Epithalon (AEDG): Synthetic Tetrapeptide in Cellular Aging Research

Classification

Synthetic Tetrapeptide / Bioregulator

Molecular Formula

C₁₄H₂₂N₄O₈

Molecular Weight

~374 Da

Sequence

Ala-Glu-Asp-Gly (AEDG)

Parent Protein

Epithalamin (pineal peptide complex)

Year Synthesized

1990s

Research Focus

Cellular aging, pineal function, circadian rhythm, telomere biology

Introduction

Epithalon (also referred to as Epitalon or AEDG tetrapeptide) is a synthetic peptide with the sequence alanyl-glutamyl-aspartyl-glycine (Ala-Glu-Asp-Gly). It was designed as a synthetic analogue of the active site of epithalamin, a peptide complex originally isolated from the bovine pineal gland by Russian researchers led by Professor Vladimir Khavinson (Khavinson et al., 2002). The tetrapeptide was developed to recapitulate the biological activities of the larger epithalamin complex while providing chemical stability and reproducibility for research purposes. Research on Epithalon has been conducted primarily within the framework of the Russian peptide bioregulator school, which has investigated short peptides for their effects on age-related physiological decline. The peptide has been studied for its effects on pineal gland function, circadian rhythm regulation, telomerase activity, and various parameters associated with cellular aging (Khavinson & Malinin, 2005).

Molecular Characteristics

Epithalon is a linear tetrapeptide composed of four amino acids in sequence: L-alanine (Ala), L-glutamic acid (Glu), L-aspartic acid (Asp), and glycine (Gly). With a molecular weight of approximately 374 Da, it is one of the smallest peptides studied in the context of aging research.

The small size and simple linear structure of Epithalon contribute to its stability and facilitate its synthesis through standard solid-phase peptide synthesis (SPPS) methods.

For researchers studying Epithalon and other short bioactive peptides, high-purity research compounds with comprehensive analytical documentation are available through RPL Peptides.

The peptide is highly hydrophilic, with a predicted isoelectric point around pH 3.5, reflecting the presence of two acidic amino acid residues (glutamic and aspartic acids).

The peptide chain lacks any secondary structure stabilizing elements such as disulfide bridges or proline-induced turns, suggesting that its biological activities are mediated through the specific spatial arrangement of its charged side chains upon interaction with target proteins.

The rationale for the AEDG sequence was derived from structure-activity relationship studies of epithalamin, which identified this tetrapeptide motif as the minimal active fragment responsible for the biological effects of the parent pineal peptide complex.

Research has suggested that the C-terminal glycine residue is important for biological activity, as its removal substantially reduces the peptide's effects in cell-based assays (Khavinson et al., 2002).

Detailed molecular characterization data for Epithalon and similar research peptides can be accessed through the RPL Peptides Data Center.

Biological Research Background

The research history of Epithalon is rooted in investigations of the pineal gland's role in aging. The pineal gland, which produces the hormone melatonin, undergoes functional decline with age, characterized by reduced melatonin secretion and altered circadian rhythms. Khavinson and colleagues hypothesized that peptide regulators derived from the pineal gland could counteract this age-related decline (Khavinson & Malinin, 2005).

Mechanism of Action

The proposed mechanisms of Epithalon action are multifaceted and not fully characterized at the molecular level:

• Telomerase Activation: One of the most distinctive reported effects of Epithalon is its ability to activate telomerase, the enzyme responsible for maintaining telomere length.

Studies have reported that Epithalon treatment can increase telomerase activity in cultured human fibroblasts, potentially counteracting telomere shortening associated with cellular senescence (Khavinson et al., 2003). - Gene Expression Regulation: Epithalon has been shown to influence the expression of genes involved in cell cycle regulation, apoptosis, and differentiation.

Research using cDNA microarrays has identified changes in the expression of genes related to telomere maintenance, DNA repair, and cellular stress response following Epithalon treatment. - Circadian Rhythm Modulation: As a pineal-derived peptide, Epithalon has been studied for its effects on circadian rhythm regulation.

Research in animal models has reported that Epithalon can restore age-related declines in melatonin production and normalize circadian patterns of activity (Khavinson et al., 2002). - Antioxidant Effects: Some studies have reported that Epithalon can reduce oxidative stress markers in various tissues, potentially through modulation of antioxidant enzyme expression and activity.

Current Research Landscape

The research landscape for Epithalon is characterized by a substantial body of work from Russian and Eastern European research groups, with increasing international interest in recent years. Researchers exploring peptide bioregulators and aging research may also find relevant information in the FOXO4-DRI profile, another peptide investigated in cellular senescence research. Key research areas include:

• Cellular Senescence Models: Studies examining the effects of Epithalon on replicative senescence in cultured cells.

Research has reported that Epithalon can extend the replicative lifespan of human fibroblasts and delay the onset of senescence-associated phenotypes (Khavinson et al., 2003). - Telomere Biology: Investigation of Epithalon's effects on telomere length and telomerase activity.

Studies have used various experimental systems, including cultured human cells and animal models, to evaluate the peptide's ability to influence telomere dynamics. - Pineal and Neuroendocrine Research: Continued research on the effects of Epithalon on pineal gland function, melatonin production, and neuroendocrine regulation.

This work builds on the original identification of epithalamin as a pineal peptide complex. - Cancer Research: Some studies have investigated Epithalon in the context of cancer cell biology, evaluating its effects on tumor cell proliferation and differentiation.

Results have been mixed and context-dependent. - Retinal and Vision Research: Several studies have examined Epithalon's effects on retinal function and morphology, with reports suggesting protective effects in models of retinal degeneration (Khavinson et al., 2011).

For research planning and experimental design support, the RPL Peptides Research Tools platform provides peptide calculators and utilities for researchers working with short peptides and bioregulators.

Research Status: Epithalon is a research chemical and is not approved for clinical use by the FDA, EMA, or other major Western regulatory agencies. It has been used in clinical research settings in Russia and some Eastern European countries. All information is presented for educational and research informational purposes only.

Related Research

MOTS-c Research Profile

Mitochondrial peptide in aging and metabolic regulation.

FOXO4-DRI Research Profile

Interfering peptide in cellular senescence research.

SS-31 Research Profile

Mitochondria-targeted peptide for cellular health research.

Frequently Asked Questions

What is the relationship between Epithalon and epithalamin? +

Epithalamin is a peptide complex originally isolated from the bovine pineal gland by Russian researchers. Epithalon (AEDG) is a synthetic tetrapeptide representing the minimal active fragment of epithalamin. The tetrapeptide was developed to provide a chemically defined, reproducible molecule that retains the biological activities of the parent complex.

Does Epithalon activate telomerase? +

Some published studies have reported that Epithalon treatment can increase telomerase activity in cultured human cells. Research by Khavinson and colleagues demonstrated that Epithalon could activate telomerase in human fibroblasts and increase the expression of the telomerase catalytic subunit (hTERT). However, these findings require further independent replication and the molecular mechanism of this effect remains to be fully characterized.

Has Epithalon been studied in human clinical trials? +

Epithalon has been studied in clinical settings primarily in Russia and Eastern Europe. Studies have reported effects on immune function, endocrine parameters, and measures of biological age in human subjects. However, these studies have generally been small in scale and do not meet the rigorous standards of randomized controlled trials required for regulatory approval in Western jurisdictions.

How does Epithalon affect circadian rhythms? +

Epithalon has been reported to normalize age-related disruptions in melatonin production and circadian rhythm patterns. In animal models, treatment with Epithalon has been shown to restore melatonin levels and improve circadian patterns of locomotor activity in aged animals. The peptide is thought to act on pinealocytes to support normal melatonin synthesis.

What is the significance of the AEDG sequence? +

The AEDG sequence (alanine-glutamic acid-aspartic acid-glycine) was identified as the minimal active fragment of the epithalamin peptide complex. Structure-activity studies determined that this tetrapeptide sequence retains the biological activity of the larger parent molecule. The C-terminal glycine residue appears to be particularly important for biological activity.

What is the peptide bioregulator concept? +

The peptide bioregulator concept, developed by Russian scientists Vladimir Khavinson and colleagues, proposes that short peptides derived from tissue-specific protein hydrolysates can regulate cellular function and gene expression in a tissue-specific manner. Epithalon is one of several peptides developed within this framework, which also includes peptides derived from the thymus, cartilage, and other tissues.

Does Epithalon affect immune function? +

Some research has suggested that Epithalon may have immunomodulatory effects. Studies in animal models have reported changes in T-cell数量和功能 after Epithalon treatment, particularly in aged animals. These immune effects may be secondary to the peptide's effects on the neuroendocrine axis, given the close relationship between the pineal gland and the immune system.

About RPL Peptides: RPL Peptides is a supplier of high-purity research peptides with comprehensive analytical documentation including HPLC, LC-MS, and Certificates of Analysis (COA). For researchers requiring certified reference materials for laboratory investigations, visit rplpeptides.com or explore detailed molecular data at the RPL Peptides Data Center.

References

1. Khavinson VK, Malinin VV. Gerontological aspects of genome peptide regulation. Biochemistry (Moscow). 2005;70(4):404-413. doi:10.1007/s10541-005-0138-1
2. Khavinson VK, Morozov VG, Malinin VV, et al. Effect of epithalon on the function of the pineal gland in elderly humans. Advances in Gerontology. 2002;9:101-109.
3. Khavinson VK, Bondarev IE, Butyugov AA, et al. Peptide promotes overcoming of the division limit in human somatic cells. Bulletin of Experimental Biology and Medicine. 2003;135(5):503-506. doi:10.1023/A:1024946820347
4. Khavinson VK, Linkova NS, Kornev AB, et al. Peptide regulation of gene expression and protein synthesis in bronchial epithelium. Advances in Gerontology. 2011;24(4):555-565.
5. Korkushko OV, Khavinson VK, Shatilo VB, et al. The effect of epithalon on the circadian rhythm of melatonin secretion in elderly humans. Neuroendocrinology Letters. 2004;25(4):259-262.
6. Khavinson VK, Solovyov AY, Zhilinskaya IN, et al. Epithalon peptide as a telomerase activator. Bulletin of Experimental Biology and Medicine. 2012;152(5):601-604. doi:10.1007/s10517-012-1586-4
7. Khavinson VK, Kuznik BI, Linkova NS, et al. Peptide regulation of the expression of genes involved in cell cycle regulation. Molecular Biology. 2013;47(6):857-864. doi:10.1134/S0026893313060035
8. Khavinson VK, Linkova NS, Kornev AB, et al. Peptide regulation of gene expression and protein synthesis in retinal pigment epithelium cells. Bulletin of Experimental Biology and Medicine. 2011;151(5):640-642. doi:10.1007/s10517-011-1395-1
9. Khavinson VK, Zemchikhina VN, Trofimov AV. Peptide regulation of pineal gland function in aging. Neuroendocrinology Letters. 2003;24(Suppl 1):53-56.
10. Khavinson VK, Popovich IG, Linkova NS, et al. Peptide regulation of aging: the role of the pineal gland and thymus. Advances in Gerontology. 2015;5(2):77-83. doi:10.1134/S207905701502007X