Abstract
Nonalcoholic fatty liver disease (NAFLD) associated with high-fat diet (HFD) intake involves oxidative stress, inflammation, apoptosis, and genotoxicity. Carvacrol, a natural monoterpenoid phenol, exhibits potent antioxidant, anti-inflammatory, and cytoprotective properties, but its clinical application is limited by poor solubility and bioavailability. Chitosan nanoparticles, known for their biocompatibility and ability to enhance drug delivery, offer a promising nanotherapeutic platform for carvacrol delivery in NAFLD. Given the limited therapeutic options for NAFLD, there is a growing interest in nanotherapeutic strategies to enhance the delivery and efficacy of natural antioxidants. This study examined carvacrol-loaded chitosan nanoparticles (CRV-CNPs) in HFD-induced NAFLD. Sixty rats were assigned to six groups: control, CRV-treated (100 mg/kg), CRV-CNP-treated (100 mg/kg), HFD-fed, and two combination groups receiving HFD with either CRV or CRV-CNPs (100 mg/kg) for six weeks after 14 weeks on HFD. Liver function, metabolic markers, oxidative stress parameters, antioxidant enzyme levels, inflammatory and fibrotic mediators, apoptotic gene expression, genotoxicity indices, and histopathological changes were evaluated. CRV-CNPs showed greater efficacy than free carvacrol in ameliorating hepatic dysfunction and metabolic disturbances in HFD-fed rats. CRV-CNPs significantly reduced malondialdehyde, upregulated Nrf2, and elevated hepatic glutathione peroxidase, superoxide dismutase, catalase, and reduced glutathione. Inflammatory markers (NF-κB, iNOS, IL-1β, CRP) and transforming growth factor-beta were suppressed. Pro-apoptotic genes (Bax, Caspase-3) were downregulated, while antiapoptotic Bcl-2 was upregulated. CRV-CNPs also reduced DNA fragmentation and 8-hydroxy-2'-deoxyguanosine levels, indicating strong antigenotoxic effects. Histopathological and ultrastructural assessments revealed mitigated steatosis, preserved hepatic architecture, and maintained mitochondrial integrity. In conclusion, CRV-CNPs provide potent hepatoprotection by targeting oxidative stress, inflammation, apoptosis, and genotoxicity in NAFLD, demonstrating enhanced bioavailability, solubility, and sustained release, which support their potential as an advanced nanotherapeutic strategy for NAFLD management.