Vitexin-loaded phytosomes protect against high-fat diet-induced MASLD modulating PI3K/AKT/mTOR/SREBP-1c, Nrf2/HO-1, NF-κB/COX-2, and apoptotic pathways.

Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is a progressive liver disorder driven by high-fat diet (HFD)-induced metabolic stress, oxidative damage, inflammation, and apoptosis. This study investigated the hepatoprotective effects of vitexin (VX) and vitexin-loaded phytosomal nanoparticles (VX-PHY) in HFD-fed rats. Sixty male albino rats were randomly assigned to six groups: standard diet control, standard diet + VX, standard diet + VX-PHY, HFD only, HFD + VX, and HFD + VX-PHY. HFD feeding caused significant weight gain, elevated liver and fat indices, disrupted serum proteins, impaired liver function, and dysregulated lipid profiles. At the molecular level, HFD induced oxidative stress, depleting GSH and antioxidant enzymes while activating the Nrf2/HO-1 pathway. It also triggered hepatic inflammation via NF-κB/COX-2 signaling, increasing TNF-α, IL-1β, and IL-6, and promoted apoptosis by upregulating BAX, Caspase-3, Caspase-8, and downregulating BCL2. HFD additionally activated the PI3K/AKT/mTOR/SREBP-1c axis, enhancing AKT/mTOR phosphorylation, nuclear SREBP-1c, and lipogenic gene expression (FASN, ACC), contributing to hepatic lipid accumulation, which was effectively suppressed by VX-PHY, highlighting its superior anti-lipogenic effect compared with crude VX. VX-PHY co-treatment further enhanced antioxidant defenses, modulated Nrf2/HO-1, suppressed NF-κB/COX-2-mediated inflammation, and attenuated pro-apoptotic signaling, restoring these pathways to near-control levels. Histopathological and ultrastructural analyses confirmed reduced steatosis, hepatocyte ballooning, necrosis, and organelle damage in VX-PHY-treated rats. Overall, vitexin, particularly when delivered via phytosomal nanoparticles, exerts potent hepatoprotective effects in HFD-induced MASLD by simultaneously mitigating oxidative stress, inflammation, apoptosis, and lipid dysregulation via inhibition of PI3K/AKT/mTOR/SREBP-1c, highlighting the therapeutic potential of nanoparticle-based delivery for natural compounds like vitexin.