Stability of curcumin in buffer solutions and characterization of its degradation products

Curcumin: A Natural Warrior Against Inflammatory Liver Diseases

Curcumin (CUR), a bioactive compound found in turmeric, has garnered attention for its potential anti-inflammatory properties and impact on liver health. Numerous studies suggest that CUR may be crucial in mitigating liver inflammation. The compound's anti-inflammatory effects are believed to be attributed to its ability to modulate various molecular pathways involved in the inflammatory response. Research indicates that CUR may suppress the activation of inflammatory cells and the production of pro-inflammatory cytokines in the liver. Additionally, it has been observed to inhibit the activity of transcription factors that play a key role in inflammation. By targeting these molecular mechanisms, CUR may help alleviate the inflammatory burden on the liver. Moreover, CUR's antioxidant properties are thought to contribute to its protective effects on the liver. Oxidative stress is closely linked to inflammation, and CUR's ability to neutralize free radicals may further support its anti-inflammatory action. While the evidence is promising, it is essential to note that more research is needed to fully understand the precise mechanisms through which CUR influences liver inflammation. Nevertheless, these findings suggest that CUR could be a potential therapeutic agent in managing liver inflammatory conditions. In this review, we explore the potential impact of CUR on inflammation, highlighting the key mechanisms involved, as reported in the literature.

Variability of Lactic Acid Bacteria in Curcumin Metabolism and Its Biological Implications

The interaction between lactic acid bacteria (LAB) and curcumin can influence curcumin bioactivity; however, the strain-specific metabolic transformations of curcumin by LAB remain unclear. In our study, two LAB exhibiting distinct metabolic activities on curcumin were selected: Lactobacillus gasseri ATCC 33323 (LM) could metabolize curcumin, while Limosilactobacillus reuteri ATCC 23272 (LUM) could not. Liquid chromatography-mass spectrometry (LC-MS) analysis showed that LUM preserved curcumin's native form, whereas LM metabolized it completely. Time-course studies indicated that LM metabolized curcumin via hydrogenation and demethylation, producing over 70% tetrahydrocurcumin. Additionally, LUM fermentation exhibited superior anti-inflammatory effects than LM in LPS-induced RAW264.7 macrophages. Conversely, LM broth demonstrated higher antioxidant activity than LUM. These findings indicate that different LAB strains interact with curcumin in ways that significantly alter its bioactivities. This research enhances our understanding of the biological effects of curcumin under the influence of LAB strains.

Curcumin Microcapsule Formulations for Prolong Persistence in the Photodynamic Inactivation of Aedes aegypti Larvae

Background: Viral diseases including dengue, zika, chikungunya, and yellow fever remain a significant public health challenge, primarily due to the increasing resistance of these vectors, the Aedes aegypti mosquito, to conventional control methods. Objectives: Herein, a microencapsulated curcumin formulation was developed and characterized using spray-drying technology, with D-mannitol and starch as encapsulating agents. After microencapsulation, photolarvicidal tablet formulations (Formulated Curcumin Tablets-FCT) were prepared, varying the proportions of starch and pectin: FCT1 (60% starch), FCT2 (35% pectin and 25% starch), and FCT3 (42.5% pectin and 17.5% starch), while maintaining 10% curcumin and 30% D-mannitol in all formulations. The main goal was to enhance the stability and efficacy of curcumin as a photolarvicidal agent. Methods: The formulation was characterized by UV-Vis spectroscopy, confocal microscopy, thermal analysis (TG and DSC), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and photodegradation assays under fluorescent light. Results: The photodynamic inactivation (PDI) of Ae. aegypti larvae was evaluated under white, fluorescent light exposure, and the formulation exhibited a significantly enhanced larvicidal activity compared to free curcumin, with a 57-fold reduction in LC50 (LC50-24h = 0.27 mg/L). Additionally, the most effective formulation, FCT2, maintained its residual activity for 27 days, reinforcing that curcumin microencapsulation, combined with PDI, can extend vector control. Release studies under different pH conditions confirmed a controlled release mechanism, favoring environmental stability. Conclusions: The results indicate that microencapsulated curcumin has great potential as a sustainable photoinsecticidal agent, offering stability, efficacy, and a promising alternative for managing Ae. aegypti larval populations.

Hydroxypropyl methylcellulose E5 with molecular energy-enhancement ability contributes to improving wettability, drug delivery and taste masking effect for curcumin solid dispersions

Curcumin (Cur) solid dispersions are a promising strategy to enhance the anti-inflammatory properties of Cur. However, challenges remain in creating effective food and nutritional products containing Cur. This study focuses on the biological macromolecule hydroxypropyl methylcellulose E5 (HPMC E5) to elucidate its advantages in solid dispersions formulated with Eudragit E100 (E100). The aim is to improve wettability, drug delivery and taste masking effect, while also revealing the primary mechanisms underlying these advantages. Raman imaging was used to identify the tautomeric form of Cur in the dispersions, and molecular docking was applied to study the interactions between tautomeric Cur and the excipient. The superior wettability of Cur solid dispersions was studied mainly through contact angle measurements. Results demonstrated that appropriate amounts of HPMC E5 enhanced the surface tension of E100 and significantly improved the total molecular energy of Cur when mixed with E/H, resulting in increased wettability, in vitro drug release, in vivo bioavailability, in vivo anti-inflammatory effects, and effective taste masking. Cur-6E/H with carrier-controlled wetting mechanism presented optimal performances. In summary, the addition of HPMC E5 significantly enhanced the molecular energy and overall efficacy of Cur solid dispersions.

Investigation of Curcumin-β-Cyclodextrin Complex Release in Injectable Hyaluronic Acid/Quince Seed Gum Hydrogel

Injectable hydrogels play a crucial role in various biomedical applications, serving as fillers in tissue engineering, facilitating cell repair, and contributing to the development of drug delivery systems. This study aims to investigate the release of dissolved curcumin from a new injectable hyaluronic acid/quince seed gum (HA/QSG) hydrogel. Curcumin possesses numerous biological activities, including anti-cancer, antioxidant, antimicrobial, and anti-inflammatory properties. However, due to its very low water solubility, its bioavailability is poor. To address this, curcumin was encapsulated in three inclusion complexes: Cur 1:2 β-CD, Cur 1:4 β-CD, and Cur 1:6 β-CD. These Cur-β-CD inclusion complexes were lyophilized and converted into a water-soluble form. The curcumin, bisdemethoxycurcumin, and desmethoxycurcumin content of the obtained lyophilized Cur-β-CD complexes were analyzed using the HPLC method. HA-QSG hydrogels were loaded with Cur 1:2 β-CD inclusion complex in compositions of 0.75% (w/w), 0.50% (w/w), and 0.25% (w/w). The dissolution profiles of the HA-QSG hydrogels were examined in a pH 6.8 phosphate buffer medium, used as the swelling medium in intra-articular hydrogels. The initial burst of the 0.75% (w/w) hydrogel reached 9% release within the first 15 min, whereas the 0.25% (w/w) hydrogel exhibited only 6% release during the same period. The 0.75%(w/w) and 0.50% (w/w) hydrogels displayed very similar dissolution profiles, with a slightly faster release in the early stages of dissolutions, compared to the 0.25%(w/w) Cur β-CD-HA-QSG hydrogel. The 0.25%(w/w) Cur β-CD-HA-QSG hydrogel demonstrated a relatively slower release rate particularly during the initial stage of dissolution period. However, all three formulations reached approximately 98% release within 24 h. While the 0.75%(w/w) and 0.50%(w/w) curcumin-loaded HA-QSG hydrogels, with their rapid initial release, may be suited for intra-articular applications requiring quick drug availability, the 0.25%(w/w) curcumin-loaded HA-QSG hydrogel, with its slower release, may be more beneficial for sustained intra-articular delivery.

Alkali-Induced Hydrolysis Facilitates the Encapsulation of Curcumin by Fish (Cyprinus carpio L.) Scale Gelatin

Curcumin-loaded alkali-induced fish scale gelatin (AFSG) was fabricated to evaluate its efficacy as a potential carrier for hydrophobic nutrients. In this study, the effect of the alkali hydrolysis period on the AFSG hydrolysate structure and corresponding curcumin loading efficiency have been elucidated. Results showed that alkali-induced degradation of gelatin yields different polymers with molecular weights (Mw) from 19319 to 3881 Da. Moderate alkali hydrolysis of fish scale gelatin exposes hydrophobic amino acids, enhancing hydrophobic interactions and increasing the proportion of these amino acids. This process also promotes a structural shift, favoring β-sheet formation while reducing α-helix content. Moreover, the curcumin loading efficiency of AFSG (2 h) (10.06 ± 0.27 μg/mL) was significantly higher than that of untreated gelatin (2.16 ± 0.39 μg/mL), while its excessive hydrolysis weakens hydrophobic interactions among hydrophobic amino acids, limiting their binding sites for curcumin. Fluorescence spectroscopy indicated that curcumin-induced fluorescence quenching in AFSG follows a static mechanism. Thus, the above results demonstrated AFSG's potential as an effective carrier for lipophilic nutrients with high encapsulation efficiency.

Design and Synthesis of Bis-Chalcones as Curcumin Simplified Analogs and Assessment of Their Antiproliferative Activities Against Human Lung Cancer Cells and Trypanosoma cruzi Amastigotes

Background: Anticancer therapies represent the primary treatment option for a significant number of cancer patients globally; however, many of these treatments are associated with severe side effects as they target molecular structures present in both cancerous and healthy cells. In a similar context, the treatment of Chagas disease, a neglected tropical illness, is hindered by the high toxicity of the currently available drugs. Researchers are increasingly focusing on the development of safer and more selective alternatives, with natural compounds being studied as potential starting points for the creation of more effective drug candidates with a favorable therapeutic index. Objectives: The aim of this study was to design simplified curcumin-derived structures that preserved or enhanced their therapeutic activity against human lung cancer cell lines and T. cruzi, while also improving bioavailability and minimizing toxicity. Methods: In this study, curcumin and two natural curcuminoids inspired the synthesis of a chalcone and a set of bis-chalcones, compound classes known for their enhanced stability compared with their natural parent derivatives. The synthetic strategy used was the acid-catalyzed aldol condensation reaction. The stability profiles, IC50 values against A549 and H460 tumor cell lines, and trypanocidal activity against T. cruzi amastigotes of these derivatives were assessed. Results: The synthesized derivatives exhibited improved stability compared with the parent compounds, along with lower IC50 values in both A549 and H460 tumor cell lines. Additionally, one of the new analogs showed promising trypanocidal activity against T. cruzi amastigotes. Conclusions: This study provides a potential pathway toward the development of more effective and less toxic treatments for both cancer and Chagas disease. The simplified curcumin derivatives represent a promising foundation for designing new therapeutic agents with improved bioavailability and efficacy.

Physicochemical Characterization and Oral Bioavailability of Curcumin-Phospholipid Complex Nanosuspensions Prepared Based on Microfluidic System

Background: Curcumin has been proved to have promising prospects in the fields of anti-inflammation, antibacterial, anti-oxidation, and neuroprotection. However, its poor water solubility and stability in strong acid, as well as fast metabolism, lead to low bioavailability, making it difficult to develop further. This study aimed to improve the bioavailability of curcumin by using microfluidic preparation technology. Methods: Using a self-built microfluidic system, polyvinylpyrrolidone K30 and sodium dodecyl sulfate were used as stabilizers to further prepare curcumin-phospholipid complex nanoparticles (CPC-NPs) on the basis of curcumin-phospholipid complex (CPC). The CPC-NPs were characterized and evaluated by X-ray powder diffraction (XRD), differential scanning caborimetry (DSC), dynamic light scattering, and transmission electron microscopy (TEM). Blood samples were collected from rats after oral administration of curcumin, CPC, curcumin nanoparticles (CUR-NPs), and CPC-NPs, respectively. The pharmacokinetics were analyzed by enzymatic digestion and HPLC. Results: The optimized CPC-NPs had a particle size of 71.19 ± 1.37 nm, a PDI of 0.226 ± 0.047, and a zeta potential of -38.23 ± 0.89 mV, which showed a spherical structure under TEM and good stability within 5 days at 4 °C and 25 °C. It was successfully characterized by XRD combined with DSC, indicating the integrational state of curcumin-soy lecithin and conversion to an amorphous form. The results of the pharmacokinetic study showed that the Cmax of curcumin, CUR-NPs, CPC, and CPC-NPs were 133.60 ± 28.10, 270.23 ± 125.42, 1894.43 ± 672.65, and 2163.87 ± 777.36 ng/mL, respectively; the AUC0-t of curcumin, CUR-NPs, CPC, and CPC-NPs were 936.99 ± 201.83, 1155.46 ± 340.38, 5888.79 ± 1073.32, and 9494.28 ± 1863.64 ng/mL/h. Conclusions: CPC-NPs prepared by microfluidic technology had more controllable quality than that of traditional preparation and showed superior bioavailability compared with free drug, CPC, and CUR-NPs. Pharmacodynamic evaluation of anti-inflammatory, anti-oxidation, and neuroprotection needs to be confirmed in follow-up studies.

Design and evaluation of curcumin-derived aldopentose compounds: Unlocking their antidiabetic potential through integrative in vitro, in vivo, and in silico studies on carbohydrate-degrading enzymes

Natural polyphenol compounds such as curcumin can inhibit carbohydrate-hydrolyzing enzymes, which may offer an alternative to expensive and potentially side-effect-inducing α-glucosidase inhibitors like acarbose. Hence, this study carried out the synthesis of curcumin aldopentose derivatives, examining their capacity to inhibit the α-glucosidase and α-amylase enzymes with the aim to alleviate hyperglycemia. Initially, the aldopentose derivatives from curcumin were synthesized and confirmed by spectroscopic methods such as MS, 13CNMR, 1HNMR, and FTIR. Afterward, we investigated the inhibitory effects of all derivatives on the α-amylase and α-glucosidase enzymes spectroscopically and determined their inhibition mechanism. We assessed the antioxidant activity and the stability of the synthetic derivatives in the simulated intestinal environment. Finally, we measured the postprandial blood glucose level after administering saturated starch in vivo. The modified compounds showed improved inhibitory effects compared to curcumin alone, with compound C3 demonstrating particularly strong enzyme inhibition. However, when compared with acarbose, a known commercial antidiabetic drug, the synthetic compounds showed lower inhibitory activity against both enzymes, resulting in fewer side effects related to undigested polysaccharides in the gut. Molecular docking studies show introducing a pentose moiety to the curcumin backbone enhanced docking affinities toward both enzymes and subsequently altered the associated IC50 and Ki values. Overall, compound C3 has the potential to be an inhibitor of carbohydrate-degrading enzymes and can effectively reduce glucose absorption in vivo. Given its antioxidant capabilities and reasonable stability, the compound in question shows promises as a potent derivative for the development of new anti-hyperglycemic drugs in future research endeavours.

Preparation, characterization and antibacterial investigation of water-soluble curcumin-chitooligosaccharide complexes

Curcumin has a wide range of application prospects, with various bioactivities in the food industry and in the biomedical field. However, curcumin has poor water solubility and is sensitive to pH, light and temperature. In this study, curcumin-chitooligosaccharide (CUR-COS) complexes were prepared via mechanochemical methods, and the CUR-COS complex was more soluble after freeze-drying (up to 862-fold greater than that of curcumin). The complex was characterized by SEM, XRD, FT-IR and thermal analysis, and its stability against pH, light and thermal treatment was evaluated. COSs could serve as carriers for curcumin delivery. Additionally, the antibacterial activity of the formed complex was determined. As a result, CUR-COS exhibited significantly better water solubility, enhanced stability, and stronger antibacterial properties than did pure CUR, offering a promising pathway for the extensive application of lipophilic natural products in foods, especially water-based products.

Curcumin Electroanalysis at a Disposable Graphite Electrode

Curcumin (CU, turmeric), a polyphenolic phytochemical that is largely used as a food spice, has benefits for human health, which have led to increased interest in its therapeutic applications and its analysis from different matrices. The two guaiacol moieties of CU are responsible for its antioxidant properties and allow for its voltammetric quantification. Cyclic and differential pulse voltammetry (DPV) investigations at a single-use pencil graphite electrode (PGE) emphasized complex pH-dependent electrode processes, involving an equal number of protons and electrons. Theoretical calculations predicted a folded geometry for the β-diketone CU conformers, which interact with the PGE surface, exposing the electroactive moieties of only one aromatic ring. The Gibbs energy variations of the structures involved in CU electro-oxidation and the theoretical electrochemical potential values were calculated. CU's DPV cathodic peak intensity recorded at an HB-type PGE in 0.05 mol × L-1 H2SO4 varied linearly in the range 5.00 × 10-8-5.00 × 10-6 mol × L-1 CU. The method's detection and quantification limits were 2.12 × 10-8 mol × L-1 and 6.42 × 10-8 mol × L-1, respectively. The practical applicability of the developed method, successfully tested by CU assessment in dietary supplements, provided a recovery of 99.28 ± 2.04%.

Theranostic nanoemulsions suppress macrophage-mediated acute inflammation in rats

In inflammatory diseases or following an injury, dysregulated inflammation is a common driver of pain and tissue damage. Macrophages are immune cells that contribute to the initiation, maintenance, and resolution of inflammation due to their phenotypic plasticity in response to signals from inflammatory microenvironments. Macrophages infiltrate and polarize toward a pro-inflammatory phenotype (M1-like), thereby increasing the severity of inflammation. Therefore, we aimed to suppress the pro-inflammatory activity of M1-like macrophages and decrease their infiltration at the site of inflammatory insult to resolve tissue inflammation. To achieve this, we developed a theranostic curcumin-loaded nanoemulsion platform that delivers a low dose of curcumin, a known anti-inflammatory phytochemical, to macrophages and allows in vivo tracking of macrophages by near-infrared fluorescence (NIRF) imaging technique. In vitro, we showed that curcumin-loaded nanoemulsion suppressed polarization of macrophages towards M1-like phenotype, consequently decreasing the release of pro-inflammatory cytokines and mediators like IL-6, IL-[Formula: see text] TNF-[Formula: see text], and nitric oxide (NO). Furthermore, curcumin-loaded nanoemulsion increased the level of IL-10, an anti-inflammatory cytokine, and protected macrophages against ferroptosis compared to drug-free nanoemulsion. In a rodent model of Complete Freund's adjuvant (CFA)-induced inflammation, we demonstrated that infiltrating macrophages sequestered curcumin-loaded nanoemulsion droplets and acted as cellular drug depots at the site of inflammation. This consequently decreased macrophage infiltration at the CFA-induced inflammation site in both sexes compared to drug-free nanoemulsion, as demonstrated by NIRF imaging, H&E staining, and immunofluorescence. Taken together, our results indicated that the anti-inflammatory efficacy of curcumin was significantly improved when directly delivered to pro-inflammatory macrophages via theranostic nanoemulsion. This work opens an avenue for exploring theranostic nanoemulsions as a platform for delivering natural anti-inflammatory products for immune modulation.

Complexation between curcumin and walnut protein isolate modified by pH shifting combined with protein-glutaminase

The poor techno-functional properties of walnut protein isolate (WPI) limit its application as carrier to improve bioavailability of curcumin. In this study, WPI was modified by pH-shifting (PS) and protein-glutaminase (PG). Changes on the physicochemical and structural characteristics of WPI and effects on complexation with curcumin were investigated. Treatment of PS plus PG increased electrostatic repulsion of WPI with altered secondary and tertiary structure. Solubility of WPI was greatly improved from 18.09% to 52.90%. The increased flexibility resulted in reduced particle size and increased exposure of hydrophobic groups. The improved amphiphilicity of WPI provided more binding sites for complexation with curcumin. Encapsulation efficiency of curcumin was increased from 32.50% to 94.48%. Interestingly, the formed complexes were able to protect curcumin from degradation with improved storage stability and bioaccessibility. Thus, PS plus PG could serve as effective modification strategy for utilization of WPI as a promising delivery vehicle for hydrophobic bioactives.

Copper-Induced Neurodegenerative Disorders and Therapeutic Potential of Curcumin-Loaded Nanoemulsion

Copper accumulation in neurons induces oxidative stress, disrupts mitochondrial activity, and accelerates neuronal death, which is central to the pathophysiology of neurodegenerative diseases like Wilson disease. Standard treatments for copper toxicity, such as D-penicillamine, trientine, and chloroquine, are frequently associated with severe side effects, creating a need for safer therapeutic alternatives. To address this, we developed a curcumin-loaded nanoemulsion (CUR-NE) using the spontaneous emulsification technique, aimed at enhancing the bioavailability and therapeutic efficacy of curcumin. The optimized nanoemulsion displayed a particle size of 76.42 nm, a zeta potential of -20.4 mV, and a high encapsulation efficiency of 93.69%, with a stable and uniform structure. The in vitro tests on SH-SY5Y neuroblastoma cells demonstrated that CUR-NE effectively protected against copper-induced toxicity, promoting significant cellular uptake. Pharmacokinetic studies revealed that CUR-NE exhibited a longer half-life and extended circulation time compared to free curcumin. Additionally, pharmacodynamic evaluations, including biochemical assays and histopathological analysis, confirmed that CUR-NE provided superior neuroprotection in copper overload conditions. These results emphasize the ability of CUR-NE to augment the therapeutic effects of curcumin, presenting a novel approach for managing copper-induced neurodegeneration. The study highlights the effectiveness of nanoemulsion-based delivery platforms in improving chelation treatments for neurological diseases.

Chemodynamic covalent adaptable network-induced robust, self-healing, and degradable fluorescent elastomers for multicolor information encryption

Elastomers are of great significance in developing smart materials for information encryption, and their unique self-healing and highly flexible properties provide innovative solutions to enhance security and anti-counterfeiting effectiveness. However, challenges remain in the multifunctional combination of mechanical properties, self-healing, degradability, and luminescence of these materials. Herein, a chemodynamic covalent adaptable network (CCAN)-induced robust, self-healing, and degradable fluorescent elastomer is proposed. Thanks to the CCANs, the resulting elastomer exhibits a tensile strength of 33.44 MPa (300 times higher than that of a linear elastomer) and an elongation at break of 1265%, and its mechanical properties can be restored to about 20 MPa after 72 h of healing at room temperature, and a self-healing efficiency of 94.67% can be realized for 24 h at 70 °C. Simultaneously, the dynamic chemical balance of keto and enol structural transitions of curcumin chain segments can be driven by CCANs, realizing multi-color (from yellow to violet) display and broad wavelength (300-500 nm) excitation, which in turn enables surface read-write and color rosette and QR code pattern printing. In addition, it can also achieve adaptive degradation under biological, alkaline, and hot water conditions. This work has guiding significance for developing the next generation of high-performance multifunctional elastomer materials, which have potential applications in the field of smart anti-counterfeiting materials and smart flexible optoelectronics.

Investigating the effect of femtosecond laser pulses on noscapine and curcumin cellular uptake and improving drug delivery in gastric cancer cells

The MKN45 cell line, a type of gastric cancer cell, exhibits resistance to chemotherapy agents through various mechanisms. Curcumin and noscapine, two plant-derived anticancer compounds, exhibit selective cytotoxicity towards cancer cells. However, their bioavailability is poor both in vitro and in vivo. In this study, we used femtosecond laser pulses in the near-infrared region (central wavelength of 1040 nm) with a pulse duration of 200 fs, a beam diameter of 4 mm, and different pulse energies and average powers to perforate the plasma membrane. We standardized the necessary conditions while minimizing cellular necrosis. MKN45 cells were treated with 25-200 μM curcumin and noscapine for 24 h after irradiation with an optimized femtosecond laser exposure (40 mW, 40sec) or without irradiation. The MTT cell viability assay revealed that pre-treatment with femtosecond (fs) laser pulses significantly increased cellular sensitivity to the treatment. Overall, the findings suggest that fs laser pulses irradiation enhance the bioavailability of both curcumin and noscapine. The combined treatment of femtosecond laser pulses and drugs can improve the drug's efficacy and the overall treatment outcome.

Complexed hyaluronic acid-based nanoparticles in cancer therapy and diagnosis: Research trends by natural language processing

Hyaluronic acid (HA) is a popular surface modifier in targeted cancer delivery due to its receptor-binding abilities. However, HA alone faces limitations in lipid solubility, biocompatibility, and cell internalization, making it less effective as a standalone delivery system. This comprehensive study aimed to explore a dynamic landscape of complexation in HA-based nanoparticles in cancer therapy, examining diverse aspects from influential modifiers to emerging trends in cancer diagnostics. We discovered that certain active substances, such as 5-aminolevulinic acid, adamantane, and protamine, have been on trend in terms of their usage over the past decade. Dextran, streptavidin, and catechol emerge as intriguing conjugates for HA, coupled with nanostar, quantum dots, and nanoprobe structures for optimal drug delivery and diagnostics. Strategies like hypoxic conditioning, dual responsiveness, and pulse laser activation enhance controlled release, targeted delivery, and real-time diagnostic techniques like ultrasound imaging and X-ray computed tomography (X-ray CT). Based on our findings, conventional bibliometric tools fail to highlight relevant topics in this area, instead producing merely abstract and broad-meaning keywords. Extraction using Named Entity Recognition and topic search with Latent Dirichlet Allocation successfully revealed five representative topics with the ability to exclude irrelevant keywords. A shift in research focuses from optimizing chemical toxicity to particular targeting tactics and precise release mechanisms is evident. These findings reflect the dynamic landscape of HA-based nanoparticle research in cancer therapy, emphasizing advancements in targeted drug delivery, therapeutic efficacy, and multimodal diagnostic approaches to improve overall patient outcomes.

Optical sensing of albumin in human serum and urine-A historical review of the transition from classical dye-binding assays to advanced technologies

Human serum albumin (HSA) is the most abundant protein in human plasma playing essential roles in transporting various biomolecules, metal ions, therapeutic agents, and metabolites. Additionally, it is crucial for maintaining oncotic pressure, scavenging free radicals, and preventing protein aggregation. Accurate quantification of HSA is vital for diagnosing various conditions, including hypertension, diabetes mellitus (DM), liver disorders, and renal diseases. While prevalent in clinical laboratories, traditional dye-binding methods have notable limitations: they can be time-consuming, lack sensitivity, and may suffer from interference from other serum components. These methods often require complex sample preparation and do not readily lend themselves to rapid or point-of-care testing (POCT). Consequently, there is a pressing need for innovative techniques that are rapid, cost-effective, and user-friendly. This review explores various dyes utilized for HSA determination, categorized into groups such as sulfonphthaleins, phenolphthaleins, azo dyes, etc., and provides a historical overview of the limitations of these methods. We critically assess the pros and cons of traditional dye-binding assays and emphasize the potential of emerging technologies, including microfluidic systems, smartphone-based detection, and nanopaper sensors, to address these gaps and enhance the efficiency and accessibility of HSA quantification in clinical settings.

Bioadhesive Chitosan Films Loading Curcumin for Safe and Effective Skin Cancer Topical Treatment

Background/Objectives: This study aimed to evaluate the safety and efficacy of chitosan-based bioadhesive films for facilitating the topical delivery of curcumin in skin cancer treatment, addressing the pharmacokinetic limitations associated with oral administration. Methods: The films, which incorporated curcumin, were formulated using varying proportions of chitosan, polyvinyl alcohol, Poloxamer® 407, and propylene glycol. These films were assessed for stability, drug release, in vitro skin permeation, cell viability (with and without radiotherapy), and skin irritation. Results: The films demonstrated physical stability and preserved curcumin content at room temperature for 90 days. Drug release was effectively controlled during the first 8 h, with release rates ranging from 51.6 ± 4.8% to 65.6 ± 13.0%. The films also enhanced drug penetration into the skin compared to a curcumin solution used as a control (stratum corneum: 1.3 ± 0.1 to 1.9 ± 0.8 µg/cm²; deeper skin layers: 1.7 ± 0.1 to 2.7 ± 0.2 µg/cm²). A cytotoxicity test on metastatic melanoma cells showed that curcumin at topical doses exerted activity similar to that delivered via the skin. Furthermore, curcumin alone was more effective in inhibiting tumor cells than radiotherapy alone (p < 0.01), with no additional benefit observed when curcumin was combined with radiotherapy. Finally, irritation tests confirmed that the films were safe for topical application. Conclusion: The developed chitosan-based bioadhesive films represent a promising alternative for the topical treatment of skin tumors using curcumin.

Development of a Novel Co-Amorphous Curcumin and L-Arginine (1:2): Structural Characterization, Biological Activity and Pharmacokinetics

Background: Curcumin appears to be well tolerated and effective for managing chronic inflammatory pain, but its poor oral bioavailability has been a hurdle in its use as a therapeutic agent. The current study was performed to characterize a novel co-amorphous compound based on curcumin/L-arginine 1:2 (CAC12). Methods: Stability, solubility and structural characterization of the CAC12 were carried out by spectrometry techniques and in vitro assays, whereas the antinociceptive and anti-inflammatory effects were evaluated by CFA or carrageenan models. The mechanism of action was determined by cytokine quantification, and pharmacokinetic parameters were obtained through UPLC-MS/MS. The co-amorphous compound was prepared by fast solvent evaporation. Powder XRD, 13C-NMR, ATR-FTIR and TGA/DSC thermal analysis showed a 1:2 stoichiometry for the CAC12. Results: CAC12 was 1000 times more soluble than curcumin, and it was stable for 1 month at 40 °C and 75% relative humidity or for 60 min in physiological medium at pH 4.5-6.8. Co-amorphous curcumin/L-arginine, but not curcumin + L-arginine, decreased carrageenan- or CFA-induced inflammation and nociception by decreasing IL-1α, IL-1β, IL-6, TNF-α, MCP-1 and CXCL1 cytokines. The bioavailability of free plasmatic curcumin increased about 22.4 times when it was given as CAC12 relative to a phytosome formulation at the equivalent dose. Conclusions: Results suggest the possible use of CAC12 to treat inflammatory pain disorders in human beings.

Comparative Investigation of Untargeted and Targeted Metabolomics in Turmeric Dietary Supplements and Rhizomes

In the present study, we analyzed the bioactive curcuminoids content in eight capsules (DS-1-DS-7 and DS-9), one tablet (DS-8), three ground turmeric samples (DS-10-DS-12), and three ground turmeric rhizomes (TR-1, TR-2, and TR-3). Initial screening with infrared and ultraviolet-visible spectroscopy coupled with a principal component analysis (PCA) revealed distinct differences between the samples analyzed. Hence, targeted and untargeted analyses were performed using ultra-high-performance liquid chromatography and gas chromatography coupled with mass spectrometry detections. The results show that the total curcuminoids content ranged from 1.3 to 69.8 mg/100 mg and the volatile component ranged from 0.7 to 9.1 mg/100 mg. The percentage ratio of the three prominent curcuminoids, bisdesmethoxycurcumin (BMC), desmethoxycurcumin (DMC), and curcumin (CUR), also varied remarkably compared to the expected ratio (BMC:DMC:CUR ratio of 1:2:6) described in the literature. The three prominent volatile compounds identified in most samples were ar-turmerone, turmerone, and curlone. The results demonstrated significant differences in the volatile compound levels among the DS and dried rhizome samples. The non-targeted analysis resulted in the identification of over 40 compounds, including bioactives such as piperine, phenolic acids, and amino acids. A disintegration study was performed on limited DS according to the United States Pharmacopeia protocol. The results reveal that all the selected DS samples passed the disintegration test. An analysis of curcuminoids from DS samples in neutral and acidic solutions demonstrated that all curcuminoids (BMC, DMC, and CUR) existed in the keto and enol forms and their concentrations changed with pH. This study will be of significant interest to manufacturers, consumers, and pharmacologists to accurately understand the bioactivities of three curcuminoids in different isomeric forms.

Progress in the study of curcumin metabolism in vivo

Curcumin has diverse biological functions, especially antioxidant and anti-inflammatory properties, but clinical trials have been hindered by its low bioavailability and pharmacokinetic properties. To achieve therapeutic efficacy, understanding curcumin's in vivo metabolism is crucial. We reviewed current research on curcumin metabolism in PubMed, Google Scholar, and CNKI. This article outlines curcumin's metabolic processes in the body via oral and intravenous injection. It suggests that upon entering the human body, curcumin may undergo oxidation, reduction, binding, and microbial community influence.

The Dynamic Role of Curcumin in Mitigating Human Illnesses: Recent Advances in Therapeutic Applications

Herbal medicine, particularly in developing regions, remains highly popular due to its cost-effectiveness, accessibility, and minimal risk of adverse effects. Curcuma longa L., commonly known as turmeric, exemplifies such herbal remedies with its extensive history of culinary and medicinal applications across Asia for thousands of years. Traditionally utilized as a dye, flavoring, and in cultural rituals, turmeric has also been employed to treat a spectrum of medical conditions, including inflammatory, bacterial, and fungal infections, jaundice, tumors, and ulcers. Building on this longstanding use, contemporary biochemical and clinical research has identified curcumin-the primary active compound in turmeric-as possessing significant therapeutic potential. This review hypothesizes that curcumin's antioxidant properties are pivotal in preventing and treating chronic inflammatory diseases, which are often precursors to more severe conditions, such as cancer, and neurological disorders, like Parkinson's and Alzheimer's disease. Additionally, while curcumin demonstrates a favorable safety profile, its anticoagulant effects warrant cautious application. This article synthesizes recent studies to elucidate the molecular mechanisms underlying curcumin's actions and evaluates its therapeutic efficacy in various human illnesses, including cancer, inflammatory bowel disease, osteoarthritis, atherosclerosis, peptic ulcers, COVID-19, psoriasis, vitiligo, and depression. By integrating diverse research findings, this review aims to provide a comprehensive perspective on curcumin's role in modern medicine and its potential as a multifaceted therapeutic agent.

Pd(II)/diphosphine/curcumin complexes as potential anticancer agents

Palladium(II) complexes have stimulated research interest mainly due to their in vitro cytotoxicity against various cancer cell lines and their low cytotoxicity in healthy cells. Thus, in this work, we combined Pd(II)/phosphine systems with the natural product curcumin as a ligand, obtaining a series of complexes, [Pd(cur)(PPh3)2]PF6 (A1), [Pd(cur)(dppe)]PF6 (A2), [Pd(cur)(dppp)]PF6 (A3), [Pd(cur)(dppb)]PF6 (A4) and [Pd(cur)(dppf)]PF6 (A5), where dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, and dppf = 1,1'-bis(diphenylphosphino)ferrocene (P-P), which were characterized by elemental analysis, molar conductivity analysis, and mass, NMR (1H, 13C, 31P{1H}), UV-vis, and IR spectroscopies, and four of them (A1, A2, A4, and A5) by X-ray crystallography. The in vitro cell viability of the complexes A1-A5, cisplatin, and the free ligand curcumin against MDA-MB-231 (human triple-negative breast tumor cells), SK-BR-3 (human breast tumor cells), A549 (human lung tumor cells), MRC-5 (non-tumor human lung cells), A2780 (human ovarian carcinoma cells), and A2780cis (cisplatin-resistant human ovarian carcinoma cells), was evaluated by the MTT colorimetric assay. For the tumor cell lines tested, the complexes showed good anticancer activities. The results showed that in general the complexes had lower IC50 values than free curcumin and the precursors [PdCl2(P-P)]. IC50 results obtained for the A1-A5 complexes, in the MCF-7 cell line, are similar to those that had already been observed for some Pd/bipy/curcumin complexes. In the MDA-MB-231 cell line, complexes A1 and A5 stood out, with their lowest IC50 values, around 5 μmol L-1, and the complexes appeared to be more active (lower IC50 values) against the ovarian cell lines. Complex A1 was 23 and 22-fold more cytotoxic than cisplatin, against the A2780 and A2780cis cells, respectively. The complex A1 was studied on A2780cis cells and it was found that this complex inhibits colony formation and induces cell cycle arrest in the sub-G1 phase in a concentration-dependent manner and leads to cell death by apoptosis. The DCFDA assay revealed a potent ROS induction for complex A1.

Exploring the World of Curcumin: Photophysics, Photochemistry, and Applications in Nanoscience and Biology

Curcumin is a bright yellow naturally occurring polyphenol which is the principal component of turmeric. It is used as herbal supplement, cosmetics ingredient, and food coloring agent. Over the years, the therapeutic properties of the natural product curcumin have gone unexploited but not unnoticed. Curcumin cannot be employed as a drug due to limitations such as low aqueous solubility and limited bioavailability. Many attempts have been made to overcome these limitations by confining the drug in various confined media to enhance its bioavailability. The biomolecule is emissive and undergoes fundamental excited state processes such as solvation dynamics and excited state intramolecular proton transfer (ESIPT). Curcumin based biomaterials and nanomaterials are also a fast advancing field where curcumin is an intrinsic component necessary for formation of these materials and no longer added as an external free drug. In this review, we will summarize the recent research on the photophysical and photochemical properties of curcumin and its excited state dynamics in various bio-mimicking systems. At the same time we wish to also incorporate the various applications of curcumin, especially in biology. Lastly due to the growing importance of materials science, we will briefly discuss some recent advances on curcumin based biomaterials and nanomaterials. We believe such a compilation of recent research surrounding curcumin will provide an overall understanding of its potentialities in different areas.

Advancements in curcumin-loaded PLGA nanoparticle delivery systems: progressive strategies in cancer therapy

Cancer is a leading cause of death worldwide, and imposes a substantial socioeconomic burden with little impact especially on aggressive types of cancer. Conventional therapies have many serious side effects including generalised systemic toxicity which limits their long-term use. Tumour resistance and recurrence is another main problem associated with conventional therapy. Purified or extracted natural products have been investigated as cost-effective cancer chemoprotective agents with the potential to reverse or delaying carcinogenesis. Curcumin (CUR) as a natural polyphenolic component, exhibits many pharmacological activities such as anti-cancer, anti-inflammatory, anti-microbial, activity against neurodegenerative diseases including Alzheimer, antidiabetic activities (type II diabetes), anticoagulant properties, wound healing effects in both preclinical and clinical studies. Despite these effective protective properties, CUR has several limitations, including poor aqueous solubility, low bioavailability, chemical instability, rapid metabolism and a short half-life time. To overcome the pharmaceutical problems associated with free CUR, novel nanomedicine strategies (including polymeric nanoparticles (NPs) such as poly (lactic-co-glycolic acid) (PLGA) NPs have been developed. These formulations have the potential to improve the therapeutic efficacy of curcuminoids. In this review, we comprehensively summarise and discuss recent in vitro and in vivo studies to explore the pharmaceutical significance and clinical benefits of PLGA-NPs delivery system to improve the efficacy of CUR in the treatment of cancer.

Unveiling the role of gut microbiota in curcumin metabolism using antibiotic-treated mice

Curcumin might exert its therapeutic effects by interacting with gut microbiota. However, the role of gut microbiota in curcumin metabolism in vivo remains poorly understood. To address this, we used antibiotics to deplete gut microbiota and compared curcumin metabolism in control and antibiotic-treated mice. Using Q-TOF and triple quadrupole mass spectrometry, we identified and quantified curcumin metabolites, revealing distinct metabolic pathways in these two mice groups. The novel metabolites, hexahydro-dimethyl-curcumin and hexahydro-didemethyl-curcumin were exclusively derived from gut microbiota. Additionally, gut bacteria deconjugated curcumin metabolites back into their bioactive forms. Moreover, control mice exhibited significantly lower curcumin degradation, suggesting a protective role of gut microbiota against degradation. In conclusion, our results indicated that gut microbiota might enhance the effectiveness of curcumin by deconjugation, production of active metabolites, and protection against degradation in the large intestine. This study enhances our understanding of the interactions between curcumin and gut microbiota.

Curcumin: A Potential Weapon in the Prevention and Treatment of Head and Neck Cancer

Head and neck cancers (HNC) are aggressive, difficult-to-treat tumors that can be caused by genetic factors but mainly by lifestyle or infection caused by the human papillomavirus. As the sixth most common malignancy, it presents a formidable therapeutic challenge with limited therapeutic modalities. Curcumin, a natural polyphenol, is appearing as a promising multitarget anticancer and antimetastatic agent. Numerous studies have shown that curcumin and its derivatives have the potential to affect signaling pathways (NF-κB, JAK/STAT, and EGFR) and molecular mechanisms that are crucial for the growth and migration of head and neck tumors. Furthermore, its ability to interact with the tumor microenvironment and trigger the immune system may significantly influence the organism's immune response to the tumor. Combining curcumin with conventional therapies such as chemotherapy or radiotherapy may improve the efficacy of treatment and reduce the side effects of treatment, thereby increasing its therapeutic potential. This review is a comprehensive overview that discusses both the benefits and limitations of curcumin and its therapeutic effects in the context of tumor biology, with an emphasis on molecular mechanisms in the context of HNC. This review also includes possibilities to improve the limiting properties of curcumin both in terms of the development of new derivatives, formulations, or combinations with conventional therapies that have potential as a new type of therapy for the treatment of HNC and subsequent use in clinical practice.

Bridging pyrimidine hemicurcumin and Cisplatin: Synthesis, coordination chemistry, and in vitro activity assessment of a novel Pt(II) complex

In the upcoming decades, the incidence and mortality rates of cancer are expected to rise globally, with colorectal and prostate cancers among the most prevalent types. Despite advancements in molecular targeted therapy, platinum-based chemotherapies remain the cornerstone of treatment, especially for colorectal and prostate cancer, with oxaliplatin and cisplatin being extremely effective due to their DNA-targeting capabilities. In our pursuit of new platinum-based chemotherapeutics that are potentially less toxic and more effective, we have explored the combination of the Pt-binding groups of the diaminocyclohexane ring used in oxaliplatin, with the stable amino-pyrimidine hemicurcumin moiety. This new derivative exhibit improved stability in physiological conditions and increased solubility in aqueous media, demonstrating promising effects on cell proliferation of both colorectal and prostate cells. We report herein the complete synthesis and chemical characterization in solution of the new derivative [(1R,2R)-N1-(3-(4-((E)-2-(2-Amino-6-methylpyrimidin-4-yl)vinyl)-2-methoxyphenoxy) propyl) cyclohexane-1,2-diamine] (MPYD). Our analysis includes an examination of its acid-base equilibria, speciation and stability in physiological conditions. The synthesis and in situ formation of Pt(II) complexes were investigated by nuclear magnetic resonance spectroscopy, while density functional theory calculations were employed to elucidate the chemical structure in solution. Results on the biological activity were obtained through cell viability assays on different colorectal and prostate cell lines (HCT116, HT29, PC3 and LNCaP).

Evaluating the binding mechanism, structural changes and stability of ternary complexes formed by the interaction of folic acid with whey protein concentrate-80 and L-ascorbyl 6-palmitate

In the present study, we investigated the mechanisms associated with the stabilizing effects of whey protein concentrate-80 (WPC80) and L-ascorbyl 6-palmitate (LAP) on folic acid (FA). Multispectral techniques show that WPC80 binds to FA and LAP mainly through hydrophobic interactions, and that energy is transferred from WPC80 to FA and LAP in a nonradiative form (FA/LAP); The combination of FA/LAP resulted in a change in the conformation and secondary structure content of WPC80, an increase in the absolute zeta potential of the system, and a shift in the particle size distribution towards smaller sizes. The compound system exhibits strengthened antioxidant properties and favorable binding properties. Besides, WPC80 improves the storage stability of FA under different conditions. These results demonstrated that the ternary complex formed by FA co-binding with WPC80 and LAP is an effective way to improve the stability against of FA.

Mechanism of 5-fluorouracil induced resistance and role of piperine and curcumin as chemo-sensitizers in colon cancer

Among cancer-related deaths worldwide, colorectal cancer ranks second, accounting for 1.2% of deaths in those under 50 years and 0.6% of deaths in those between 50 and 54 years. The anticancer drug 5-fluorouracil is widely used to treat colorectal cancer. Due to a better understanding of the drug's mechanism of action, its anticancer activity has been increased through a variety of therapeutic alternatives. Clinical use of 5-FU has been severely restricted due to drug resistance. The chemoresistance mechanism of 5-FU is challenging to overcome because of the existence of several drug efflux transporters, DNA repair enzymes, signaling cascades, classical cellular processes, cancer stem cells, metastasis, and angiogenesis. Curcumin, a potent phytocompound derived from Curcuma longa, functions as a nuclear factor (NF)-κB inhibitor and sensitizer to numerous chemotherapeutic drugs. Piperine, an alkaloid found in Piper longum, inhibits cancer cell growth, causing cell cycle arrest and apoptosis. This review explores the mechanism of 5-FU-induced chemoresistance in colon cancer cells and the role of curcumin and piperine in enhancing the sensitivity of 5-FU-based chemotherapy. CLINICAL TRIAL REGISTRATION: Not applicable.

Effect of pH on the soybean whey protein-gum arabic emulsion delivery systems for curcumin: Emulsifying, stability, and digestive properties

A novel curcumin (CUR) delivery system was developed using soybean whey protein (SWP)-based emulsions, enhanced by pH-adjustment and gum arabic (GA) modification. Modulating electrostatic interactions between SWP and GA at oil/water interface, pH provides favorable charging conditions for stable distribution between droplets. GA facilitated the SWP form a stable interfacial layer that significantly enhanced the emulsifying properties and CUR encapsulation efficiency of the system at pH 6.0, which were 90.15 ± 0.67%, 870.53 ± 3.22 m2/g and 2157.62 ± 115.31%, respectively. Duncan's test revealed significant improvements in thermal, UV, oxidative, and storage stabilities of CUR (P < 0.05). At pH 6.0, GA effectively protected CUR by inhibiting SWP degradation during gastric digestion and promoting the release of CUR by decreasing steric hindrance with oil droplets during intestinal digestion, achieving the highest CUR bioaccessibility (69.12% ± 0.28%) based on Duncan's test. The SWP-GA-CUR emulsion delivery system would be a novel carrier for nutrients.

The potential of natural products to inhibit abnormal aggregation of α-Synuclein in the treatment of Parkinson's disease

Parkinson's disease (PD), as a refractory neurological disorder with complex etiology, currently lacks effective therapeutic agents. Natural products (NPs), derived from plants, animals, or microbes, have shown promising effects in PD models through their antioxidative and anti-inflammatory properties, as well as the enhancement of mitochondrial homeostasis and autophagy. The misfolding and deposition of α-Synuclein (α-Syn), due to abnormal overproduction and impaired clearance, being central to the death of dopamine (DA) neurons. Thus, inhibiting α-Syn misfolding and aggregation has become a critical focus in PD discovery. This review highlights NPs that can reduce α-Syn aggregation by preventing its overproduction and misfolding, emphasizing their potential as novel drugs or adjunctive therapies for PD treatment, thereby providing further insights for clinical translation.

Development of transferosomes for topical ocular drug delivery of curcumin

BACKGROUND

Transferosomes (TFS) are ultra-deformable elastic bilayer vesicles that have previously been used to enhance gradient driven penetration through the skin. This study aimed to evaluate the potential of TFS for topical ocular drug delivery and to compare their penetration enhancing properties in different ocular tissues.

METHODS

Curcumin-loaded TFS were prepared using Tween 80 as the edge activator. Drug release and precorneal retention of the TFS were evaluated in vitro, while their ocular biocompatibility and bioavailability were evaluated ex vivo using a curcumin solution in medium chain triglycerides as the oily control.

RESULTS

The TFS had a narrow size distribution with a particle size less than 150 nm and an entrapment efficiency greater than 99.96 %. Burst release from the TFS was minimal and the formulation showed good corneal biocompatibility. Moreover, enhanced corneal and conjunctival drug penetration with significantly greater and deeper drug delivery was observed with TFS in all ocular tissues.

CONCLUSION

TFS offer a promising platform for ocular delivery of hydrophobic drugs. This study, for the first time, elucidates the effect of tissue morphology and osmotic gradients on drug penetration in different ocular tissues.

Curcumin suppressed the proliferation and apoptosis of HPV-positive cervical cancer cells by directly targeting the E6 protein

Most human papillomavirus (HPV) types, including HPV16 and HPV18, are closely related to the occurrence of cervical cancer, predominantly through the action of viral oncoproteins E6 and E7. Curcumin, the active ingredient of the turmeric plant, has been gaining attention over the past two decades as an antioxidant, anti-inflammatory, and anticancer agent. In the present study, the HPV-positive cervical cancer cells HeLa and CaSki were treated with curcumin, and the results showed that curcumin has a dose-dependent and time-dependent inhibitory effect on cell viability. In addition, apoptosis induction was further quantitatively confirmed through flow cytometric analysis. Furthermore, the influence of different concentrations of curcumin on the mitochondrial membrane potential was evaluated through JC-1 staining and found to dramatically decrease the membrane potential in treated HeLa and CaSki cells, suggesting the critical role of the mitochondrial pathway in their apoptosis-inducing effect. This study also demonstrated the wound-healing potential of curcumin, and the results of transwell assays showed that curcumin treatment inhibited HeLa and CaSki cell invasion and migration in a dose-dependent manner compared with the control treatment. Curcumin also downregulated the expression of Bcl-2, N-cadherin, and Vimentin and upregulated the expression of Bax, C-caspase-3, and E-cadherin in both cell lines. Further research showed that curcumin also selectively inhibited the expression of the viral oncoproteins E6 and E7, as demonstrated by western blot analysis; moreover, the downregulation of E6 was more significant than that of E7. Our research also showed that coculture with cells infected with siE6 lentivirus (siE6 cells) can inhibit the proliferation, invasion, and metastasis of HPV-positive cells. While the siE6 cells were also treated with curcumin, the effect of curcumin monotherapy was offset. In summary, our research shows that curcumin regulates the apoptosis, migration, and invasion of cervical cancer cells, and the mechanism may be related to its ability to downregulate E6. This study provides a foundation for future research on the prevention and treatment of cervical cancer.

Research progress on the therapeutic effects of nanoparticles loaded with drugs against atherosclerosis

Presently, there are many drugs for the treatment of atherosclerosis (AS), among which lipid-lowering, anti-inflammatory, and antiproliferative drugs have been the most studied. These drugs have been shown to have inhibitory effects on the development of AS. Nanoparticles are suitable for AS treatment research due to their fine-tunable and modifiable properties. Compared with drug monotherapy, experimental results have proven that the effects of nanoparticle-encapsulated drugs are significantly enhanced. In addition to nanoparticles containing a single drug, there have been many studies on collaborative drug treatment, collaborative physical treatment (ultrasound, near-infrared lasers, and external magnetic field), and the integration of diagnosis and treatment. This review provides an introduction to the therapeutic effects of nanoparticles loaded with drugs to treat AS and summarizes their advantages, including increased targeting ability, sustained drug release, improved bioavailability, reduced toxicity, and inhibition of plaque and vascular stenosis.

Isolation and Identification of Human Gut Bacteria Capable of Converting Curcumin to Its Hydrogenated Metabolites

Curcumin is widely recognized for its health benefits, though the role of gut microbiota in its metabolic transformation was not well studied. In this study, bacterial strains capable of metabolizing curcumin were isolated from human stool samples. Using 16S rRNA and whole-genome sequencing, two novel strains (Clostridium butyricum UMA_cur1 and Escherichia coli UMA_cur2) were identified. In addition, the metabolic products were analyzed using liquid chromatography-mass spectrometry. These strains efficiently converted curcumin into dihydro-curcumin (DHC) and tetrahydro-curcumin (THC). Notably, E. coli UMA_cur2 also produced hexahydro-curcumin (HHC) and octahydro-curcumin (OHC), marking the first identification of a strain capable of such transformations. The absence of the YncB gene (typically involved in curcumin conversion) in C. butyricum UMA_cur1 suggests an alternative metabolic pathway. Curcumin metabolism begins during the stationary growth phase, indicating that it is not crucial for primary growth functions. Furthermore, E. coli UMA_cur2 produced these metabolites sequentially, starting with DHC and THC and progressing to HHC and OHC. These findings identified two novel strains that can metabolize curcumin to hydrogenated metabolites, which enhance our understanding of the interaction between curcumin and gut microbiota.

Dry Heating of Curcumin in the Presence of Basic Salts Yields Anti-inflammatory Dimerization Products

Curcumin exerts some of its biological effects via degradation products formed by spontaneous oxidation at physiological, i.e., weakly basic, pH. Here, we analyzed products formed by dry heating of curcumin in the presence of a basic salt (sodium bicarbonate and others). Under the dry heating conditions employed, curcumin was completely consumed, yielding products entirely different from those obtained by autoxidative degradation in buffer. Bioassay-guided fractionation of the reaction mixture was used to identify and isolate compounds with anti-inflammatory activity in a cell-based assay. This provided two dimers of curcumin, dicurmins A and B, featuring a partly saturated naphthalene core that inhibited lipopolysaccharide-induced activation of NF-κB in RAW264.7 cells. Dicurmin A and B are unusual derivatives of curcumin lacking key functional moieties yet exhibit increased anti-inflammatory activity. The process of dry heating of polyphenols in the presence of a basic salt can serve as a novel approach to generating bioactive compounds.

Enhanced photodynamic inactivation against Escherichia coli O157:H7 provided by chitosan/curcumin coating and its application in food contact surfaces

Sterilisation technologies are essential to eliminate foodborne pathogens from food contact surfaces. However, most of the current sterilisation methods involve high energy and chemical consumption. In this study, a photodynamic inactivation coating featuring excellent antibacterial activity was prepared by dispersing curcumin as a plant-based photosensitiser in a chitosan solution. The coating generated abundant reactive oxygen species (ROS) after light irradiation at 420 nm, which eradicated ≥99.999 % of Escherichia coli O157:H7. It was also found that ROS damaged the cell membrane, leading to the leakage of cell contents and cell shrinkage on the basis of chitosan. In addition, the production of ROS first excited the bacterial antioxidant defence system resulting in the increase of peroxidase (POD) and superoxide dismutase (SOD). ROS levels exceed its capacity, causing damage to the defence system and further oxidative decomposition of large molecules, such as DNA and proteins, eventually leading to the death of E. coli O157:H7. We also found the curcumin/chitosan coating could effectively remove E. coli O157:H7 biofilms by oxidative of extracellular polysaccharides and proteins. All the contributors made the chitosan/curcumin coating an efficient detergent comparable with HClO.

Curcumin as a regulator of Th17 cells: Unveiling the mechanisms

Curcumin, a polyphenol natural product derived from turmeric, possesses diverse pharmacological effects due to its interactions with various cells and molecules. Recent studies have highlighted its immunomodulatory properties, including its impact on immune cells and mediators involved in immune responses. Th17 cells play a crucial role in promoting immune responses against extracellular pathogens by recruiting neutrophils and inducing inflammation. These cells produce inflammatory cytokines such as TNF-α, IL-21, IL-17A, IL-23, IL-17F, IL-22, and IL-26. Curcumin has been shown to significantly inhibit the proliferation of Th17 cells and reduce the production of inflammatory cytokines, including TNF-α, IL-22, and IL-17. This review aims to assess the effectiveness of curcumin and its underlying mechanisms in modulating Th17 cells.

One-step synthesis of amphiphilic copolymers PDMS-b-PEG using tris(pentafluorophenyl)borane and subsequent study of encapsulation and release of curcumin

A series of amphiphilic block copolymer (BCP) micelles based on poly(dimethylsiloxane) (PDMS) and poly(ethylene glycol) (PEG) were synthesized by a one-step reaction in the presence of tris(pentafluorophenyl)borane (BCF) as a catalyst. The structural composition of PDMS-b-PEG (PR11) and PEG-b-PDMS-b-PEG (PR12) was corroborated by FTIR, 29Si NMR, and TGA. The BCPs were assembled in an aqueous solution, obtaining micelles between 57 and 87 nm in size. PR11 exhibited a higher (2.0 g L-1) critical micelle concentration (CMC) than PR12 (1.5 g L-1) due to the short chain length. The synthesized nano micelles were used to encapsulate curcumin, which is one of three compounds of turmeric plant 'Curcuma longa' with significant biological activities, including antioxidant, chemoprotective, antibacterial, anti-inflammatory, antiviral, and anti-depressant properties. The encapsulation efficiency of curcumin was 60% for PR11 and 45% for PR12. Regarding the release study, PR11 delivered 53% curcumin after five days under acidic conditions (pH of 1.2) compared to 43% at a pH of 7.4. The degradation products of curcumin were observed under basic conditions and were more stable at acidic pH. In both situations, the release process is carried out by breaking the silyl-ether bond, allowing the release of curcumin. PR11 showed prolonged release times, so it could be used to reduce ingestion times and simultaneously work as a nanocarrier for other hydrophobic drugs.

Natural products and derivatives for breast cancer treatment: From drug discovery to molecular mechanism

BACKGROUND

Breast cancer stands as the most common malignancy among women globally and a leading cause of cancer-related mortality. Conventional treatments, such as surgery, hormone therapy, radiotherapy, chemotherapy, and small-molecule targeted therapy, often fall short of addressing the complexity and heterogeneity of certain breast cancer subtypes, leading to drug resistance and metastatic progression. Thus, the search for novel therapeutic targets and agents is imperative. Given their low toxicity and abundant variety, natural products and their derivatives are increasingly considered valuable sources for small-molecule anticancer drugs.

PURPOSE

This review aims to elucidate the pharmacological impacts and underlying mechanisms of active compounds found in select natural products and their derivatives, primarily focusing on breast cancer treatment. It intends to underscore the potential of these substances in combating breast cancer and guide future research directions for the development of natural product-based therapeutics.

METHODS

We conducted comprehensive searches in electronic databases such as PubMed, Web of Science, and Scopus until October 2023, using keywords such as 'breast cancer', 'natural products', 'derivatives', 'mechanism', 'signaling pathways', and various keyword combinations.

RESULTS

The review presents a spectrum of phytochemicals, including but not limited to flavonoids, polyphenols, and alkaloids, and examines their actions in various animal and cellular models of breast cancer. The anticancer effects of these natural products and derivatives are manifested through diverse mechanisms, including induction of cell death via apoptosis and autophagy, and suppression of tumor angiogenesis.

CONCLUSION

An increasing array of natural products and their derivatives are proving effective against breast cancer. Future therapeutic strategies can benefit from strategic enhancement of the anticancer properties of natural compounds, optimization for targeted action, improved bioavailability, and minimized side effects. The forthcoming research on natural products should prioritize these facets to maximize their therapeutic potential.

Microwave-Assisted, Solid-State Procedure to Covalently Conjugate Hyaluronic Acid to Curcumin: Validation of a Green Synthetic Protocol

A microwave-assisted esterification reaction to prepare hyaluronan-curcumin derivatives by employing a solvent-free process was developed. In particular, a solid-state strategy to react two molecules characterized by totally different solubility profiles was developed. Hyaluronic acid, a highly hydrosoluble polysaccharide, was reacted with hydrophobic and even water-unstable curcumin. Microwave (MW) irradiation was employed to activate the reaction between the two solid compounds through the direct interaction with them and to preserve the integrity of the sensitive curcumin species. This new protocol can be considered efficient, fast, and also eco-friendly, avoiding the employment of toxic organic bases and solvents. A cytotoxicity test suggested that the developed hyaluronan-curcumin conjugate (HA-CUR) could be considered a candidate for its implementation as a new material. In addition, preliminary studies revealed promising anti-inflammatory activity and open future perspectives of further investigation.

The Multifaceted Actions of PVP-Curcumin for Treating Infections

Curcumin is a natural compound that is considered safe and may have potential health benefits; however, its poor stability and water insolubility limit its therapeutic applications. Different strategies aim to increase its water solubility. Here, we tested the compound PVP-curcumin as a photosensitizer for antimicrobial photodynamic therapy (aPDT) as well as its potential to act as an adjuvant in antibiotic drug therapy. Gram-negative E. coli K12 and Gram-positive S. capitis were subjected to aPDT using various PVP-curcumin concentrations (1-200 µg/mL) and 475 nm blue light (7.5-45 J/cm2). Additionally, results were compared to aPDT using 415 nm blue light. Gene expression of recA and umuC were analyzed via RT-qPCR to assess effects on the bacterial SOS response. Further, the potentiation of Ciprofloxacin by PVP-curcumin was investigated, as well as its potential to prevent the emergence of antibiotic resistance. Both bacterial strains were efficiently reduced when irradiated with 415 nm blue light (2.2 J/cm2) and 10 µg/mL curcumin. Using 475 nm blue light, bacterial reduction followed a biphasic effect with higher efficacy in S. capitis compared to E. coli K12. PVP-curcumin decreased recA expression but had limited effect regarding enhancing antibiotic treatment or impeding resistance development. PVP-curcumin demonstrated effectiveness as a photosensitizer against both Gram-positive and Gram-negative bacteria but did not modulate the bacterial SOS response.

Biomacromolecular carriers based hydrophobic natural products for potential cancer therapy

Cancer is the second leading cause of death worldwide. It was estimated that 90 % of cancer-related deaths were attributable to the development of multi-drug resistance (MDR) during chemotherapy, which results in ineffective chemotherapy. Hydrophobic natural products plays a pivotal role in the field of cancer therapy, with the potential to reverse MDR in tumor cells, thereby enhancing the efficacy of tumor therapy. However, their targeted delivery is considered a major hurdle in their application. The advent of numerous approaches for encapsulating bioactive ingredients in the nanodelivery systems has improved the stability and targeted delivery of these biomolecules. The manuscript comprehensively analyses the nanodelivery systems of bioactive compounds with potential cancer therapy applications, including liposomes, emulsions, solid lipid nanoparticles (NPs), and polymeric NPs. Then, the advantages and disadvantages of various nanoagents in the treatment of various cancer types are critically discussed. Further, the application of multiple-compbine delivery methods to overcome the limitations of single-delivery have need critically analyzed, which thus could help in the designing nanodrug delivery systems for bioactive compounds in clinical settings. Therefore, the review is timely and important for development of efficient nanodelivery systems involving hydrophobic natural products to improve pharmacokinetic properties for effective cancer treatment.

Curcumin and its nano-formulations combined with exercise: From molecular mechanisms to clinic

Curcumin is a strong substance derived from turmeric, a popular spice, renowned for its antioxidant and anti-inflammatory abilities. The study delved deeply into a thorough examination of various sources to evaluate the impact of both regular curcumin and nano-formulated curcumin on elements that impact physical performance, including muscular strain, discomfort, swelling, and oxidative tension. While engaging in exercise, the body experiences a rise in reactive oxygen species and inflammation. As a result, it is important to ensure a proper balance between internal and external sources of antioxidants to maintain stability in the skeletal muscle. Without this balance, there is a risk of muscle soreness, damage, and ultimately, a decline in exercise performance. Curcumin possesses the ability to enhance physical performance and reduce the symptoms of muscle fatigue and injury by virtue of its antioxidative and anti-inflammatory properties. Including curcumin supplements appears to have advantageous effects on various aspects of exercise, such as enhancing performance, assisting with recovery, lessening muscle damage and discomfort, and lowering levels of inflammation and oxidative stress. However, a thorough assessment is necessary to precisely gauge the healing advantages of curcumin in enhancing exercise ability and reducing recovery time.

Characterizations on a GRAS Electrospun Lipid-Polymer Composite Loaded with Tetrahydrocurcumin

Electrospun/sprayed fiber films and nanoparticles were broadly studied as encapsulation techniques for bioactive compounds. Nevertheless, many of them involved using non-volatile toxic solvents or non-biodegradable polymers that were not suitable for oral consumption, thus rather limiting their application. In this research, a novel electrospun lipid-polymer composite (ELPC) was fabricated with whole generally recognized as safe (GRAS) materials including gelatin, medium chain triglyceride (MCT) and lecithin. A water-insoluble bioactive compound, tetrahydrocurcumin (TC), was encapsulated in the ELPC to enhance its delivery. Confocal laser scanning microscopy (CLSM) was utilized to examine the morphology of this ELPC and found that it was in a status between electrospun fibers and electrosprayed particles. It was able to form self-assembled emulsions (droplets visualized by CLSM) to deliver active compounds. In addition, this gelatin-based ELPC self-assembled emulsion was able to form a special emulsion gel. CLSM observation of this gel displayed that the lipophilic contents of the ELPC were encapsulated within the cluster of the hydrophilic gelatin gel network. The FTIR spectrum of the TC-loaded ELPC did not show the fingerprint pattern of crystalline TC, while it displayed the aliphatic hydrocarbon stretches from MCT and lecithin. The dissolution experiment demonstrated a relatively linear release profile of TC from the ELPC. The lipid digestion assay displayed a rapid digestion of triglycerides in the first 3-6 min, with a high extent of lipolysis. A Caco-2 intestinal monolayer transport study was performed. The ELPC delivered more TC in the upward direction than downwards. MTT study results did not report cytotoxicity for both pure TC and the ELPC-encapsulated TC under 15 μg/mL. Caco-2 cellular uptake was visualized by CLSM and semi-quantified to estimate the accumulation rate of TC in the cells over time.

Time-resolved keto-enol tautomerization of the medicinal pigment curcumin

Curcumin is a medicinal agent that exhibits anti-cancer and anti-Alzheimer's disease properties. It has a keto-enol moiety that gives rise to many of its chemical properties including metal complexation and acid-base equilibria. A previous study has shown that keto-enol tautomerization at this moiety is implicated in the anti-Alzheimer's disease effect of curcumin, highlighting the importance of this process. In this study, tautomerization of curcumin in methanol, acetone and acetonitrile was investigated using time-resolved 1H nuclear magnetic resonance spectroscopy. Curcumin undergoes hydrogen-deuterium exchange with the solvents and the proton resonance peak corresponding to the hydrogen at the α-carbon position (Cα) decays as a function of time, signifying deuteration at this position. Because tautomerization is the rate limiting step in the deuteration of curcumin at the Cα position, the rate of tautomerization is inferred from the rate of deuteration. The rate constant of tautomerization of curcumin shows a temperature dependence and analysis using the Arrhenius equation revealed activation energies (Ea) of tautomerization of (80.1 ± 5.9), (64.1 ± 1.0) and (68.3 ± 5.5) kJ mol-1 in methanol, D2O/acetone and D2O/acetonitrile, respectively. Insight into the role of water in tautomerization of curcumin was further offered by density functional theory studies. The transition state of tautomerization was optimized in the presence of water molecules. The results show a hydrogen-bonded solvent bridge between the diketo moiety and Cα of curcumin. The Ea of tautomerization of curcumin shows a strong dependence on the number of water molecules in the solvent bridge, indicating the critical role played by the solvent bridge in catalyzing tautomerization of curcumin.

Comprehensive spectroscopic and computational insight into the binding of vanillin with human transferrin: targeting neuroinflammation in Alzheimer's disease therapeutics

In present times, vanillin stands out as a promising therapeutic molecule that can be implicated in the treatment of neurodegenerative disorders (NDs), notably Alzheimer's disease (AD). This can be attributed to the highly potent scavenging activity of vanillin against reactive oxygen species (ROS). Oxidative stress leads to generation of ROS that serves a critical role in AD's pathological progression. It is apparent from various studies that diets rich in polyphenols prevent oxidative stress associated with AD development, implying the crucial role of vanillin in AD therapeutics. It is crucial to maintain iron balance to manage AD associated oxidative stress, unveiling the significance of human transferrin (hTf) that maintains iron homeostasis. Here, we have performed an integrated study of spectroscopic and computational approaches to get insight into the binding mechanism of vanillin with hTf. In the preliminary study, molecular docking deciphered that vanillin primarily occupies the hTf binding pocket, forming multiple interactions with its key residues. Moreover, the binding mechanism was evaluated at an atomistic level employing comprehensive molecular dynamic (MD) simulation. MD analysis demonstrated that binding of vanillin to hTf stabilizes its structure, without inducing any significant alterations in its native conformation. The docked complex was maintained throughout the simulations without changing its original conformation. Essential dynamics analysis further confirms that hTf achieved a stable conformation with vanillin. The outcomes were further supplemented by fluorescence spectroscopy which confirms the formation of stable hTf-vanillin complex. Taken together, the current study unveils the interaction mechanism of vanillin with hTf and providing a platform to use vanillin in AD therapeutics in the context of iron homeostasis.