Bronchogen

A synthetic tetrapeptide (Ala-Glu-Asp-Leu) from the Khavinson bioregulator family, attributed to bronchial mucosa and studied in rat lung-injury models and human bronchial epithelial cell cultures, with no human trials.

Also referenced as: AEDL, Ala-Glu-Asp-Leu, ADEL, Ala-Asp-Glu-Leu, Bronchogen peptide, AKS-B peptide complex

Also appears in: Longevity

What is Bronchogen?

Bronchogen is a synthetic tetrapeptide with the sequence Ala-Glu-Asp-Leu (AEDL), developed by Vladimir Khavinson’s group at the Saint Petersburg Institute of Bioregulation and Gerontology and patented in the United States in 2009 as a “peptide substance restoring respiratory organs function.” It belongs to the same family of short bioregulator peptides as Cardiogen, Vesugen, Pinealon and Vilon, each attributed to a particular tissue; Bronchogen is the member assigned to the bronchial mucosa. It appears in the research-peptide market as a lung and airway bioregulator, and in Russia the same peptide is sold in capsule form as a dietary supplement, not as a registered drug.

How it works

The Khavinson group’s working model is that very short peptides enter the cell nucleus, bind DNA at preferred sequences and shift the expression of tissue-specific genes. For Bronchogen the published support is in vitro and comes from the originating group and its collaborators.

• DNA binding and chromatin effects — differential scanning microcalorimetry showed the peptide raised the melting temperature of calf-thymus and mouse-liver DNA by about 3.1 °C over a narrow peptide-to-base-pair ratio, with binding to both strands and no adenine-thymine or guanine-cytosine preference (Monaselidze et al., Bulletin of Experimental Biology and Medicine, 150(3):375–377, 2011); in rat liver chromatin stripped of histone H1 and non-histone proteins, the same tetrapeptide unfolded nucleosome cores enough to release about 15% of core DNA (Monaselidze et al., Georgian Medical News, 2011)
• Sequence-preferential oligonucleotide binding — fluorescence-quenching work found that bronchogen, like epithalon and pinealon, preferentially bound deoxyribooligonucleotides containing CNG sites, with bronchogen favoring CTG-containing sequences; a later docking study mapped AEDL (and the tripeptide EDL) to a “ctcc” motif (Fedoreyeva et al., Biochemistry (Moscow), 76(11):1210–1219, 2011; Khavinson et al., Bulletin of Experimental Biology and Medicine, 162(2):288–292, 2016)
• Bronchial epithelial gene expression in culture — in human embryonic bronchoepithelial cell cultures the peptide altered levels of Ki67, Mcl-1, p53, CD79 and NOS-3 and the expression of the differentiation genes NKX2-1, SCGB1A1, SCGB3A2, FOXA1 and FOXA2, plus MUC4, MUC5AC and SFTPA1, with the strongest proliferative effect in late-passage (“old”) cultures; spectrophotometry, viscometry and circular dichroism placed the peptide-DNA interaction in the major groove at guanine N7 (Khavinson et al., Lung, 2014). An earlier paper reported tissue-specific stimulation of CXCL12 and Hoxa3 in aging bronchial cultures (Khavinson et al., Bulletin of Experimental Biology and Medicine, 153(1):148–151, 2012)
• Promoter methylation — in the same bronchial culture system, aging-related changes in NKX2-1 and SCGB1A1 expression tracked promoter methylation, while FOXA1, FOXA2, SCGB3A2 and SFTPA1 changed expression without methylation changes, so the authors concluded the peptide acts through more than one mechanism (Ashapkin et al., Biochemistry (Moscow), 80(3):310–322, 2015)

Research status

The evidence base is preclinical, almost entirely Russian-language or Russian-authored, and concentrated in a single school and its collaborators. No human study of Bronchogen has been published, and no clinical trial is registered.

• Patent-stage animal pharmacology (2004–2009): US Patent 7,625,870 (Russian priority June 2004, granted December 2009) describes rat models of Staphylococcus aureus lung infection, bleomycin-induced pulmonary fibrosis and sublethal hyperoxia in which daily intraperitoneal peptide at 0.2 µg/kg was reported to accelerate repair, reduce fibrosis and right-ventricular hypertrophy and raise alveolar-macrophage phagocytic indices, plus acute toxicity in mice, 90-day subacute toxicity in rats and six-month chronic toxicity in guinea pigs with no adverse effects reported other than a leukocyte-count rise at six months. These experiments appear only in the patent; the 2014 Lung paper cites the patent (its reference 9) as the source for its statement that the peptide “was effective on models of acute bacterial lung inflammation, fibrosis, and toxic lung damage.”
• Organotypic explant culture: Zakutskii et al. (2006) reported that bronchogen at 0.05 ng/mL stimulated lung explants from young and aged rats in a tissue-specific manner, alongside cardiogen, prostamax and pancragen in their respective tissues (Advances in Gerontology, 19:93–96, in Russian).
• Rat COPD model (2015–2017): a Saint Petersburg pulmonology group modeled COPD by 60-day intermittent nitrogen dioxide exposure and reported that one month of Bronchogen reversed goblet-cell hyperplasia, squamous metaplasia, lymphocytic infiltration and emphysema, restored ciliated cells, raised secretory IgA in lavage fluid and normalized bronchoalveolar cell counts and pro-inflammatory cytokines (Kuzubova et al., Bulletin of Experimental Biology and Medicine, 159(5):685–688, 2015); a follow-up report from the same group added a rise in surfactant protein B and a cytokine-enzyme profile of the lavage fluid (Titova et al., Russian Journal of Physiology, 103(2):201–208, 2017, in Russian). Group sizes, randomization and blinding are not described in the abstracts.
• Human cell culture: the Lung 2014 paper (192(5):781–791) and the 2012 and 2015 Bulletin and Biochemistry papers above are the only work in human tissue, and all use embryonic bronchial epithelial cultures rather than patient samples.
• Reviews and modeling: Khavinson et al. (2020) list AEDL among peptides that “induce lung and pancreatic cell differentiation” in a review of peptide regulation of cell differentiation (Stem Cell Reviews and Reports, 16(1):118–125), and a 2023 docking study included AEDL among 26 ultrashort peptides modeled as LAT1/LAT2/PEPT1 transporter ligands (Biomolecules, 13(3):552). Neither adds new experimental data on the lung.
• Plant work: the same tetrapeptide has been used by Moscow collaborators as a growth regulator in tobacco callus and seedling cultures (Biochemistry (Moscow), 82(4):521–528, 2017; International Journal of Molecular Sciences, 26(1):289, 2024), which says nothing about airway biology but shows how broadly the group applies the peptide.
• Human trials: none. A ClinicalTrials.gov search for Bronchogen, AEDL or Ala-Glu-Asp-Leu returns no interventional or observational study as of October 2026, and no human case series or trial is indexed on PubMed. There is no FDA or EMA filing, and in Russia the product is registered as a dietary supplement rather than a medicine, so no regulator has reviewed efficacy data.

Common dosage forms

Research vendors sell Bronchogen as lyophilized powder in vials for reconstitution, most often labeled 20 mg or 10 mg per vial and marked for research use only; it is also packaged in Khavinson-family combination sets alongside other organ-specific bioregulators, and some research retailers list a nasal-spray format. In Russia the peptide is sold under the Khavinson “Cytogen” label as oral capsules (0.2 g, with a later 0.275 g presentation) and tablets registered as a biologically active food supplement, each capsule stated to contain 100 µg of an “AKS-B” peptide complex of alanine, glutamic acid, aspartic acid and leucine. No pharmaceutical formulation exists in any market.

Key considerations

• Regulatory status: no approval in the United States or any other market as a drug, no registered clinical trial and no active clinical development. The Russian capsule product is a dietary supplement, which carries no efficacy review; the US patent on the peptide lapsed in 2017 for non-payment of maintenance fees. The Research Market status reflects regional supplement registration with no US approval or development program.
• Sequence is written two ways in the originating group’s own papers: the US patent (SEQ ID NO:1), the 2012 and 2016 Bulletin papers, the 2011, 2013 and 2015 Biochemistry (Moscow) papers and the 2020 review all give Ala-Glu-Asp-Leu (AEDL), while the two 2011 Tbilisi microcalorimetry papers and the 2014 Lung paper write Ala-Asp-Glu-Leu (ADEL) for a compound the Lung paper labels “Bronchogen” in its figures and ties to the AEDL patent. Research-market listings use AEDL. The two orders are chemically different peptides, and no publication addresses the discrepancy; a researcher comparing products against the literature should check which sequence a certificate of analysis actually reports.
• Single-school, preclinical evidence: every mechanistic and efficacy paper comes from the Khavinson group, its Saint Petersburg and Moscow collaborators or a Tbilisi biophysics group working with Khavinson; there is no independent replication, no human data and no dose-response or pharmacokinetic study in any species. The peptide-DNA gene-regulation model underpinning the whole family is not widely accepted outside this school.
• Safety data are thin and old: the only toxicology is the rodent and guinea-pig work in the 2004–2009 patent, which reported no adverse effects apart from a leukocyte rise in the six-month chronic study; nothing has been published in humans.
• Naming: Bronchogen should not be confused with Chonluten (Glu-Asp-Gly), a different Khavinson tripeptide that research vendors also market for the airways.