Liposomal Myricetin Nanoantioxidants Attenuate Methotrexate-Induced Hepatotoxicity by Modulating Oxidative Stress,...

Methotrexate (MTX) is widely used for its chemotherapeutic and immunosuppressive properties, but is limited by oxidative stress-mediated hepatotoxicity. Nanoantioxidant delivery systems can enhance the stability, solubility, and in vivo efficacy of natural antioxidants. This study investigated the hepatoprotective effects of myricetin (MYR), a flavonoid with potent antioxidant activity, and its liposomal nanoantioxidant formulation (MYR-loaded liposomal nanoparticles, MYR-LNPs) against MTX-induced liver injury in male albino Sprague Dawley rats. Sixty rats were randomly allocated to six groups: control, MTX, MYR, MYR-LNPs, and combinations of MTX with MYR-LNPs. MYR-LNPs were successfully formulated and physicochemically characterized, exhibiting a mean particle size of 95.6 nm, a zeta potential of -32 mV, and a narrow polydispersity index, collectively confirming their colloidal stability and suitability for hepatic delivery. MTX markedly disrupted liver function, increasing serum AST, ALT, ALP, and bilirubin and decreasing total protein, albumin, and globulin, whereas co-treatment with MYR-LNPs substantially restored these parameters and outperformed free MYR. MTX-induced oxidative stress, reflected by depleted hepatic GSH and antioxidant enzymes (GPx, SOD, CAT, GST), elevated reactive oxygen species (ROS), malondialdehyde (MDA), and protein carbonyls and downregulated NRF2/HO-1, was significantly counteracted by MYR-LNPs. In addition, MYR-LNPs mitigated MTX-evoked inflammation and nitrosative stress by reducing NF-κB, TNF-α, IL-1β, nitric oxide, and iNOS expression. They corrected apoptotic imbalance by lowering Bax and caspase 3 while increasing Bcl-2. Histopathological and ultrastructural assessments confirmed that MYR-LNPs preserved hepatic architecture and mitochondrial integrity. These findings indicate that MYR-loaded liposomal nanoantioxidants provide superior protection against MTX-induced hepatotoxicity by modulating oxidative stress, inflammation, and apoptosis, supporting their potential as an advanced nanodrug delivery strategy for antioxidant therapy.