New Compounds Block the Hunger Hormone Receptor to Fight Obesity and Diabetes
Novel triazole-based inverse agonists of the ghrelin receptor reduced appetite and improved insulin secretion in animal models.
Quick Facts
What This Study Found
The ghrelin receptor (GHSR) has unusually high constitutive activity, meaning it sends hunger and metabolic signals even when ghrelin is not present. An inverse agonist does not just block the receptor; it actively reduces this baseline signaling.
The researchers developed a series of compounds based on the 1,2,4-triazole chemical scaffold. By varying substituents at positions 3, 4, and 5, they created highly potent and selective GHSR inverse agonists. These compounds stabilize a specific inactive conformation of the receptor, effectively silencing its constant output.
In living systems, one of the most promising compounds affected insulin secretion in isolated rat pancreatic islets and counteracted ghrelin's appetite-stimulating effects in mice. This demonstrates both metabolic and appetite-related activity in vivo.
Key Numbers
Triazole scaffold; positions 3,4,5 varied; lead compound active on insulin and appetite in animals
How They Did This
Medicinal chemistry study with in vitro and in vivo testing. Researchers synthesized a library of triazole-based compounds, tested them for GHSR binding affinity and inverse agonist activity using cell-based assays measuring G protein activation. The most promising compounds were tested for effects on insulin secretion in rat pancreatic islets (ex vivo) and on feeding behavior in mice (in vivo).
Why This Research Matters
Ghrelin is called the hunger hormone. Its receptor (GHSR) is a compelling target for obesity and diabetes, but previous attempts to block it have struggled. Inverse agonists are more powerful than simple blockers because they silence the receptor's constant baseline activity. Small molecules (non-peptides) are easier to develop into pills than peptide-based drugs.
The Bigger Picture
Ghrelin receptor drugs have been difficult to develop because the receptor has unusually high constitutive activity. Inverse agonists address this by reducing baseline signaling, not just blocking ghrelin binding. This could lead to more effective anti-obesity drugs.
What This Study Doesn't Tell Us
Animal testing was limited (rat islets and mouse feeding). No human safety or efficacy data. The triazole compounds' pharmacokinetics (absorption, distribution, metabolism) were not fully characterized. Long-term effects of suppressing GHSR constitutive activity are unknown and could have unintended consequences on growth hormone and glucose regulation.
Questions This Raises
- ?What are the long-term safety profiles of chronic ghrelin receptor inverse agonism?
- ?Will these compounds work in obese humans where ghrelin signaling may be altered?
- ?Could inverse agonists be combined with GLP-1 drugs for enhanced weight loss?
Trust & Context
- Key Stat:
- Inverse agonist actively suppresses the ghrelin receptor's constitutive hunger signaling, going beyond simple blockade
- Evidence Grade:
- Preliminary evidence. Animal studies showed effects on appetite and insulin, but no human safety or efficacy data exists.
- Study Age:
- Published in 2020. Ghrelin receptor pharmacology continues to be explored for obesity and metabolic disease.
- Original Title:
- Development of Nonpeptidic Inverse Agonists of the Ghrelin Receptor (GHSR) Based on the 1,2,4-Triazole Scaffold.
- Published In:
- Journal of medicinal chemistry, 63(19), 10796-10815 (2020)
- Authors:
- Haj Salah, Khoubaib Ben, Maingot, Mathieu(2), Blayo, Anne-Laure(2), M'Kadmi, Céline, Damian, Marjorie, Mary, Sophie, Cantel, Sonia, Neasta, Jérémie, Oiry, Catherine, Péraldi-Roux, Sylvie, Fernandez, Gimena, Romero, Guadalupe García, Perello, Mario, Marie, Jacky, Banères, Jean-Louis, Fehrentz, Jean-Alain, Denoyelle, Séverine
- Database ID:
- RPEP-04835
Evidence Hierarchy
Frequently Asked Questions
What is the difference between blocking ghrelin and inverse agonism?
A blocker prevents ghrelin from activating the receptor, but the receptor still sends some signals on its own. An inverse agonist goes further — it reduces the receptor's activity below its baseline, potentially providing stronger appetite suppression.
Could this become a weight loss drug?
Possibly, but it is very early in development. Animal results are promising, but human clinical trials would need to confirm safety and effectiveness before any drug could be approved.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-04835APA
Haj Salah, Khoubaib Ben; Maingot, Mathieu; Blayo, Anne-Laure; M'Kadmi, Céline; Damian, Marjorie; Mary, Sophie; Cantel, Sonia; Neasta, Jérémie; Oiry, Catherine; Péraldi-Roux, Sylvie; Fernandez, Gimena; Romero, Guadalupe García; Perello, Mario; Marie, Jacky; Banères, Jean-Louis; Fehrentz, Jean-Alain; Denoyelle, Séverine. (2020). Development of Nonpeptidic Inverse Agonists of the Ghrelin Receptor (GHSR) Based on the 1,2,4-Triazole Scaffold.. Journal of medicinal chemistry, 63(19), 10796-10815. https://doi.org/10.1021/acs.jmedchem.9b02122
MLA
Haj Salah, Khoubaib Ben, et al. "Development of Nonpeptidic Inverse Agonists of the Ghrelin Receptor (GHSR) Based on the 1,2,4-Triazole Scaffold.." Journal of medicinal chemistry, 2020. https://doi.org/10.1021/acs.jmedchem.9b02122
RethinkPeptides
RethinkPeptides Research Database. "Development of Nonpeptidic Inverse Agonists of the Ghrelin R..." RPEP-04835. Retrieved from https://rethinkpeptides.com/research/haj-2020-development-of-nonpeptidic-inverse
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.