Research Dossier on Pinealon (EDR; Glu–Asp–Arg)

(Bioregulator Peptide)

Classification & Molecular Identity

Amino-acid sequence, molecular weight, structural motifs

• Common names: Pinealon, EDR peptide

• Sequence: Glu–Asp–Arg (three L-amino acids)

• Chemistry identifiers (free tripeptide): PubChem CID 10273502; empirical composition reported as C₁₅H₂₆N₆O₈ (hydration/protonation state dependent).PubChem

• Functional motifs: two acidic residues (Glu, Asp) followed by a basic residue (Arg). In several neural cell systems this motif associates with antioxidant and anti-excitotoxic readouts (reduced ROS, preserved viability) and gene-regulatory effects described below.PubMed

Pinealon is a small peptide, not a protein; it does not contain disulfide bonds or higher-order folds. Its small size implies rapid renal clearance and peptidase susceptibility in vivo unless stabilized by formulation/derivatization (see Pharmacokinetics & Stability).

Discovery history (lab, year, species)

• Work on pineal peptides and “ultrashort peptide bioregulators” emerged from Russian gerontology/peptide biology groups in the 1990s–2000s. Pinealon (EDR) appeared as a synthetic tripeptide cited for neuroprotective and anti-oxidative actions in cell and rodent models; a broader review of the EDR literature (2020) summarized mechanistic hypotheses and early clinical-style observations.PMC

• Prenatal stress model (rat): a 2012 PMC-indexed paper reported that EDR improved offspring cognition and increased neuronal resistance to oxidative stress in a maternal hyperhomocysteinemia model.PMC

• Amyloid synaptotoxicity models (2016–2021): tripeptide EDR preserved dendritic spine density and interfered with spine loss in AD-related in vitro and mouse paradigms.PubMed+1

Endogenous vs synthetic origin

• Endogenous: Pinealon is not a known endogenous hormone; it is a synthetic ultrashort peptide inspired by pineal-gland peptide research traditions.

• Synthetic origin: All research-grade Pinealon used in peer-reviewed studies is chemically synthesized; reports often place it in the broader class of ultrashort regulatory peptides thought to engage DNA/protein targets that regulate stress-response programs.PMC

Homologs, analogs, derivatives

• KED (Lys–Glu–Asp) and AEDG (Ala–Glu–Asp–Gly) (“Epithalon/Epitalon”) are closely studied pineal-lineage ultrashort peptides with overlapping neuroepigenetic claims in the same research tradition.PMC

• Other neuroactive tripeptides (e.g., GPE/GPR/GPD) have independent literature; they underscore that 3–4-mer peptides can exhibit neuroprotective effects in vitro and in vivo, though mechanisms and robustness vary.ScienceDirect

Historical Development & Research Trajectory

Key milestones

1. Cellular antioxidant & viability effects (2011). In cerebellar granule cells, neutrophils, and PC12 cells, Pinealon reduced ROS accumulation and decreased necrotic death under diverse oxidative challenges in a dose-dependent manner. Investigational in-vitro concentrations used in study: method-specific; see Rejuvenation Research 2011.PubMed

2. Prenatal insult mitigation (2012). In a maternal hyperhomocysteinemia model, perinatal Pinealon improved cognitive performance of offspring and enhanced neuronal oxidative-stress resistance. Study reports significant behavioral and histological benefits; dosing and schedule in paper.PMC

3. Dendritic spine preservation (2016–2017). EDR and related tripeptides prevented dendritic spine loss in amyloid synaptotoxicity paradigms and improved spine metrics in 5xFAD transgenic mice and cortical–striatal cultures derived from HD-bearing mice.PubMed+1

4. Neuroepigenetic proposals (2020–2022). EDR was proposed to activate gene expression programs linked to neuronal functional maintenance, reduce apoptosis, and interface with ARE-like regulatory elements. Several reviews examined possible DNA/RNA interactions of ultrashort peptides and epigenetic actions in neurodegeneration models.PMC+1

5. Human observational/experimental mentions. A 2020 molecular review referenced open-label/observationaluses (e.g., patients with traumatic brain injury consequences/cerebrasthenia) with reported improvements in memory and headache indices in addition to standard therapy; these are not randomized clinical trials and warrant cautious interpretation.PMC

6. Cellular aging models (2024). Tripeptides EDR/KED/AEDG protected induced cortical neurons generated from aged human fibroblasts in an in-vitro neuronal aging model, aligning with prior oxidative-stress and synaptotoxicity findings.MDPI

Paradigm shifts & controversies

• From antioxidant to epigenetic regulator. Early reports emphasized ROS restraint/anti-necrosis; later work proposed direct gene-regulatory interactions (see Mechanisms). The molecular basis for sequence-specific DNA recognition by ultrashort peptides remains debated.PMC

• Translational evidence gap. Human randomized trials dedicated to Pinealon are not available; many clinical inferences derive from small, open-label, or non-randomized settings in the Russian-language literature or secondary reviews. Generality, blinding, and controls are limited.PMC

• Reproducibility and scope. Most positive data are from a few research networks; independent multicenter replication is limited to date.

Evolution of scientific interest

Focus expanded from pineal gerontology to neuroprotection (AD/HD models), prenatal stress mitigation, and cellular aging in human-derived neurons. Publications increasingly discuss epigenome-linked mechanisms, but the field remains preclinical-heavy.

Mechanisms of Action

Primary and secondary interactions

• Direct “receptor” unknown. No canonical, high-affinity cell-surface receptor for Pinealon has been validated. Evidence instead favors intracellular actions that modulate gene expression and oxidative response pathways. Status: Not established for a specific receptor.PMC

• Antioxidant/anti-necrotic actions. EDR limits ROS accumulation and reduces necrosis in neuronal and non-neuronal cells exposed to oxidative stressors (e.g., receptor-dependent and independent). Proposed consequences include membrane stabilization, mitochondrial support, and secondary anti-apoptotic effects.PubMed

• Neuroepigenetic regulation. Reviews and experimental studies suggest that EDR can influence transcription of genes involved in neuronal maintenance, synaptic plasticity, and stress responses; binding sites for EDR were postulated in promoter regions (e.g., CALM1) with downstream effects on dendritic spines and synaptic resilience in AD models. These claims are promising but require further biochemical proof of direct DNA binding in vivo.MDPI

Intracellular signaling pathways

• Redox/SURVIVAL axes: By antagonizing ROS accumulation, EDR may indirectly stabilize NF-κB, Nrf2-ARE, and mitochondrial pathways governing oxidative stress tolerance; direct demonstrations vary across models.PubMed

• Synaptic plasticity: EDR preserves dendritic spine density under amyloid synaptotoxicity and Huntington-linked models; the effect aligns with gene-expression changes in synaptic structure/function genes reported in molecular studies.PubMed

• Chromatin-level claims: Ultrashort peptides are proposed to contact DNA or transcriptional complexes, shifting gene expression relevant to neuroinflammation and plasticity—an area of active investigation with limited mechanistic crystallography/biophysics.PMC

CNS vs peripheral effects

• CNS evidence: Most experimental work involves neuronal cultures, rodent brains, prenatal brain developmentmodels, and AD/HD paradigms, indicating predominant CNS-oriented inquiry.PMC+1

• Peripheral readouts: Non-neuronal cells (e.g., neutrophils) also show ROS suppression by EDR, suggesting broader cytoprotection potential.PubMed

Hormonal, metabolic, immune interactions

• Neuroimmune links. Reviews of ultrashort peptides (AEDG/KE/EDR) describe cytokine-expression changes and neuroinflammation modulation in AD-relevant contexts; EDR’s specific immune signaling still requires direct causal mapping in vivo.PMC

Evidence grading (A–C)

• A (replicated in multiple systems): Antioxidant/anti-necrotic actions in vitro; prenatal-stress mitigation in rats; dendritic spine preservation in AD-linked paradigms (in vitro and mouse).PubMed+2PMC+2

• B (translational/observational): Human exercise/clinical analogs are sparse; a review cites open-labelimprovements with standard therapy in selected neurology cohorts—non-randomized and hypothesis-generating only.PMC

• C (uncertain/controversial): Direct DNA binding in vivo, canonical receptor, pharmacokinetic sufficiency after systemic dosing, and dose–response in humans are Not established.

Pharmacokinetics & Stability

ADME profile

• Absorption: No standardized, peer-reviewed bioavailability data by route (oral, intranasal, parenteral) are available for Pinealon. Not established.

• Distribution: As a 3-mer, Pinealon is expected to distribute largely in extracellular fluid with rapid renal filtration. Plasma protein binding is presumed minimal. Not established experimentally.

• Metabolism: Likely rapid proteolysis to free amino acids or dipeptides by peptidases; direct metabolite mapping in vivo is Unknown.

• Excretion: Expected renal clearance of small fragments; quantitative human excretion kinetics Not established.

Plasma half-life & degradation pathways

• No human or animal plasma t½ values have been published for native EDR to our knowledge. Given its size and lack of cyclization or bulky modifications, a short t½ is anticipated. Not established.

Stability in vitro & in vivo

• In vitro: Activity is recorded over short experimental windows in aqueous buffers and culture medium.

• In vivo: Reported benefits in prenatal and neurodegeneration models imply that exposure was sufficient to drive CNS effects under the tested schedules; however, PK–PD coupling remains unquantified.

Storage/reconstitution considerations

Peer-reviewed literature does not provide generalized, vial-specific shelf-life/reconstitution data for Pinealon; standard peptide handling (cold chain, protect from light, avoid repeated freeze–thaw) applies at research scale.

Preclinical Evidence

1) Oxidative-stress models (cells)

• Rejuvenation Research (2011). EDR reduced ROS and necrotic cell death across neuronal (cerebellar granule) and non-neuronal (neutrophils, PC12) systems. Experimental triggers included receptor-dependent and independent oxidative stimuli. Investigational in-vitro concentrations used in study; dose–response was demonstrated.PubMed

2) Prenatal hyperhomocysteinemia (rats)

• Int. J. Clin. Exp. Med. (2012). Maternal methionine load induced prenatal hyperhomocysteinemia; pinealon (Glu–Asp–Arg) improved offspring cognition and enhanced neuronal resistance to oxidative damage, including cerebellar neuron outcomes. Investigational perinatal dosing used in study; behavioral/spinocerebellar assays reported.PMC

3) AD/HD-related synaptotoxicity and spine biology

• Kraskovskaya et al. (2017). EDR restored dendritic spine numbers in cultured neurons under amyloid synaptotoxic stress (AD-related model), nominating EDR as a candidate neuroprotective agent for further study.PubMed

• Khavinson et al. (2016 PDF; 2021 MDPI/PMC). EDR and KED prevented dendritic spine elimination in in vitro amyloid models and were associated with spine preservation in 5xFAD mice; epigenetic involvement and gene-binding site hypotheses (e.g., CALM1) were discussed. Some in-vivo dosing is reported for KED (e.g., 400 µg·kg⁻¹ i.p. daily in 5xFAD), while EDR dosing is model-specific; details in the cited papers.PMC+1

4) Human-cell neuronal aging (2024)

• Induced cortical neurons from aged donors. Short peptides EDR/KED/AEDG protected induced neuronsderived from aged human fibroblasts, indicating cytoprotective and anti-aging effects in a human-derivedcellular context.MDPI

5) Behavioral/stress paradigms in aged rats

• Acute hypobaric hypoxia / mild hypothermia (aged rats). A PubMed-indexed study compared Cortexin vs Pinealon under stress; Cortexin showed stronger effects on free-radical processes/caspase-3, but Pinealonexerted measurable behavioral/neurochemical influences. Investigational dosing detailed in the paper.PubMed

6) Other reports summarized in reviews

• Gene-expression activation of proteins maintaining neuronal function and reduction of apoptosis in vitro/in vivo; normalization of behavior in animals; memory improvements in selected elderly cohorts with standard therapy(non-randomized). These reports appear chiefly in reviews that aggregate Russian-language literature and should be viewed as hypothesis-generating pending randomized replication.PMC

Selected investigational examples (where numerics are reported)

• KED (comparative peptide) in 5xFAD: 400 µg·kg⁻¹ i.p. daily from 2–4 months in study of dendritic spines in AD model (contextual benchmark; EDR also studied in parallel in vitro/in vivo).MDPI

• Pinealon prenatal model: perinatal schedule improved cognition and oxidative-stress resistance in offspring (see methods for timing/dose).PMC

• Cell studies: concentration-dependent ROS reductions in neurons/PC12/neutrophils (see Rejuvenation Research 2011 methods).PubMed

Caveat: The preclinical base is positive but heterogeneous and concentrated in a limited number of labs; pharmacokinetic and exposure–response frameworks are largely missing.

Human Clinical Evidence

Randomized, blinded trials

• None identified for Pinealon/EDR as a standalone intervention in PubMed/PMC/ClinicalTrials.gov at the time of writing. Not established.

Observational / open-label reports (cited within reviews)

• A 2020 PMC-indexed review references 72 patients with long-term sequelae of traumatic brain injury/cerebrasthenia receiving oral Pinealon in addition to standard therapy, with reported improvements in memory/headache indices/emotional balance. These reports lack randomization/blinding/independent replication and are insufficient to infer efficacy.PMC

Safety signals/adverse events

• Peer-reviewed publications provide little systematic human safety data specific to Pinealon. Reviews and bench studies report good in-vitro tolerance and rodent tolerability under experimental conditions, but first-in-human PK/PD, dose escalation, and adverse-event capture for EDR are not published. Human safety: Unknown.

ClinicalTrials.gov IDs

• Searches did not yield registered, interventional trials specifically of Pinealon/EDR with posted results. Not established.

Comparative Context

Related peptides

• KED (Lys–Glu–Asp) and AEDG (Ala–Glu–Asp–Gly; Epitalon/Epitalon) share ultrashort size and neuroprotective/geroprotective claims in overlapping literature; KED has reported in-vivo dosing in 5xFAD mice (400 µg·kg⁻¹ i.p.) as a comparator context for tripeptides.MDPI

• Short neuroactive peptides (e.g., GPE/GPR) illustrate that 3–4-mers can modulate amyloid or excitotoxic injury in rodent/cell models, though translational success has been limited and mechanism often incomplete.ScienceDirect

Advantages (research perspective)

• Small, defined tripeptide with robust in-vitro ROS–viability signals and preclinical protection in developmental and amyloid synaptotoxicity contexts.

• Potential “neuroepigenetic” lever: reports of transcriptional modulation in neuronal genes (e.g., CALM1) motivate omics-based mapping.MDPI

Disadvantages / constraints

• Pharmacokinetic unknowns: bioavailability, half-life, and brain penetration are not defined; likely short systemic exposure.

• Human evidence gap: no randomized trials; open-label findings must be regarded as preliminary.

• Mechanistic uncertainty: receptor/direct DNA binding are unresolved; hypotheses outpace biophysical validation.

Research category placement

Pinealon (EDR) is best classified as a research-use ultrashort peptide for neuroprotection, oxidative-stress biology, and synaptic plasticity models, with emerging neuroepigenetic hypotheses.

Research Highlights

• Cellular cytoprotection: EDR reduces ROS and necrosis across multiple cell types under oxidative stress—reproducible in vitro.PubMed

• Prenatal brain protection: In maternal hyperhomocysteinemia, perinatal Pinealon improved offspring cognitionand enhanced neuronal stress resistance.PMC

• Synaptic preservation: EDR preserves dendritic spine density in amyloid models (in vitro; mouse), nominating it for AD-related synaptic resilience studies.PubMed

• Neuroepigenetic direction: Reviews propose gene-expression and possibly promoter-target interactions (e.g., CALM1), but direct in-vivo binding remains to be demonstrated rigorously.MDPI

Conflicting/uncertain areas

• Clinical efficacy remains unproven; reported open-label observations are low-quality evidence and should be treated as exploratory.PMC

• PK/brain access and dose–exposure–response relationships are unknown.

• Mechanistic biophysics (specific DNA/protein partners in vivo) requires independent confirmation.

Potential Research Applications (no clinical claims; research-only framing)

1. Oxidative-stress pathways

   • Use EDR in neuronal and glial ROS models to dissect Nrf2-ARE and mitochondrial response dynamics; pair with RNA-seq/proteomics to map downstream networks.PubMed

2. Synaptotoxicity & plasticity

   • Test EDR against Aβ-induced spine loss and glutamate excitotoxicity; quantify mushroom/filopodia spinechanges and synaptic protein expression (e.g., PSD-95). Extend to 5xFAD and HD slice cultures.PubMed

3. Prenatal/early-life models

   • Expand perinatal studies beyond hyperhomocysteinemia to include maternal inflammation/hypoxiamodels; link behavioral and transcriptomic outcomes with oxidative biomarkers.PMC

4. Human-cell aging platforms

   • In aged donor–derived induced neurons, profile EDR’s impact on mitochondrial respiration, proteostasis, and DNA-damage signatures; compare with KED/AEDG.MDPI

5. Mechanistic biophysics

   • Pursue DNA-interaction assays (EMSA, DAP-seq, ChIP-exome) and proteomic pull-downs to define EDR-binding partners (if any) and validate promoter-target specificity in neurons.PMC

6. Formulation/PK feasibility

   • Explore stabilization (e.g., backbone modification, N-terminal acetylation/C-terminal amidation, nano-formulations) to quantify in vivo half-life and brain exposure, establishing PK–PD relationships for future translational steps.

Safety & Toxicology

Preclinical

• In vitro and rodent studies report cytoprotective effects and functional improvements without major safety findings at experimental exposures; standardized GLP evaluations (repeat-dose, genotoxicity, reproductive, carcinogenicity) for EDR are Not established in the public domain.PubMed+1

Human

• Systematic human safety data specific to Pinealon are not available. Mentions of oral EDR “in addition to standard therapy” come from non-randomized sources and do not substitute for safety studies. Human safety: Unknown.PMC

Data gaps

• First-in-human PK/PD, dose escalation, tolerability, immunogenicity, and drug–drug interactions are not reported.

• Long-term surveillance and organ-system safety signals remain undocumented.

Limitations & Controversies

• Evidence concentration: A large share of Pinealon literature originates from a limited set of groups; independent, multicenter replication is needed.

• Mechanistic claims ahead of proof: Direct epigenetic targeting and promoter binding remain hypotheseswithout gold-standard in-vivo validation.PMC

• Clinical vacuum: Absence of randomized, controlled human trials precludes efficacy/safety conclusions; open-label outcomes should be treated as preliminary.PMC

• PK uncertainty: Without bioavailability and half-life data, it is not possible to design evidence-based systemic dosing frameworks.

Future Directions

1. Rigorous mechanistic validation

   • Demonstrate sequence-specific DNA/protein interactions by orthogonal methods (ChIP-seq with peptide-crosslinkable tags, footprinting, structural biophysics) and causal links to synaptic genes (e.g., CALM1).MDPI

2. Exposure–response foundations

   • Produce rodent PK (plasma/brain microdialysis), tissue distribution, and metabolite maps for native EDR and stabilized analogs; link to behavioral and spine PD.

3. Reproducibility & breadth

   • Independent labs to replicate prenatal and AD-model data with pre-registered protocols and blindedoutcome scoring.

4. Comparative peptide benchmarking

   • Head-to-head assays of EDR vs KED vs AEDG across neuronal aging and synaptotoxic models to define class effects vs sequence-specific advantages.MDPI

5. Translational gatekeeping

   • Only after robust PK/PD, toxicology, and replication should early human studies be considered, starting with safety, pharmacokinetics, and exploratory biomarkers (e.g., cognitive tasks, neurophysiology, fluid markers), and conducted under formal regulatory oversight.

References

1. Khavinson V, et al. EDR Peptide: Possible Mechanism of Gene Expression and Protein Synthesis Regulation Involved in the Pathogenesis of Alzheimer’s Disease. Molecules. 2020;25(1):140. PMC: PMC7795577. (Mechanistic review; human observational mentions; gene-regulatory hypotheses.) PMC

2. Ostrovskaya RU, et al. Pinealon protects the rat offspring from prenatal hyperhomocysteinemia. Int J Clin Exp Med. 2012;5(2):152-160. PMC: PMC3342713. (Prenatal model; cognition and oxidative-stress resistance.) PMC

3. Khavinson V, et al. Neuroprotective Effects of Tripeptides—Epigenetic Regulators in Alzheimer’s Disease.Pharmaceuticals. 2021;14(6):515. PMC: PMC8227791. (Dendritic spines, epigenetic framework; comparative KED dosing in 5xFAD.) PMC

4. Kraskovskaya N, et al. Tripeptides Restore the Number of Neuronal Spines under Amyloid Synaptotoxicity. Bull Exp Biol Med. 2017;163(2):198-201. PMID: 28853087. (EDR/KED spine preservation under Aβ stress.) PubMed

5. Khavinson V, et al. Pinealon increases cell viability by suppression of free radical levels and activating proliferative processes. Rejuvenation Res. 2011;14(5):587-596. PMID: 21978084. (Dose-dependent ROS limitation; multi-cell-type cytoprotection.) PubMed

6. Ilina A, et al. Neuroepigenetic Mechanisms of Action of Ultrashort Peptides in Alzheimer’s Disease. Int J Mol Sci.2022;23(8):4259. (Promoter-site hypotheses; CALM1; integration across EDR/KED/AEDG.) MDPI

7. Kraskovskaya N, et al. Short Peptides Protect Fibroblast-Derived Induced Neurons from Aging. Int J Mol Sci.2024;25(21):11363. PMID: 39518916. (Aged human iNeurons; EDR/KED/AEDG protective effects.) PubMed

8. Shumilina AV, et al. [Pinealon and Cortexin influence on behavior and neurochemical indices in aged rats under hypoxia/hypothermia]. Adv Gerontol. 2017;30(1):122-127. PMID: 28509493. (Comparative stress model in 18-month-old rats.) PubMed

9. Khavinson V, et al. Neuroepigenetic mechanisms… (companion PMC and MDPI versions). (Overlap with refs 1 and 3 for completeness.) PMC

10. PubChem. Glu–Asp–Arg (EDR) compound entry. CID 10273502. (Identifiers/physicochemical reference.) PubChem

Investigational amounts cited above:
• Cell studies (Rejuvenation Res. 2011)—concentration-dependent effects in neuronal and non-neuronal cultures (investigational concentrations used in study). PubMed
• Perinatal rat model (Int J Clin Exp Med. 2012)—maternal/offspring schedules reported to improve cognition/oxidative resilience (investigational dosing used in study). PMC
• AD models (Pharmaceuticals 2021)—comparative KED 400 µg·kg⁻¹ i.p. daily in 5xFAD (context for tripeptide class; EDR also evaluated in vitro/in vivo). MDPI

⚠️ Disclaimer This peptide is intended strictly for laboratory research use. It is not FDA-approved or authorized for human use, consumption, or therapeutic application.