Investigating binding dynamics of trans resveratrol to HSA for an efficient displacement of aflatoxin B₁ using...

Resveratrol is a polyphenol belonging to the class stilbenes. The active and stable form of resveratrol is trans-resveratrol. This polyphenol is bestowed with numerous biological properties. Aflatoxin B₁ is a hepato-carcinogen and mutagen that is produced by Aspergillus species. In this study, the interaction of trans-resveratrol with HSA followed by competitive dislodging of AFB₁ from HSA by trans-resveratrol has been investigated using spectroscopic studies. The UV-absorption studies revealed ground state complex formation between HSA and trans-resveratrol. Trans-resveratrol binds strongly to HSA with the binding constant of ~ 10⁷ M^-1 to a single binding site (n = 1.58), at 298.15 K. The Stern-Volmer quenching constant was calculated as 7.83 × 10⁴ M^-1 at 298.15 K, suggesting strong fluorescence quenching ability of trans-resveratrol. Site markers displacement assay projected subdomain IIA as the binding site of trans-resveratrol to HSA. The molecular docking approach envisages the amino acid residues involved in the formation of the binding pocket. As confirmed from the site marker displacement assays, both trans-resveratrol and AFB₁ binds to HSA in the same binding site, subdomain IIA. The study explores the ability of trans-resveratrol to displace AFB₁ from the HSA-AFB₁ complex, thereby affecting the toxicokinetic behavior of AFB₁ associated with AFB₁ exposure.