Researchers cut off blood to part of a rat's brain for 90 minutes, then let it flow back. It's a standard lab model of stroke. Some of the rats got a seven-amino-acid peptide called Semax. The rest got saline.
A day later, 394 genes had changed activity in the Semax brains. For 312 of them, Semax pushed in the opposite direction to the stroke. Genes for nerve-cell communication switched up. Inflammation genes switched down. (Read the 2020 study, free.)
Then a second team checked whether the proteins followed. They did, and the answer depended on which part of the brain they sampled.
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Seven amino acids, borrowed from a hormone
Semax starts with four amino acids lifted from ACTH, the hormone that tells your adrenal glands to make cortisol. Researchers bolted three more on the end so the body breaks it down more slowly. That's the whole molecule.
The question was simple: after a stroke, when blood comes back but the damage keeps spreading, does Semax change how the injured tissue responds?
394 genes moved. 312 moved back.
Cells copy genes into RNA messages before making proteins. Read those messages and you can see which genes a cell is using right now. The team read messages from more than 17,000 genes in the injured brain tissue.
At four and a half hours, nothing cleared their bar. At 24 hours, 394 genes did: 191 up, 203 down.
Then they lined that list up against what the stroke itself did. For 312 genes, Semax pushed the opposite way. Genes the stroke had suppressed became more active. Genes the stroke had switched on quieted down.
Filippenkov et al., Genes, 2020, Figures 2–3. Counts of genes meeting the study's expression and statistical thresholds at 24 hours. These counts do not measure rescued cells or cognitive improvement. Tap the chart to open the paper.
The proteins followed
RNA is only an instruction. So in 2021 a second team measured the proteins themselves, 24 hours after the stroke (free full text).
JNK, a stress signal, went down. The stroke raised its active form in the deep injured region and in the cortex next to it. Semax lowered it in both.
CREB, a survival signal, came back. The stroke cut its active form in the deep region. Semax raised it again.
That's the RNA story showing up one level deeper: less stress signaling, more survival signaling.
The tissue next door responded too
The cortex beside the injury looked mostly intact under the microscope. Its proteins still moved.
Semax cut MMP-9, an enzyme that chews through the material around cells and blood vessels and can help break down the blood-brain barrier after a stroke. It also cut c-Fos, a stress-response switch. Both drops showed up in the cortex. Neither was significant in the deep injured core.
Same drug, same rats, different pattern right next door. Sample one spot and you miss half the story.
Sudarkina et al., International Journal of Molecular Sciences, 2021, Figures 2–3. Directions show statistically significant treatment-versus-saline differences at 24 hours. A dash means no significant difference was detected for that comparison. Tap the chart to open the paper.
Semax isn't available at Rebody Health yet. My company is planning a prescription Semax nasal spray, filled by a licensed U.S. compounding pharmacy instead of a research-chemical vial labeled "not for human use." Join the waitlist to hear if it launches.
What this does and doesn't show
These are injured rat brains, measured a day later. Sequencing groups were three rats each, and protein groups were five to seven. Neither study tested memory, focus or recovery of a skill. So this tells you where Semax acts after a stroke. It doesn't tell you what Semax does for a healthy person's concentration.
Before you buy any brain claim, ask what the study actually measured. Gene activity, a memory test and a patient regaining speech are three different answers.
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References
1. Filippenkov IB et al. Novel Insights into the Protective Properties of ACTH(4–7)PGP (Semax) Peptide at the Transcriptome Level Following Cerebral Ischaemia–Reperfusion in Rats. Genes, 2020;11:681. Open-access full text. 2. Sudarkina OY et al. Brain Protein Expression Profile Confirms the Protective Effect of the ACTH(4–7)PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia–Reperfusion. International Journal of Molecular Sciences, 2021;22:6179. Open-access full text.
For entertainment and education only. Not medical advice. Talk to your doctor before starting anything.