Compound C (Merck Research Laboratories)

AMPK is AMP‐activated protein kinase that plays a major role in regulating energy metabolism. AMPK has attracted widespread interest as a potential therapeutic target for neurodegenerative diseases. However, its effects on glaucoma remain unclear. Here, we established the oxygen–glucose deprivation/recovery (OGD/R) model and retinal ischemia‐reperfusion injury (I/R) model to simulate the glaucomatous injury. Our results demonstrated that OGD/R induced apoptosis. Retinal I/R caused thinner retinas, retinal ganglion cells (RGCs) loss, and an increase in the number of apoptotic RGCs by using H‐E staining, TUNEL staining, and immunofluorescence staining. A slight increase in phosphorylation‐AMPK (p‐AMPK) level and a significant upregulation in phosphorylated‐mTOR (p‐mTOR) level were detected in experimental glaucoma models. Activating AMPK led to the downregulation of p‐mTOR, Bax, and cleaved‐caspase 3, upregulation of Bcl‐2 as well as inhibition of apoptosis. I/R induced the loss of RGCs and an increase in the number of apoptotic RGCs, which was markedly relieved by using AMPK activator. Inhibiting AMPK by Compound C reversed the effects, led to the inhibition of p‐AMPK and the upregulation of p‐mTOR as well as promoting apoptosis. These findings indicate that activating AMPK attenuates RGCs apoptosis in glaucoma models via inhibiting mTOR. This study suggests that AMPK may be a novel target for glaucoma treatment.

Previous studies highlight the critical role of AMP-activated protein kinase (AMPK) in hepatic lipid metabolism, yet natural activators for metabolic dysfunction-associated steatohepatitis (MASH) remain underexplored. This study investigated whether cichoriin from Cichorium intybus mitigates MASH fibrosis. C57BL/6J mice fed a Gubra-Amylin NASH diet for 20 weeks received cichoriin (100 or 200 mg/kg/day, oral gavage) for 6 weeks. Primary murine hepatocytes and hepatic stellate cells (HSCs) were co-cultured under fatty acid stimulation with cichoriin intervention to examine cellular mechanisms. AMPK dependency was validated using the pharmacological inhibitor Compound C. Cichoriin treatment significantly reduced hepatic steatosis, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and fibrotic markers while improving histological features. Mechanistically, molecular dynamics simulations indicated stable binding between cichoriin and AMPK. Cichoriin enhanced AMPK and acetyl-CoA carboxylase (ACC) phosphorylation, promoted fatty acid β-oxidation, suppressed lipogenesis, and reduced oxidative stress and pro-inflammatory cytokine production. Proteomic analysis revealed significant enrichment in AMPK-related and lipid metabolic pathways. Importantly, cichoriin decreased platelet-derived growth factor-AA (PDGF-AA) secretion by hepatocytes, thereby inhibiting HSCs activation and extracellular matrix deposition indirectly. Inhibition of AMPK via Compound C or siRNA knockdown reversed these protective effects, confirming AMPK dependency. This study demonstrates that cichoriin protects against MASH-associated liver injury through AMPK pathway activation and disruption of profibrotic hepatocyte-stellate cell signaling, supporting its development as a MASH fibrosis therapeutic.