EPA-loaded silica nanoemulsions attenuate DEN-induced hepatic fibroinflammation by modulating homocysteine, PKCα/NF-κB, and Nrf2 signaling.

Hepatic fibroinflammation is a progressive pathological process characterized by persistent inflammation, oxidative stress, and extracellular matrix deposition, ultimately leading to liver fibrosis. Alterations in membrane fatty acid composition, particularly the imbalance between pro-inflammatory arachidonic acid (AA) and anti-inflammatory eicosapentaenoic acid (EPA), contribute significantly to disease progression. Despite the anti-inflammatory properties of EPA are well established, its clinical application is limited by poor bioavailability. Therefore, this study investigated the therapeutic efficacy and molecular mechanisms of an EPA-loaded silica nanoemulsion (EPA-NE) in a diethylnitrosamine (DEN)-induced rat model of hepatic fibroinflammation. Thirty-two male Wistar albino rats were randomly allocated into four groups: control, DEN-induced hepatic fibroinflammation, DEN + EPA, and DEN + EPA-NE. Biochemical, molecular, histopathological, and bioinformatic analyses were performed to evaluate treatment outcomes. Both EPA and EPA-NE significantly restored membrane EPA/AA homeostasis, increasing the EPA/AA ratio, and attenuated hepatic injury. EPA and EPA-NE reduced serum homocysteine levels by 57.4% and 72.3%, respectively, and suppressed NF-κB levels by 27.5% and 54.5%, respectively, compared with the DEN group (P < 0.0001). Moreover, EPA and EPA-NE enhanced antioxidant defenses, as evidenced by increased hepatic catalase activity by 1.7-fold and twofold, respectively, while reducing malondialdehyde levels by 23.1% and 46.2% (P < 0.0001), respectively. Molecular analyses demonstrated significant downregulation of PKCα expression and upregulation of Nrf2 and miR-34a expression, indicating attenuation of inflammatory and oxidative stress pathways. Histopathological examination further confirmed the marked reduction of hepatic fibroinflammatory alterations following treatment, with EPA-NE exhibiting superior efficacy compared with EPA. In conclusion, EPA-loaded silica nanoemulsion effectively attenuated DEN-induced hepatic fibroinflammation, restored fatty acid homeostasis, reduced homocysteine levels, and modulated molecular markers associated with oxidative stress and inflammation. These findings suggest that nanoemulsion-based delivery enhances the biological activity of EPA and support the potential of EPA-NE as a promising therapeutic strategy for hepatic fibroinflammation.