2,2'- Bipyridine Derivatives Exert Anticancer Effects by Inducing Apoptosis in Hepatocellular Carcinoma (HepG2) Cells.

Purpose: To elucidate the therapeutic potential of 2,2'-bipyridine derivatives [NPS (1-6)] on hepatocellular carcinoma HepG2 cells. Methods: The effects on cell survival, colony formation, cellular and nuclear morphology, generation of reactive oxygen species (ROS), change in the integrity of mitochondrial membrane potential (MMP), and apoptosis were investigated. Additionally, docking studies were conducted to analyze and elucidate the interactions between the derivatives and AKT and BRAF proteins. Results: NPS derivatives (1, 2, 5 and 6) significantly impaired cell viability of HepG2 cell lines at nanogram range concentrations - 72.11 ng/mL, 154.42 ng/mL, 71.78 ng/mL, and 71.43 ng/mL, while other derivatives were also effective at concentrations below 1 µg/mL. These compounds reduced the colony formation capacity of HepG2 cells in a dose-dependent manner following treatment. Mechanistic studies revealed that these derivatives induce reactive oxygen species (ROS) accumulation and cause mitochondrial membrane depolarization, ultimately triggering apoptosis in HepG2 cells. In the presence of these derivatives, cells demonstrated that 75% of cells underwent apoptosis, compared to 25% in the control group. Additionally, there was a marked increase in mitochondrial depolarization (95% cells) and a threefold rise in ROS levels compared to the controls. Docking studies revealed interactions between the derivatives and the signaling proteins AKT (PDB ID: 6HHF) and BRAF (PDB ID: 8C7Y) with binding affinities ranging from -7.10 to -9.91, highlighting their pivotal role in targeting key players in hepatocellular carcinoma progression. Conclusion: The findings of this study underscore the therapeutic potential of these derivatives against HepG2 cells and offer valuable insights for further experimental validation of their efficacy as inhibitors targeting AKT or BRAF signaling pathways.