curcumin and cyanidin

In situ, real timely and dynamically monitoring the processes of theaflavin (TF), curcumin (Cur) and cyanidin (Cy) binding to human whole saliva (WS) surface has been investigated by surface plasmon resonance (SPR) technique at the molecular level.. The affinity between pigments and WS, association rate constant (k(a)), dissociation rate constant (k(d)), association equilibrium constant (K(A)) and dissociation equilibrium constant (K(D)) of pigments binding on WS surface had been determined by SPR and the Langmuir model as well as the Freundlich model. The data were analyzed by one-way ANOVA and SNK-q test.. There were significant differences among TF, Cur and Cy in k(a), k(d), K(A) and K(D) (P<0.05). Our results showed that the adsorption isotherm of pigments on WS surface could be better described by the Freundlich model than the Langmuir model. The pigments adsorption on WS surface was dominant by specific interactions, such as hydrogen bonding. The affinity of pigments to WS were TF> Cur>Cy (P<0.05), as evidenced by the rate constants and equilibrium constants.. Compared with Cur and Cy, TF shows much higher adsorption capacity on WS surface, suggesting the importance of the hydroxyl group in pigment/protein interactions.

Topics: Adsorption; Anthocyanins; Biflavonoids; Catechin; Curcumin; Humans; Saliva; Surface Plasmon Resonance

The aim of the present study was to assess the null hypothesis that there are no differences of affinity between pigments and human whole saliva (WS), and the affinity is not influenced by the functional groups of pigments, temperatures, pH values, and salt concentrations.. The affinity constants of interactions between WS and theaflavin (TF)/curcumin (Cur)/cyanidin (Cy) were determined by surface plasmon resonance (SPR) and fluorescence quenching. Mass-uptake at various temperatures, pH values, and salt concentrations was also carried out.. The order of affinity of the pigments binding to WS is TF>Cur>Cy. A large number of complexes and precipitations of pigments/proteins were formed through a quick, strong, and almost irreversible binding process. The mass-uptake of pigments was affected not only by the functional groups, but also by molecular weight of pigments, temperatures, pH values, and salt concentrations.. The complex of pigments may easily and rapidly deposit onto the WS film, and are difficult to remove from the WS surface. However, the complex of pigments can be reduced by properly regulating the physicochemical conditions, such as temperatures, pH values, and salt concentrations.

Topics: Adsorption; Adult; Analysis of Variance; Anthocyanins; Biflavonoids; Binding, Competitive; Catechin; Curcumin; Dental Pellicle; Female; Humans; Hydrogen-Ion Concentration; Immobilized Proteins; Male; Middle Aged; Molecular Weight; Pigments, Biological; Protein Binding; Saliva; Salivary Proteins and Peptides; Spectrometry, Fluorescence; Statistics, Nonparametric; Surface Plasmon Resonance; Temperature; Tooth Discoloration; Young Adult