Curcumin and piperine modulate the TBP2-ASK1-JNK-caspase-3 axis associated with prevention of DEN and TAA-induced hepatocellular carcinoma in rats

Curcumin and piperine are natural bioactive compounds with reported hepatoprotective and anticancer properties. The present study aimed to evaluate oxidative stress, lipid peroxidation, and the chemopreventive effect of curcumin, piperine, and their combination against diethylnitrosamine (DEN) and thioacetamide (TAA)-induced hepatocellular carcinoma (HCC) in rats, with special focus on the TBP2-ASK1-JNK-Caspase-3 apoptotic axis. HCC was induced by DEN followed by TAA for 20 weeks. Rats were orally pre-treated with curcumin, piperine, or their combination throughout the experimental period. Serum biochemical markers, alpha-fetoprotein, interleukin-6, hepatic lipid peroxidation, antioxidant status, and histopathology were assessed. Immunohistochemistry and Western blotting were performed to evaluate treatment-associated changes in the TBP2–ASK1–JNK–caspase-3 axis in liver tissue. Data were analyzed by one-way analysis of variance followed by Tukey’s post hoc test, with p < 0.05 considered statistically significant. DEN- and TAA-treated rats showed increased tumor burden, elevated liver enzymes and oxidative stress, depleted antioxidant status, and severe hepatic architectural distortion, along with dysregulation of the TBP2-ASK1-JNK-caspase-3 axis. Preventive treatment with curcumin, and piperine, improved key biomarkers and antioxidant function, restored normal tissue structure, and normalized the expression of proteins involved in cellular signaling and apoptosis. Curcumin and piperine, especially in combination, exhibit significant chemopreventive and hepatoprotective effects in DEN/TAA-induced HCC in rats. These benefits are associated with reduced oxidative stress, inflammation, histological damage, and correlate with treatment-associated modulation of the TBP2–ASK1–JNK–caspase-3 axis.