Hepatic necrosis and regenerative hyperplasia are central to hepatotoxicity development; chronic hepatotoxicity playing a vital role in the initiation and persistence of hepatocellular carcinoma. This study evaluated the alleviative effects of chitosan nanoparticles (CNPs) and marine sponge extract bioactive agents (BAAs), individually and in combination, on 1,2-dimethylhydrazine (DMH)-induced hepatotoxicity in a rat model. Five experimental groups are studied here: normal control, DMH-induced hepatotoxicity, DMH/CNPs, DMH/BAAs, and DMH/BAAs-loaded CNPs. Hepatotoxicity was assessed through immunohistochemical examination of caspase 3 (CASP3), western blot analysis of CASP3 and P27 expressions, and qRT-PCR analysis of Ctnnb1 and Ccnd1 gene expressions. DMH administration resulted in severe hepatocellular damage, characterized by elevated CASP3 and decreased P27 levels, and upregulation of Ctnnb1 and Ccnd1 gene expression. CNPs or BAAs treatment reduced CASP3, elevated P27 expression, and downregulated Ctnnb1 and Ccnd1 gene expression. The most pronounced recovery was observed in the BAAs-loaded CNPs group, where synergistic effects of the combined treatment normalized apoptotic markers, and suppressed Wnt/Ctnnb signaling. These findings demonstrate that CNPs and BAAs exert hepatoprotective effects by modulating oxidative stress, apoptosis, and cell cycle regulation, with combination therapy offering the greatest protective potential. This study highlights the promise of natural compounds in mitigating a chemical-induced hepatotoxicity and provides a foundation for further research into their mechanisms and clinical applications.