Palladium(II) oxime complex: synthesis, structural characterization, and antiproliferative effects on HepG-2 cells via the P53/Caspase-3 pathway

Quadridentate oxime organic ligand (H₂L) and its Pd(II) chelate were prepared and structurally elucidated using analytical and spectroscopic techniques. The geometry optimization and structural analysis of palladium(II)-based oxime complex was achieved by density functional theory approach and PXRD data processing of [PdL] complex spectrum by Expo 2014 software.

The slightly distorted square–planar is the coordination polyhedron geometry of [PdL] complex. The ability of free H₂L and [PdL] to bind to ct-DNA was tested, and the results obtained showed good agreement with the results of biological studies and molecular docking calculations. The findings from biological studies demonstrate that the [PdL] complex has significant antiproliferative effects on various human cancer cell lines, with the strongest efficacy observed in HepG-2 cells. The [PdL] complex induces apoptosis without causing necrosis and leads to cell cycle arrest at the Pre G1 and G2/M phases while reducing the S phase and cell proliferation. This apoptotic cell death is associated with the P53/caspase 3 pathway, as treatment with the [PdL] complex results in increased P53 expression and activation of caspase 3. Furthermore, the [PdL] complex reduces metastasis in HepG-2 cells after 48 h of treatment, likely due to its strong binding affinity to cancer cell DNA. In conclusion, the [PdL] complex shows potential as a chemotherapeutic agent for liver cancer, as it can induce apoptosis and decrease both cell proliferation and metastasis, which are essential characteristics of effective chemotherapeutic agents.