of female C57BL/6 mice at T9-T10. Functional recovery in SCI mice was evaluated using histochemical methods, along with footprint analysis, Basso scores and inclined plane tests. Marker levels and distributions in the SCI model and in the PC12 cell neuroinflammation model were analysed using immunofluorescence, Western blot, RT-qPCR and transmission electron microscopy. RNA sequencing, network pharmacology and molecular docking were used to identify possible molecular targets of Semax. Semax improved SCI functional recovery and inhibited LMP-related pyroptosis in SCI mice and neuroinflammation models, by decreasing oxidative stress. RNA-seq and other analyses found that Semax regulated the ubiquitin specific protease USP18. USP18 knockdown confirmed Semax's role in SCI recovery. Network pharmacology and docking revealed the μ-opioid receptor as a Semax target. Semax promoted SCI functional recovery by targeting μ-opioid receptors, which regulated USP18 and, subsequently, deubiquitination of the fat mass and obesity-associated protein (FTO), suggesting its potential for SCI treatment.
ACTH-like Peptides Compensate Rat Brain Gene Expression Profile Disrupted by Ischemia a Day After Experimental Stroke.
Background: Ischemic stroke results from a disruption of cerebral blood flow. Adrenocorticotropic hormone (ACTH) serves as the basis for the creation of synthetic peptides as neuroprotective agents for stroke therapy. Previously, using RNA-Seq we first revealed differential expressed genes (DEGs) associated with ACTH(4-7)PGP (Semax) and ACTH(6-9)PGP peptides under cerebral ischemia conditions. Analysis was carried out at 4.5 h after transient middle cerebral artery occlusion (tMCAO) model in the ipsilateral frontal cortex of a rat brain. Methods: Here, we analyzed the penumbra-associated frontal cortex of rats and actions under the same peptides at 24 h after tMCAO using RNA-Seq. Results: 3774 DEGs (fold change > 1.5 and Padj < 0.05) were identified under ischemia conditions, whereas 1539 and 2066 DEGs were revealed under Semax and ACTH(6-9)PGP peptides at 24 h after tMCAO. Furthermore, both peptides significantly reduced expression distortions caused by ischemia for 1171 genes associated with immune and neurosignaling pathways. Concomitantly, there were 32 DEGs under ACTH(6-9)PGP versus Semax administration at 24 h after tMCAO. Besides, neurogenesis-, angiogenesis-, protein kinase- and growth factor-related DEGs were revealed under peptides action. Previously, we observed the neuroprotective effect of peptides at the histological level in rat brains at 24 h after tMCAO. Thus, here we demonstrate the transcriptome manifestation of this histological effect. Furthermore, comparison with previous data at the 4.5 h post-tMCAO time point showed that the pattern of peptide action on the transcriptome depends on the time elapsed after tMCAO. Conclusions: We revealed that the effect of ACTH(6-9)PGP was more similar to Semax than different from it a day after tMCAO. At this time point, ACTH-like peptides compensated rat brain gene expression profiles disrupted by ischemia. Thus, our results may be useful for selecting more effective structures for future anti-stroke drugs and appropriate post-stroke time points for their testing.
Semax, a Synthetic Regulatory Peptide, Affects Copper-Induced Abeta Aggregation and Amyloid Formation in Artificial Membrane Models.
Alzheimer's disease, the most common form of dementia, is characterized by the aggregation of amyloid beta protein (Aβ). The aggregation and toxicity of Aβ are strongly modulated by metal ions and phospholipidic membranes. In particular, Cu2+ ions play a pivotal role in modulating Aβ aggregation. Although in the last decades several natural or synthetic compounds were evaluated as candidate drugs, to date, no treatments are available for the pathology. Multifunctional compounds able to both inhibit fibrillogenesis, and in particular the formation of oligomeric species, and prevent the formation of the Aβ:Cu2+ complex are of particular interest. Here we tested the anti-aggregating properties of a heptapeptide, Semax, an ACTH-like peptide, which is known to form a stable complex with Cu2+ ions and has been proven to have neuroprotective and nootropic effects. We demonstrated through a combination of spectrofluorometric, calorimetric, and MTT assays that Semax not only is able to prevent the formation of Aβ:Cu2+ complexes but also has anti-aggregating and protective properties especially in the presence of Cu2+. The results suggest that Semax inhibits fiber formation by interfering with the fibrillogenesis of Aβ:Cu2+ complexes.
Influence of the N-terminus acetylation of Semax, a synthetic analog of ACTH(4-10), on copper(II) and zinc(II) coordination and biological properties.
Semax is a heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) that encompasses the sequence 4-7 of N-terminal domain of the adrenocorticotropic hormone and a C-terminal Pro-Gly-Pro tripeptide. N-terminal amino group acetylation (Ac-Semax) modulates the chemical and biological properties of parental peptide, modifying the ability of Semax to form complex species with Cu(II) ion. At physiological pH, the main complex species formed by Ac-Semax, [CuLH-2]2-, consists in a distorted CuN3O chromophore with a weak apical interaction of the methionine sulphur. Such a complex differs from the Cu(II)-Semax complex system, which exhibits a CuN4 chromophore. The reduced ligand field affects the [CuLH-2]2- formal redox potential, which is more positive than that of Cu(II)-Semax corresponding species. In the amino-free form, the resulting complex species is redox-stable and unreactive against ascorbic acid, unlike the acetylated form. Semax acetylation did not protect from Cu(II) induced toxicity on a SH-SY5Y neuroblastoma cell line, thus demonstrating the crucial role played by the free NH2 terminus in the cell protection. Since several brain diseases are associated either to Cu(II) or Zn(II) dyshomeostasis, here we characterized also the complex species formed by Zn(II) with Semax and Ac-Semax. Both peptides were able to form Zn(II) complex species with comparable strength. Confocal microscopy imaging confirmed that peptide group acetylation does not affect the Zn(II) influx in neuroblastoma cells. Moreover, a punctuate distribution of Zn(II) within the cells suggests a preferred subcellular localization that might explain the zinc toxic effect. A future perspective can be the use of Ac-Semax as ionophore in antibody drug conjugates to produce a dysmetallostasis in tumor cells.
Therapeutic peptides in gerontology: mechanisms and applications for healthy aging.
Peptide therapeutics represent an emerging frontier in gerontological medicine, targeting fundamental hallmarks of aging including metabolic dysfunction, telomere attrition, tissue repair impairment, and hormonal decline. To comprehensively review the mechanisms, clinical applications, evidence base, and safety profiles of therapeutic peptides with demonstrated or potential applications in healthy aging and age-related conditions. A comprehensive narrative review was conducted through systematic searches of PubMed, Scopus, and regulatory databases (FDA, WADA) from inception through January 2026. Search terms included "peptide therapeutics," "aging," "gerontology," "healthspan," combined with specific peptide names (tirzepatide, epitalon, GHK-Cu, BPC-157, TB-500, Semax, CJC-1295, ipamorelin, bremelanotide). Peer-reviewed articles, clinical trials, regulatory documents, and preclinical studies were evaluated. A total of 20 primary sources were selected based on relevance, methodological quality, and contribution to understanding peptide mechanisms and clinical outcomes in aging populations. Nine peptides were identified spanning diverse aging interventions: metabolic restoration (tirzepatide), telomere biology (epitalon), dermal regeneration (GHK-Cu), tissue repair (BPC-157, TB-500), neuroprotection (Semax), growth hormone modulation (CJC-1295, ipamorelin), and sexual function (bremelanotide). FDA-approved agents demonstrated robust safety profiles from large-scale trials. Non-approved peptides showed promising preclinical and limited clinical evidence but lack long-term safety data and systematic validation. Significant knowledge gaps include optimal dosing regimens, combination therapy effects, and biomarkers for monitoring efficacy. Therapeutic peptides offer mechanistically diverse approaches to multiple aging hallmarks. While FDA-approved agents demonstrate clinical potential, investigational peptides require rigorous validation through well-designed clinical trials to establish safety and efficacy for healthspan extension.
Modulation of neuropathological pathways by bioactive peptides and proteins/polypeptides: Targeting oxidative stress in neurodegenerative diseases.
Neurodegenerative disorders (NDDs) pose a growing global health burden, primarily due to their progressive nature and the limited efficacy of existing treatments. Bioactive peptides and proteins/polypeptides, particularly those derived from dietary and natural sources, show promise in modulating neurobiological pathways central to neurodegeneration. This review aims to critically examine the neuroprotective roles of Bioactive peptides and proteins/polypeptides in NDDs, elucidating their mechanisms of action, potential therapeutic applications in conditions like Alzheimer's, Parkinso's disease, Huntington's disease, and others, as well as the trends in peptide-based therapeutics. Bioactive peptides and proteins/polyspeptides, such as NGF, BDNF, GDNF, Semax, and Exendin-4, have been found to modulate several critical mechanisms, including the reduction of oxidative stress (OS), inhibition of neuroinflammation, preservation of mitochondria, and enhancement of synaptic plasticity. These peptides have demonstrated efficacy in preclinical and early-phase clinical trials across a spectrum of NDDs. Delivery challenges, such as blood-brain barrier (BBB) permeability and enzymatic degradation, have been acknowledged. Ongoing innovations in peptide engineering, nanoparticle-based delivery systems, CRISPR-assisted design, and AI-driven screening are addressing these limitations. By targeting multiple pathogenic mechanisms simultaneously, peptide-based therapeutics present a rational and innovative approach to NDD management. Their multifunctional action profiles and ability to target specific molecular pathways highlight their potential as next-generation neuroprotective agents. However, future clinical validation and advanced strategies are essential for translating these promising molecules into effective treatments.
The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis.
The nootropic neuroprotective peptide Semax (Met-Glu-His-Phe-Pro-Gly-Pro) has proved efficient in the therapy of brain stroke; however, the molecular mechanisms underlying its action remain obscure. Our genome-wide study was designed to investigate the response of the transcriptome of ischemized rat brain cortex tissues to the action of Semax in vivo. The gene-expression alteration caused by the action of the peptide Semax was compared with the gene expression of the "ischemia" group animals at 3 and 24 h after permanent middle cerebral artery occlusion (pMCAO). The peptide predominantly enhanced the expression of genes related to the immune system. Three hours after pMCAO, Semax influenced the expression of some genes that affect the activity of immune cells, and, 24 h after pMCAO, the action of Semax on the immune response increased considerably. The genes implicated in this response represented over 50% of the total number of genes that exhibited Semax-induced altered expression. Among the immune-response genes, the expression of which was modulated by Semax, genes that encode immunoglobulins and chemokines formed the most notable groups. In response to Semax administration, 24 genes related to the vascular system exhibited altered expression 3 h after pMCAO, whereas 12 genes were changed 24 h after pMCAO. These genes are associated with such processes as the development and migration of endothelial tissue, the migration of smooth muscle cells, hematopoiesis, and vasculogenesis. Semax affects several biological processes involved in the function of various systems. The immune response is the process most markedly affected by the drug. Semax altered the expression of genes that modulate the amount and mobility of immune cells and enhanced the expression of genes that encode chemokines and immunoglobulins. In conditions of rat brain focal ischemia, Semax influenced the expression of genes that promote the formation and functioning of the vascular system.The immunomodulating effect of the peptide discovered in our research and its impact on the vascular system during ischemia are likely to be the key mechanisms underlying the neuroprotective effects of the peptide.
[Evolution of the stress concept].
New aspects of the classical Selye stress theory are considered. Stress is interpreted as a systemic response of the organism. In the last years the stress concept h as undergone transformation to the notion of emotional stress. In the context of the theory of functional systems, emotional stress is regarded as developing in the so-called conflict situations in which the participating subjects are unable to achieve useful adaptive goals. The primary cerebral mechanisms of emotional stress and the role played by neuromediators and neuropeptides are discussed. Dynamics of impairment of various functional systems under stressful conditions is discussed with special emphasis on individual tolerance to emotional stress and the role of oligopeptides (substance P), delta sleep inducing peptide, beta-endorphin and semax as antistress factors increasing resistance to stressful impacts.
[The efficacy of semax in the tretament of patients at different stages of ischemic stroke].
To evaluate the efficacy of semax and timing of rehabilitation on the dynamics of plasma BDNF levels, motor performance, and Barthel index score in patients after ischemic stroke (IS). One hundred and ten patients after IS (43 men, 67 women, mean age 58.0±9.7, Ме 63 years) were examined. All patients were divided into early (89±9 days) and late (214±22 days) rehabilitation groups. Each group was subdivided into semax+ and semax- subgroups. Standard regimen of semax included 2 courses (6000 mcg/day) for 10 days with 20 day interval. Plasma BDNF levels, motor performance on the British Medical Research Council scale and Barthel index were assessed in all groups. Administration of semax, regardless of the timing of rehabilitation, increased BDNF plasma levels which remained high during the whole study period. In semax- subgroups high BDNF plasma levels were positively correlated with early rehabilitation. Administration of semax and high BDNF levels accelerated the improvement and ameliorated the final outcome of Barthel score index. There was a positive correlation between BDNF plasma levels and Barthel score, as well as a correlation between early rehabilitation and motor performance improvement. The correlation between BDNF plasma levels and Barthel score was modified by the timing of rehabilitation. Early rehabilitation and administration of semax increase BDNF plasma level, speed functional recovery, and improve motor performance.
Semax and Pro-Gly-Pro activate the transcription of neurotrophins and their receptor genes after cerebral ischemia.
Consisting of a fragment of ACTH(4-7) and C-terminal PGP tripeptide, the polypeptide Semax is successfully used for acute stroke therapy. Previous experiments showed rapid induction of Bdnf, Ngf, and TrkB expression in intact rat hippocampus following Semax treatment. To investigate the mRNA expression of neurotrophins and their receptors after treatment with either Semax or PGP, the rat brains were analyzed at three time points following a permanent middle cerebral artery occlusion (pMCAO). We have shown for the first time that both Semax and PGP activate the transcription of neurotrophins and their receptors in the cortex of rats subjected to pMCAO. The profiles of transcription alteration under PGP and Semax treatment were partially overlapped. Semax enhanced the transcription of Bdnf, TrkC, and TrkA 3 h after occlusion, Nt-3 and Ngf 24 h after occlusion, and Ngf 72 h after occlusion. PGP enhanced the transcription of Bdnf and TrkC 3 h after pMCAO and Ngf, TrkB, TrkC, and TrkA 24 h after pMCAO. The analysis of the transcription alterations under PGP and Semax treatment in the cortex of rats without surgery, sham-operated rats and rats subjected to pMCAO revealed that Semax selectively affected the transcription of neurotrophins and their receptors in the ischemic rat cortex, whereas the influence of PGP was mainly unspecific.
[POSSIBLE ROLE OF TRANSTHYRETIN IN THE BIOLOGICAL MECHANISM OF THE REGULATORY PEPTIDE NEUROPROTECTION.].
The peptide preparation Semax has been effectively used for therapy of ischemic stroke. However, the mechanisms of its action are insufficiently understood and actively studied. The full-genome analysis of the transcriptome implemented in our recent work dem- onstrated that under conditions of focal ischemia of rat brain the Semax modified the profile of the transcription activity of many genes. In this case, the difference in the transcription levels of the gene encoding the protein transthyretin (Ttr) expression in rats under the pathological conditions of ischemia and in the presence of Semax was very high. High similarity between the effects of Ttr and coupled molecular systems with the Semax effects in ischemic stroke allowed us to suggest that the neuroprotection mechanisms of Semax (and, possibly, of other neuroprotection mechanisms of Semax) could be mediated by Ttr. In this review, we discussed the role of Ttr in CNS and its possible role in the neuroprotection mechanism of Semax.
Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents.
Corticotrophin (ACTH) and its analogues, particularly Semax (Met-Glu-His-Phe-Pro-Gly-Pro), demonstrate nootropic activity. Close functional and anatomical links have been established between melanocortinergic and monoaminergic brain systems. The aim of present work was to investigate the effects of Semax on neurochemical parameters of dopaminergic- and serotonergic systems in rodents. The tissue content of 5-hydroxyindoleacetic acid (5-HIAA) in the striatum was significantly increased (+25%) 2 h after Semax administration. The extracellular striatal level of 5-HIAA gradually increased up to 180% within 1-4 h after Semax (0.15 mg/kg, ip) administration. This peptide alone failed to alter the tissue and extracellular concentrations of dopamine and its metabolites. Semax injected 20 min prior D: -amphetamine dramatically enhanced the effects of the latter on the extracellular level of dopamine and on the locomotor activity of animals. Our results reveal the positive modulatory effect of Semax on the striatal serotonergic system and the ability of Semax to enhance both the striatal release of dopamine and locomotor behavior elicited by D-amphetamine.
Synacton and individual activity of synthetic and natural corticotropins.
Short endogenous peptides represent one of the most important constituents of the mammalian body's general regulatory system. Some synthesized analogs and modified natural peptides (eg, corticotropins) also show high biological activity. Nevertheless, the mechanism of action of regulatory peptides remains unclear. To explain the effects of peptides of intermolecular processes, the hypothesis that a synactonal mechanism underlies the action of regulatory peptides, exemplified by the heptapeptide Semax, has been proposed. Thus, in the total pool of Semax metabolites, which includes the cleavage products of the parental molecule, we can distinguish the functional core, represented by the major metabolic products-peptides HFPGP and PGP. These peptides have their own binding sites with similar although differing characteristics. Together with Semax, they constitute a single complex of bioregulators acting in a certain sequence and in interaction, ie, synacton. It can be assumed that the diverse clinically significant effects of the drug Semax are determined by its synacton. Specific interactions between some tritium-labeled peptides (basic constituents of the Semax synacton) and plasma membranes of neurons have been characterized. Only a few peptides of the Semax synacton showed competitive activity for the Semax binding sites. Fragments comprising 5 amino acid residues (EHFPG and HFPGP) showed the highest competitive activity. We also characterized the processes of specific ligand-receptor interactions of some tritium-labeled corticotropins ([3 H-Pro]MEHFPGP, [3 H-Pro]HFPGP, and [3 H-Pro]PGP) by applying mathematical discriminative models (Scatchard, Hill, Bjerrum, and Lineweaver-Burk plots). So the intermolecular interactions of these peptides with plasma membranes of neuronal brain targets are probably not limited by specific binding at orthosteric sites. The effect of peptides that act in the synacton considerably extends the regulatory potential of the initial molecule.
Sigmoidal maximal effect modeling of low-density lipoprotein cholesterol concentration and annual incidence of coronary heart disease events in secondary prevention trials.
To evaluate the relationship between low-density lipoprotein cholesterol (LDL-C) concentration and the annual incidence of combined coronary heart disease (CHD) events—death or nonfatal myocardial infarction (NFMI)—by using sigmoidal maximal effect (sEmax) modeling of published data in various populations at risk for CHD events, and to use the best performing sEmax model generated to calculate the number needed to treat (NNT) to prevent a single CHD death or NFMI event across a range of LDL-C concentrations. Literature-based modeling analysis. A total of 95,955 patients from 22 published cardiovascular secondary prevention trials. Four distinct sEmax models were created based on intervention approach and CHD event risk for each trial population. Model outputs included the following: Emax (maximum CHD death/NFMI rate), E0 (minimum CHD death/NFMI rate), and fit parameters. The best-fitting sEmax model was compared with linear, log-linear, and logit models, and it was used for calculation of annualized NNT to prevent one CHD death or NFMI event with statins. The best fitting sEmax model was constructed from nine statin intervention trials in 60,483 clinically stable patients with CHD or CHD risk equivalents (Emax = 4.84%/year [95% confidence interval (CI) 4.11–5.41%/year], E0 = 1.24%/year [95% CI 0.64–1.83%/year]) and was superior to linear, log-linear, and logit models. Reduction of CHD death/NFMI incidence diminished at an LDL-C level near 90 mg/dl and became near static at an LDL-C level of 60–70 mg/dl. Annual NNT for LDL-C reduction from a baseline of 130–100 mg/dl, 90, and 70 mg/dl was 129, 104, and 83, respectively, and from a baseline of 100–70 mg/dl was 232. An sEmax model fully characterized the relationship between LDL-C concentration and incidence of CHD death or NFMI in a high-risk population receiving statins, with diminishing event reduction at an LDL-C level less than 90 mg/dl, and limited projected event reduction beyond an LDL-C level of ~60–70 mg/dl. As baseline LDL-C level declines, the NNT sharply increases.
Semax, an analogue of adrenocorticotropin (4-10), binds specifically and increases levels of brain-derived neurotrophic factor protein in rat basal forebrain.
The heptapeptide Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is an analogue of the N-terminal fragment (4-10) of adrenocorticotropic hormone which, after intranasal application, has profound effects on learning and memory formation in rodents and humans, and also exerts marked neuroprotective effects. A clue to the molecular mechanism underlying this neurotropic action was recently given by the observation that Semax stimulates the synthesis of brain-derived neurotrophic factor (BDNF), a potent modulator of synaptic plasticity, in astrocytes cultured from rat basal forebrain. In the present study, we investigated whether Semax affects BDNF levels in rat basal forebrain upon intranasal application of the peptide. In addition, we examined whether cell membranes isolated from this brain region contained binding sites for Semax. The binding of tritium-labelled Semax was found to be time dependent, specific and reversible. Specific Semax binding required calcium ions and was characterized by a mean+/-SEM dissociation constant (KD) of 2.4+/-1.0 nm and a BMAX value of 33.5+/-7.9 fmol/mg protein. Sandwich immunoenzymatic analysis revealed that Semax applied intranasally at 50 and 250 microg/kg bodyweight resulted in a rapid increase in BDNF levels after 3 h in the basal forebrain, but not in the cerebellum. These results point to the presence of specific binding sites for Semax in the rat basal forebrain. In addition, these findings indicate that the cognitive effects exerted by Semax might be associated, at least in part, with increased BDNF protein levels in this brain region.
Effects of Semax on the Default Mode Network of the Brain.
The effects of nootropic drug Semax on the neuronal network of the brain were studied by the resting state functional magnetic-resonance imaging (resting state fMRI). The study was carried out on two groups of healthy volunteers (11 men and 13 women aged 43.9±9.5 years). Resting state fMRI was carried out 3 times: directly before and 5 and 20 min after intranasal 1% Semax (14 subjects) or placebo (10 subjects). The topography of the resting state default mode network was studied. A greater volume of the default mode network rostral (medial frontal cortex) subcomponent was detected in the Semax group in comparison with controls. Resting state fMRI confirmed Semax effects on the neuronal network of the brain and demonstrated topography of these effects.
Genes That Associated with Action of ACTH-like Peptides with Neuroprotective Potential in Rat Brain Regions with Different Degrees of Ischemic Damage.
In the treatment of ischemic stroke, an innovative approach is the use of neuroprotective compounds. Natural peptides, including adrenocorticotropic hormone (ACTH), can serve as the basis for such drugs. Previously, a significant effect of non-hormonal ACTH(4-7)PGP (Semax) and ACTH(6-9)PGP peptides on the functions of the nervous system was shown. Also, while using RNA-Seq, we firstly revealed differentially expressed genes (DEGs) that associated with peptides in the penumbra-associated region of the frontal cortex (FC) of rats at 24 h after transient middle cerebral artery occlusion (tMCAO) model. Peptides significantly reduced profile disturbances caused by ischemia for almost two-thousand DEGs in FC related to the neurotransmitter and inflammatory response. Here, we studied how peptides affected the expression of genes in the striatum with an ischemic focus, predominantly. The same animals from which we previously acquired FC were used to collect striatum samples. Peptides generated fewer DEGs in the striatum than in the FC. Both peptides tended to normalize the profile of disturbances caused by ischemia for hundreds of DEGs, whereas 152 genes showed an even more affected profile in the striatum under ACTH(6-9)PGP action. These DEGs were associated with inflammation, predominantly. About hundred genes were overlapped between both peptides in both tissues and were associated with neuroactive ligand-receptor interaction, predominantly. Thus, genes that are associated with the ACTH-like peptide action in rat brain regions with varying levels of ischemia injury were identified. Moreover, differential spatial regulation of the ischemia process in the rat brain at the transcriptome levels was discovered under peptides with different ACTH structures. We suppose that our results may be useful for selecting more effective neuroprotective drug structures in accordance with their specific tissue/damage therapeutic impact.
Semax, synthetic ACTH(4-10) analogue, attenuates behavioural and neurochemical alterations following early-life fluvoxamine exposure in white rats.
Selective serotonin reuptake inhibitors (SSRI) are commonly used to treat depression during pregnancy. SSRIs cross the placenta and may influence the maturation of the foetal brain. Clinical and preclinical findings suggest long-term consequences of SSRI perinatal exposure for the offspring. The mechanisms of SSRI effects on developing brain remain largely unknown and there are no directional approaches for prevention of the consequences of maternal SSRI treatment during pregnancy. The heptapeptide Semax (MEHFPGP) is a synthetic analogue of ACTH(4-10) which exerts marked nootropic and neuroprotective activities. The aim of the present study was to investigate the long-term effects of neonatal exposure to the SSRI fluvoxamine (FA) in white rats. Additionally, the study examined the potential for Semax to prevent the negative consequences of neonatal FA exposure. Rat pups received FA or vehicle injections on postnatal days 1-14, a time period equivalent to 27-40 weeks of human foetal age. After FA treatment, rats were administered with Semax or vehicle on postnatal days 15-28. During the 2nd month of life, the rats underwent behavioural testing, and monoamine levels in brain structures were measured. It was shown that neonatal FA exposure leads to the impaired emotional response to stress and novelty and delayed acquisition of food-motivated maze task in adolescent and young adult rats. Furthermore, FA exposure induced alterations in the monoamine levels in brains of 1- and 2- month-old rats. Semax administration reduced the anxiety-like behaviour, improved learning abilities and normalized the levels of brain biogenic amines impaired by the FA exposure. The results demonstrate that early-life FA exposure in rat pups produces long-term disturbances in their anxiety-related behaviour, learning abilities, and brain monoamines content. Semax exerts a favourable effect on behaviour and biogenic amine system of rats exposed to the antidepressant. Thus, peptide Semax can prevent behavioural deficits caused by altered 5-HT levels during development.
[Nootropic and analgesic effects of Semax following different routes of administration].
Heptapeptide Semax (MEHFPGP) is the fragment of ACTH(4-10) analogue with prolonged neurotropic activity. The aim of the present work was to study the Semax effects on learning capability and pain sensitivity in white rats following intraperitoneal and intranasal administration in different doses. Semax nootropic effects were studied in the test of acquisition of passive avoidance task. Pain sensitivity was estimated in Randall-Selitto paw-withdrawal test. It was shown that Semax exerts nootropic and analgesic activities following intraperitoneal administration. Analysis of dependence of these effects on dose resulted in different dose-response curves. Following intranasal administration, Semax was more potent in learning improvement compared to intraperitoneal administration. The peptide failed to affect the animal pain sensitivity following intranasal administration as opposed to intraperitoneal administration. The data obtained suggest different mechanisms and brain structures involved in realization of the nootropic and analgesic effects of Semax.
Novel Insights into the Protective Properties of ACTH(4-7)PGP (Semax) Peptide at the Transcriptome Level Following Cerebral Ischaemia-Reperfusion in Rats.
Cerebral ischaemia is the most common cause of impaired brain function. Biologically active peptides represent potential drugs for reducing the damage that occurs after ischaemia. The synthetic melanocortin derivative, ACTH(4-7)PGP (Semax), has been used successfully in the treatment of patients with severe impairment of cerebral blood circulation. However, its molecular mechanisms of action within the brain are not yet fully understood. Previously, we used the transient middle cerebral artery occlusion (tMCAO) model to study the damaging effects of ischaemia-reperfusion on the brain transcriptome in rats. Here, using RNA-Seq analysis, we investigated the protective properties of the Semax peptide at the transcriptome level under tMCAO conditions. We have identified 394 differentially expressed genes (DEGs) (>1.5-fold change) in the brains of rats at 24 h after tMCAO treated with Semax relative to saline. Following tMCAO, we found that Semax suppressed the expression of genes related to inflammatory processes and activated the expression of genes related to neurotransmission. In contrast, ischaemia-reperfusion alone activated the expression of inflammation-related genes and suppressed the expression of neurotransmission-related genes. Therefore, the neuroprotective action of Semax may be associated with a compensation of mRNA expression patterns that are disrupted during ischaemia-reperfusion conditions.
Functional Connectomic Approach to Studying Selank and Semax Effects.
The present study was aimed at the assessment of effects of anxiolytic Selank and nootropic Semax on the whole-brain resting-state functional connectivity (FC) of each of the predefined regions of interest (ROIs) in 52 healthy participants. The ROIs included amygdala (one of the key regions for the regulation of anxiety) and dorsolateral prefrontal cortex (DLPFC; the key region for executive functions, including working memory) in the right and left hemisphere. Resting-state fMRI was carried out three times, namely before, after 5 and 20 min of the injection of either Semax, or Selank, or placebo. Between-group alongwith between-condition differences were revealed in FC between the right amygdala and a region in fusiform, inferior and middle temporal as well as parahippocampal gyri in the right hemisphere. Post hoc analysis allowed us to define both general and specific effects of Selank and Semax on FC between the right amygdala and the right temporal cortex for the first time.
[A comparative chemoreactome analysis of mexidol].
To compare mexidol with control molecules (choline alfoscerate, piracetam, glycine, semax) using chemoreactome analysis. The chemical structure of mexidol was compared to molecule metabolites extracted from the Human Metabolome Database (HMDB) and a drug database. More than 40 000 of metabolites from HMDB were used as a model of human metabolome. The chemoreactome analysis showed that mexidol may be (1) an agonist of acetylcholine and GABA-A receptors; (2) an anti-inflammatory agent, the effects of which are carried out by inhibiting the synthesis of pro-inflammatory prostaglandins; (3) a neurotrophic agent with neuroprotective properties; (4) a coagulation inhibitor; (5) a diabetes medication and (6) a hypolipidemic agent. Compared to 'control' molecules, mexidol has a more pronounced safety profile (a lower impact on serotonin, dopamine and adrenergic receptors, a lesser degree of interaction with the potassium channels of the heart, MAO and P450 cytochromes). The results of modeling allow to specify the mechanisms of action of mexidol at the molecular level.
Synthetic corticotropins and the GABA-receptor system: Direct and delayed effects.
The central effectors of the stress system are greatly interconnected and include, among others, a large group of peptides derived from proopiomelanocortin. In addition to natural corticotropins, a number of artificial molecules that contain some ACTH fragments in their structure are also referred to members of this family. Some of them possess a wide range of biological activity. The molecular mechanism underlying the biological activity of such peptides is partly based on allosteric modulation of various receptors. We analyzed the ability of some biologically active synthetic corticotropins (ACTH(4-7)PGP, ACTH(6-9)PGP, ACTH(7-10)PGP), and glyproline PGPL to affect the GABA-receptor system of rat brain. The effects of the peptides were studied in the isolated plasma membranes of brain cells, as well as after systemic peptide administration in the rat model of acute restraint stress. The delayed effect of stress or preadministration of each of the studied peptides on [3 H]GABA binding was different for its high- and low-affinity-specific sites. The studied peptides individually affected the binding of [3 H]GABA in their own way. Acute restraint stress caused a decrease in [3 H]GABA binding at its low-affine site and did not affected the high-affine site. Preliminary peptide administration did not influence this effect of stress.
Therapeutic possibility of "Semax" for depression.
Insight into Glyproline Peptides' Activity through the Modulation of the Inflammatory and Neurosignaling Genetic Response Following Cerebral Ischemia-Reperfusion.
Glyprolines are Gly-Pro (GP)- or Pro-Gly (PG)-containing biogenic peptides. These peptides can act as neutrophil chemoattractants, or atheroprotective, anticoagulant, and neuroprotective agents. The Pro-Gly-Pro (PGP) tripeptide is an active factor of resistance to the biodegradation of peptide drugs. The synthetic Semax peptide, which includes Met-Glu-His-Phe (MEHF) fragments of adrenocorticotropic hormone and the C-terminal tripeptide PGP, serves as a neuroprotective drug for the treatment of ischemic stroke. Previously, we revealed that Semax mostly prevented the disruption of the gene expression pattern 24 h after a transient middle cerebral artery occlusion (tMCAO) in a rat brain model. The genes of this pattern were grouped into an inflammatory cluster (IC) and a neurotransmitter cluster (NC). Here, using real-time RT-PCR, the effect of other PGP-containing peptides, PGP and Pro-Gly-Pro-Leu (PGPL), on the expression of a number of genes in the IC and NC was studied 24 h after tMCAO. Both the PGP and PGPL peptides showed Semax-unlike effects, predominantly without changing gene expression 24 h after tMCAO. Moreover, there were IC genes (iL1b, iL6, and Socs3) for PGP, as well as IC (iL6, Ccl3, Socs3, and Fos) and NC genes (Cplx2, Neurod6, and Ptk2b) for PGPL, that significantly changed in expression levels after peptide administration compared to Semax treatment under tMCAO conditions. Furthermore, gene enrichment analysis was carried out, and a regulatory gene network was constructed. Thus, the spectra of the common and unique effects of the PGP, PGPL, and Semax peptides under ischemia-reperfusion were distinguished.
Brain Protein Expression Profile Confirms the Protective Effect of the ACTH(4-7)PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia-Reperfusion.
The Semax (Met-Glu-His-Phe-Pro-Gly-Pro) peptide is a synthetic melanocortin derivative that is used in the treatment of ischemic stroke. Previously, studies of the molecular mechanisms underlying the actions of Semax using models of cerebral ischemia in rats showed that the peptide enhanced the transcription of neurotrophins and their receptors and modulated the expression of genes involved in the immune response. A genome-wide RNA-Seq analysis revealed that, in the rat transient middle cerebral artery occlusion (tMCAO) model, Semax suppressed the expression of inflammatory genes and activated the expression of neurotransmitter genes. Here, we aimed to evaluate the effect of Semax in this model via the brain expression profiling of key proteins involved in inflammation and cell death processes (MMP-9, c-Fos, and JNK), as well as neuroprotection and recovery (CREB) in stroke. At 24 h after tMCAO, we observed the upregulation of active CREB in subcortical structures, including the focus of the ischemic damage; downregulation of MMP-9 and c-Fos in the adjacent frontoparietal cortex; and downregulation of active JNK in both tissues under the action of Semax. Moreover, a regulatory network was constructed. In conclusion, the suppression of inflammatory and cell death processes and the activation of recovery may contribute to the neuroprotective action of Semax at both the transcriptome and protein levels.
Semax, an analog of ACTH(4-7), regulates expression of immune response genes during ischemic brain injury in rats.
Brain stroke continues to claim the lives of million people every year. To build the effective strategies for stroke treatment it is necessary to understand the neuroprotective mechanisms that are able to prevent the ischemic injury. Consisting of the ACTH(4-7) fragment and the tripeptide Pro-Gly-Pro (PGP), the synthetic peptide Semax effectively protects brain against ischemic stroke. However, the molecular mechanisms underlying its neuroprotection and participation of PGP in them are still needed to be clarified. To reveal biological processes and signaling pathways, which are affected by Semax and PGP, we performed the transcriptome analysis of cerebral cortex of rats with focal cerebral ischemia treated by these peptides. The genome-wide biochip data analysis detected the differentially expressed genes (DEGs) and bioinformatic web-tool Ingenuity iReport found DEGs associations with several biological processes and signaling pathways. The immune response is the process most markedly affected by the peptide: Semax enhances antigen presentation signaling pathway, intensifies the effect of ischemia on the interferon signaling pathways and affects the processes for synthesizing immunoglobulins. Semax significantly increased expression of the gene encoding the immunoglobulin heavy chain, highly affects on cytokine, stress response and ribosomal protein-encoding genes after occlusion. PGP treatment of rats with ischemia attenuates the immune activity and suppresses neurotransmission in the CNS. We suppose that neuroprotective mechanism of Semax is realized via the neuroimmune crosstalk, and the new properties of PGP were found under ischemia. Our results provided the basis for further proteomic investigations in the field of searching Semax neuroprotection mechanism.
Gateways to clinical trials.
Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables have been retrieved from the Clinical Trials Knowledge Area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: 3-AP, Adalimumab, adefovir dipivoxil, AeroDose albuterol inhaler, agalsidase alfa, alemtuzumab, aminolevulinic acid methyl ester, anidulafungin, anthrax vaccine, anti-CTLA-4 MAb, azimilide hydrochloride; Bevacizumab, BG-12, bimatoprost, bortezomib, bosentan, botulinum toxin type B; Caspofungin acetate, ceftobiprole, certolizumab pegol, CG-53135, cilansetron; Darbepoetin alfa, degarelix acetate, dimethylfumarate, duloxetine hydrochloride, dutasteride; Eicosapentaenoic acid/docosahexaenoic acid, eletriptan, entecavir, esomeprazole magnesium, exatecan mesilate, exenatide, ezetimibe; Falecalcitriol, fampridine, fondaparinux sodium, fontolizumab; Gefitinib, gepirone hydrochloride; Human insulin; IDEA-070, imatinib mesylate, iodine (I131) tositumomab; Lanthanum carbonate, lubiprostone; Mafosfamide cyclohexylamine salt, melatonin; NC-531, nemifitide ditriflutate, neridronic acid, nolatrexed dihydrochloride; Oral insulin; Palifermin, parecoxib sodium, PEG-filgrastim, peginterferon alfa-2a, peginterferon alfa-2b, plerixafor hydrochloride, posaconazole, pramlintide acetate, pregabalin, PT-141; Quercetin; Ranibizumab, renzapride hydrochloride, RSD-1235; Sabarubicin hydrochloride, semapimod hydrochloride, Semax, SHL-749; Tegaserod maleate, tenatoprazole, tetrodotoxin, tolevamer sodium, trabectedin, travoprost, travoprost/timolol; Valdecoxib, visilizumab, Xcellerated T cells, XP-828L; Zoledronic acid monohydrate.
Effects of behaviorally active ACTH (4-10) analogue - Semax on rat basal forebrain cholinergic neurons.
It is well established that cholinergic neurons of the basal forebrain degenerate in Alzheimer's dementia. Although recent studies were concentrated on screening molecules that might reduce the concomitant cell loss, little is known about therapeutically promising molecules. We studied the effect of Semax (Met-Glu-His-Phe-Pro-Gly-Pro), a behaviorally active adrenocorticotropic hormone (4-10) analogue, on survival of cholinergic basal forebrain neurons in vitro. Semax is known to stimulate learning and memory and can be successfully used for treatment of ischemic stroke. Primary cultures of neuronal and glial cells from basal forebrain of rats were used in all experiments. The stability of Semax in cell cultures was tested by HPLC analysis. Cell survival in neuronal cultures was quantitated using immocytochemical and cytochemical analyses as well as detection of choline acetyltransferase activity. We have shown that Semax may approximately 1.5-1.7 fold increase survival of cholinergic basal forebrain neurons in vitro. Moreover, Semax (100 nM) stimulated activity of choline acetyltransferase in dissociated basal forebrain tissue cultures. However, the numbers of GABA-ergic neurons, total neuron specific enolase neurons were not affected. In concentration from 1 nM to 10 microM, Semax did not affect proliferation of glial cells in primary cultures. Implications of these findings with respect to Alzheimer's disease remain to be clarified.
[Comparison of anticoagulant effects of regulatory proline-containing oligopeptides. Specificity of glyprolines, semax, and selank and potential of their practical application].
Experimental and theoretical demonstration of different effect of certain regulatory peptides (RPs) on blood coagulation is available. The problem of the role of RPs in hemostatic processes becomes particularly significant since, first, the peptides are widespread in nature both in animal and plant tissues, second, there is a relationship between the peptide structure and function and, third, both natural and synthetic peptides are used in practical medicine to correct functions of some factors of the hemostatic system. Many peptide inhibitors of the primary and plasma hemostasis potentiating anticoagulant effects in the body have been described.
Diagnostic Value of Different 3-D Shear Wave Elastography Sections in the Diagnosis of Thyroid Nodules.
The aim of the study was to explore the value of 3-D shear wave elastography (SWE) in differentiating malignant from benign thyroid nodules. A total of 188 patients with 216 nodules who underwent conventional ultrasound, 2-D SWE and 3-D SWE were included in this study. All patients underwent surgical excision, and the pathological results were the gold standard. Receiver operating characteristic (ROC) curves of the American College of Radiology's Thyroid Imaging Reporting and Data System (ACR TI-RADS), 2-D SWE and 3-D SWE were plotted, and the areas under the curves (AUCs) were compared using a Z-test. There were 62 benign thyroid nodules and 154 malignant thyroid nodules in this study. Young's modulus (Emin, Emean, Emax, Esd) values of thyroid malignant nodules in different sections of 2-D SWE and 3-D SWE were significantly higher than those of thyroid benign nodules (p < 0.001). The AUC of Emax in 2-D SWE transverse sections was significantly lower than that in 3-D SWE transverse sections and 3-D SWE sagittal sections (0.768 vs. 0.831 and 0.844, p < 0.05). The AUC of 3-D S-Emax combined with ACR TI-RADS was 0.859; the specificity increased from 54.84% to 85.71%, and the diagnostic accuracy increased from 74.54% to 85.19%, compared with ACR TI-RADS. The difference was statistically significant (p < 0.05). Three-dimensional SWE combined with ACR TI-RADS for the diagnosis of thyroid nodules significantly improved the diagnostic ability of ACR TI-RADS, and was significantly better than 2-D SWE combined with ACR TI-RADS.
Semax prevents learning and memory inhibition by heavy metals.
Separate and joint effect of Semax, ascorbic acid, lead diacetate, and ammonium molybdate on avoidance conditioning in rats was studied. It was established that the heavy metal salts inhibited the avoidance response, and the peptide counteracted this inhibition as strongly as ascorbic acid or to a comparable degree. These findings confirm the antioxidant properties of Semax.
Synthetic Adrenocorticotropic Peptides Modulate the Expression Pattern of Immune Genes in Rat Brain following the Early Post-Stroke Period.
Ischemic stroke is an acute local decrease in cerebral blood flow due to a thrombus or embolus. Of particular importance is the study of the genetic systems that determine the mechanisms underlying the formation and maintenance of a therapeutic window (a time interval of up to 6 h after a stroke) when effective treatment can be provided. Here, we used a transient middle cerebral artery occlusion (tMCAO) model in rats to study two synthetic derivatives of adrenocorticotropic hormone (ACTH). The first was ACTH(4-7)PGP, which is known as Semax. It is actively used as a neuroprotective drug. The second was the ACTH(6-9)PGP peptide, which is elucidated as a prospective agent only. Using RNA-Seq analysis, we revealed hundreds of ischemia-related differentially expressed genes (DEGs), as well as 131 and 322 DEGs related to the first and second peptide at 4.5 h after tMCAO, respectively, in dorsolateral areas of the frontal cortex of rats. Furthermore, we showed that both Semax and ACTH(6-9)PGP can partially prevent changes in the immune- and neurosignaling-related gene expression profiles disturbed by the action of ischemia at 4.5 h after tMCAO. However, their different actions with regard to predominantly immune-related genes were also revealed. This study gives insight into how the transcriptome depends on the variation in the structure of the related peptides, and it is valuable from the standpoint of the development of measures for early post-stroke therapy.
Semax, a Copper Chelator Peptide, Decreases the Cu(II)-Catalyzed ROS Production and Cytotoxicity of aβ by Metal Ion Stripping and Redox Silencing.
Alzheimer's disease (AD) is the most common neurodegenerative disorder associated with cognitive decline and loss of memory. It is postulated that the generation of reactive oxygen species (ROS) in Fenton-like reaction connected with Cu(II)/Cu(I) redox cycling of the Cu(II)-aβ complex can play a key role in the molecular mechanism of neurotoxicity in AD. Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic regulatory peptide that possesses a high affinity for Cu(II) ions. The ability of the peptide Semax to inhibit the copper-catalyzed oxidation of aβ was studied in vitro and discussed. The results indicate that Semax is able to extract Cu(II) from Cu(II)-aβ species as well as to influence the redox cycling of the Cu(II)-aβ complex and decrease the level of associated ROS production. Finally, our data suggest that Semax shows cytoprotective properties for SH-SY5Y cells against oxidative stress induced by copper-catalyzed oxidation of the aβ peptide. This study provides valuable insights into the potential role of Semax in neurodegenerative disorders and into the design of new compounds with therapeutic potential for AD.
[The Peptide Drug ACTH(4-7)PGP (Semax) Suppresses mRNA Transcripts Encoding Proinflammatory Mediators Induced by Reversible Ischemia of the Rat Brain].
Due to its nootropic, neuroprotective, and immunomodulatory effects, the peptide Semax is utilized in the treatment of ischemic stroke. Our earlier RNA-Seq analysis of the transcriptome in an ischemic model of transient occlusion of the middle cerebral artery showed an increase in the mRNA levels of many proinflammatory genes, and the suppression of their induction by Semax. However, for many relevant genes, including Il1a, Il1b, Il6 and Tnfa, the levels of their expression were too low for detailed quantitative evaluation. Here we utilize qRT-PCR to analyze the effects of the Semax peptide on the expression of weakly expressed mRNAs encoding several proinflammatory mediators, and show that exposure to Semax leads to a statistically significant decrease in the Il1a, Il1b, Il6, Ccl3, and Cxcl2 mRNAs, which compensates for the increase in the transcription of these genes induced by ischemia-reperfusion. We conclude that the observed protective effect of Semax in the model of stroke may be due to its anti-inflammatory effects. We also discuss the limitations of the RNA-Seq when applied to quantifying less abundant transcripts as compared to the real-time RT-PCR method.
[Neonatal injections of pharmacological agents and their remote genotype-dependent effects in mice and rats].
Experimental data were reviewed which demonstrated that the neonatal injection effects of certain biologically active drugs (ACTH(4-10) fragment and its analogue Semax, piracetam, caffeine, levetiracetam, busperone, etc.) could be detected in adult animals as changes in physiological and behavioral reactions and in several morphological traits as well. Audiogenic seizures proneness, anxiety-fear and exploration behavior as well as pain sensitivity were analyzed. The remote effects discovered were either similar in direction to those applied to an adult organism, or opposite to it. Pharmacological treatments of such type presumably interfere the CNS development during early postnatal ontogeny and change the normal pattern ofbrain development. These modulatory influences could be due to changes in neurotransmitter system development and are presumably capable to induce CNS morphological deviations (numbers of neurons, adult neurogenesis).
Neurotrophin gene expression in rat brain under the action of Semax, an analogue of ACTH 4-10.
The heptapeptide Semax, an analogue of the N-terminal adrenocorticotropic hormone fragment (4-10) (ACTH(4-10)), has been shown to exert a number of neuroprotective effects. There are some investigations that connected these effects with the increase of neurotrophin gene expression under the peptide drug application in neuron cell cultures [M.I. Shadrina, O.V. Dolotov, I.A. Grivennikov, P.A. Slominsky, L.A. Andreeva, L.S. Inozemtseva, S.A. Limborska, N.F. Myasoedov, Rapid induction of neurotrophin mRNAs in rat glial cell cultures by Semax, an adrenocorticotropic hormone analogue, Neurosci. Lett. 308 (2001) (2) 115-118]. In this work, we examined the action of Semax on rapid changes of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) gene expression in vivo. Male Wistar rats were treated for 1h with Semax (50 microg/kg, single intranasal application) and neurotrophin gene expression in rat brain was analyzed by real-time polymerase chain reaction (PCR). It was revealed that an intranasal application of Semax increased the expression of both neurotrophin genes in rat hippocampus. Bdnf gene expression also increased in the brainstem and cerebellum. Ngf gene expression decreased in rat frontal cortex. Thus, Semax induces rapid, gene- and region-specific changes in neurotrophin gene expression in normal rat brain.
The Influence of Selank on the Level of Cytokines Under the Conditions of "Social" Stress.
It was previously thought that inflammation and an immune response were the only factors capable of causing IL-1β, IL-6 and other cytokine`s production. In recent years data have appeared that stressful effects can also occupy an important place, enhancing production of IL- 1β, IL-6 and other cytokines; the result will be a change in the functional activity of a particular cell element, for example immunocompetent cells with subsequent development of inflammation, or a change in the functional activity of neurons. This experiment is aimed at studying the effect of the Selank glyprolin neuropeptide drug on the level of cytokines in animals under conditions of "social" stress, the results of which indicate the presence of stress-protective activity. White nonlinear rats were used as experimental animals. A model of confrontations between males was chosen to create a "social" stress. The animals were in pairs in a cage which were separated by a septum preventing physical contact but having openings that provide sensory contact. Each day, the septum was removed for 10 minutes leading in an overwhelming majority to agonistic collisions (confrontations). Laboratory animals were divided into 3 groups: a group of intact males, a group of animals that were subjected to stress (sensory contact) for 20 days and a group that received intraperitoneally Selank at a dose of 100 mcg/kg/day under conditions of 20-day stress. The level of cytokines under study was determined by enzyme-linked immunosorbent assay. As a result of the work performed to determine the concentration of pro-inflammatory and anti- inflammatory cytokines, it was found that in the serum of animals exposed to stress, there was a statistically significant increase in the level of IL-1β, IL-6 and TGF-β1 in individuals with both types of behavior. It should be noted that, under the conditions of this stressful impact, there was a tendency to decrease the concentration of IL-4 and increase the level of TNF-α but these indicators were not statistically significant. Evaluation of the effect of Semax on the level of the cytokines in a stress-induced state showed that this neuropeptide causes a decrease in the concentration of IL-1β and IL-6, restoration of the level of IL-4, as well as suppression of the production of TGF-β1 and TNF-α in these conditions. This peptide is able to reduce the concentration of IL-1β, IL-6 and TNF-α, as well as TGF-β1, practically reaching control values, when studying the effect of Selank on the level of cytokines under conditions of " social" stress. There is the need for a detailed study of the role of cytokines in the development of stress-induced changes in order to find optimal correction tools.
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