Interaction of Two Commercial Azobenzene Food Dyes, Amaranth and New Coccine, with Human Serum Albumin: Biophysical Characterization

Food processing and storage cause natural food color to diminish, leading to the addition of synthetic dyes by the industry. Unfortunately, these dyes have potential health risks, such as accumulation in blood plasma and interaction with human serum albumin (HSA). To address this issue, the present study utilized spectroscopic techniques and in silico calculations to report the biophysical profile of the HSA:Amaranth and HSA:New coccine interactions. The study showed that the HSA:Dye interaction is spontaneous (Delta G degrees < 0) and driven by enthalpy (Delta H degrees approximate to -12 kJ mol-1) and entropy (Delta S degrees approximate to 0.05 kJ mol-1 K-1). These interactions perturb the secondary structure of HSA weak to moderately. Furthermore, the binding of the dyes to HSA is moderate (KSV approximate to 104 M-1), and the dyes interact with site I. Importantly, this site is the binding region for anticoagulant and anti-inflammatory drugs, such as warfarin, dicoumarol, diflunisal, and naproxen, suggesting that Amaranth and New coccine may negatively impact the pharmacokinetics of these medicines.