Therapeutic Potential of Food-Derived Rutin Phytosome Nanoparticles: Anti-Tumor, Antioxidant, and Anti-Inflammatory Activity in Ehrlich Ascites Carcinoma

<b>Background/Objectives:</b> Rutin (RT), a promising bioflavonoid, faces clinical limitations due to its poor solubility and bioavailability. In this study, we formulated RT-loaded phytosome nanoparticles (RT-PNPs) via thin-layer hydration and characterized their morphology, size distribution, and zeta potential. <b>Methods:</b> We established a mouse model of Ehrlich ascites carcinoma (EAC), randomly allocating ninety female Swiss albino mice into six groups: untreated controls, RT-treated, RT-PNP-treated, EAC, EAC + RT, and EAC + RT-PNPs. Tumor induction and treatment protocols were controlled, with the oral administration of 25 mg/kg/day of RT or RT-PNPs for 20 days. We comprehensively assessed survival, body weight, ascitic fluid/tumor volume, and cell viability and performed detailed hematological, serum biochemical, and tumor marker analyses. Multiorgan (liver and kidney) function and redox homeostasis were evaluated through enzymatic assays for SOD, CAT, GSH-Px, and GSH, as well as lipid peroxidation assessment. Proinflammatory cytokines and tumor markers (AFP, CEA, CA19-9, CA125, and CA15-3) were quantified via ELISA. <b>Results:</b> Gene expression profiling (<i>TP53</i>, <i>Bax</i>, and <i>Bcl-2</i>) and flow cytometry (p53 and Ki-67) elucidated the modulation of apoptosis. Histopathological scoring documented organ protection, while advanced multivariate (heatmap and principal component) analyses revealed distinct treatment clusterings. The RT-PNPs demonstrated potent anti-tumor, antioxidant, anti-inflammatory, and apoptosis-inducing effects, outperforming free RT in restoring physiological markers and tissue integrity. <b>Conclusions:</b> The current results underscore the potential of RT-PNPs as a multifaceted therapeutic approach to EAC, leveraging nanoparticle technology to optimize efficacy and systemic protection.