Cardiogen

Cardiogen (H-Ala-Glu-Asp-Arg-OH; AEDR tetrapeptide; molecular formula C18H31N7O9; molecular weight 489.48 g/mol) is a synthetic tetrapeptide bioregulator developed by Vladimir Khavinson and colleagues at the Saint Petersburg Institute of Bioregulation and Gerontology as the cardiac-specific member of the Khavinson ultrashort peptide bioregulator family [1, 2]. The compound belongs to a class of synthetic two-to-seven-residue peptide sequences modeled on tissue-specific peptide fragments isolated from mammalian organ extracts, and is designated as the cardiovascular system bioregulator within this peptide family. Cardiogen shares the Ala-Glu-Asp tripeptide core with the cortical bioregulator Cortagen (Ala-Glu-Asp-Pro) and the pineal bioregulator Epithalon (Ala-Glu-Asp-Gly), differing from these compounds by the fourth-position arginine residue, a single amino acid substitution that determines cardiac tissue specificity within the Khavinson classification system [3, 4]. The principal molecular mechanism of Cardiogen, characterized through molecular modeling, cell culture, and organotypic myocardial tissue studies, is epigenetic regulation of gene expression through direct interaction of the tetrapeptide with double-stranded DNA in gene promoter regions and with histone proteins (H1, H2B, H3, H4), producing chromatin decondensation and reactivation of transcriptional programs in cardiac cells [5, 6, 7]. The cardioprotective activity, characterized in organotypic myocardial tissue cultures, embryonic fibroblast cultures, and coronary artery ligation animal models, includes stimulation of cardiomyocyte proliferation with concurrent suppression of cardiomyocyte apoptosis through p53 protein downregulation, upregulation of cytoskeletal proteins (actin, vimentin, tubulin) by up to five-fold and nuclear matrix proteins (lamin A, lamin C) by up to 2.5-fold relative to control, preservation of myocardial glycogen stores and cellular energy production structures under ischemic conditions, and a reported threefold reduction in mortality following experimental coronary artery ligation in treated versus control groups [8, 9, 10, 11]. In a separate line of investigation, Cardiogen demonstrated tumor-modifying activity against transplanted M-1 sarcoma in senescent rats, with dose-dependent inhibition of tumor growth mediated by hemorrhagic necrosis and stimulation of tumor cell apoptosis through a vascular mechanism rather than direct cytostatic effect [12]. The compound has been characterized in the context of the senescence-associated secretory phenotype of cardiovascular system cells and inflammaging, with evidence that the AEDR tetrapeptide regulates molecules involved in the inflammatory pathways contributing to age-related cardiovascular decline [13]. No formal pharmacokinetic studies have been published for Cardiogen as the isolated synthetic AEDR tetrapeptide. As a linear tetrapeptide with unprotected termini, the compound is expected to undergo rapid proteolytic degradation by aminopeptidases and carboxypeptidases in plasma and gastrointestinal fluid; however, molecular modeling studies have demonstrated that ultrashort peptides are substrates of the proton-coupled oligopeptide transporter (PEPT1/PEPT2) family carriers, supporting intestinal absorption and cellular uptake through active transport mechanisms [14, 15]. No human clinical trials have been published. The compound is not approved by the United States Food and Drug Administration, the European Medicines Agency, or any major Western regulatory authority. Cardiogen is registered in the Russian Federation as a biologically active additive and is commercially available there in capsule and sublingual formulations. It is supplied internationally as a research-grade lyophilized peptide by multiple peptide synthesis vendors at greater than 95 percent purity by high-performance liquid chromatography. This monograph reviews the chemistry, synthesis, and structural characterization of Cardiogen; the discovery and development history within the Khavinson bioregulatory peptide program; the molecular pharmacology including peptide-DNA binding, histone interaction, and cardiac gene expression modulation; the pharmacokinetic considerations for ultrashort peptides; the preclinical pharmacology across cardiac, inflammatory, and aging cell models; the clinical evidence base (absent); sourcing and quality verification; reconstitution and handling; stack interactions and combinations; adverse events and safety signal; and a comparative assessment of five cardioprotective or cardiac-repair peptide candidates (Vesugen, Thymosin beta-4, BPC-157, Cortagen, GHK-Cu) against Cardiogen on five competency standards.