Abstract
BACKGROUND: Fibrosis is a pathological condition that affects various organs by increasing fibrous connective tissue while reducing parenchymal cells. This imbalance can lead to compromised organ function and potential failure, posing significant health risks. The condition's complexity necessitates the exploration of effective treatments to mitigate its progression and adverse outcomes. AIMS: This study aims to investigate the role of ghrelin, a peptide hormone known for its anti-inflammatory and anti-fibrotic properties, in modulating fibrosis across different organs. By binding to the growth hormone secretagogue receptor type 1a (GHSR-1a), ghrelin has shown potential in attenuating the fibrotic process, particularly through its interaction with the TGF-β signalling pathway. METHODS: An extensive review of clinical and animal model studies focusing on liver, kidney, lung, and myocardial fibrosis was conducted. The primary focus was on examining how ghrelin influences the TGF-β signalling pathway, with an emphasis on the regulation of TGF-β expression and the suppression of Smad signalling molecules. The methodology involved analysing data from various studies to understand ghrelin's molecular mechanisms in combating fibrosis. RESULTS: The findings from the reviewed studies indicate that ghrelin exerts significant anti-fibrotic effects across multiple organ systems. Specifically, ghrelin was found to downregulate TGF-β expression and suppress Smad signalling molecules, leading to a marked reduction in fibrous tissue accumulation and preservation of organ function. In liver fibrosis models, ghrelin reduced TGF-β1 levels and Smad3 phosphorylation, while in kidney and cardiac fibrosis, similar protective effects were observed. The data also suggest that ghrelin's effects are mediated through both canonical and non-canonical TGF-β pathways. CONCLUSIONS: Ghrelin presents a promising therapeutic agent in the management of fibrosis due to its potent anti-inflammatory and anti-fibrotic actions. Its ability to modulate the TGF-β signalling pathway underscores a vital molecular mechanism through which ghrelin can mitigate fibrotic progression in various organs. Future research should focus on further elucidating ghrelin's molecular interactions and potential clinical applications in fibrosis treatment, offering new avenues for developing effective anti-fibrotic therapies.