Unveiling Nano-Resveratrol induced by oil-in-water binding to human haemoglobin in the presence of holo-transferrin as binary and ternary systems: Spectroscopy, molecular dynamic and hemoglobin oxygenation approaches

Abstract

Resveratrol (RES) is a member of polyphenols compounds capable of performing antioxidant activities and exhibiting anti-inflammatory and anticancer properties. This study attempted to increase the bioavailability and solubility of RES through an O/W nano-emulsion process. The performance of synthesized Nano-RES with hemoglobin (Hb) and human holo transferrin (HTF) as the binary and ternary systems was investigated by the means of various spectroscopic techniques and cancer cell experiments. Fluorescence quenching measurement configured the static quenching mechanism of Hb-Nano-RES and (Hb-HTF) interaction with Nano-RES complexes. According to the results, the measurements for binding constant of Hb-Nano-RES and (Hb-HTF) Nano-RES complexes were observed to be (6.62 ± 0.08) × 104 and (6.37 ± 0.09) × 104 M−1 at 298 K respectively. Thermodynamic parameters revealed the participation of electrostatic forces throughout the binding of ligands and proteins. Furthermore, the resonance light scattering signal of Hb and Hb-HTF in the presence of Nano-RES displayed the formation and production of complexes in larger sizes. According to the data of far-UV CD and UV/vis, the secondary structure of proteins was altered by the interaction of Nano-RES with both proteins. The results of melting point assessment confirmed the impact of Nano-RES on increasing the thermal stability of Hb-HTF complex as a ternary system. As the different behavior of Hb and Hb-HTF in the presence of Nano-RES concentrations was approved by the conductivity analysis, the distances between donor and acceptor was determined by fluorescence resonance energy transfer measurements (FRET) to be 1.68 nm and 1.77 nm for Hb-Nano-RES and (Hb-HTF) Nano-RES complexes, respectively. Molecular dynamic study was carried out to investigate the binding interactions of RES to Hb and Hb-HTF complex and was followed by MD simulation under the calculation of 100 ns. Lastly, we evaluated the cytotoxicity of Nano-RES in different concentrations on A549 and BEAS-2B cells, which increased the rate of apoptosis in A549 cells.