Green-Synthesized Rutin-Capped Gold Nanoparticles Attenuate Experimental Liver Fibrosis by Targeting Oxidative Stress and TGF-β Signaling

Liver fibrosis is driven by persistent oxidative stress and inflammatory signaling, with transforming growth factor-β (TGF-β) acting as a key profibrotic mediator. Rutin (Ru) is a plant-derived flavonoid with antioxidant and anti-inflammatory effects, but its low bioavailability limits therapeutic efficacy. This study investigated whether rutin-phytoreduced gold nanoparticles (RuAuNPs) enhanced rutin delivery leading to antifibrotic and anti-inflammatory effects in a rat model of liver fibrosis. Liver fibrosis was induced by oral administration of thioacetamide (TAA, 150 mg/kg body weight, p.o.) for six weeks. Following fibrosis induction, the animals were treated with free rutin (30 mg/kg body weight), RuAuNPs (0.3 mg/kg body weight), or AuNPs (0.3 mg/kg body weight), both expressed as nanoparticle mass, all administered orally for four weeks. RuAuNPs were synthesized by green rutin-mediated reduction and further characterized by TEM, DLS, and FTIR spectroscopy; they were spherical, showing an average hydrodynamic size of 104.1 nm (PDI 0.345). FTIR confirmed rutin capping. Biological effects were evaluated by liver morphology (H&E histology, TEM), biochemical assessment of liver aminotransferases and glico-lipidic status, ELISA and spectrophotometry measurement of redox biomarkers (lipid peroxidation, glutathione status, antioxidant enzymes), cytokines (TNF-α, IL-1β, IL-6), and TGF-β. TAA-induced hepatic injury and remodeling with increased profibrotic signaling, oxidative stress, and inflammation. Free rutin slightly ameliorated the liver damage, whereas RuAuNP improved histological features, reduced TGF-β and pro-inflammatory cytokines, decreased lipid peroxidation, and supported antioxidant defenses. Overall, RuAuNP may enhance rutin efficacy in TAA-induced liver fibrosis, with novelty stemming from the integrated in vivo evaluation of tissue changes and key profibrotic/oxidative/inflammatory pathway.