In vitro and in silico assessment of DNA interaction, topoisomerase I and II inhibition properties of chrysosplenetin

Abstract

Chrysosplenetin is a methoxyflavone with reported anti-cancer effect. We tested its cytotoxic effect on the MCF-7 breast cancer cell line, and determined its effect on DNA intercalation and on the activity of topoisomerases I and II. The compound inhibited proliferation MCF-7 with an IC50 value of 0.29 µM. Chrysosplenetin did not initiate plasmid DNA cleavage but, in a concentrationdependent manner, protected plasmid DNA against damage induced by Fenton reagents. Furthermore, it possessed dual Topoisomerase I and II inhibitory properties. Especially, it inhibited topoisomerase II by 83-96% between the range 12.5-100 µM. In the light of these experimental findings, molecular docking studies were performed to understand binding mode, interactions and affinity of chrysosplenetin with DNA, and with topoisomerases I and II. These studies showed that of 4-chromone core and the hydroxyl and methoxy groups important for both intercalation with DNA and topoisomerase I and II inhibition.

Dichloromethane Crude Extract of Gymnanthemum extensum Combined with Low Piperine Fractional Piper nigrum Extract Induces Apoptosis on Human Breast Cancer Cells

“…As we mentioned previously, palmitic acid and kusunokinin showed intercalation to DNA topoisomerase-I together with PFPE, enabling degradation of DNA topoisomerase-II [36,49] . Due to their important role as a DNA controller, DNA topoisomerase-I and DNA topoisomerase-II are targeted for promising anticancer treatment [50,51] . A synergistic effect against MCF-7 cells from a PFPE-combined DEGE led to a further study for the relevant information to strengthen our hypothesis that MCF-7 cells could not escape from cell death since it was attacked by several death pathways of this combination.…”

Total phenolic, total flavonoid contents, and in vitro biological activities of Cephalaria procera

“…The total phenolic content analyses of the extracts were evaluated utilizing the Folin-Ciocalteu colorimetric assay according to study of Barut & Şöhretoğlu (Barut & Şöhretoğlu, 2020). The results were expressed as mg gallic acid equivalent (GAE) per g of dry weight of the extracts.…”

“…The DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging effects of the extracts were determined using spectrophotometric assay according to previous study conducted by (Barut & Şöhretoğlu, 2020). The results were expressed as IC 50 (Halfmaximal inhibitory concentration) values.…”

“…The acetylcholinesterase (AChE) and buthyrylcholinesterase (BuChE) inhibitory effects of the extracts were evaluated using the previously reported method (Barut & Şöhretoğlu, 2020). The results were expressed as IC 50 values.…”

“…The supercoiled pBR322 plasmid DNA damage effects of CEP-1 and CEP-3 was determined using agarose gel electrophoresis according to the previous study (Şöhretoğlu, Barut, Sari, Özel, & Arroo, 2020). In this study, Tris-HCl (50 mM, pH 7), plasmid DNA, extracts at various concentrations (50, 100, and 200 µg/ mL) was mixed at 37 ºC for 1 h. Afterwards, loading buffer (bromophenol blue, sodium dodecyl sulphate, xylene cyanol, glycerol) was added and the mixtures were loaded on gel (0.8% (m/v)) with ethidium bromide staining for 90 min at 100 V in Tris-acetic acid-EDTA (TAE) buffer.…”