GLX351322-Loaded Nanoparticles Alleviate Chronic Stress-Induced Depressive Behaviors Through Inhibition of Ferroptosis and Oxidative Stress.

Purpose: Depression is a widespread neuropsychiatric disorder with limited treatment efficacy and frequent adverse effects. Ferroptosis, an iron-dependent and oxidative stress (OS) - related form of regulated cell death, is emerging as a key pathogenic mechanism in neurological diseases, yet its role in depression remains largely unexplored. This study aimed to evaluate the antidepressant and neuroprotective potential of GLX351322 (GLX), a selective inhibitor of NADPH oxidase 4 (NOX4), by formulating it into a nanocarrier system to overcome its pharmacokinetic limitations. Methods: GLX was encapsulated into methoxy poly (ethylene glycol)-poly(ε-caprolactone) (mPEG-PCL) nanoparticles (GLX-NPs) via a simple nanoprecipitation method. Including particle size, zeta (ζ) potential, morphology, drug loading (DL), encapsulation efficiency (EE), biodistribution, and release efficiency, were characterized. In vivo, the antidepressant effect was assessed using a chronic unpredictable mild stress (CUMS) mouse model, while in vitro, the safety profile was evaluated in CORT-induced HT22 cells. Fluorescence, Quantitative real-time PCR (qRT-PCR), and Western blot (WB) experiments were conducted to explore the underlying neuroprotective mechanisms. Results: The average particle size of GLX-NPs was 43.58 ± 3.09 nm, with a ζ potential of approximately -12.13 ± 0.35 mV, a DL of 6.90%, and an EE of 88.79%. GLX-NPs increased the accumulation of the drug in brain tissues. In CUMS mice, GLX-NPs improved depressive-like behaviors and preserved hippocampal neuronal integrity. Mechanistically, GLX-NPs inhibited NOX4 expression, suppressed reactive oxygen species (ROS) production and lipid peroxidation, and activated the Nrf2/HO-1/GPX4 pathway to alleviate ferroptosis. Co-administration with ferroptosis inducers or Nrf2 inhibitors reversed these protective effects. Conclusion: GLX-NPs effectively alleviate depressive-like behaviors by inhibiting neuronal ferroptosis and OS via modulation of the NOX4/Nrf2/HO-1/GPX4 signaling pathway. This study supports the therapeutic potential of GLX-NPs as a novel nanomedicine targeting ferroptosis in the treatment of depression.