Probing the physico-chemical, antioxidant and anticancer influence of β-lactoglobulin on dietary flavonoid daidzein

Abstract The molecular nature, antioxidant, and anticancer actions of the dietary flavonoid daidzein binding to two types of β-lactoglobulin (βLG) are investigated in this work by using different kinds of spectroscopic techniques, electrochemical analysis, molecular docking, and molecular dynamics simulation. The results showed that hydrogen bonds and van der Waals interactions played a major role in the development of the stable complex. It may be deduced from molecular docking studies and competitive assays that daidzein binds to the outer surface of βLG with appropriate binding energies. The results of molecular dynamics showed the creation of a relatively stable complex in which daidzein binding reduced the flexibility of key residues in the binding site. In terms of the masking effect of βLG, the best antioxidant activity was found at low concentrations of the βLG-daidzein complex. After 48 hours of exposure to a 50 μM mixture of βLG and daidzein, the complexes showed increased anticancer activity with maximal mortalities of 38.62 and 47.08% for HeLa and MCF-7 cells, respectively. The improvement of daidzein's solubility and anticancer activity as a result of its complexation with βLG, as well as its light and heat stability, could be a beneficial approach in the food and pharmaceutical industries.