Concentrations Of Cur Research Articles

Ratiometric fluorescence method comprising carbon dots and rhodamine 6G encapsulated in metal-organic framework microcubes for curcumin detection.

A ratiometric fluorescence method comprising carbon dots (CDs) and rhodamine 6G (Rh-6G) encapsulated in the microcubes of metal-organic framework (MOF-5) is introduced for the sensitive detection of curcumin (Cur) in condiments. CDs@MOF-5@Rh-6G, synthesized by the adsorption of Rh-6G on MOF-5 embedded with CDs, showed two distinct emission peaks at 435 and 560nm under excitation at 335nm, and could be used for Cur detection by ratiometric fluorescence. In the presence of Cur, the fluorescence of the CDs at 435nm (F435) was quenched by Cur owing to internal filtering and dynamic quenching effects, whereas the emission of Rh-6G at 560nm (F560) remained unchanged (335nm is the excitation wavelength, 435 and 560nm are the emission wavelengths, in which F435/F560 values are used as the output results). Under optimal conditions, a linear relationship was observed between the Cur concentration (in the range 0.1-5μmol/L) and F435/F560 value for CDs@MOF-5@Rh-6G, with a detection limit of 15nmol/L. Notably, the proposed method could accurately detect Cur in mustard, curry, and red pepper powders. Therefore, this study could improvethe quality control of food and facilitate the development of sensitive ratiometric fluorescence probes.

Curcumin-loaded soybean-dextran conjugate nanogels: Construction, characterization, and incorporation into orange juice beverage

Although the health benefits of lipophilic bioactive compounds have received tremendous attention from both researchers and manufacturers, the practical application of these micronutrients in aqueous foods is still challenging due to their water insolubility and environmental instability. Therefore, curcumin (Cur) was selected to be encapsulated in soybean protein isolate-dextran conjugate-based nanogels (SDCNG) via the Maillard reaction combined with protein self-assembly to be incorporated into orange juice beverage (OJB) in this study. Cur-loaded SDCNG (Cur-SDCNG) prepared by adding Cur into the SDCNG solution exhibited an encapsulation efficiency of 89.10% ± 1.40% and a loading capacity of 17.11% ± 0.27%, enhanced 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical (•OH)-scavenging activities and ferrous reducing power, increased retention rate at both natural light and dark environment, and strengthened storage stability. Moreover, the loaded Cur showed a greater bioaccessibility (55.41% ± 0.71%) than free Cur (17.41% ± 1.04%). The OJB fortified with Cur by adding Cur-SDCNG exhibited an increasing color difference, particle size, polydispersity index (PDI), protein content, total soluble solid (TSS), and sensory score with the increasing Cur concentration. DPPH radical and •OH-scavenging activities and ferrous reducing power also further enhanced. The Cur-fortified OJB with an orange juice concentration of 30% exhibited improved quality attributes and satisfactory stability reflected by the increased TSS and sensory score, acceptable particle size, PDI, centrifugal sedimentation rate, and Cur retention rate under cold conditions. In conclusion, the findings confirmed the effectiveness of Cur encapsulation in SDCNG and the application feasibility of Cur-SDCNG in acidic beverages simultaneously fortified with lipophilic bioactive compounds and vegetable proteins.

Pickering emulsion stabilized by sugarcane leaf polyphenols-zein covalent nanoparticles for curcumin delivery: In-vitro and inhibition of oxidative hemolytic activity evaluation

Pickering emulsion have been widely used to encapsulate bioactives with the aim of preventing degradation, improving bioavailability and achieving the effect of slow release. Curcumin (Cur), as a bioactive compound, was famous as its excellent beneficial human health functions. However, the low solubility and susceptibility to environmental influences limit the application of Cur. In our previous study, the covalent nanoparticles (sugarcane leaf polyphenols-zein, SGLpZ) with excellent antioxidant capacity were successfully fabricated. In addition, the pickering emulsion stabilized using SGLpZ with significance storage stability and antioxidant properties, which inspired us for Cur delivery application. Therefore, in this study, SZP (pickering emulsion stabilized by SGLpZ) were prepared and were firstly used to delivery Cur evaluation. Results exhibited that the mechanism of excellent stabilization of SZP may be due to the wide range of O/W phase interfaces with SGLpZ, which could be further used as a delivery system for Cur. An in-vitro simulated digestion suggested that SZP provided better protection to Cur under three different conditions (different Na+ concentration, temperatures and UV exposure times), compared to ZZP (pickering emulsion stabilized by zein nanoparticles alone). SZP was able to achieve a slow release of Cur as well as the high bioaccessibility of Cur during the in-vitro simulated digestion. Finally, Cur, Cur-ZZP and Cur-SZP inhibited respectively by 33.20±1.00%, 53.26±0.94% and 71.59±0.14% (p＜0.05) at the Cur concentration of 20 μg/mL in the in-vitro inhibition of AAPH-induced erythrocyte hemolysis assay. The study indicated that the pickering emulsion stabilized by SGLpZ was a reliable Cur delivery system and provided a novel idea of food material application for bioacitive substances delivery.

The nanocrystalline cellulose from Ananas comosus leaf wastes: An overview to extraction, purification, and applications as curcumin drug delivery system

Currently, antibacterial materials are attracting considerable attention across various fields. In this study, curcumin (Cur) was prepared with nanocrystal cellulose (NCC) into the polyvinyl alcohol (PVA) matrix to improve the functional properties of a pure Cur-NCC-PVA film. The NCC was obtained from Ananas comosus leaves and characterized by Fourier transform infrared (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), and particle size analysis. The variations of Cur concentrations (50, 75, and 100 μg) were added to prepare Cur-NCC-PVA films. The release kinetics of Cur from the films was determined using a spectrophotometer and the release kinetic model was obtained using Korsmeyer-Peppas kinetic model. The antibacterial activity of Cur-NCC-PVA films was established using the diffusion method. The results of NCC characteristics showed satisfactory significance. The FTIR showed a functional group of chemical composition that confirmed the removal of non-cellulosic constituents. XRD confirmed the crystallinity index of NCC of 75.89%. Meanwhile, the particle size of NCC of 268.45 nm. The development of Cur-NCC-PVA films showed a uniform yellow color. The release of curcumin in all films was increased depending on the time following the zero-order kinetic reaction. The non-Fickian kinetics demonstrated the mechanism of Cur release from the film. The Cur-NCC-PVA films in Cur concentration of 100 μg were confirmed to have the highest antibacterial activity and significantly different between 50 and 75 μg Cur-NCC-PVA films against Bacillus subtilis, Streptococcus spp., and Escherichia coli. The Cur-NCC-PVA films described the potential activity for topical formulation in skin disease treatment.

Revealing the Synergistic Anticancer Efficacy of Curcumin and Iota‐Carrageenan‐Stabilized Silver Nanoparticles Derived From Solieria robusta

In this study, a red seaweed (Solieria robusta) containing ι‐carrageenan (Carr) was used for nanoparticles (NPs) synthesis using silver (Ag) ions. Initially, the ι‐Carr was extracted from S. robusta using the alkali method. The Carr extracted was fractionated into 3 fractions and > 14 kDa fraction showing high yield with maximum sulfate content characterized using Fourier transform infrared (FT‐IR) as ι‐Carr was used for AgNPs synthesis. The synthesized CarrAgNPs were again used for curcumin (Cur) encapsulation. The cytotoxicity of Carr, Cur, CarrAgNPs, and CurCarrAgNPs was evaluated using HeLa cell lines by MTT assay. The CarrAgNPs and CurCarrAgNPs were characterized using UV‐visible spectroscopy, as well as FT‐IR and XRD analysis. The UV‐visible spectrum confirms the CarrAgNPs showing characteristic SPR bands recorded between 344 and 490 nm with broad peak at 430 nm. The shape of the NPs is spherical, arranged in order of seven per chain. The XRD and FT‐IR characteristics confirm the orthorhombic crystal structure of these NPs. Remarkably, Cur‐loaded CarrAgNPs demonstrate potent anticancer properties by maximum reduction of HeLa cell viability after 24 h at 200 μg/mL in pH 7.4 in an MTT assay medium. A significant increase in the cancer cell viability was recorded at high concentrations of CurCarrAgNPs, confirming its less diffusion and dissolution properties and bioavailability due to lipophilic Cur encapsulation, whereas cytotoxicity was increased proportionately by increasing concentrations of Cur, Carr, and CarrAgNPs that confirm a direct relation with size, dissolution, and bioavailability recorded on the basis of cell death in 24 h of introduction at pH 7.4. The cytotoxicity results suggest the potential of Cur, Carr, CarrAgNPs, and CurCarrAgNPs for drug delivery in selective biomedical product developments. This study highlights the versatility and effectiveness of CurCarrAgNPs in cancer therapy by enhancing the efficacy of therapeutic interventions and targeted drug delivery.

Dual strategy to improve the oral bioavailability of efavirenz employing nanomicelles and curcumin as a bio-enhancer

The present investigation was focused on the development of Soluplus®-based nanomicelles (NMs) (10 % w/v) loaded with Efavirenz (EFV) (5 mg/mL) and Curcumin (natural bio-enhancer) (CUR) (5, 10 and 15 mg/mL) to improve the oral bioavalability of EFV. Micellar formulations were obtained employing an acetone-diffusion technique. Apparent aqueous solubility was increased up to ∼1250-fold and 25,000-fold for EFV and CUR, respectively. Drug-loaded nanoformulations showed an excellent colloidal stability with unimodal size distribution and PDI values < 0.30. In vitro drug release was 41.5 % (EFV) and 2.6 % (CUR) from EFV-CUR-NMs over 6 h in simulated gastrointestinal fluids. EFV-CUR-loaded NMs resulted as safe nanoformulations according to the in vitro cytocompatibility assays in Caco-2 cells. Furthermore, CUR bio-enhancer activity was demonstrated for those nanoformulations. A CUR concentration of 15 mg/mL produced a significant (p < 0.05) increment (2.64-fold) of relative EFV oral bioavailability. Finally, the active role of the lymphatic system in the absorption process of EFV, after its oral administration was assessed in a comparative pharmacokinetic study in presence and absence of cycloheximide, a lymphatic transport inhibitor.Overall our EFV-CUR-NMs denoted their potential as a novel nanotechnological platform, representing a step towards an optimized “nano-sized” therapy for AIDS patients.

High-efficiency fluorescent coordination polymer nanoparticles co-doped with Ce3+/Tb3+ ions for curcumin detection.

Curcumin (Cur) possesses diverse biological and pharmacologic effects. It is widely used as a food additive and therapeutic medicine. A study to determine a sensitive detection method for Cur is necessary and meaningful. In this work, double rare earth ions co-doped fluorescent coordination polymer nanoparticles (CPNPs) were developed for the Cur detection. The CPNPs were synthesized by using adenosine monophosphate (AMP) as bridge ligands via coordination self-assembly with Ce3+ and Tb3+. The AMP-Ce/Tb CPNPs exhibited the characteristic green fluorescence of Tb3+ and had high luminescence efficiency. Under the optimal conditions, the fluorescence intensity of AMP-Ce/Tb CPNPs could be significantly quenched by Cur. The fluorescence quenching extent at λex/λem of 300 nm/544 nm showed a good linear relationship with the Cur concentration in the range of 10 to 1000 nM. The detection limit was as low as 8.0 nM (S/N = 3). This method was successfully applied to the determination of Cur in real samples with satisfactory results. The luminescence mechanism of AMP-Ce/Tb CPNPs and the fluorescence quenching mechanism of the CPNPs by Cur were both examined.

Improvement of delivery properties of soybean 7S protein by high-pressure homogenization: In the case of curcumin

In this study, curcumin@high-pressure homogenization-soybean 7S protein/nanoparticles (CUR@HPH-7S-NPs) were prepared by an anti-solvent method. The physicochemical properties results showed at a CUR concentration of 4 mg/mL, CUR@HPH-7S-NPs had better size, encapsulation efficiency (EE), and zeta-potential values of 151.9 nm, 88.80 %, and −23.1 mV, respectively. Fourier transforms infrared (FTIR) and endogenous fluorescence spectroscopy results indicated CUR bound to HPH-7S through hydrophobic interactions, and the force between HPH-7S and CUR molecules was greater than that between untreated 7S protein and CUR. Furthermore, the pH stability results showed the size of CUR@HPH-7S-NPs was barely affected by pH away from adjacent area of the isoelectric point of 7S protein. The physical thermal stability and bio-accessibility results suggested that HPH-7S was more effective in delaying the degradation, had more physical thermal stability, and had a significant improvement in the bio-accessibility of CUR than that of untreated 7S protein. What's more, the antioxidant activity results showed at a CUR equivalent concentration of 40 μg/mL, the DPPH and ABTS radical scavenging activity of CUR@HPH-7S-NPs was 85.10 % and 96.64 %, respectively, both of which were significantly higher than that of free CUR. Finally, this study aimed to provide a theoretical basis for the delivery of other hydrophobic bioactive substances.

Curcumin suppresses cell proliferation and reduces cholesterol absorption in Caco-2 cells by activating the TRPA1 channel

BackgroundCurcumin (Cur) is a bioactive dietary polyphenol of turmeric with various biological activities against several cancers. Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths. Intestinal cholesterol homeostasis is associated with CRC. Chemotherapy for CRC is related to varied adverse effects. Therefore, natural products with anti-cancer properties represent a potential strategy for primary prevention of CRC.MethodsThe present study used Cur as a therapeutic approach against CRC using the Caco-2 cell line. The cells were treated with different concentrations of Cur for different duration of time and then the proliferation ability of cells was assessed using Cell Counting Kit-8 and 5-Ethynyl-2′-deoxyuridine assays. Oil red O staining and cholesterol assay kit were used to evaluate cellular lipid content and cholesterol outward transportation. Finally, the protein expressions of cholesterol transport-related protein and signal transduction molecules were assessed using Western blot assay.ResultsCur inhibited cell proliferation in Caco-2 cells in a dose- and time-dependent manner by activating the transient receptor potential cation channel subfamily A member 1 (TRPA1) channel. Activation of the TRPA1 channel led to increased intracellular calcium, peroxisome proliferator-activated receptor gamma (PPARγ) upregulation, and the subsequent downregulation of the specificity protein-1 (SP-1)/sterol regulatory element-binding protein-2 (SREBP-2)/Niemann-Pick C1-like 1 (NPC1L1) signaling pathway-related proteins, and finally reduced cholesterol absorption in Caco-2 cells.ConclusionsCur inhibits cell proliferation and reduces cholesterol absorption in Caco-2 cells through the Ca2+/PPARγ/SP-1/SREBP-2/NPC1L1 signaling by activating the TRPA1 channel, suggesting that Cur can be used as a dietary supplement for the primary prevention of CRC.Graphical In Caco-2 cells, Cur first stimulates calcium influx by activating the TRPA1 channel, further upregulates PPARγ and downregulates SP-1/SREBP-2/NPC1L1 signaling pathway, and finally inhibits the absorption of cholesterol. TRPA1, transient receptor potential cation channel subfamily A member 1; NPC1L1, Niemann-Pick C1-like 1; PPARγ, peroxisome proliferator-activated receptor gamma; SP-1, specificity protein-1; SREBP-2, sterol regulatory element-binding protein-2; Cur, curcumin.

Pickering emulsions stabilized by reassembled oleosome protein nanoparticles for co-encapsulating hydrophobic nutrients

In this study, oleosome proteins were disassembled using guanidine hydrochloride to form shell-core colloidal particles (reassembled oleosome proteins, ROPs). These particles were then used to prepare a dual-compartment-structured Pickering emulsion to co-deliver curcumin (Cur) and vitamin D. The results showed that ROP can effectively encapsulate Cur inside the hollow structure. Moreover, at a Cur concentration of 100 μM, the ROP-Cur contact angle was 71.5°, which aids the preparation of stable Pickering emulsions. The most stable Pickering emulsion was then prepared by adjusting the ROP-Cur emulsifier and oil phase concentrations. The Pickering emulsion prepared with 2.0 mg/mL emulsifier and the addition of 10% oil phase displayed the best stability, with an average particle size, ζ-potential, and Turbiscan Stability Index of 2.2 μm, −31.5 mV, and 3.63, respectively. Notably, the emulsification process doesn't destroy the shell-like structure of ROP-Cur. Instead, it triggers the aggregation of ROP-Cur, which is finally adsorbed at the oil–water interface. Our designed strategy successfully affords double-compartment microdroplets and improves the storage stability of biologically active compounds.

Activity of curcumin against human cytomegalovirus infection in vitro

This study aimed to investigate the effect of curcumin (Cur) against human cytomegalovirus (HCMV) in vitro. Human embryonic lung fibroblasts were cultured in vitro. The tetrazolium salt (MTS) method was used to detect the effects of Cur on cell viability. The cells were divided into control group, HCMV group, HCMV + (PFA) group and HCMV + Cur group in this study. The cytopathic effect (CPE) of each group was observed by plaque test, then the copy number of HCMV DNA in each group was detected by quantitative polymerase chain reaction (qPCR), and the expression of HCMV proteins in different sequence was detected by Western blot. The results showed that when the concentration of Cur was not higher than 15 μmol/L, there was no significant change in cell growth and viability in the Cur group compared with the control group (P>0.05). After the cells were infected by HCMV for 5 d, the cells began to show CPE, and the number of plaques increased with time. Pretreatment with Cur significantly reduced CPE in a dose-dependent manner. After the cells were infected by HCMV, the DNA copy number and protein expression gradually increased in a time-dependent manner. Pretreatment with Cur significantly inhibited HCMV DNA copies and downregulate HCMV protein expression levels in a concentration-dependent manner, and the difference was statistically significant (P<0.05). In conclusion, Cur may exert anti-HCMV activity by inhibiting the replication of HCMV DNA and down-regulating the expression levels of different sequence proteins of HCMV. This study provides a new experimental basis for the development of anti-HCMV infectious drugs.

New Insights into Dose-Dependent Effects of Curcumin on ARPE-19 Cells

Opposing dose-dependent effects of curcumin (Cur) have been documented in Retinal Pigment Epithelium (RPE); therefore, to shed the light on the mechanisms of action is crucial for ophthalmic applications. On this basis we explored new insights about the dose-dependent mechanisms triggered by Cur in human retinal pigment epithelial cells (ARPE-19). Three concentrations (0.01 mM; 0.05 mM; 0.1 mM) of Cur were tested, followed by morphological, molecular, and functional analysis of the cells. Cur 0.01 mM promotes a significant increase in cell proliferation, not affecting cell cycle progression and apoptosis; by contrast, Cur 0.05 mM and 0.1 mM block cellular proliferation and trigger S-phase cell cycle arrest without inducing apoptosis. The observation of neuronal-like morphological changes in Cur 0.05 mM and 0.1 mM were not associated with neuronal differentiation, as observed by the quantification of Neurofilament-200 and by the analysis of voltage-dependent currents by patch clamp. Evaluation of autophagic markers LC3BII and p62 revealed significant modulations, suggesting an important activation of autophagy in ARPE-19 cells treated with Cur 0.05 mM and Cur 0.1 mM; conversely, Cur 0.01 mM did not affect autophagy. Altogether, our findings show new dose-dependent mechanisms of action of Cur that suggest a wide therapeutic application in ocular diseases with different pathogenesis (i.e., proliferative vitreoretinopathy or Age-Related Macular Degeneration).

Enhancement of Release and Solubility of Curcumin from Electrospun PEO-EC-PVP Tripolymer-Based Nanofibers: A Study on the Effect of Hydrogenated Castor Oil.

This study reveals the state-of-the-art fabrication of a tripolymer-based electrospun nanofiber (NF) system to enhance the release, solubility, and transdermal penetration of curcumin (Cur) with the aid of in situ release of infused castor oil (Co). In this regard, Cur-loaded Co-infused polyethylene oxide (PEO), ethyl cellulose (EC), and polyvinyl pyrrolidone (PVP) tripolymer-based NF systems were developed to produce a hybridized transdermal skin patch. Weight percentages of 1–4% Cur and 3–10% of Co were blended with PEO–EC–PEO and PEO–EC–PVP polymer systems. The prepared NFs were characterized by SEM, TEM, FT-IR analysis, PXRD, differential scanning calorimetry (DSC), and XPS. Dialysis membranes and vertical Franz diffusion cells were used to study the in vitro drug release and transdermal penetration, respectively. The results indicated that maintaining a Cur concentration of 1–3 wt % with 3 wt % Co in both PEO–EC–Co–Cur@PEO and PEO–EC–Co–Cur@PVP gave rise to nanofibers with lowered diameters (144.83 ± 48.05–209.26 ± 41.80 nm and 190.20 ± 59.42–404.59 ± 45.31 nm). Lowered crystallinity observed from the PXRD patterns and the disappearance of exothermic peaks corresponding to the melting point of Cur suggested the formation of an amorphous NF structure. Furthermore, the XPS data revealed that the Cur loading will possibly take place at the inner interface of PEO–EC–Co–PEO and PEO–EC–Co–PVP NFs rather than on the surface. The beneficiary role of Co on the release and dermal penetration of Cur was further confirmed from the respective release data which indicated that PEO–EC–Co–Cur@PEO would lead to a rapid release (4–5 h), while PEO–EC–Co–Cur@PVP would lead to a sustained release over a period of 24 h in the presence of Co. Transdermal penetration of the released Cur was further evidenced with the development of color in the receiver compartment of the diffusion cell. DPPH results further corroborated that a sustained antioxidant activity is observed in the released Cur where the free-radical scavenging activity is intact even after subjecting to an electrospinning process and under extreme freeze–thaw conditions.

Curcumin-loaded electrospun peanut protein isolate/ poly-l-lactic acid nanofibre membranes: Preparation and characterisation and release behaviour

Curcumin (Cur) is a natural polyphenol with well-established health benefits. However, its rapid degradation and metabolism limit its use. In this study, Cur was successfully incorporated into peanut protein isolate/poly-l-lactic acid (PPI/PLLA) nanofibres with different loading amounts (5, 10, and 15 g/100 g) for functional ingredient delivery by electrospinning. As determined by SEM, the average diameter of the composite nanofibres decreased as the Cur concentration increased. The diameter of Cur(10 g/100 g)/PPI/PLLA nanofibres was 132 ± 46 nm and the distribution of nanofibre diameters was highly concentrated. Cur was uniformly dispersed in the PPI/PLLA nanofibre and showed excellent compatibility, as evidenced by FTIR and X-ray diffraction. TGA showed that Cur did not decrease the thermal stability of the PPI/PLLA nanofibre membranes. The contact angle decreased gradually; however, when the Cur content was 15 g/100 g, θ = 127.5° still showed hydrophobicity. The Cur release behaviour from the Cur/PPI/PLLA nanofibre membrane revealed an initial sudden release, and the total amount of Cur released in the first hour could reach up to 49.76%. The release mechanism conformed to Fick diffusion. The research improves the bioavailability of insoluble drugs and opens up a new way for active substances to protect carrier materials.

Efficient Delivery of Curcumin by Alginate Oligosaccharide Coated Aminated Mesoporous Silica Nanoparticles and In Vitro Anticancer Activity against Colon Cancer Cells.

We designed and synthesized aminated mesoporous silica (MSN-NH2), and functionally grafted alginate oligosaccharides (AOS) on its surface to get MSN-NH2-AOS nanoparticles as a delivery vehicle for the fat-soluble model drug curcumin (Cur). Dynamic light scattering, thermogravimetric analysis, and X-ray photoelectron spectroscopy were used to characterize the structure and performance of MSN-NH2-AOS. The nano-MSN-NH2-AOS preparation process was optimized, and the drug loading and encapsulation efficiencies of nano-MSN-NH2-AOS were investigated. The encapsulation efficiency of the MSN-NH2-Cur-AOS nanoparticles was up to 91.24 ± 1.23%. The pH-sensitive AOS coating made the total release rate of Cur only 28.9 ± 1.6% under neutral conditions and 67.5 ± 1% under acidic conditions. According to the results of in vitro anti-tumor studies conducted by MTT and cellular uptake assays, the MSN-NH2-Cur-AOS nanoparticles were more easily absorbed by colon cancer cells than free Cur, achieving a high tumor cell targeting efficiency. Moreover, when the concentration of Cur reached 50 μg/mL, MSN-NH2-Cur-AOS nanoparticles showed strong cytotoxicity against tumor cells, indicating that MSN-NH2-AOS might be a promising tool as a novel fat-soluble anticancer drug carrier.

Delivery of curcumin by fucoidan-coated mesoporous silica nanoparticles: Fabrication, characterization, and in vitro release performance

Mesoporous silica nanoparticles (MSN) are effective drug delivery carriers because of their adjustable large pore size and high porosity. In this study, complex nanoparticles containing disulfide bonds (SS) were designed and prepared as curcumin (Cur) carriers by using fucoidan (FUC) and MSN as the polymer matrix. The product was characterized using scanning electron microscopy, transmission electron microscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, and an N2 adsorption and desorption test. When the mass ratio of MSN to FUC was 2:1, the nanospheres particle size was the smallest (295.6 ± 0.98 nm, −35.2 ± 0.8 mV). Furthermore, the curcumin encapsulation rate by MSN-Cur-SS-FUC was over 90%, and the cumulative release rate in 24 h was over 80% due to the combined effect of weak acidity and high glutathione concentration in the tumor site microenvironment. When the Cur concentration was 50 μg/mL, the cell viability of free Cur was 63.8%, the cell viability of MSN-Cur-SS-FUC was 14.5%, and the cell viability of MSN-SS-FUC at the same concentration remained above 74.6%. MSN-SS-FUC composite nanoparticles showed a good delivery of Cur, a lipid-soluble active compound, and provides a new delivery route for other lipid-soluble and poorly bioavailable active compounds.

Keto-enol tautomerism of curcumin in the preparation of nanobiocomposites with fumed silica

The tautomerism of curcumin (Cur) in water–ethanol solutions in the presence of fumed silica was studied by UV–visible spectroscopy. The results showed that the enol tautomer exists at an ethanol concentration in solution >50%, and with an increase in the water content, the tautomeric equilibrium shifts towards the formation of the keto tautomer. Quantum-chemical calculations (solvation model SM 5.42/6-31G (d), GAMESSPLUS) of various curcumin isomers confirmed that the existence of curcumin keto tautomer in aqueous solution is more thermodynamically favorable. The ratio of keto and enol forms also depends on the dielectric constant of water–ethanol solutions: at ε < 45, only the enol form of curcumin exists, while at ε > 45, the relative amount of the keto tautomer increases in proportion to the dielectric constant. Curcumin tautomers adsorb on fumed silica in different ways. At a low curcumin concentration in the initial solutions (<1.5 × 10−4 M), only the enol tautomer forms a monolayer on the sorbent surface, apparently due to its planar structure. The keto tautomer, characterized by a bent structure, begins to adsorb only at a concentration of Cur > 1.5 × 10−4 M, being a component of molecular aggregates with coplanar geometry.

Gelatin/Chitosan Films Incorporated with Curcumin Based on Photodynamic Inactivation Technology for Antibacterial Food Packaging.

Photodynamic inactivation (PDI) is a new type of non-thermal sterilization technology that combines visible light with photosensitizers to generate a bioactive effect against foodborne pathogenic bacteria. In the present investigation, gelatin (GEL)/chitosan (CS)-based functional films with PDI potency were prepared by incorporating curcumin (Cur) as a photosensitizer. The properties of GEL/CS/Cur (0.025, 0.05, 0.1, 0.2 mmol/L) films were investigated by evaluating the surface morphology, chemical structure, light transmittance, and mechanical properties, as well as the photochemical and thermal stability. The results showed a strong interaction and good compatibility between the molecules present in the GEL/CS/Cur films. The addition of Cur improved different film characteristics, including thickness, mechanical properties, and solubility. More importantly, when Cur was present at a concentration of 0.1 mM, the curcumin-mediated PDI inactivated >4.5 Log CFU/mL (>99.99%) of Listeria monocytogenes, Escherichia coli, and Shewanella putrefaciens after 70 min (15.96 J/cm2) of irradiation with blue LED (455 ± 5) nm. Moreover, Listeria monocytogenes and Shewanella putrefaciens were completely inactivated after 70 min of light exposure when the Cur concentration was 0.2 mM. In contrast, the highest inactivation effect was observed in Vibrio parahaemolyticus. This study showed that the inclusion of Cur in the biopolymer-based film transport system in combination with photodynamic activation represents a promising option for the preparation of food packaging films.

Study on the Synthesis of Methylated Reference and Their Application in the Quantity of Curcuminoids Using Single Reference Liquid Chromatography Based on Relative Molar Sensitivity.

We report on the recommendation of the simple and versatility of methylated reference (MR) to improve applications in the single reference (SR)-LC based on relative molar sensitivity (RMS). Three curcuminoids (Curs) such as curcumin, demethoxycurcumin and bisdemethoxycurcumin in turmeric products were determined using authentic standards and methylated curcumin. In addition, high-speed countercurrent chromatography (HSCCC) purification is necessary to separate Curs for indicating the RMS. For HSCCC separation, a biphasic solvent system was used to obtain these fractions, which were then subjected to 1H quantitative NMR to determine their contents in each test solution. Using these solutions, the RMS of Curs are calculated from slopes ratios of calibration curves (three ranges from 0-100 µmol/L, r2 > 0.998). The averaged RMS of Curs were 8.92 (relative standard deviation (RSD), 1.17%), 8.97 (2.18%), and 9.61 (0.77%), respectively. Cur concentrations in turmeric products can be determined using RMS, peak area, and MR content added in these samples. This proposed method, which is based on chemical methylation and the SR-LC assay has been successfully applied for the simple and reliable estimation of Curs in turmeric products.

Co-Treatments of Edible Curcumin from Turmeric Rhizomes and Chemotherapeutic Drugs on Cytotoxicity and FLT3 Protein Expression in Leukemic Stem Cells.

This study aims to enhance efficacy and reduce toxicity of the combination treatment of a drug and curcumin (Cur) on leukemic stem cell and leukemic cell lines, including KG-1a and KG-1 (FLT3+ LSCs), EoL-1 (FLT3+ LCs), and U937 (FLT3− LCs). The cytotoxicity of co-treatments of doxorubicin (Dox) or idarubicin (Ida) at concentrations of the IC10–IC80 values and each concentration of Cur at the IC20, IC30, IC40, and IC50 values (conditions 1, 2, 3, and 4) was determined by MTT assays. Dox–Cur increased cytotoxicity in leukemic cells. Dox–Cur co-treatment showed additive and synergistic effects in several conditions. The effect of this co-treatment on FLT3 expression in KG-1a, KG-1, and EoL-1 cells was examined by Western blotting. Dox–Cur decreased FLT3 protein levels and total cell numbers in all the cell lines in a dose-dependent manner. In summary, this study exhibits a novel report of Dox–Cur co-treatment in both enhancing cytotoxicity of Dox and inhibiting cell proliferation via FLT3 protein expression in leukemia stem cells and leukemic cells. This is the option of leukemia treatment with reducing side effects of chemotherapeutic drugs to leukemia patients.