Identification of potential benzoxazolinones as CYP1B1 inhibitors via molecular docking, dynamics, waterswap, and in vitro analysis

Abstract

Overexpression of cytochrome P450 1B1 in malignancies is accountable for the biotransformation-based inactivation of various chemotherapeutics such as docetaxel, paclitaxel, cisplatin, and tamoxifen. Additionally, it also plays a major role in the development of metabolic disorders including cancer progression, diabetes, obesity, glaucoma, fatty liver, etc. Currently, numerous small molecule inhibitors of this enzyme are being explored to prevent cancer progression and drug resistance problems to the above-mentioned chemotherapeutics. In this work, several benzoxazolinone derivatives have been designed and explored as CYP1B1 inhibitors using various in silico approaches including molecular docking, molecular dynamics (MD), and waterswap analysis. Molecular docking studies revealed that all the designed compounds mimic the crucial active site interactions of the co-crystal ligand, i.e. Alpha naphthoflavone (ANF). To understand the interaction stability of the top four docked compounds, a 100 ns MD analysis was performed. Furthermore, binding free energies of the top docked molecules were computed using three different free energy algorithms, namely Bennet, thermodynamic integration (TI), and free energy perturbation (FEP). The proposed compounds were tested for inhibitory activity towards recombinant human CYP1B1 using an EROD assay. Among them all, compounds R-7 and R-8 were found to be the most promising potent CYP1B1 inhibitors with IC₅₀ values of 0.06 and 0.09 μM, respectively. This research shows that the reported compounds could be used as possible adjuvants with resistance-reversing properties, potentially improving cancer therapy quality.