Objective To investigate the effect and mechanism of berberine (BBR) on the activity and proliferation of hepatoma cells. Methods Normal human hepatocytes (MIHA) and human hepatoma cells (Hep3B, HepG2) were respectively divided into control group (high glucose) and different concentration (0, 12.5, 25, 50 μmol/L) of BBR groups (glucose-free). CCK-8 and clone formation experiment were used to explore the effect of BBR on the viability and clone formation. SYTOX Green nucleic acid stain was used to determine the cell death and flow cytometry to detect the changes in reactive oxygen species (ROS) levels in hepatoma cells. The changes of Nrf2 and its related proteins after BBR incubation were measured by Western blotting. We incubated the proteasome inhibitor MG132 and the protein synthesis inhibitor cycloheximide (CHX) with BBR to study its effect on the Nrf2 protein. We quantified the expressions of Nrf2 and HO-1 in Hep3B cells cultured with BBR using Quantitative real-time PCR (qRT-PCR). We established a tumor model by subcutaneous injection of Hep3B cells into nude mice. To observe the effect of BBR on tumor growth, we injected tumor-bearing nude mice in the BBR groups and the control group with BBR or the same amount of normal saline, respectively. We evaluated the effect of BBR on Nrf2 and its related proteins in vivo with HE and immunohistochemical staining. Results The viability of Hep3B and HepG2 cells decreased after BBR incubation in a glucose-free environment (P<0.05). No appreciable changes were observed in MIHA cell viability under the same experiment condition. BBR could inhibit clone formation and promote the death of hepatoma cells in a concentration-dependent manner (P<0.05). We observed an increase in the ROS and a decrease in Nrf2, HO-1, and c-Myc with no significant change in Keap1 in hepatoma cells after BBR treatment. While total GSK3β remained unchanged, the treatment-induced decrease in P-GSK3β (Ser9) decreased but increase in P-GSK3β (Tyr216). MG132 co-treatment reversed the BBR-induced reduction of Nrf2 protein while CHX enhanced the BBR-induced reduction of Nrf2 protein in hepatoma cells. BBR treatment-induced increase in Nrf2 mRNA and a decrease in HO-1 mRNA (P<0.05). BBR could significantly inhibit the growth of Hep3B cells in vivo in nude mice. BBR treatment increased tumor tissue necrosis and suppressed the expression of Nrf2 and c-Myc but did not affect the Keap1 level. Conclusions BBR could inhibit the activity and proliferation of hepatoma cells and promote cell death. In vivo experiments showed that BBR injection could significantly inhibit the growth of tumor cells and lead to increased necrosis of tumor cells. We verified that BBR may lead to the death of hepatoma cells through the non-Keap1-dependent Nrf2/GSK3β pathway. We infer that the degradation of Nrf2 protein through the ubiquitin-proteasome system by the non-Keap1-dependent Nrf2/GSK3β pathway, thereby reducing the anti-oxidative stress ability of tumor cells and leading to the death of hepatoma cells ultimately.