Hepatocellular Carcinoma is one of the most frequently diagnosed cancer and highly refractory for chemotherapeutics agents. Therefore, the study aims to explore the new therapeutic agents for HCC. Phenolics rich fraction of leaves of P. lanceifolium was studied against hepatic cancer cell lines (HepG2) and NDEA-induced HCC rat model system. The obtained results showed that PLE induces reactive oxygen species (ROS) generation and chromatin condensation in nucleus and, alters the mitochondrial membrane potential (MMP) in HepG2 cell lines. The acridine orange/propidium iodide analysis and annexin-V FITC/PI analysis confirms that PLE induces apoptosis-mediated cell death in HepG2-cell lines. In In Vivo analysis, the administration of PLE in NDEA-induced rats declined the elevated biochemicals markers (ALT, AST, ALP, and GGT), interleukins, TNF-α, α-fetoprotein, carcinoembryonic antigen, and total bilirubin. PLE reinstated the level of antioxidant enzyme (GSH, GST, catalase, SOD, and GPX) and the expression of pro-apoptotic (p53, caspase-3, caspase-9, and Bax) and anti-apoptotic (Bcl-2) genes in a dose-dependent manner. The GC-MS analysis of Pterospermum lanceifolium fraction (PLE) represents the presence of palmitic acid, myristic acid, β-sitosterol, and catechin as major bioactive phytocompounds. The study discloses the new lead for HCC that can be further useful for development of new chemopreventive agent.