Complexation of curcumin using proteins to enhance aqueous solubility and bioaccessibility: Pea protein vis-à-vis whey protein

Enhanced solubility, bioaccessibility, and antioxidant activity of curcumin via lipase complexation: Structural insights and stability assessment

Curcumin, a bioactive compound with diverse therapeutic properties, faces challenges in clinical applications owing to its limited solubility and poor bioaccessibility. This study proposes a novel strategy to enhance the aqueous solubility, bioaccessibility, and antioxidant potential of curcumin by complexation with lipase (PersiLip1). The optimal condition for complex formation was determined to be pH 7.0, resulting in a 90-fold increase in solubility, reaching 96.92 %. Antioxidant activity assays (ABTS and DPPH) revealed significant radical scavenging capacity. Structural characterization, including Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD), indicated a notable transformation of curcumin from its crystalline to amorphous state. Atomic Force Microscopy (AFM) confirmed the formation of larger, stable molecular assemblies, with a particle size increase from 4.68 nm (free curcumin) to 121 nm (Cur-Lip complex). Dynamic Light Scattering (DLS) analysis revealed a further increase in the particle size to 3214.10 nm, coupled with a reduced Polydispersity Index (PDI) of 0.23, suggesting enhanced homogeneity. Zeta potential analysis showed a reduction in surface charge. Storage stability assessments confirmed the sustained solubility of the Cur-Lip complex for over 30 days. These findings highlight lipase-assisted complexation as an effective strategy for enhancing the therapeutic potential of curcumin.

Formation of polyphenol-based nanoparticles in dried hawthorn with enhanced cellular absorption over free polyphenols

Plant-derived nanoparticles are gaining attention for enhancing the delivery and bioavailability of bioactive compounds, though the mechanisms remain unclear. This study aims to investigate dried hawthorn-derived nanoparticles (DHNPs), focusing on their composition, molecular interactions and impact on polyphenol absorption. The results showed that DHNPs, averaging 275.7 nm, were primarily composed of polysaccharides and high content of polyphenolic compounds (∼25%), with covalent and non-covalent interactions forming between them. Saponification increased the polyphenol release, and metabolomics identified 252 polyphenolic compounds, with 195 showing a relative increase post-treatment, including caffeic acid and (-)-catechin. An in vitro intestinal absorption test using Caco-2 cell monolayer model demonstrated that DHNPs-bound polyphenols exhibited significantly higher permeability (27.90%) compared to free polyphenols (12.38%), indicating that endocytosis may serve as a potential pathway through which DHNPs enhance polyphenol absorption. This study provides new insights into the role of plant-derived nanoparticles contributing to bioactive compound delivery and bioavailability.

Optimization and Modeling of Ultrasound- and Microwave-Assisted Extraction of Turmeric to Efficiently Recover Curcumin and Phenolic Antioxidants Followed by Food Enrichment to Enhance Health-Promoting Effects

Phenolic antioxidants and curcuminoids are biologically important molecules playing a crucial role in combating reactive species under oxidative stress conditions. In this study, microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) processes for the extraction of phenolic antioxidants and curcumin from turmeric using an ethanol-water mixture were optimized and modeled with the face-centered composite design of the response surface methodology. Under optimal conditions, CUPRAC total antioxidant capacity (TAC), curcumin content (CC), DPPH free radical scavenging capacity, ABTS radical scavenging capacity, and total phenolic contents (TPC) of the extracts obtained using MAE, UAE, and automated soxhlet-assisted extraction were determined to distinguish the water ratio of the ethanolic solvent as the most important operational factor affecting TAC and CC responses. The highest TAC and CC yields were obtained at a 200 μm particle size, 100°C temperature, 30 min time, and 20% water in ethanol conditions for MAE. The highest TAC and CC yields were obtained at a 200 μm particle size, 48 min time, G = 600 W ultrasonic power, and 26% water in ethanol conditions for UAE. In addition, the red lentil (R.L.) soup was selected as a model food system and was enriched with extracts obtained by the UAE process. The effects of curcumin addition to a protein-rich food matrix, spontaneous protein-curcumin interaction, and the existence of olive oil as an oil/water emulsion delivery system in the prepared soup samples were investigated in association with simulated gastrointestinal digestion. The (R.L + water + 5% turmeric extract) sample was shown to have a higher TPC value than analogous mixtures after in vitro digestion. TPC values of enriched soup samples with olive oil were higher than those enriched without olive oil due to the potential ability of olive oil to provide solubility and stability of curcuminoids together with its potential as a phenolic source. The solubility, oil-water interfacial absorption, and stability of curcuminoids were important in the measured TAC response before and after simulated digestion. Curcumin addition to protein-rich foods may be recommended considering the health-promoting effects of functional foods. The proposed extraction processes show a potential to recover bioactive compounds with high efficiency through green chemistry to design new functional foods.

Double Emulsion Microencapsulation System for Lactobacillus rhamnosus GG Using Pea Protein and Cellulose Nanocrystals

Microencapsulation using a double emulsion system can improve the viability of probiotic cells during storage and digestion. In this study, a double emulsion system WC/O/WF was designed to microencapsulate Lactobacillus rhamnosus GG using pea protein (PP) and cellulose nanocrystals (CNCs) at various proportions, and the effect of their proportions on the stability and efficacy of the encapsulation system was studied. The double emulsions were prepared by a two-step emulsification process: the internal aqueous phase containing probiotic strain (WC) was homogenized into the oil phase (O), which was then homogenized into the external aqueous phase (WF) containing 15% wall materials with varying proportions of PP and CNCs [F1 (100:0), F2 (96:4), F3 (92:8), F4 (88:12), F5 (84:16), F6 (80:20)]. The incorporation of CNCs significantly lowered the average particle size and improved the stability of the emulsions. The encapsulation efficiency did not differ significantly across the tested formulations (63-68%). To check the effectiveness of the designed system, a simulated digestion study was conducted in two phases: gastric phase and intestinal phase. The double emulsion microencapsulation significantly improved the viability of encapsulated cells during digestion compared against free cells. Microscopic analysis along with assessment of protein hydrolysis of the double emulsions during the simulated digestion demonstrated a two-stage protection mechanism. This study presented promising results for employing a double emulsion system for the microencapsulation of probiotics and the potential of PP and CNCs in designing such systems.

Natural pigments in the food industry: Enhancing stability, nutritional benefits, and gut microbiome health

Natural pigments are increasingly favored in the food industry for their vibrant colors, fewer side effects and potential health benefits compared to synthetic pigments. However, their application in food industry is hindered by their instability under harsh environmental conditions. This review evaluates current strategies aimed at enhancing the stability and bioactivity of natural pigments. Advanced physicochemical methods have shown promise in enhancing the stability of natural pigments, enabling their incorporation into food products to enhance sensory attributes, texture, and bioactive properties. Moreover, recent studies demonstrated that most natural pigments offer health benefits. Importantly, they have been found to positively influence gut microbiota, in particular their regulation of the beneficial and harmful flora of the gut microbiome, the reduction of ecological dysbiosis through changes in the composition of the gut microbiome, and the alleviation of systemic inflammation caused by a high-fat diet in mice, suggesting a beneficial role in dietary interventions.

Structural characterization and binding interaction of rice glutelin fibrils complexing with curcumin

The rice glutelin (RG), the separated retentate (RGFs) and filtrate (FGFs) fractions from total glutelin fibrils (TGFs) at pH 3.5 were used as carrier for curcumin in this test. The solubility and antioxidant activities of curcumin were improved after binding with protein and fibrils. Compared to other complexes, the RGFs-curcumin complex exhibited a highest curcumin solubility (48.05%) and a superior sustained release property, probably owing to the stable hydrogen bond between the surface groups of fibrils and hydroxyl groups of polyphenols. In addition, thermodynamic parameters revealed that the RG/TGFs/RGFs-curcumin complexes were stabilized by hydrogen bonds and van der Waals forces, whereas FGFs interacted with curcumin through specific electrostatic interaction. Besides, after interacting with curcumin, the fibrils gathered into coarsened and agglutinated fibrillar aggregates, relating to the increment of a-helix and β-sheet structure. These results suggested that RGFs could be a good alternative for curcumin delivery in food industry.

Probabilistic Modelling of the Food Matrix Effects on Curcuminoid's In Vitro Oral Bioaccessibility

The bioaccessibility of bioactive compounds plays a major role in the nutritional value of foods, but there is a lack of systematic studies assessing the effect of the food matrix on bioaccessibility. Curcuminoids are phytochemicals extracted from Curcuma longa that have captured public attention due to claimed health benefits. The aim of this study is to develop a mathematical model to predict curcuminoid's bioaccessibility in biscuits and custard based on different fibre type formulations. Bioaccessibilities for curcumin-enriched custards and biscuits were obtained through in vitro digestion, and physicochemical food properties were characterised. A strong correlation between macronutrient concentration and bioaccessibility was observed (p = 0.89) and chosen as a main explanatory variable in a Bayesian hierarchical linear regression model. Additionally, the patterns of food matrix effects on bioaccessibility were not the same in custards as in biscuits; for example, the hemicellulose content had a moderately strong positive correlation to bioaccessibility in biscuits (p = 0.66) which was non-significant in custards (p = 0.12). Using a Bayesian hierarchical approach to model these interactions resulted in an optimisation performance of r2 = 0.97 and a leave-one-out cross-validation score (LOOCV) of r2 = 0.93. This decision-support system could assist the food industry in optimising the formulation of novel food products and enable consumers to make more informed choices.

Interaction between curcumin and ultrafiltered casein micelles or whey protein, and characteristics of their complexes

This work evaluated the interaction between micellar casein (MC) or whey protein (WP) in ultrafiltration retentate with curcumin (Cur), as well as the physicochemical and functional properties of Cur-MC and Cur-WP complexes. The MC had a higher affinity for Cur than WP, shown by higher binding constants of Cur-MC at various temperatures. Thermodynamic analysis of the binding process indicated that the interaction between Cur and MC or WP was hydrophobic in nature. Cur promoted the size and polydispersity index of MC and WP at 4 mM but did not alter the morphology of spray-dried MC and WP. The Cur-MC complexes showed better aqueous solubility at pH 2-3 and 6-10 compared to free MC. Combination with MC or WP improved the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical scavenging activity of Cur. In addition, combination with MC and WP promoted cumulative release of Cur during simulated gastrointestinal digestion, especially for WP. Thus, MC and WP in retentates can be good alternative protein-based carriers for Cur delivery, whereas their complexes in powder form have good functional properties that could be used as active food ingredients in several food formulations. PRACTICAL APPLICATION: Microfiltration is a cheap and convenient approach that can be used to easily produce micellar casein (MC), with whey protein (WP) as one byproduct. In this study, we proved that MC and WP in retentates have strong interaction with curcumin (Cur), whereas their complexes have good functional properties. Thus, spray-dried MC-Cur or WP-Cur complexes could be used as active food ingredients in several food formulations.

Fabrication and characterization of curcumin-loaded nanoparticles using licorice protein isolate from Radix Glycyrrhizae

Licorice was widely used in food and herbal medicine. In its extract industry, a substantial amount of licorice protein was produced and discarded as waste. Herein, we extracted Licorice Protein Isolate (LPI) and explored its potential as a curcumin nanocarrier. Using a pH-driven method, we fabricated LPI-curcumin nanoparticles with diameters ranging from 129.30 ± 3.21 nm to 75.03 ± 1.19 nm, depending on the LPI/curcumin molar ratio. The formation of LPI-curcumin nanoparticles was primarily driven by hydrophobic interactions, with curcumin entrapped in LPI being in an amorphous form. These nanoparticles significantly enhanced curcumin properties in terms of solubility, photochemical stability, and stability under varying pH, storage, and physiological conditions. Moreover, the loaded curcumin exhibited a 2.58-fold increase in cellular antioxidant activity on RAW 264.7 cells and a 1.86-fold increase in antitumor activity against HepG2 cells compared to its free form. These findings suggested that LPI could potentially serve as a promising novel delivery material.

Review: The Chemistry, Toxicity and Antibacterial Activity of Curcumin and Its Analogues

Antimicrobial resistance is a global challenge that is already exacting a heavy price both in terms of human health and financial cost. Novel ways of approaching this crisis include the investigation of natural products. Curcumin is the major constituent in turmeric, and it is commonly used in the preparation of Asian cuisine. In addition, it possesses a wide range of pharmacological properties. This review provides a detailed account of curcumin and its analogues' antibacterial activity against both gram-positive and gram-negative isolates, including its potential mechanism(s) of action and the safety and toxicity in human and animal models. We also highlight the key challenges in terms of solubility/bioavailability associated with the use of curcumin and include research on how these challenges have been overcome.

Molecular Mechanisms and Applications of Polyphenol-Protein Complexes with Antioxidant Properties: A Review

Proteins have been extensively studied for their outstanding functional properties, while polyphenols have been shown to possess biological activities such as antioxidant properties. There is increasing clarity about the enhanced functional properties as well as the potential application prospects for the polyphenol-protein complexes with antioxidant properties. It is both a means of protein modification to provide enhanced antioxidant capacity and a way to deliver or protect polyphenols from degradation. This review shows that polyphenol-protein complexes could be formed via non-covalent or covalent interactions. The methods to assess the complex's antioxidant capacity, including scavenging free radicals and preventing lipid peroxidation, are summarized. The combination mode, the type of protein or polyphenol, and the external conditions will be the factors affecting the antioxidant properties of the complexes. There are several food systems that can benefit from the enhanced antioxidant properties of polyphenol-protein complexes, including emulsions, gels, packaging films, and bioactive substance delivery systems. Further validation of the cellular and in vivo safety of the complexes and further expansion of the types and sources of proteins and polyphenols for forming complexes are urgently needed to be addressed. The review will provide effective information for expanding applications of proteins and polyphenols in the food industry.

Development of nanocubosomes co-loaded with dual anticancer agents curcumin and temozolomide for effective Colon cancer therapy

Current research aimed to develop nanocubosomes co-loaded with dual anticancer drugs curcumin and temozolomide for effective colon cancer therapy. Drugs co-loaded nanocubosomal dispersion was prepared by modified emulsification method using glyceryl monooleate (GMO), pluronic F127 and bovine serum albumin (BSA) as a lipid phase, surfactant, and stabilizer, respectively. The resulting nanocubosomes were characterized by measuring hydrodynamic particle size, particle size distribution (PSD), drug loading capacity (DL), encapsulation efficiency (EE), colloidal stability and drug release profile. We also physiochemically characterized the nanocubosomes by transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and x-rays diffraction (XRD) for their morphology, polymer drug interaction and its nature, respectively. Further, the in-vitro cell-uptake, mechanism of cell-uptake, in-vitro anti-tumor efficacy and apoptosis level were evaluated using HCT-116 colon cancer cells. The prepared nanocubosomes exhibited a small hydrodynamic particle size (PS of 150 ± 10 nm in diameter) with nearly cubic shape and appropriate polydispersity index (PDI), enhanced drug loading capacity (LC of 6.82 ± 2.03% (Cur) and 9.65 ± 1.53% (TMZ), high entrapment efficiency (EE of 67.43 ± 2.16% (Cur) and 75.55 ± 3.25% (TMZ), pH-triggered drug release profile and higher colloidal stability in various physiological medium. Moreover, the nanocubosomes showed higher cellular uptake, in-vitro cytotoxicity and apoptosis compared to free drugs, curcumin and temozolomide, most likely because its small particle size. In addition, BSA-stabilized nanocubosomes were actively taken by aggressive colon cancer cells that over-expressed the albumin receptors and utilized BSA as nutrient source for their growth. In short, this study provides a new and simple strategy to improve the efficacy and simultaneously overawed the adaptive treatment tolerance in colon cancer.

Strategies for Improving Bioavailability, Bioactivity, and Physical-Chemical Behavior of Curcumin

Curcumin (CCM) is one of the most frequently explored plant compounds with various biological actions such as antibacterial, antiviral, antifungal, antineoplastic, and antioxidant/anti-inflammatory properties. The laboratory data and clinical trials have demonstrated that the bioavailability and bioactivity of curcumin are influenced by the feature of the curcumin molecular complex types. Curcumin has a high capacity to form molecular complexes with proteins (such as whey proteins, bovine serum albumin, β-lactoglobulin), carbohydrates, lipids, and natural compounds (e.g., resveratrol, piperine, quercetin). These complexes increase the bioactivity and bioavailability of curcumin. The current review provides these derivatization strategies for curcumin in terms of biological and physico-chemical aspects with a strong focus on different type of proteins, characterization methods, and thermodynamic features of protein–curcumin complexes, and with the aim of evaluating the best performances. The current literature review offers, taking into consideration various biological effects of the CCM, a whole approach for CCM-biomolecules interactions such as CCM-proteins, CCM-nanomaterials, and CCM-natural compounds regarding molecular strategies to improve the bioactivity as well as the bioavailability of curcumin in biological systems.

Influence of Proteins on the Absorption of Lipophilic Vitamins, Carotenoids and Curcumin - A Review

While proteins have been widely used to encapsulate, protect, and regulate the release of bioactive food compounds, little is known about the influence of co-consumed proteins on the absorption of lipophilic constituents following digestion, such as vitamins (A, D, E, K), carotenoids, and curcumin. Their bioavailability is often low and very variable, depending on the food matrix and host factors. Some proteins can act as emulsifiers during digestion. Their liberated peptides have amphiphilic properties that can facilitate the absorption of microconstituents, by improving their transition from lipid droplets into mixed micelles. Contrarily, the less well digested proteins could negatively impinge on enzymatic accessibility to the lipid droplets, slowing down their processing into mixed micelles and entrapping apolar food compounds. Interactions with mixed micelles and proteins are also plausible, as shown earlier for drugs. This review focuses on the ability of proteins to act as effective emulsifiers of lipophilic vitamins, carotenoids, and curcumin during digestion. The functional properties of proteins, their chemical interactions with enzymes and food constituents during gastro-intestinal digestion, potentials and limitations for their use as emulsifiers are emphasized and data from human, animal, and in vitro trials are summarized.

Fabrication and characterization of octenyl succinic anhydride modified pullulan micelles for encapsulating curcumin

BACKGROUND

Curcumin has become increasingly popular in functional foods and beverages field as a result of its high biological activity. Nevertheless, the application of curcumin is usually limited by its poor water solubility, low absorption, rapid metabolism and instability. Accordingly, the development of an appropriate wall material is crucial for its effective use. In the present study, curcumin-octenyl succinic anhydride modified pullulan (Cur-OSAP) micelles were successfully prepared by an anti-solvent co-precipitation method.

RESULTS

Octenyl succinic anhydride modified pullulan (OSAP) micelles exhibited the highest encapsulation efficiency (57.31%) and loading capacity (5.73%) of curcumin when the mass ratio of OSAP to curcumin was 10:1 and the degree of substitution of OSAP was 0.0469, at which point Cur-OSAP micelles formed via hydrogen binding and hydrophobic interactions, as confirmed by Fourier transform infrared and fluorescence techniques. The transmission electron microscopy results showed that the Cur-OSAP micelles were roughly spherical in shape with diameters in the approximate range 30-60 nm.

CONCLUSION

The encapsulation of OSAP greatly improved photostability and sustained release properties of curcumin in Cur-OSAP micelles. These findings suggest that OSAP can be used as a carrier to encapsulate and protect hydrophobic food ingredients. © 2021 Society of Chemical Industry.

Highly Soluble and Stable, High Release Rate Nanocellulose Codrug Delivery System of Curcumin and AuNPs for Dual Chemo-Photothermal Therapy

As a natural antitumor drug, curcumin (CUR) has received increasing attention from researchers and patients due to its various medicinal properties. However, currently CUR is still restricted due to its low and stand-alone therapeutic effects that seriously limit its clinical application. Here, by using cellulose nanocrystals (CNCs) as a nanocarrier to load CUR and AuNPs simultaneously, we developed a hybrid nanoparticle as a codrug delivery system to enhance the low and stand-alone therapeutic effects of CUR. Aided with the encapsulation of β-cyclodextrin (βCD), both the solubility and the stability of CUR are greatly enhanced (solubility increased from 0.89 to 131.7 μg/mL). Owing to the unique rod-like morphology of CNCs, the system exhibits an outstanding loading capacity of 31.4 μg/mg. Under the heat effects of coloaded AuNPs, the system demonstrates a high release rate of 77.63%. Finally, with CNC as a bridge nanocarrier, all aforementioned functions were integrated into one hybrid nanoparticle. The all-in-one integration ensures CUR to have enhanced therapeutic effects and enables the delivery system to exhibit combined chemo-photothermal therapy outcomes. This work presents a significant step toward CUR's clinical application and provides a new strategy for effective and integrative treatment of tumor disease.

Plant Protein-Based Delivery Systems: An Emerging Approach for Increasing the Efficacy of Lipophilic Bioactive Compounds

The development of plant protein-based delivery systems to protect and control lipophilic bioactive compound delivery (such as vitamins, polyphenols, carotenoids, polyunsaturated fatty acids) has increased interest in food, nutraceutical, and pharmaceutical fields. The quite significant ascension of plant proteins from legumes, oil/edible seeds, nuts, tuber, and cereals is motivated by their eco-friendly, sustainable, and healthy profile compared with other sources. However, many challenges need to be overcome before their widespread use as raw material for carriers. Thus, modification approaches have been used to improve their techno-functionality and address their limitations, aiming to produce a new generation of plant-based carriers (hydrogels, emulsions, self-assembled structures, films). This paper addresses the advantages and challenges of using plant proteins and the effects of modification methods on their nutritional quality, bioactivity, and techno-functionalities. Furthermore, we review the recent progress in designing plant protein-based delivery systems, their main applications as carriers for lipophilic bioactive compounds, and the contribution of protein-bioactive compound interactions to the dynamics and structure of delivery systems. Expressive advances have been made in the plant protein area; however, new extraction/purification technologies and protein sources need to be found Their functional properties must also be deeply studied for the rational development of effective delivery platforms.

Eggshell MembraneBased Turmeric Extract Loaded Orally Disintegrating Films

BACKGROUND

The increasing interest in using natural bioactive compounds as new drug candidates and their low solubility led to designing and developing novel drug delivery systems. Out of those, orally disintegrating films (ODFs) are a very eminent drug delivery system among pediatrics and geriatrics.

OBJECTIVE

In our study, the solvent casting method was used to prepare eggshell membrane-based and turmeric extract loaded orally disintegrating films.

METHOD

Characterization of the prepared films was done with FTIR, AFM, and SEM analysis. The release profile of the turmeric extract was determined and fitted to the mathematical models.

RESULTS

AFM results showed that the best interaction between components was achieved in Film-2. The highest cumulative release percentage was obtained for the film with 7.5 % (w/w) turmeric extract (Film-2) as 41.98% based on the HPLC measurements. The Higuchi model was the best-fitted model for Film-2.

CONCLUSION

In this study, SEP and CMCH were used for the first time as biopolymers to prepare the orally disintegrating film. Turmeric extract was successfully integrated into films prepared from SEP and CMCH.