Inhibitory kinetics and mechanism of kaempferol on α-glucosidase

Curcumin is the main polyphenol of the curcuminoid class of turmeric, a well-known spice belonging to the ginger family. In addition to its common applications like coloring and antioxidant agent as food additives, it has a broad range of favorable biological functions, such as anti-inflammatory, anti-microbial, anti-diabetic activities, and anti-cancer potentials against various cancers. However, curcumin suffers from some limitations including short shelf life due to its poor chemical stability, low bioavailability due to its poor absorption, low water solubility, rapid metabolism and rapid systemic elimination. Nanoencapsulaion has been addressed as an innovative and emerging technology for resolving these shortcomings. In this review, the different delivery systems used for loading of curcumin have been considered and explained including lipid-based, chemical polymer and biopolymer-based, nature-inspired, special equipment-based and surfactant-based techniques. Also, implications of nanoencapsulated curcumin in food, pharmaceutical and cosmetic uses are discussed. In this sense, the relevant recent studies in the past few years along with upcoming challenges have been covered. Although incorporation of curcumin into nanocarriers can be a possible solution to overcome its inherent constraints, there are some rational concerns about their toxicological safety once they enter into the biological paths. Therefore, future investigations could focus on assessment of their biological fate during digestion and absorption within human body.

Application of different nanocarriers for encapsulation of curcumin.

The biological activity and techno-functional properties of phenolic compounds have gained great importance due to the epidemiologically-proved health benefits. Use of polyphenols as fortification agents for functional food production and nanotechnological approaches using natural vehicles for polyphenol delivery have been recently discussed. In this respect, milk proteins and dairy products represent unique characteristics for polyphenol studies. The conflicting results on the functionality of polyphenols interacting with milk proteins either in model systems or in complex dairy matrices reveal the need for future studies.

Interactions between milk proteins and polyphenols: Binding mechanisms, related changes, and the future trends in the dairy industry

Binding, stability, and antioxidant activity of quercetin with soy protein isolate particles.

Enhancement of the solubility, stability and bioaccessibility of quercetin using protein-based excipient emulsions.

The interaction of quercetin with β-casein nanoparticle micelle was studied at various temperatures in order to do a complete thermodynamic and molecular analysis on the binding process. The results of fluorescence studies showed the possibility of fluorescence energy transfer between excited tryptophan and quercetin. The determined values of critical transfers distance and the mean distance of ligand from Trp-143 residues in β-casein micelle represents a non-radiative energy transfer mechanism for quenching and the existence of a significant interaction between this flavonoid and β-casein nanoparticle. The equilibrium binding of quercetin with β-casein micelle at different temperatures was studied by using UV-Vis absorption spectroscopy. The chemometric analysis (principal component analysis (PCA) and multivariate curve resolution-alternating least squares (MCR-ALS) methods) on spectrophotometric data revealed the existence of two components in solution (quercetin and β-casein-quercetin complex) and resolved their pure concentration and spectral profiles. This information let us to calculate the equilibrium binding constant at various temperatures and the relevant thermodynamic parameters of interaction (enthalpy, entropy and Gibbs free energy) with low uncertainty. The negative values of entropy and enthalpy changes represent the predominate role of hydrogen binding and van der Waals interactions in the binding process. Docking calculations showed the probable binding site of quercetin is located in the hydrophobic core of β-casein where the quercetin molecule is lined by hydrophobic residues and make five hydrogen bonds and several van der Waals contacts with them. Moreover, molecular dynamic (MD) simulation results suggested that this flavonoid can interact with β-casein, without affecting the secondary structure of β-casein. Simulations, molecular docking and experimental data reciprocally supported each other.

A combined spectroscopic, molecular docking and molecular dynamic simulation study on the interaction of quercetin with β-casein nanoparticles

Factors affecting the emission of pollutants in different types of transportation: A literature review

Binding analysis for interaction of diacetylcurcumin with β-casein nanoparticles by using fluorescence spectroscopy and molecular docking calculations

Spectrofluoremetric and molecular docking study on the interaction of bisdemethoxycurcumin with bovine β-casein nanoparticles

The micellar properties of b-casein in solution with a homologous series of cationic surfactants have been investigated using turbidity, fluorescence spectroscopy, and quenching fluorescence measurements. Turbidity mea- surements indicated that monomeric cationic surfactants initially bind cooperatively with a site on the b-casein micelle in negatively charged amino acids. This leads to the formation of low-soluble b-casein micelle-monomeric surfactants complexes. Further addition of surfactant leads to the formation of more highly soluble complexes of b- casein micelle-cationic surfactant. The fluorescence experiments were also used to study the formation of b- casein-cationic surfactant complexes and to determine critical micelle concentration of surfactants and b-casein. The mean aggregation number of b-casein and cationic surfactant micelles at various experimental conditions and the dependence of aggregation phenomenon on the chain length of cationic surfactants were investigated. The mean aggregation number for b-casein micelle has been deter- mined to be 45.70 using quenching fluorescence.

Fahimeh Mehranfar

Papers

A combined spectroscopic, molecular docking and molecular dynamic simulation study on the interaction of quercetin with β-casein nanoparticles

Factors affecting the emission of pollutants in different types of transportation: A literature review

Binding analysis for interaction of diacetylcurcumin with β-casein nanoparticles by using fluorescence spectroscopy and molecular docking calculations

Spectrofluoremetric and molecular docking study on the interaction of bisdemethoxycurcumin with bovine β-casein nanoparticles

Micellar properties of β-casein–cationic surfactant solutions