**Background**
Liver fibrosis is a pathological response to chronic liver injury, characterized by the excessive accumulation of extracellular matrix proteins. A central event in this process is the activation of hepatic stellate cells (HSCs), which transform into myofibroblast-like cells that secrete collagen and other pro-fibrotic factors. Transforming growth factor-beta (TGF-β) is a primary driver of this activation, making the TGF-β signaling pathway a critical target for therapeutic intervention. Beyond fibrosis, the regulation of inflammation and apoptosis is essential for mitigating organ dysfunction and treating associated malignancies. In this context, we will introduce a pyridine derivative with potent anti-fibrotic and anti-inflammatory properties – Hydronidone.
**Definition**
Hydronidone is an orally active pyridine derivative that acts as an inhibitor of phosphodiesterase-4 (PDE4), cyclo-oxygenase (COX), and TGF-β.
**In Vitro and In Vivo Studies**
The Hydronidone description highlights its ability to induce mitochondrial dysfunction and trigger apoptosis, making it valuable for liver fibrosis, anti-inflammation, and Hydronidone Cancer studies. In terms of Hydronidone in vitro activity, treatment with 200-400 μM inhibits the activation of HSCs and reduces liver fibrosis by regulating Smad7 expression. Specifically, at 400 μM, it promotes the degradation of TGFβRI via a Smad7-dependent ubiquitin-proteasome pathway. In LX-2 cells, Hydronidone (400 μM, 24 h) significantly promotes apoptosis through the intrinsic mitochondrial pathway, evidenced by increased Bax expression, decreased Bcl-2 expression, and the flow of cytochrome c from the mitochondria to the cytoplasm. Furthermore, it triggers endoplasmic reticulum stress (ERS), activating the IRE1α-ASK1-JNK pathway, as shown by upregulated Bip and phosphorylated IRE1α, ASK1, and JNK.
Regarding Hydronidone in vivo efficacy, administration of 50-100 mg/kg via oral gavage in mice models induced by carbon tetrachloride (CCl4) or 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) significantly ameliorates liver fibrosis and hepatic injury. These results are characterized by reduced collagen fiber content, decreased hepatic hydroxyproline levels, and the downregulation of fibrosis-related genes including Acta2, Col1a1, Col3a1, Mmp9, and Timp1. Additionally, it reduces α-SMA and Col1 levels in liver tissues while upregulating Smad7 protein expression. In conclusion, Hydronidone is a multi-target inhibitor that effectively suppresses HSC activation and promotes the apoptosis of activated HSCs to alleviate liver fibrosis.
Keywords
Hydronidone, 851518-71-3, Apoptosis, Mitochondrial Metabolism, Phosphodiesterase (PDE), TGF-beta/Smad, COX, Transforming growth factor beta, Cyclooxygenase, antifibrotic, agent, hepatic fibrosis, pyridine derivative, anti-inflammation, anti-cancer
References
[1] Xu X, et al. Hydronidone ameliorates liver fibrosis by inhibiting activation of hepatic stellate cells via Smad7-mediated degradation of TGFβRI. Liver Int. 2023 Nov;43(11):2523-2537.
[2] Sun Z, et al. Hydronidone induces apoptosis in activated hepatic stellate cells through endoplasmic reticulum stress-associated mitochondrial apoptotic pathway. J Gastroenterol Hepatol. 2024 Aug;39(8):1695-1703.
[3] Juillerat-Jeanneret L, et al. Fibrogenic Disorders in Human Diseases: From Inflammation to Organ Dysfunction. J Med Chem. 2018 Nov 21;61(22):9811-9840.