Cardiogen (AEDR): The Cardiac Bioregulator and What the Research Shows

Cardiogen is usually presented as the heart peptide of the Khavinson bioregulator family. The published record behind that label is small, and this article sets out what each study actually tested.

What Cardiogen is

Cardiogen is the tetrapeptide H-Ala-Glu-Asp-Arg-OH, abbreviated AEDR, with the molecular formula C18H31N7O9 and a molecular weight of about 489.5. The sequence is set out in a US patent filed by Khavinson and colleagues in 2004 and granted in 2010, which describes it as a synthetic peptide. The group's 2021 systematic review lists the name Cardiogen against the AEDR sequence, and a 2022 review describes AEDR as an active component of a polypeptide complex extracted from heart tissue, reporting that it was detected in that complex by mass spectrometry (Khavinson et al., 2021; Khavinson et al., 2022).

The heart association is consistent across the group's papers. It follows earlier work by the same network on peptide extracts of heart tissue, tested in rat infarction and ischaemia models and published in Russian. One 1990 report on such an extract, not on Cardiogen itself, described benefit in the first day after infarction alongside slower healing of the damaged zone later on (Pavlenko et al., 1990).

The proposed mechanism

The general bioregulator hypothesis holds that peptides of two to four residues can enter cells, reach the nucleus and interact with DNA and histone proteins, changing which genes are expressed. For AEDR the supporting evidence is indirect:

• Histone binding: in fluorescence experiments, AEDR was one of six short peptides that bound labelled wheat histones (Fedoreyeva et al., 2013). This is test tube biochemistry with plant proteins.
• Structural proteins: in cultured mouse embryonic fibroblasts, AEDR raised the cytoskeletal proteins actin, tubulin and vimentin two to five fold, and the nuclear lamins A and C two to three fold (Khavinson et al., 2012). The authors proposed this as the basis of its cardioprotective activity, but the cells were fibroblasts, not heart muscle cells.
• Cell entry: computer docking predicts that AEDR could bind the amino acid and peptide transporters LAT1, LAT2 and PEPT1 (Khavinson et al., 2023). This is a modelling result, not a measurement.

Notably, the group's own 2021 systematic review classes AEDR as a regulator of cardiovascular function, yet the references it gives for that entry are two in vitro binding studies rather than cardiac experiments.

What the studies show

Tissue cultures. In explant cultures from young and aged rats, Cardiogen stimulated the growth of heart tissue, in parallel experiments in which three other bioregulators stimulated lung, prostate and pancreas explants (Zakutskii et al., 2006). A follow-up in heart explants from rats aged 3 and 24 months reported that Cardiogen stimulated cell proliferation at both ages, whereas only two of 20 amino acids tested were active in tissue from old rats, and that it lowered the apoptosis-related protein p53 (Chalisova et al., 2009). Both are short reports in Russian.

Activity outside the heart. Cardiogen also increased the expression of differentiation factors, including the chemokine CXCL12 and ghrelin, in ageing cultures of human prostate fibroblasts (Kheifets et al., 2010). Taken with the fibroblast work above, this sits awkwardly with the idea of a heart-specific peptide.

Tumour model. In aged rats carrying a transplanted M-1 sarcoma, Cardiogen increased apoptosis of tumour cells and slowed tumour growth through haemorrhagic necrosis. The authors argued that it acted through the tumour's blood vessels rather than by killing tumour cells directly (Levdik and Knyazkin, 2009).

Heart protection. The findings most often quoted for Cardiogen come from the patent. It describes rat heart explants, isolated heart muscle cells under low oxygen, isolated perfused rat and guinea pig hearts recovering from ischaemia, and rats with coronary artery ligation, in which mortality was reported as 15% in the peptide group against 45% in controls, with smaller areas of necrosis. The group's 2022 review repeats the threefold reduction in mortality and cites the patent as its source. A patent is not peer reviewed, and we could not find these experiments published in a journal.

How strong is the evidence?

By conventional standards, weak. Four points stand out:

• One research network. Every study above came from Khavinson's group or close collaborators. We found no replication by an unaffiliated laboratory.
• Language and format. Three of the experimental papers are brief Russian language reports, and the in vivo heart results exist only in a patent.
• No human data. We found no published human study of any design.
• Tissue specificity is assumed, not shown. Effects have also been reported in fibroblasts and prostate cells.

The fair summary is early preclinical evidence from a single source: enough to justify controlled experiments in cardiac cells, not enough to say what Cardiogen does.

For background on the whole class, including where the tissue mapping comes from, see Bioregulator Peptides: What the Khavinson Research Actually Claims. The same approach is applied to Cartalax and Chonluten.

References

1. Khavinson VKh, et al. 2012. "Tetrapeptide H-Ala-Glu-Asp-Arg-OH stimulates expression of cytoskeletal and nuclear matrix proteins." Bulletin of Experimental Biology and Medicine 153(4):559-562. PMID 22977870
2. Chalisova NI, et al. 2009. "The effect of the amino acids and cardiogen on the development of myocard tissue culture from young and old rats." Advances in Gerontology 22(3):409-413. In Russian. PMID 20210190
3. Zakutskii AN, et al. 2006. "The tissue-specific effect of synthetic peptides-biologic regulators in organotypic tissues culture in young and old rats." Advances in Gerontology 19:93-96. In Russian. PMID 17152728
4. Kheifets OV, et al. 2010. "Peptidergic regulation of the expression of signal factors of fibroblast differentiation in the human prostate gland in cell aging." Advances in Gerontology 23(1):68-70. In Russian. PMID 20586252
5. Levdik NV, Knyazkin IV. 2009. "Tumor-modifying effect of cardiogen peptide on M-1 sarcoma in senescent rats." Bulletin of Experimental Biology and Medicine 148(3):433-436. PMID 20396706
6. Fedoreyeva LI, et al. 2013. "Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides." Biochemistry (Moscow) 78(2):166-175. PMID 23581987
7. Khavinson VK, et al. 2021. "Peptide Regulation of Gene Expression: A Systematic Review." Molecules 26(22):7053. PMID 34834147
8. Khavinson V, et al. 2022. "Senescence-Associated Secretory Phenotype of Cardiovascular System Cells and Inflammaging: Perspectives of Peptide Regulation." Cells 12(1):106. PMID 36611900
9. Khavinson VK, et al. 2023. "Feasibility of Transport of 26 Biologically Active Ultrashort Peptides via LAT and PEPT Family Transporters." Biomolecules 13(3):552. PMID 36979488
10. Pavlenko VS, et al. 1990. "Effects of a cardiac peptide preparation on the myocardium in ischemia." Biulleten Eksperimentalnoi Biologii i Meditsiny 110(8):127-129. In Russian. PMID 2291951
11. Khavinson VKh, et al. 2010. "Peptide substance restoring myocardium function." US Patent 7,662,789 B2.