Bronchogen peptide: the lung bioregulator, from cell and rat studies to what is unknown

Bronchogen is a four-amino-acid synthetic peptide from the family of peptide bioregulators developed by Vladimir Khavinson and colleagues at the St Petersburg Institute of Bioregulation and Gerontology. The group designed short peptides from the amino-acid composition of organ extracts and tested each on the tissue it was meant for; the bronchogen bioregulator is the lung-directed member, first reported in 2006 alongside cardiogen for the heart, prostamax for the prostate and pancragen for the pancreas ^[9]. It belongs to the same series as epitalon, cortagen, pinealon, cartalax and the thymus-derived products thymalin and vilon.

A note on the sequence. Most of the group’s papers, and the PubChem record for bronchogen, give the sequence as Ala-Glu-Asp-Leu (AEDL) ^{[4] [7] [8]}. Two papers, including the 2014 study in the journal Lung and a 2011 DNA-binding study, write it as Ala-Asp-Glu-Leu (ADEL), with the two acidic residues in the other order ^{[1] [5]}. The authors treat these as the same product, and the difference may be a transcription inconsistency, but the two sequences are chemically different peptides with the same mass. A buyer comparing certificates of analysis should be aware that a mass of about 446.5 g/mol does not distinguish them.

Bronchogen should not be confused with chonluten, a tripeptide (Glu-Asp-Gly) that the group also describes as derived from bronchial epithelial cells and studied for anti-inflammatory effects on monocytes ^[12]. As with every one of the Khavinson peptides, the evidence base is narrow: the work comes from one group and its collaborators, much of it in the Bulletin of Experimental Biology and Medicine and in Russian-language journals, and no independent laboratory has replicated the lung findings.

The Khavinson group’s hypothesis is that short peptides enter the nucleus and change gene expression by binding DNA or histones. Bronchogen has more direct physical evidence for DNA binding than most of its relatives. In 2011, calorimetry in Tbilisi showed that bronchogen raised the melting temperature of calf thymus and mouse liver DNA by 3.1 °C at low peptide-to-base-pair ratios, stabilising the double helix without preferring AT-rich or GC-rich regions, and binding both strands mainly through the bases ^[5]. A companion study found that the tetrapeptide unfolded nucleosome cores in rat liver chromatin depleted of histone H1, releasing about 15% of core DNA, which the authors interpreted as increased accessibility of DNA for transcription ^[6]. In a 2011 fluorescence study, bronchogen bound preferentially to DNA fragments containing CTG sequences, whereas epitalon, pinealon and testagen preferred CAG ^[7], and a 2013 follow-up showed AEDL binding to the N-terminal tails of wheat histones H1, H2B, H3 and H4 ^[13].

The 2014 Lung paper added spectrophotometry, viscometry and circular dichroism data showing ADEL interacting with DNA in the major groove at the N7 position of guanine, and linked this to changes in gene expression in cultured human bronchial epithelial cells ^[1]. A 2023 modelling study proposed that the AEDL peptide, with EDR and AEDR, is among the short peptides best able to use the LAT1, LAT2 and PEPT1 transporters to enter cells ^[11]. All of this is consistent with the group’s model. None of it shows what happens to a dose of bronchogen given by mouth or injection to an animal or a person, because no pharmacokinetic study exists.

Claims about bronchogen benefits focus on the lungs: repair of the airway lining, protection against chronic bronchitis and COPD, and healthier lung ageing. The evidence is from cells, rats and plants.

Bronchial epithelial cells: in cultures of human embryonic bronchial epithelium at the first, seventh and fourteenth passages, ADEL regulated the levels of the proliferation marker Ki67, the anti-apoptotic protein Mcl-1, p53, CD79 and NOS-3, with the strongest activation of proliferation in the oldest cultures. It also raised expression of the differentiation genes NKX2-1, SCGB1A1, SCGB3A2, FOXA1 and FOXA2, and of MUC4, MUC5AC and SFTPA1, whose loss the authors associated with abnormal lung development ^[1]. An earlier study found that bronchogen tissue-specifically stimulated the differentiation factors CXCL12 and Hoxa3 in ageing bronchial cell cultures, while pancragen did the same in pancreatic cells and vesugen in fibroblasts, with the effect strongest in the oldest cultures ^[4]. The group’s 2020 review lists AEDL among the peptides that induce lung cell differentiation ^[10].

Bronchogen COPD research in rats: rats were exposed intermittently to nitrogen dioxide for 60 days to produce a model of chronic obstructive pulmonary disease, then treated with bronchogen for one month. The treated animals lost the goblet-cell hyperplasia, squamous metaplasia, lymphocytic infiltration and emphysema typical of the model, ciliated cells were restored, secretory IgA rose and the cell composition and cytokine profile of the bronchoalveolar space normalised, indicating less neutrophilic inflammation ^[2]. A 2017 Russian-language report from the same St Petersburg pulmonology group described the same model with additional measurements, including restored surfactant protein B in lavage fluid ^[3]. This is the most clinically relevant bronchogen research, and it was run by a university pulmonology institute rather than the peptide’s developers, though with the developers’ peptide. It is a single animal model, without a dose-response study or an independent replication.

Explant cultures: the first bronchogen paper found that, at 0.05 ng/mL, bronchogen stimulated lung explant cultures from young and old rats, while cardiogen, prostamax and pancragen stimulated their own target tissues ^[9].

Plants: unusually for a research peptide, bronchogen has a second life as a plant growth regulator. Russian agricultural biotechnologists found that AEDL, epitalon and vilon at 10⁻⁷ to 10⁻⁹ M altered growth and differentiation of tobacco callus cultures and the expression of CLE, KNOX1 and GRF genes ^[8], and later that AEDL stimulated root development in tobacco seedlings ^[14]. These studies are interesting as evidence that the peptide is biologically active at very low concentrations, but they say nothing about lungs.

There are none. We searched PubMed for bronchogen, AEDL, ADEL and both spellings of the sequence and found no clinical study, case series or case report, and there is no entry on ClinicalTrials.gov. The 2014 Lung paper states that the tetrapeptide was effective in models of acute bacterial lung inflammation, fibrosis and toxic lung damage in several studies ^[1], but these are animal models, and the primary reports are not accessible in English. The human material that exists is the work on cultured human embryonic bronchial cells ^{[1] [4]}, which shows effects on gene expression in a dish and cannot show a clinical effect.

Any statement that bronchogen has been shown to help people with asthma, bronchitis or COPD therefore comes from a seller or a forum rather than a study. The rat COPD data are a reasonable basis for a clinical trial, which has not been done.

There is no human timescale, because there is no human study. In the rat COPD model, bronchogen was given for one month after the 60-day exposure that produced the disease ^[2]. In cell cultures, effects on gene expression were measured over days ^[1]. Sellers in Russia market Khavinson-series peptides as courses of 10 to 30 days, which is a marketing convention rather than a finding.

These are laboratory figures, and none is a recommendation. In lung explant cultures, bronchogen was effective at 0.05 ng/mL ^[9]. In tobacco cultures the active range was 10⁻⁷ to 10⁻⁹ M ^[8]. The rat COPD studies describe a one-month course of bronchogen without giving the dose in their English abstracts ^{[2] [3]}. The Lung paper does not state the concentration used in the bronchial cell cultures in its abstract ^[1]. No dose has been given to a person in a published study, and there are no pharmacokinetic data for any route.

Research suppliers sell bronchogen as a freeze-dried powder, most often in 10 mg or 20 mg vials, and in some markets as capsules. The peptide calculator and its bronchogen page convert vial contents to a concentration for laboratory use. The research gives no basis for choosing any quantity for a person.

In the rat COPD studies bronchogen was administered as a course of treatment, with the route not specified in the English abstracts ^{[2] [3]}; in the other studies it was added to culture medium ^{[1] [4] [9]} or to plant growth medium ^[8]. In Russia the Khavinson short peptides are sold as oral capsules marketed as food supplements; research suppliers elsewhere sell mainly lyophilised powder for injection, and some sell it for nebulisation, a route with no published research at all. The 2023 transporter modelling suggests AEDL could be carried across the gut wall by peptide transporters ^[11], but that is a computer model, not a measurement.

No bronchogen side effects have been recorded, because bronchogen has never been given to people in a published study. The animal papers do not report toxicity, and a tetrapeptide of common amino acids is unlikely to be acutely toxic. The relevant safety questions are the ones the research raises. Bronchogen is reported to stimulate proliferation of bronchial epithelial cells most strongly in old cultures, to raise the anti-apoptotic protein Mcl-1 and to increase expression of MUC5AC, the main airway mucin ^[1]. In the rat model these changes went with restored, rather than overgrown, epithelium ^[2], but no long-term study has looked at bronchogen and lung tumour incidence, and a peptide that stabilises DNA and loosens nucleosomes ^{[5] [6]} has not been assessed for genotoxicity in a standard assay.

There are no data on use in pregnancy, in children, in people with lung disease or with inhaled or oral respiratory medicines. Inhalation of an unlicensed peptide powder, which some sellers suggest, carries its own risks of airway irritation and contamination that have not been studied. None of this shows that bronchogen is harmful; it shows that it has not been studied.

For products bought from research suppliers, the practical risks are identity, purity and sterility. Our guides to third-party testing and how to read a certificate of analysis explain what a test report should show.

Bronchogen is not an approved medicine in the UK, US, EU, Canada or Australia, nor is it a registered medicine in Russia, where it is sold as a supplement. Products sold as bronchogen elsewhere are research chemicals whose sale for human use is not lawful. It is not named on the WADA Prohibited List. See our legal status overview and the pages for the UK, the US and Europe.

Bronchogen is supplied as a freeze-dried powder to be kept cold, dry and away from light; short peptides are relatively stable in this form. Reconstituted solutions are refrigerated and used within a limited period. See how to store peptides and our guide to bacteriostatic water.

A tetrapeptide is inexpensive to synthesise, and bronchogen is usually among the cheaper listings on a supplier’s site. Compare bronchogen prices, including listings in the UK and the US. Because bronchogen shares its first three amino acids with epitalon, cortagen and cardiogen, and because AEDL and ADEL have identical mass, a certificate of analysis should identify the peptide by sequence-level methods such as tandem mass spectrometry, not by mass alone. Our lists of third-party tested suppliers and suppliers that publish COAs, and our guide to spotting a fake supplier, cover what to check.