Assessing the in vitro and in silico interactions of two Palladium(II) dithiocarbamate complexes with human serum albumin

Abstract

The use of metallodrugs in the treatment of various diseases is common. Free radicals’ scavenging can prevent diseases such as cancer. Therefore, the design and synthesis of antioxidant metallodrugs can be very important. In this study, the antioxidant activity and HSA interaction of two Pd(II) complexes formulated as [(N–N)Pd(μ-pr-dtc)Pd(N–N)](NO3)2 (where pr-dtc is propylenbisdithiocarbamate, N–N are 2,2ʹ-bipyridine for complex a, and 1,10 phenanthroline for complex b) were reported. Antioxidant activity of the Pd complexes against 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) revealed that complexes have moderate antioxidant activity (IC50 = 790 mg L−1 for complex a and 1030 mg L−1 for complex b). The fluorescence spectra demonstrated that the quenching mechanism of HSA in the presence of the complexes was static quenching. The complex b (Kb = 1.23 × 104 M−1) had a tendency to HSA more than the complex a (Kb = 0.257 × 104 M−1). Thermodynamic parameters showed that hydrophobic interactions contributed to dominantly in the interaction process. The biophysical approaches, including UV–Vis spectra, CD spectroscopy, and FT-IR spectra confirmed the conformational changes in the structure of HSA in the presence of Pd complexes. Molecular dynamic and docking simulation disclosed that both complexes could interact with different residues on the surface of HSA. Theoretical results were supported by experimental evidence.