In vitro DNA Binding, Anticancer and Molecular Docking Studies of New Sydnone Compounds

Abstract

Sydnones have been a novel class of mesoionic compound due to versatility of their applications in various fields. Sydnone derivative have seen as an interesting structure grouped in the heterocyclic community, which is having regions of both positive and negative charges linked with a poly-heteroatomic system. This structural characteristic allows them to cross biological membranes and interact with biomolecules. Four sydnones namely 3-(4-decyloxybiphenyl-4′-yl) sydnone (MC-176), 3-(4-octyloxy-2,3-difluorobiphenyl-4′-yl) sydnone (MC-192), 3-(4-biphenyl-4′-yl) sydnone (MC-450) and 3-(4-butylbiphenyl-4′-yl) sydnone (MC-456) were evaluated for biophysical interactions between DNA and sydnones and antiproliferative activity. The UV-visible spectroscopic study indicates interaction between sydnone and dsDNA with a slight red and hypochromic shift in absorption spectra, which shows the intercalation mode of binding. The binding constant of DNA-Sydnone complexes were in the range from 1.4 × 104 M–1 to 7.1 × 104 M–1 for different sydnone compounds (MC-176, MC-192, MC-450, MC-456). FTIR spectra indicated that sydnone interaction with DNA occurs through base pairs and the phosphate backbone of the DNA. The cytotoxic and apoptotic effects of a sydnone derivatives on human cervical cancer (HeLa) and breast tumor (BT) 474 cancer cell lines were determined. The compounds possess antiproliferative activity in a concentration-dependent mode. The changes of morphological characteristic of cancer cells were determined by fluorescent staining techniques indicate the apoptotic cell death. The molecular docking studies of sydnone compounds with caspase 3 and EGF-TK showed better interactions (according to docking score) along with commercially available breast cancer drug molecule anastrozole. The docking score of sydnone molecules (MC-456, MC-450, MC-192 and MC-176) with EGF-TK enzyme were -6.44, -6.42, -5.46 and -4.53, respectively. The binding energy of anastrozole with EGF-TK was -6.41. As well Caspase 3 inhibition with sydnone compounds MC-456, MC-450, MC-192 and MC-176 were -6.09, -6.48, -5 and -3.49, respectively. The binding energy of anastrozole with caspase 3 was -6.24. All sydnone compounds were studied for ADME toxicity studies along with Lipinski rule of five to assess their drug likeness properties by in silico approach. MC-450 found to have good ADMET (absorption, distribution, metabolism, excretion and toxicology) properties among all the sydnone compounds. Thus, the present work indicates that these sydnone compounds would be a well prospective in developing anticancer medicines.