In vitro investigation of biophysical interactions between Ag(I) complexes of bis(methyl)(thia/selena)salen and ct‐DNA via multi‐spectroscopic, physicochemical and molecular docking methods along with cytotoxicity study

Abstract

Four silver(I) (Ag(I)) complexes: 1.PF6, 2.PF6, 1.ClO4 and 2.ClO4 of bis(methyl)thia salen (1) and bis (methyl)selena salen (2) with two different counter anions (PF6− and ClO4−) have been investigated for DNA binding properties. In vitro interactional association between the Ag(I) complexes and ct‐DNA has been examined by performing spectroscopic titrations on absorption spectrophotometer and fluorescence spectrophotometer. A competitive binding study has also been done using a fluorescence spectrophotometer with ethidium bromide as a classical intercalator. The spectroscopic methods revealed a major groove. Viscometry and agarose gel electrophoresis experiments have also been performed as physicochemical methods to confirm the binding of complex molecules with DNA. Molecular docking analysis has been executed to obtain the theoretical insight into the mode of binding. The docking study demonstrated the major groove binding of all four complexes to the DNA with electrostatic metal–phosphate interactions (between the metal and the backbone of DNA) and hydrophobic interactions. Cytotoxicity of the complexes has been studied on the Human Fibroblast foreskin (HFF) cell line. The cytotoxicity results showed positive gesture for moving ahead to the next level of screening; the values were above 10 μM which are appreciated for the normal cell lines.

Photoactive and Luminescent Transition Metal Complexes as Anticancer Agents: A Guiding Light in the Search for New and Improved Cancer Treatments

“…Their intrinsic fluorescence was used alongside other techniques to analyze DNA binding. These are promisingly non-toxic in normal cells, although assessment in cancer cell lines needs to be undertaken if they are intended to be anticancer agents [110]. Silver nanoparticles can also be fluorescent at larger physical sizes, but these are usually less cytotoxic than the smaller non-fluorescent form due to their larger size hindering cell uptake.…”