Apigenin modifies the structure and function of Lactoferrin through non-covalent and covalent binding: Antioxidant, antibacterial, and anticancer activities.

In the food industry, the addition of polyphenols to enhance functional protein performance is a research direction of great interest. In this study, non-covalent (LF + AP) and covalent (LF-AP) complexes of lactoferrin (LF) with apigenin (AP) were prepared and characterized by gel electrophoresis. Fluorescence analysis indicated that hydrophobic interactions were the main driving force for non-covalent binding, whereas the covalent complex exhibited stronger binding affinity. Fourier transform infrared spectroscopy, circular dichroism, dynamic light scattering, and differential scanning calorimetry analyses showed that covalent binding exerted a more pronounced effect on the particle size, surface hydrophobicity, secondary structure, and thermal stability of LF. Furthermore, both complexes modulated the gastrointestinal digestion behavior and exhibited enhanced in vitro antioxidant, antibacterial, and anticancer activities, with the LF-AP complex demonstrating more pronounced effects. This study presents a novel approach for improving the antibacterial and anticancer potency of LF and potential application as bioactive food ingredients.