High in vitro anticancer activity of a dinuclear palladium(II) complex with a 2‑phenylpyridine ligand

Abstract

A dinuclear palladium(II) complex, [Pd2(μ‑OAc‑κO,O)2(phpy‑κN,C)2] (1), with 2‑phenylpyridine (H‑phpy) as a ligand was synthesized and characterized by IR, ESI-MS, single-crystal X-ray diffraction, and elemental analysis. By the MTT assay, the dinuclear palladium(II) complex 1 showed lower cytotoxic activity toward normal HL-7702 cells (IC50 = 85.89 ± 0.89 μM). However, it displayed high cytotoxicity against SK-OV-3, NCI-H460, T-24, and HeLa cells, with IC50 values of 5.50 ± 1.08, 0.46 ± 0.28, 7.93 ± 1.16 and 0.35 ± 0.29 μM, respectively. Importantly, we found that this Pd(II) complex exhibited lower toxicity and better anticancer activity than that of cisplatin. Further cellular assays, including Western blotting and flow cytometry, gave evidence that apoptosis after treatment with the dinuclear palladium(II) complex 1 may be induced by the intrinsic mitochondrial dysfunction pathway.