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

Abstract

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 (ΔG°< 0) and driven by enthalpy (ΔH°≈ −12 kJ mol −1 ) and entropy (ΔS°≈ 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 (K SV ≈ 10 4 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.

Profiling the Interaction between Human Serum Albumin and Clinically Relevant HIV Reverse Transcriptase Inhibitors

“…The maximum intensity of the steady-state fluorescence spectra was used to determine the Stern–Volmer constant ( K sv ) and bimolecular quenching rate constant ( k q ) values. The observation of linear Stern–Volmer plots in Figure 4 A–C suggests a ground state association [ 21 ], which was reinforced with k q values of about two orders of magnitude ( Table 1 ) larger than the maximum diffusion rate constant in water ( k diff ≈ 7.40 × 10 9 M −1 s −1 , according to Smoluchowski–Stokes–Einstein theory at 298 K) [ 37 ]. No discernible trend in K sv values was observed with the increase in temperature.…”

“…Since TFV, TDF, and TAF do not have absorption at the excitation and maximum fluorescence emission of the biomacromolecule (295 and 340 nm, respectively), the inner filter correction was not applied. To obtain quantitative parameters describing the binding affinity between HSA and antiretrovirals, mathematical approximations from the Stern–Volmer (Equation (1)), double-logarithmic (Equation (2)), van’t Hoff (Equation (3)), and Gibbs free energy (Equation (4)) equations were used [ 18 , 19 , 20 , 21 , 22 ]: where F 0 and F are the steady-state fluorescence intensity of HSA in the absence and the presence of antiretrovirals, respectively. [ Q ] is the antiretroviral concentration, while K SV and k q are the Stern–Volmer constant and the bimolecular quenching rate constant, respectively.…”

“…Drug-displacement assays were carried out using site probes for site I (phenylbutazone, PHEN), site II (ibuprofen, IBU), and site III (digitoxin, DIG) [ 21 , 23 ]. Steady-state fluorescence measurements were obtained under the same conditions described in Section 2.3 at 310 K. Each site probe was incubated with 10 μM of HSA solution (molar ratio of 1:1) before the antiretroviral additions (8.2, 9.2, 10, 13, 16, 19, 23, and 26 μM).…”

Food Colorants Acid Yellow 23, Azorubine, and Acid Red 18 Cause Aggregation and Fibrillation of Proteins

“…There are, however, many studies reported from time to time that discuss concerns about unwarranted health risks and adverse effects . A short-term risk could be an allergic-type reaction manifested in itching, inflammations, and skin rashes called vibes, while long-term accumulation of azo dyes that are reduced to amines can elicit allergy, headache, and neurotoxic, genotoxic, and carcinogenic effects. ,− Synthetic food colors have also been associated with attention deficiency and hyperactivity symptoms. , The accumulation of food dyes in blood plasma, especially when the ingested dyes are not metabolized by the gut microbiota, can upset the homeostasis of the body . Although the cited are among the recent studies, food regulatory agents still consider the recommended levels of dyes safe unless consumers report on problematic effects.…”

Revealing the mechanistic interactions of profenofos and captan pesticides with serum protein via biophysical and computational investigations

“…Site I preferentially binds with bulky heterocyclic anions, while site II favors binding with aromatic carboxylic compounds via non-covalent bondings 4 , 5 . With the employment of multi-spectroscopic techniques, the interaction between serum albumins and ligands of interest has been extensively investigated for its toxicological profiles such as food dyes 6 , metallopharmaceuticals 7 , and photosensitizers 8 . Also, the influence of serum albumin on the blood concentration of pesticides has been widely reported.…”