Experimental and computational studies of silver(I) dibenzoylmethane-based complexes, interaction with DNA/RNA/BSA biomolecules, and in vitro cytotoxic activity

Abstract

Two silver(I) complexes of composition [Ag2(L)2] (1) and [Ag(L)(PPh3)2](2) (HL = dibenzoyl- methane, PPh3 = triphenylphosphine) were synthesized and characterized by elemental analysis, FTIR, NMR, XRPD, and UV–visible spectra. The molecular structures of the studied ligands and Ag(I) complexes have been characterized using Density Function Theory (DFT) calculations. This analysis has enabled us to determine the reactivity and the coordination site(s) for each ligand. Ag(I) ion is found to be coordinated with the ligand's oxygens in almost a linear fashion in complex (1), while in complex (2) it adopts a tetrahedral geometry. The interaction compounds with biomolecules; calf thymus (ct DNA), yeast-tRNA, and bovine serum albumin (BSA) were investigated using both absorption and fluorescence spectroscopy. The in vitro cytotoxic studies of the complexes against normal human lung fibroblast (WI38), cancerous breast (MDA-MB-231), mammary gland breast (MCF7), hepatocellular (HePG2), and prostate (PC3) cell lines indicated that the complexes are highly toxic to the cancer cells but less toxic towards the normal one when compared with the ligand. Flow cytometric results showed that complex (1) induced cell cycle arrest at the G2/M phase, and complex (2) at G2/M and S phases. Moreover, the results of apoptotic genes (caspase3 and p53) and anti-apoptotic (Bcl2) led us to suggest an apoptotic killing mechanism of cells rather than a necrotic one.