The Regulation of Hypoxia Inducible Factor (HIF)1α Expression by Quercetin: an In Silico Study.

Background: Cancer disease is a growing health problem in developing and developed countries. Hypoxia-inducible factor-1a (HIF1α) is a transcription factor responsible for expressing several proteins involved in angiogenesis. Quercetin can suppress HIF1α expression due to the inhibition of protein synthesis. However, to date, the study exploring the potential of quercetin in repressing HIF1α through its degradation mechanism has never been done. An in silico study is needed as a preliminary study to understand the mechanism underlining this possibility. Objective: This study aimed to investigate the potential of quercetin in regulating HIF1α expression through the ubiquitin degradation pathway by in silico study. Methods: This study was performed by in silico analysis, including biological activity prediction, 3D protein structure collection, protein-ligand and protein-protein docking, and the visualization of the docking results. Results: The probability activity (Pa) score of quercetin as an HIF1α expression inhibitor was 0.969. In the absence of quercetin, the center-weighted score of HIF1α - pVHL, HIF1α - FIH, and HIF1α - PHD2 was -699.4 kJ/mol, -846.0 kJ/mol, and -650.5 kJ/mol, respectively. In the presence of quercetin, the weighted score of HIF1α - pVHL, HIF1α - FIH, and HIF1α - PHD2 was reduced to -728.1 kJ/mol, -854.2 kJ/mol, and -650.5 kJ/mol, respectively. Conclusion: Quercetin could directly promote HIF1α and pVHL interaction, thus increasing the degradation of HIF1α by ubiquitin-dependent pathway.