Novel Pyrazole-Chalcone Hybrids: Synthesis and Computational Insights Against Breast Cancer.

More women die of breast cancer than of any other malignancy. The resistance and toxicity of traditional hormone therapy created an urgent need for potential molecules for treating breast cancer effectively. Novel biphenyl-substituted pyrazole chalcones linked to a pyrrolidine ring were designed by using a hybridization approach. The hybrids were assessed against MCF-7 and MDA-MB-231 cells by NRU assay. Among them, 8k, 8d, 8m, 8h, and 8f showed significantly potent IC50 values: 0.17, 5.48, 8.13, 20.51, and 23.61 µM) respectively, on MCF-7 cells compared to the positive control Raloxifene and Tamoxifen. Furthermore, most active compound 8k [3-(3-(4-fluorophenyl)-1-phenyl-1H-pyrazol-4-yl)-1-(2-(2-(pyrrolidin-1-yl)-ethoxy)-phenyl)-chalcone] showed cell death induced through apoptosis, cell cycle arrest at the G2/M phase, and demonstrated decrease of ER-α protein in western blotting study. Docking studies of 8k and 8d established adequate interactions with estrogen receptor-α as required for SERM binding. The active hybrids exhibited good pharmacokinetic properties for oral bioavailability and drug-likeness. Whereas, RMSD, RMSF, and Rg values from Molecular dynamics studies stipulated stability of the complex formed between compound 8k and receptor. All of these findings strongly indicate the antiproliferative potential of pyrazole-chalcone hybrids for the treatment of breast cancer.