The molecular basis for the pharmacokinetics and pharmacodynamics of curcumin and its metabolites in relation to cancer

Curcumin and EGCG combined formulation in nanostructured lipid carriers for anti-aging applications

Curcumin (Cur) and epigallocatechin gallate (EGCG), the primary active compounds in turmeric and green tea, respectively, have been investigated for their anti-aging potential. The Cur and EGCG combination was encapsulated in sustained-release nanostructured lipid carriers (NLCs) to enhance their bioactivities and pharmaceutical properties. A significant enhancement in the antioxidant activities of the Cur and EGCG combination was observed at an optimal ratio, as demonstrated by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay (118.83 ± 3.78 %), ferric ion reducing antioxidant power assay (217.25 ± 13.45 %), and lipid peroxidation inhibition assay (106.08 ± 12.93 %), compared to Cur alone without compromising the antioxidant activities and total phenolic content of EGCG. This is due to the enhancement of total phenolic content of the combination of 218.83 ± 10.57 %. For anti-aging activities, the combination exhibited stimulation of SIRT1 protein and inhibition of collagenase and elastase of 27.53 ± 0.73 %, 43.70 ± 1.05 % and 51.76 ± 6.52 % compared with that achieved with Cur alone, respectively. The incorporation of the Cur and EGCG combination into NLCs resulted in high entrapment efficiencies of 98.60 ± 0.05 % for Cur and 98.40 ± 0.08 % for EGCG, with corresponding loading capacities of 0.789 ± 0.001 % and 3.935 ± 0.003 %, respectively. When formulated NLCs into an emulgel base, the system demonstrated sustained release profiles over 48 h, with 12.82 ± 0.99 % release of Cur and 63.77 ± 5.76 % release of EGCG. Significant skin retention was also observed after 24 h, with 23.88 ± 1.71 % Cur and 22.79 ± 4.65 % EGCG retained in the skin. Therefore, Cur: EGCG-loaded NLCs in emulgel can deliver the active compounds into the dermis, enhancing skin penetration, sustained delivery, and anti-aging activity superior to each conventional single active compound in topical formulations.

The effect of highly bioavailable forms of curcumin on lipoprotein(a) plasma levels: A systematic review and meta-analysis of randomized clinical studies

Curcumin is a bioactive compound derived from the rhizome of Curcuma longa (turmeric) that has garnered increasing attention for its potential health benefits. However, its use in clinical practice is limited due to its generally poor bioavailability. This issue can be overcome using novel delivery systems that enhance curcumin's solubility, extend its residence time in plasma, improve its pharmacokinetic profile, and increase its cellular uptake. Novel curcumin formulations with improved bioavailability have been suggested to elevate plasma concentrations of lipoprotein(a) (Lp(a)), but there is no definitive evidence of a causal relationship. To address this, a systematic literature search was conducted in multiple electronic databases to identify relevant randomized placebo-controlled clinical studies published without a time limit. A meta-analysis of data suggested that dietary supplementation with highly bioavailable forms of curcumin significantly reduces Lp(a) levels [Standardized Mean Difference (SMD)= -0.96 (95 % Confidence Interval (CI): -1.82, -0.11)]. The effect size was robust in the leave-one-out sensitivity analysis and was not primarily driven by any single study. Of course, the clinical significance of this observation should be more thoroughly evaluated in longer-term trials, where the combined metabolic and anti-inflammatory effects of curcumin have vascular protective effects.

Carbohydrate polymer-based nanoparticles in curcumin delivery for cancer therapy

The application of natural products for cancer treatment has a long history. The safety and multifunctionality of naturally occurring substances have made them appropriate for cancer treatment and management. Curcumin affects multiple molecular pathways and is advantageous for treating both hematological and solid tumors. Nonetheless, the effectiveness of curcumin in vivo and in clinical studies has faced challenges due to its poor pharmacokinetic profile. Consequently, nanoparticles have been developed for the administration of curcumin in cancer treatment. The nanoparticles can enhance the distribution of curcumin in tissues and increase its therapeutic effectiveness. Furthermore, nanoparticles expand the uptake of curcumin in cancer cells, leading to increased cytotoxicity. Carbohydrate polymer-based nanoparticles provide a promising solution for the delivery of curcumin in cancer treatment by addressing its low solubility, limited bioavailability, and quick degradation. These biodegradable and biocompatible carriers, originating from polymers such as chitosan, hyaluronic acid, and alginate, protect curcumin, improving its stability and allowing for controlled release. Targeting ligands for functionalization provides selective and specific distribution to the tumor cells, enhancing therapeutic effectiveness and reducing off-target impacts. Their capacity to encapsulate curcumin with other agents allows for synergistic therapies, enhancing anticancer results even more. The adjustable characteristics of carbohydrate nanoparticles, along with their minimal toxicity, develop a revolutionary, functional and safe platform.

Diselenide-based nanoparticles enhancing the radioprotection to the small intestine of mice

The widespread application of ionizing radiation (IR) in medicine, while beneficial, also poses potential risks that necessitate effective countermeasures. Both 2-(3-aminopropylamino) ethanethiol (WR-1065) and curcumin are recognized as radioprotective agents; however, their clinical utility is hindered by notable shortcomings that could be addressed through reactive oxygen species (ROS)-responsive amphiphilic nanomaterials. We introduced a newly synthesized poly (ethylene glycol) (PEG)-polycaprolactone (PCL) polymer integrated with diselenide bonds and curcumin (HOOC-SeSe-Cur-PEG-SeSe-Cur-PCL, PEG-Cur-SeSe-PCL). The resulting spherical nanoparticles (NPs), which self-assembled from this polymer, were uniform with an average diameter of 118 nm. As a carrier for WR-1065, these NPs demonstrated a loading capacity of 30.9% and an efficacy of 56.7%. Importantly, the degradation of WR-1065 within the NPs was minimal in gastric fluid, decreasing by only approximately 20% over a 6-hour period. The innovative aspect of these NPs is their design to destabilize in ROS-rich environments, facilitating the release of WR-1065 and curcumin. Indeed, the survival rate of mice increased to 50% when these NPs were orally administered prior to exposure to a lethal dose of whole-body irradiation (8 Gy). The radioprotective impact of WR-1065-loaded NPs was evident in the small intestine of irradiated mice, characterized by the amelioration of radiation-induced epithelial damage, reduction of DNA damage, and inhibition of the apoptotic pathway. Collectively, this oral nanocarrier system for WR-1065 and curcumin holds promise as a potential candidate for the prophylaxis and treatment of acute intestinal injuries induced by IR.

Potential of Curcumin and Its Analogs in Glioblastoma Therapy

Curcumin, a polyphenol found in turmeric, demonstrates multifaceted anti-cancer activity against glioblastoma. Its therapeutic potential stems from its ability to modulate various molecular pathways implicated in glioblastoma development and progression, enhance the effectiveness of radiation therapy, and induce cancer cell death through diverse mechanisms, including apoptosis, autophagy, and cell cycle arrest. These combined actions make curcumin a promising candidate for glioblastoma treatment, warranting further investigation into its clinical application. In this review, we summarize the latest research on curcumin and its analogs' potential in glioblastoma therapy.

Curcumin, a bioactive compound of Turmeric (Curcuma longa) and its derivatives as α-amylase and α-glucosidase inhibitors

Diabetes mellitus (DM) is a long-term metabolic disease characterised by a controlled metabolism of fat, carbohydrates, and proteins. In recent decades, it has grown into a significant global public health issue. According to the International Diabetes Federation, there were 425 million DM globally in 2017, and the number might be increased to 629 million by 2045 (a global 48% increase). Approximately 4.2 million deaths globally attributed to DM occur before the age of 60. The existing class of anti-diabetic medications is limited by side effects, which has led to the hunt for novel inhibitors that specifically target the α-amylase and α-glucosidase enzymes. Curcumin is a small-molecular-weight compound found in the roots of the Curcuma longa L (C. longa). plant, which has been used for culinary, medicinal, and other purposes throughout Asia for thousands of years. Curcumin has potent anti-inflammatory, anti-cancer, anti-angiogenic, antispasmodic, antibacterial, and anti-parasitic qualities. Even though the potential of curcumin to cure DM has been well investigated, its low solubility, rapid metabolism, and short plasma half-life have limited its application in DM. Therefore, the objectives of this review were to review the chemical composition of C. longa, the structure of curcumin, the degradation of curcumin, and the effects of curcumin derivatives on anti-diabetic properties against α-amylase and α-glucosidase enzymes. The results showed that C. longa contains carbohydrates, moisture, protein, fat, minerals, volatiles, fibre, and curcuminoids. Among the curcuminoids, curcumin is 60-70% present in C. longa. Moreover, curcumin and its derivatives have a lot of potential for treating DM, which was highlighted in this review. This review emphasises the several biological applications of curcumin, which collectively establish the foundation for its anti-diabetic characteristics. Considering these results, curcumin derivatives may be considered as potential agents in the pharmacotherapeutic management of patients with DM.

Controlling the drug delivery efficiency of chitosan-based systems through silver nanoparticles and oxygen plasma

Today, curcumin's therapeutic properties are used in drug delivery systems. In this work, chitosan (CS) /Montmorillonite (MMT) hydrogels were synthesized to improve the performance of curcumin molecules. According to the results, drug release characteristics of CS/MMT/curcumin highly depend on the pH of the environment and properties of Ag nanoparticles. Moreover, curcumin and Ag nanoparticles were placed under the influence of oxygen plasma. Our results indicate that oxygen plasma, as a simple, clean, and environment-friendly method, can be used as an effective method for controlling the efficiency of drug release and antibacterial characteristics of curcumin molecules in hydrogels. In this case, by increasing the exposure time of the samples under the influence of oxygen plasma, their antibacterial properties and drug release efficiency are significantly enhanced.

Enhancing the efficacy of antimicrobial photodynamic therapy through curcumin modifications

Curcumin serves as a photosensitizer (PS) in the context of microbial inactivation when subjected to light exposure, to produce reactive oxygen species, which exhibit efficacy in eradicating microorganisms. This remarkable property underscores the growing potential of antimicrobial photodynamic therapy (aPDT) in the ongoing fight against bacterial infections. Considering this, we investigate the efficacy of various in vitro curcumin formulations within a PDT protocol designed to target Staphylococcus aureus. Specifically, we conduct a comparative analysis involving synthetic curcumin (Cur-Syn) and curcumin derivatives modified with chlorine (Cl), selenium (Se), and iodine (I) (Cur-Cl, Cur-Se, Cur-I). To assess the impact of aPDT, we subject S. aureus to incubation with curcumin, followed by irradiation at 450 nm with energy doses of 3.75, 7.5, and 15 J/cm2. Our investigation encompasses an evaluation of PS uptake and photobleaching across the various curcumin variants. Notably, all three modifications (Cur-Cl, Cur-Se, Cur-I) induce a significant reduction in bacterial viability, approximately achieving a 3-log reduction. Interestingly, the uptake kinetics of Cur-Syn and Cur-Se exhibit similarities, reaching saturation after 20 min. Our findings suggest that modifications to curcumin have a discernible impact on the photodynamic properties of the PS molecule.

Fungal derived dye as potential photosensitizer for antimicrobial photodynamic therapy

Photodynamic therapy (PDT) combines light with a photosensitizing agent to target and destroy abnormal cells or pathogens, offering a non-invasive and precise approach. Applying microbial dyes in PDT presents a great opportunity because these compounds may absorb specific wavelengths of light, generating reactive oxygen species (ROS) that induce oxidative stress, leading to cell or microbial death. This study evaluated the extract of Talaromyces amestolkiae containing azaphilone red dyes obtained from cultivation process as photosensitizer (PS) in antimicrobial photodynamic therapy (aPDT). Initially the crude extract was obtained in incubator shaker varying the culture media composition. Following, the crude extract containing the red dyes exhibited non-toxicity in dark conditions across all concentrations tested. PDT experiments with different amounts of the crude extract at a light dose of 80 J.cm-2 and upon irradiation at 460 nm was studied. A complete reduction of Escherichia coli and approximately 2 log10 reductions of Staphylococcus aureus, Cutibacterium acnes and Enterococcus faecalis was achieved using 25 % (v.v-1) of the crude extract while 50 % (v.v-1) of the crude extract led to a complete reduction of both E. coli and S. aureus, and around 5 log10 reductions of C. acnes and E. faecalis. Importantly, minimal photodegradation of the PS occurred during irradiation across all concentrations studied. These findings highlight the potential of T. amestolkiae-derived red dyes extract for use in aPDT, demonstrating non-toxicity in the absence of light, good aqueous solubility, high photostability, and strong microbial reduction capabilities under specific light conditions.

Effect of polymer architecture on the properties and in vitro cytotoxicity of drug formulation: A case study with mono- and di-gradient amphiphilic poly(2-Oxazoline)s

Due to the straightforward single-step synthesis, amphiphilic gradient copoly(2-oxazoline)s are becoming more popular alternative to their block analogue for the development of next-generation drug delivery systems. Here, we investigated the influence of polymer architecture on the physiochemical and biological assessment of nanoformulations formed by the self-assembly of gradient copoly(2-oxazoline)s. Two different architectures were synthesized: hydrophilic-grad-hydrophobic (mono-gradient) and hydrophobic-grad-hydrophilic-grad-hydrophobic (di-gradient) which contained a hydrophilic monomer, 2-ethyl-2-oxazoline (EtOx) and a hydrophobic monomer, 2-phenyl-2-oxazoline (PhOx). Di-gradient copolymers self-assembled in the presence of a hydrophobic model drug, curcumin and formed monodispersed or slightly polydispersed nanoparticle solution. On the other hand, mono-gradient copolymers formed polydispersed nanoparticle solutions. Di-gradient copolymer was slightly more efficient to solubilize curcumin. Mono-gradient copolymer nanoparticle showed faster monomer chain exchange kinetics and comparatively less stability in the presence of serum albumin. At longer incubation times, faster drug release was observed from the mono-gradient copolymer nanoformulations. Cytotoxicity of free curcumin and curcumin loaded nanoparticles in cancer cell of U87 MG (human glioblastoma cell) was dose and time-dependent, whereby the significant cell death occurred after 48 h. Curcumin-loaded mono-gradient copolymer nanoparticles inhibited U87MG cancel cell growth to a large extent compared to the di-gradient copolymer nanoparticles.

Photosensitizer associated with efflux pump inhibitors as a strategy for photodynamic therapy against bacterial resistance

Antimicrobial resistance is currently one of the biggest challenges in controlling infectious diseases and was listed among the top 10 threats to global health by the World Health Organization (WHO) in 2023. The antibiotics misuse has led to the widespread emergence of antimicrobial resistance, marking the beginning of the alarming increase in antibiotic resistance. In this context, Antimicrobial Photodynamic Therapy (aPDT) has garnered significant attention from the scientific community due to its potential to effectively eliminate multidrug-resistant pathogenic bacteria and its low propensity to induce drug resistance, which bacteria can quickly develop against traditional antibiotic treatments. However, some efflux pumps can expel diverse substrates from inside the cell, including photosensitizers used in aPDT, contributing to multidrug-resistance mechanisms. Efflux Pump Inhibitors are potential solutions to combat resistance mediated by these pumps and can play a crucial role in enhancing aPDT's effectiveness against multidrug-resistant bacteria. Therefore, combining efflux pumps inhibitors with photosensitizers can possible to eliminate the pathogen more efficiently. This review summarizes the mechanisms in which bacteria resist conventional antibiotic treatment, with a particular emphasis on efflux pump-mediated resistance, and present aPDT as a promising strategy to combat antibiotic resistance. Additionally, we highlighted several molecules of photosensitizer associated with efflux pump inhibitors as potential strategies to optimize aPDT, aiming to offer a perspective on future research directions on aPDT for overcoming the limitations of antibiotic resistance.

Ternary complex of soluble undenatured type II collagen-hydrophobic phytochemical-chondroitin sulfate facilitates high stability and targeted intestinal release properties to active substance

Researchers have reported that soluble undenatured type II collagen (SC II) and hydrophobic phytochemicals (HPs) can ameliorate osteoarthritis (OA) through several mechanisms. However, the solubility of HPs, the stability of SC II, and the bio-accessibility of both need to be greatly improved before they can be successfully used for this purpose. In this study, two common HPs, curcumin (CUR, a hydrophobic polyphenol) and astaxanthin (AST, a carotenoid), were first loaded into SC II, which was then complexed with chondroitin sulfate (CS) to form ternary complexes: SC II-HP-CS. The results showed that SC II had the highest loading capacity for CUR (19.00 ± 0.76 μg/mg) and AST (21.15 ± 1.67 μg/mg) at pH 2.0. The CUR and AST bound to the SC II through non-covalent interactions (mainly hydrophobic interaction) and they both existed in an amorphous form within the complexes. In addition, the binding affinity and hydrophobic interaction between SC II and CUR was higher than those of AST. The thermal stability of the SC II-CUR-CS (Td = 118.0 ± 2.1 °C) and SC II-AST-CS (Td = 118.8 ± 3.5 °C) complexes were significantly higher than that of the SC II-CUR (Td = 104.27 ± 0.28 °C) and SC II-AST (Td = 103.8 ± 1.6 °C) complexes. SC II-HP complexes dissolved in gastric fluids, resulting in serious degradation of the SC II, while SC II-HP-CS complexes existed in an insoluble form to protect the triple helix structure of SC II (24-46 % retained). The CUR release (94.2 ± 5.8 %) and the free radical scavenging activity (84.6 ± 5.3 %) of SC II-CUR-CS was relatively high after 6 h of intestinal digestion, while AST in SC II-AST and SC II-AST-CS had low solubility and antioxidant activity. Therefore, the ternary complex of SC II-HP-CS was more advantageous as multifunctional delivery systems for the encapsulation, protection, and controlled release of hydrophobic polyphenols, which may provide guidance for the synergistic use of hydrophobic polyphenols and SC II to improve OA.

Participation of lipids in the tumor response to photodynamic therapy and its exploitation for therapeutic gain

Hydroperoxides of unsaturated membrane lipids (LOOHs) are the most abundant non-radical intermediates generated by photodynamic therapy (PDT) of soft tissues such as tumors and have far longer average lifetimes than singlet oxygen or oxygen radicals formed during initial photodynamic action. LOOH-initiated post-irradiation damage to remaining membrane lipids (chain peroxidation) or to membrane-associated proteins remains largely unrecognized. Such after-light processes could occur during clinical oncological PDT, but this is not well-perceived by practitioners of this therapy. In general, the pivotal influence of lipids in tumor responses to PDT needs to be better appreciated. Of related importance is the fact that most malignant tumors have dramatically different lipid metabolism compared with healthy tissues, and this too is often ignored. The response of tumors to PDT appears especially vulnerable to manipulations within the tumor lipid microenvironment. This can be exploited for therapeutic gain with PDT, as exemplified here by the combined treatment with the antitumor lipid edelfosine.

Sexual dysfunction in dichlorvos-exposed male Wistar rat is ameliorated by curcumin and associated with the upregulation of testosterone

Dichlorvos is an organophosphate pesticide that is commonly used for agricultural and domestic control of pests and insects. Despite its usefulness, it exerts reproductive toxicity and induces male sexual dysfunction. On the other hand, curcumin has been reported to improve sexual dysfunction. However, till date, no study has reported the impact of curcumin on dichlorvos-induced sexual dysfunction. This study investigated the effect and associated mechanism of curcumin on dichlorvos-induced sexual dysfunction. Thirty-two male Wistar rats were randomized into four groups; the control (1 mL of olive oil), curcumin-treated (100 mg/kg), DDVP-treated (98.54 g/m3 of dichlorvos by inhalation), and DDVP + Curcumin-treated. Dichlorvos induced sexual dysfunction as depicted by reduced motivation to mate (8.38 ± 0.18 vs. 4.00 ± 0.33, P < 0.0001), prolonged latencies (46.63 ± 1.30 vs. 98.75 ± 1.32, P < 0.0001) and reduced frequencies of mount (14.88 ± 0.52 vs. 8.63 ± 0.38), intromission (9.38 ± 0.50 vs. 3.75 ± 0.31, P < 0.0001), and ejaculation (7.63 ± 0.38 vs. 1.50 ± 0.19, P < 0.0001). These findings were accompanied by suppression of hypothalamic-pituitary-testicular axis, evidenced by marked reductions in circulating FSH (60.00 ± 1.04 vs. 21.13 ± 0.52, P < 0.0001), LH (46.38 ± 1.38 vs. 19.00 ± 0.46, P < 0.0001), and testosterone (6.01 ± 0.50 vs. 0.74 ± 0.05, P < 0.0001). Nonetheless, the administration of curcumin in dichlorvos-exposed rats significantly attenuated dichlorvos-induced sexual dysfunction by improving the assessed indices of male sexual act. Also, curcumin significantly increased serum levels of FSH (21.13 ± 0.52 vs. 47.25 ± 0.10, P < 0.0001), LH (19.00 ± 0.46 vs. 43.00 ± 1.49), and testosterone (0.74 ± 0.05 vs. 3.98 ± 0.08, P < 0.0001). This study revealed that curcumin attenuated dichlorvos-induced sexual dysfunction by activating the hypothalamic-pituitary-testicular axis and upregulating circulating testosterone.

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.

Multifunctional composite film of curcumin Pickering emulsion stabilized by lignocellulose nanofibrils isolated from bamboo shoot shells for monitoring shrimp freshness

Concerns about food safety and environmental impact from chemical surfactants have prompted interest in natural lignocellulosic materials as alternatives. In this study, we combined hydrated deep eutectic solvent (DES) pretreatment with ultrasound treatment to prepare lignocellulosic nanofibrils (LCNF) from bamboo shoot shells with appropriate surface properties for stabilizing Pickering emulsions. The pretreatment intensity effectively modulated the surface characteristics of LCNF, achieving desirable wettability through lignin retention and in-situ esterification. The resulting LCNF/curcumin Pickering emulsion (CPE) demonstrated curcumin protection and pH-responsive color changes, while the ensuing CPE/PVA composite film exhibited ultraviolet shielding, mechanical strength, oxygen barrier, and antioxidant properties. Furthermore, the CPE/PVA film showed promise as a real-time indicator for monitoring shrimp freshness, maintaining sensitivity to spoilage even after six months of storage. These findings advance the advancement of green LCNF technologies, providing eco-friendly solutions for valorizing bamboo shoot shells and enhancing the application of LCNF in Pickering emulsions.

Phytobiotics in poultry: revolutionizing broiler chicken nutrition with plant-derived gut health enhancers

As the global population continues to expand, the demand for broiler chicken production to supply safe and high-quality meat is increasing. To meet this ever-growing demand, broiler chickens with enhanced growth performance are being developed, but they often face challenges related to oxidative stress, which can adversely affect gut health. Phytobiotics, which are plant-derived feed additives known for their antimicrobial, antioxidant, immune-modulating, and growth-promoting properties, have emerged as promising natural alternatives to synthetic antibiotics. This review consolidates recent advancements in the use of phytobiotics-derived products from leaves, roots, seeds, flowers, and their extracts in broiler diets reared under standard experimental conditions, without the introduction of stressors. The focus is on elucidating the key mechanisms through which phytobiotics improve gut health, including their effects on gut morphology, integrity, microflora composition, antioxidant capacity, and immune function. The review highlights the potential of phytobiotics to revolutionize broiler nutrition by acting as natural enhancers of gut health. Research findings reveal that phytobiotics significantly improve intestinal health, and boost growth performance, offering a sustainable approach to managing to gut dysfunction. These findings indicate a potential shift in how gut-health related challenges in broilers can be addressed, moving towards natural phytobiotic therapy. However, several challenges persist. Optimizing the dosage of phytobiotics, ensuring consistent performance, and overcoming the limitations related to their extraction and application are key areas requiring further investigation. The review emphasizes the importance of continued research to refine phytobiotic formulations, explore synergistic effects, and incorporate advanced technologies such as AI-driven methods and precision nutrition to tailor feeding strategies more effectively. Additionally, the development of innovative delivery systems, such as nanoencapsulation, is suggested as a way to enhance the effectiveness and reliability of phytobiotics. By highlighting the potential of phytobiotics to revolutionize broiler nutrition, this review supports the poultry industry's shift towards antibiotic-free and sustainable dietary solutions, offering new perspectives on the future of broiler chicken production.

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.

Lignin nanoparticles from Ayurvedic industry spent materials: Applications in Pickering emulsions for curcumin and vitamin D3 encapsulation

Lignin nanoparticles (LNP), extracted from spent materials of Dashamoola Arishta (Ayurvedic formulation), shared a molecular weight of 14.42 kDa with commercial lignin. Processed into LNPs (496.43 ± 0.54 nm) via planetary ball milling, they demonstrated stability at pH 8.0 with a zeta potential of -32 ± 0.27 mV. Operating as Pickering particles, LNP encapsulated curcumin and vitamin D3 in sunflower oil, forming LnE + Cu + vD3 nanoemulsions (particle size: 347.40 ± 0.71 nm, zeta potential: -42.27 ± 0.72 mV) with high encapsulation efficiencies (curcumin: 87.95 ± 0.21%, vitamin D3: 72.66 ± 0.11%). The LnE + Cu + vD3 emulsion exhibited stability without phase separation over 90 days at room (27 ± 2 °C) and refrigeration (4 ± 1 °C) temperatures. Remarkably, LnE + Cu + vD3 exhibited reduced toxicity, causing 29.32% and 34.99% cell death in L6 and RAW264.7 cells respectively, at the highest concentration (50 μg/mL). This underscores the potential valorization of Ayurvedic industry spent materials for diverse industrial applications.

Co-Assembled Binary Polyphenol Natural Products for the Prevention and Treatment of Radiation-Induced Skin Injury

Radiation therapy, a fundamental treatment for tumors, is often accompanied by radiation-induced skin injury (RISI). Excessive production of reactive oxygen species (ROS) and subsequent inflammation are two key factors in RISI development that will cause skin injury and affect radiotherapy. Herein, the co-assembled binary polyphenol natural products inspired the development of a dual-functional cascade microneedle system for prevention and treatment of RISI. Specifically, epigallocatechin gallate (EGCG) and curcumin (CUR) were co-assembled into nanoparticles (CEPG) by intermolecular interactions and then incorporated with catalase (CAT) to achieve a cascade system in the microneedles (this microneedle system was conducive to penetrate into the epidermal keratinocytes where RISI had the greatest impact). When using microneedles, the tip dissolved rapidly and delivered CEPG and CAT into the dermis, where CEPG NPs were able to respond to ROS and decompose into EGCG and CUR. More importantly, EGCG and CAT formed a cascade that converts superoxide anions into water step-by-step, which can reduce cell damage caused by free radicals in the early stages of radiation for prevention; meanwhile, CUR inhibited inflammatory pathways, achieving the treatment of skin inflammation in the post-radiotherapy period. These explorations broaden the strategy for the application of natural products in RISI.

Photodynamic therapy with curcumin and near-infrared radiation as an antitumor strategy to glioblastoma cells

Glioblastoma is a malignant neoplasm that develops in the central nervous system and is characterized by high rates of cell proliferation and invasion, presenting resistance to treatments and a poor prognosis. Photodynamic therapy (PDT) is a therapeutic modality that can be applied in oncological cases and stands out for being less invasive. Photosensitizers (PS) of natural origin gained prominence in PDT. Curcumin (CUR) is a natural compound that has been used in PDT, considered a promising PS. In this work, we evaluated the effects of PDT-mediated CUR and near-infrared radiation (NIR) in glioblastoma cells. Through trypan blue exclusion analysis, we chose the concentration of 5 μM of CUR and the dose of 2 J/cm2 of NIR that showed better responses in reducing the viable cell number in the C6 cell line and did not show cytotoxic/cytostatic effects in the HaCat cell line. Our results show that there is a positive interaction between CUR and NIR as a PDT model since there was an increase in ROS levels, a decrease in cell proliferation, increase in cytotoxicity with cell death by autophagy and necrosis, in addition to the presence of oxidative damage to proteins. These results suggest that the use of CUR and NIR is a promising strategy for the antitumor application of PDT.

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.

Improving the storage quality of Harbin red sausages by quaternized chitosan/sodium alginate coating curcumin nano-emulsion

In this study, the effect of sodium alginate and quaternized chitosan bis-polysaccharide-based shell transport curcumin nano-emulsions (Cur@QCS/SA) on the microbiological, physicochemical properties, quality characteristics of Harbin red sausage during storage is investigated. According to the microbiological results, the shelf life of Harbin red sausage is extended from 3 d to 6 d by adding 0.15% Cur@QCS/SA, and Bacillus is the most predominant bacterial before 6 d. Additionally, the physicochemical properties change significantly, the pH, weight loss (WL), water holding capacity (WHC), water activity (aw), L*, and a* of red sausage decrease gradually with the extension of storage time, as well as b*, lipid oxidation, proteolysis increase significantly (P < 0.05). Secondly, it is found that 0.15% treatment group can better maintain the quality characteristics of Harbin red sausage according to texture profile analysis (TPA), electronic nose (E-nose), and electronic tongue (E-tongue) (P < 0.05). This study provides a new way for nano-emulsions in food applications and a new option for the preservation of Harbin red sausage as well as other low-temperature meat products.

Comparative Pharmacokinetics and Tissue Distribution of Hexahydrocurcumin Following Intraperitoneal vs Oral Administration in Mice Using LC-MS/MS

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine hexahydrocurcumin (HHC) levels in mouse plasma, brain, liver, and kidneys using a negative ion mode electrospray ionization (ESI) source. Demonstrating a lower limit of quantification (LLOQ) of 5 ng/mL, the method showed excellent linearity across a concentration range of 5-500 ng/mL in all tested matrices. Precision evaluations reported a coefficient of variation (CV%) of less than 13.19% for both intraday and interday measurements, while accuracy ranged from 95.13 to 105.07% across all quality control levels. HHC extraction recovery was consistently observed between 70.18 and 93.28%, with a CV% deviation of less than 15%. In the pharmacokinetic evaluation of HHC in mice following a single intraperitoneal (IP) or oral administration, a noncompartment analysis was utilized. After IP administration (40 mg/kg), the C max value was 47.90 times higher than that achieved via oral administration. Peak plasma concentrations were observed approximately 5 min post-IP and 15 min post-oral dosing. The observed half-lives after these administrations were approximately 1.52 and 2.17 h for IP and oral routes, respectively. Oral administration revealed a relative bioavailability of only 12.28% compared with the IP route. Furthermore, following IP administration, the half-life values in brain, liver, and kidney were not significantly different but more than the half-life value found in plasma. The liver and kidney exhibited the highest concentrations of HHC, while the brain showed the least, suggesting that the hydrophobic nature of HHC impedes its passage through the blood-brain barrier. This study is the first to provide detailed insights into the pharmacokinetics and tissue distribution characteristics of HHC following oral and IP administration in mice, setting the stage for further focus on HHC as a potential new drug candidate.

Novel curcumin-based analogues as potential VEGFR2 inhibitors with promising metallic loading nanoparticles: synthesis, biological evaluation, and molecular modelling investigation

VEGFR2 inhibition has been established as a therapeutic approach for managing cancer. A series of curcumin-based analogues were designed, synthesized, and screened for their anticancer activity against MCF-7 and HepG-2 cell lines and WISH normal cells. Compounds 4b, 4d, 4e, and 4f showed potent cytotoxicity against MCF-7 with IC50 values of 0.49, 0.14, 0.01, and 0.32 μM, respectively, compared to curcumin (IC50 = 13.8 μM) and sorafenib (IC50 = 2.13 μM). Interestingly, compound 4e, the most active compound, exhibited potent VEGFR2 inhibition with an IC50 value of 11.6 nM (96.5% inhibition) compared to sorafenib with an IC50 value of 30 nM (94.8% inhibition). Additionally, compound 4e significantly induced apoptotic cell death in MCF-7 cells by 41.1% compared to a control group (0.8%), halting cell division during the G2/M phase by 39.8% compared to the control (21.7%). Molecular docking-coupled dynamics simulations highlighted the bias of the VEGFR2 pocket towards compound 4e compared to other synthesized compounds. Predicting superior binding affinities and relevant interactions with the pocket's key residues recapitulated in vitro findings towards higher inhibition activity for compound 4e. Furthermore, compound 4e with adequate pharmacokinetic and drug-likeness profiles in terms of ADME and safety characteristics can serve as a promising clinical candidate for future lead optimization and development. Notably, 4e-Fe2O3-humic acid NPs exhibited potent cytotoxicity with IC50 values of 2.41 and 13.4 ng mL-1 against MCF-7 and HepG-2 cell lines, respectively. Hence, compound 4e and its Fe2O3-humic acid-NPs could be further developed as promising anti-breast cancer agents.

Curcumin-Loaded Liposomes in Gel Protect the Skin of Mice against Oxidative Stress from Photodamage Induced by UV Irradiation

Prolonged exposure to ultraviolet (UV) irradiation can cause oxidative stress in the skin, accompanied by rapid immunosuppressive effects, resulting in a peroxidation reaction throughout the body. Curcumin (Cur), as the bioactive compound of turmeric, is a natural polyphenol with potent antioxidant properties but is often overlooked due to its poor solubility and low bioavailability. In this study, curcumin-loaded liposomes in a sodium alginate gel complex preparation were designed to improve the bioavailability of curcumin and to study its preventive effect on photodamage. Cur-loaded liposomes (Cur-L), Cur-loaded gel (Cur-G) based on an alginate matrix, and curcumin-loaded liposomes in gel (Cur-LG) were prepared, and their antioxidant effects and drug diffusion abilities were evaluated. The antioxidant capacity of Cur, Cur-L, Cur-G, and Cur-LG was also studied in a mouse model of photodamage. Cur had the highest antioxidant activity at about 4 mg/mL. Cur-LG at this concentration showed antioxidant effects during 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and H2O2 experiments. During the UV light damage test, Cur-LG demonstrated the ability to effectively neutralize free radicals generated as a result of lipid peroxidation in the skin, serum, and liver, thereby enhancing the overall activity of superoxide dismutase (SOD). In conclusion, using Cur-LG may protect against epidermal and cellular abnormalities induced by UV irradiation.

Clinical Trial Findings and Drug Development Challenges for Curcumin in Infectious Disease Prevention and Treatment

Since ancient times, turmeric, scientifically known as Curcuma longa, has been renowned for its therapeutic properties. Recently, extensive documentation has highlighted the prevalence of microbial diseases without effective treatments, the increased expense of certain antimicrobial medications, and the growing occurrence of antimicrobial drug resistance. Experts predict that drug resistance will emerge as a significant global cause of death by the middle of this century, thereby necessitating intervention. Curcumin, a major curcuminoid molecule, has shown extensive antimicrobial action. Improving and altering the use of natural antimicrobial agents is the most effective approach to addressing issues of targeted specificity and drug resistance in chemically synthesized medicines. Further research is required to explore the efficacy of curcumin and other natural antimicrobial substances in combating microbial infections. The solubility and bioavailability of curcumin impede its antimicrobial capability. To enhance curcumin's antimicrobial effectiveness, researchers have recently employed several methods, including the development of curcumin-based nanoformulations. This review seeks to compile the latest available literature to assess the advantages of curcumin as a natural antimicrobial agent (particularly antiviral and antibacterial) and strategies to enhance its medical efficacy. The future application of curcumin will help to alleviate microbial infections, thereby promoting the sustainability of the world's population.

Role of Curcuma longae Rhizoma in medical applications: research challenges and opportunities

Curcuma longae Rhizoma, commonly known as turmeric, is extensively utilized not only in Traditional Chinese Medicine (TCM) but also across various traditional medicine systems worldwide. It is renowned for its effectiveness in removing blood stasis, promoting blood circulation, and relieving pain. The primary bioactive metabolites of Curcuma longae Rhizoma-curcumin, β-elemene, curcumol, and curdione-have been extensively studied for their pharmacological benefits. These include anti-tumor properties, cardiovascular and cerebrovascular protection, immune regulation, liver protection, and their roles as analgesics, anti-inflammatories, antivirals, antibacterials, hypoglycemics, and antioxidants. This review critically examines the extensive body of research regarding the mechanisms of action of Curcuma longae Rhizoma, which engages multiple molecular targets and signaling pathways such as NF-κB, MAPKs, and PI3K/AKT. The core objective of this review is to assess how the main active metabolites of turmeric interact with these molecular systems to achieve therapeutic outcomes in various clinical settings. Furthermore, we discuss the challenges related to the bioavailability of these metabolites and explore potential methods to enhance their therapeutic effects. By doing so, this review aims to provide fresh insights into the optimization of Curcuma longae Rhizoma for broader clinical applications.

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.

Chondroitin sulfate-tocopherol succinate modified exosomes for targeted drug delivery to CD44-positive cancer cells

Exosomes (Exos), natural nanovesicles released by various cell types, show potential as an effective drug delivery platform due to their intrinsic role as transporters of biomolecules between different cells. However, Exos functionalization with targeting ligands is a critical step to enhance their targeting capability, which could be challenging. In this study, Exos were modified to specifically bind to CD44-positive cells by anchoring chondroitin sulfate (CS) to their surface. Exo modification was facilitated with CS conjugation with alpha-tocopherol succinate (TOS) as an anchorage. The modified Exos were utilized for delivering curcumin (Cur) to pancreatic cancer (PC) cells. In vitro Cur release studies revealed that Exos play a crucial role in maintaining Cur within themselves, demonstrating their potential as effective carriers for drug delivery to targeted locations. Notably, Cur loaded into the modified Exos exhibited enhanced cytotoxicity compared to unmodified Exo-Cur. Meanwhile, Exo-Cur-TOS-CS induced apoptosis more effectively in AsPC-1 cells than unmodified Exos (70.2 % versus 56.9 %). It is worth mentioning that with CD44-mediated cancer-specific targeting, Exo-CS enabled increased intracellular accumulation in AsPC-1 cells, showing promise as a targeted platform for cancer therapy. These results confirm that Exo modification has a positive impact on enhancing the therapeutic efficacy and cytotoxicity of drugs.

The role of tetrahydrocurcumin in disease prevention and treatment

In recent decades, natural compounds derived from herbal medicine or dietary sources have played important roles in prevention and treatment of various diseases and have attracted more and more attention. Curcumin, extracted from the Curcumae Longae Rhizoma and widely used as food spice and coloring agent, has been proven to possess high pharmacological value. However, the pharmacological application of curcumin is limited due to its poor systemic bioavailability. As a major active metabolite of curcumin, tetrahydrocurcumin (THC) has higher bioavailability and stability than curcumin. Increasing evidence confirmed that THC had a wide range of biological activities and significant treatment effects on diseases. In this paper, we reviewed the research progress on the biological activities and therapeutic potential of THC on different diseases such as neurological disorders, metabolic syndromes, cancers, and inflammatory diseases. The extensive pharmacological effects of THC involve the modulation of various signaling transduction pathways including MAPK, JAK/STAT, NF-κB, Nrf2, PI3K/Akt/mTOR, AMPK, Wnt/β-catenin. In addition, the pharmacokinetics, drug combination and toxicology of THC were discussed, thus providing scientific basis for the safe application of THC and the development of its dietary supplements and drugs.

Enhanced absorption of prenylated cinnamic acid derivatives from Brazilian green propolis by turmeric in humans and rats

Prenylated cinnamic acid derivatives are the bioactive components of Brazilian green propolis (BGP). The effect of other botanical components on the pharmacokinetic profiles of these derivatives remains relatively unexplored. In the present study, we investigated the influence of several herbal extracts (turmeric, ginkgo leaf, coffee fruit, soybean, and gotu kola) on the plasma concentrations of cinnamic acid derivatives after BGP consumption. When the herbal extracts were co-administered with BGP in the clinical study, the area under the curve (AUC) values of artepillin C and drupanin, the major BGP components in plasma, were significantly increased by 1.7- and 1.5-fold, respectively, compared to those after BGP administration alone. Among the herbal extracts administered to rats, turmeric extract increased the AUC. Furthermore, a bidirectional transport assay suggested that artepillin C and drupanin are substrates of breast cancer resistance protein (BCRP), a drug elimination transporter. These results suggest that curcumin-containing turmeric extract may increase the plasma concentrations of artepillin C and drupanin via BCRP. Our findings enabled us to estimate the food-herb and herb-herb interactions in vivo in foods and herbal medicines containing cinnamic acid derivatives and prenylated compounds.

Neuroprotective Effects of Curcumin in Neurodegenerative Diseases

Curcumin, a hydrophobic polyphenol extracted from the rhizome of Curcuma longa, is now considered a candidate drug for the treatment of neurological diseases, including Parkinson's Disease (PD), Alzheimer's Disease (AD), Huntington's Disease (HD), Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), and prion disease, due to its potent anti-inflammatory, antioxidant potential, anticancerous, immunomodulatory, neuroprotective, antiproliferative, and antibacterial activities. Traditionally, curcumin has been used for medicinal and dietary purposes in Asia, India, and China. However, low water solubility, poor stability in the blood, high rate of metabolism, limited bioavailability, and little capability to cross the blood-brain barrier (BBB) have limited the clinical application of curcumin, despite the important pharmacological activities of this drug. A variety of nanocarriers, including liposomes, micelles, dendrimers, cubosome nanoparticles, polymer nanoparticles, and solid lipid nanoparticles have been developed with great success to effectively deliver the active drug to brain cells. Functionalization on the surface of nanoparticles with brain-specific ligands makes them target-specific, which should significantly improve bioavailability and reduce harmful effects. The aim of this review is to summarize the studies on curcumin and/or nanoparticles containing curcumin in the most common neurodegenerative diseases, highlighting the high neuroprotective potential of this nutraceutical.

Review: bioavailability and efficacy of 'free' curcuminoids from curcumagalactomannoside (CGM) curcumin formulation

The golden spice turmeric with its main bioactive component curcumin is one of the most popular and extensively studied nutraceuticals. Despite numerous pre-clinical studies reporting positive pharmacodynamics of turmeric extracts and curcumin, the main issues in translating the pharmacological effects to clinical efficacy have been to overcome its poor pharmacokinetics and to deliver significant amounts of the biologically relevant forms of the actives to various tissues. This review is aimed at providing a first critical evaluation of the current published literature with the novel curcumagalactomannoside (CGM) formulation of curcumin using fenugreek galactomannan dietary fibre, specifically designed to address curcumin poor pharmacokinetics. We describe CGM and its technology as a food-grade formulation to deliver 'free' unconjugated curcuminoids with enhanced bioavailability and improved pharmacokinetic properties. The therapeutic relevance of improving bioavailability of 'free' curcuminoids and some of the technical challenges in the measurement of the 'free' form of curcuminoids in plasma and tissues are also discussed. A total of twenty-six manuscripts are reviewed here, including fourteen pre-clinical and twelve clinical studies that have investigated CGM pharmacokinetics, safety and efficacy in various animal models and human conditions. Overall current scientific evidence suggests CGM formulation has improved bioavailability and tissue distribution of the biologically relevant unconjugated forms of turmeric actives called 'free' curcuminoids that may be responsible for the superior clinical outcomes reported with CGM treatments in comparison with unformulated standard curcumin across multiple studies.

Longevity and anti-aging effects of curcumin supplementation

Aging is a gradual and irreversible process that is accompanied by an overall decline in cellular function and a significant increase in the risk of age-associated disorders. Generally, delaying aging is a more effective method than treating diseases associated with aging. Currently, researchers are focused on natural compounds and their therapeutic and health benefits. Curcumin is the main active substance that is present in turmeric, a spice that is made up of the roots and rhizomes of the Curcuma longa plant. Curcumin demonstrated a positive impact on slowing down the aging process by postponing age-related changes. This compound may have anti-aging properties by changing levels of proteins involved in the aging process, such as sirtuins and AMPK, and inhibiting pro-aging proteins, such as NF-κB and mTOR. In clinical research, this herbal compound has been extensively examined in terms of safety, efficacy, and pharmacokinetics. There are numerous effects of curcumin on mechanisms related to aging and human diseases, so we discuss many of them in detail in this review.

NF-κB pathway as a molecular target for curcumin in diabetes mellitus treatment: Focusing on oxidative stress and inflammation

Diabetes mellitus (DM) is a collection of metabolic disorder that is characterized by chronic hyperglycemia. Recent studies have demonstrated the crucial involvement of oxidative stress (OS) and inflammatory reactions in the development of DM. Curcumin (CUR), a natural compound derived from turmeric, exerts beneficial effects on diabetes mellitus through its interaction with the nuclear factor kappa B (NF-κB) pathway. Research indicates that CUR targets inflammatory mediators in diabetes, including tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6), by modulating the NF-κB signaling pathway. By reducing the expression of these inflammatory factors, CUR demonstrates protective effects in DM by improving pancreatic β-cells function, normalizing inflammatory cytokines, reducing OS and enhancing insulin sensitivity. The findings reveal that CUR administration effectively lowered blood glucose elevation, reinstated diminished serum insulin levels, and enhanced body weight in Streptozotocin -induced diabetic rats. CUR exerts its beneficial effects in management of diabetic complications through regulation of signaling pathways, such as calcium-calmodulin (CaM)-dependent protein kinase II (CaMKII), peroxisome proliferator-activated receptor gamma (PPAR-γ), NF-κB, and transforming growth factor β1 (TGFB1). Moreover, CUR reversed the heightened expression of inflammatory cytokines (TNF-α, Interleukin-1 beta (IL-1β), IL-6) and chemokines like MCP-1 in diabetic specimens, vindicating its anti-inflammatory potency in counteracting hyperglycemia-induced alterations. CUR diminishes OS, avert structural kidney damage linked to diabetic nephropathy, and suppress NF-κB activity. Furthermore, CUR exhibited a protective effect against diabetic cardiomyopathy, lung injury, and diabetic gastroparesis. Conclusively, the study posits that CUR could potentially offer therapeutic benefits in relieving diabetic complications through its influence on the NF-κB pathway.

Concentration-Dependent Effects of Curcumin on Membrane Permeability and Structure

Growing evidence suggests that many bioactive molecules can nonspecifically modulate the physicochemical properties of membranes and influence the action of embedded membrane proteins. This study investigates the interactions of curcumin with protein-free model membranes consisting of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and DOPC with cholesterol (4/1 mol ratio). The focus is on the capability of curcumin to modify membrane barrier properties such as water permeability assayed through the droplet interface bilayer (DIB) model membrane. For pure DOPC, our findings show a concentration-dependent biphasic effect: a reduction in water permeability is observed at low concentrations (up to 2 mol %), whereas at high concentrations of curcumin, water permeability increases. In the presence of cholesterol, we observed an overall reduction in water permeability. A combination of complementary experimental methods, including phase transition parameters studied by differential scanning calorimetry (DSC) and structural properties measured by attenuated total reflectance (ATR)-FTIR, provides a deeper understanding of concentration-dependent interactions of curcumin with DOPC bilayers in the absence and presence of cholesterol. Our experimental findings align with a molecular mechanism of curcumin's interaction with model membranes, wherein its effect is contingent on its concentration. At low concentrations, curcumin binds to the lipid-water interface through hydrogen bonding with the phosphate headgroup, thereby obstructing the transport of water molecules. Conversely, at high concentrations, curcumin permeates the acyl chain region, inducing packing disorders and demonstrating evidence of phase separation. Enhanced knowledge of the impact of curcumin on membranes, which, in turn, can affect protein function, is likely to be beneficial for the successful translation of curcumin into effective medicine.

Construction of endothelial cell signatures for predicting the diagnosis, prognosis and immunotherapy response of bladder cancer via machine learning

We subtyped bladder cancer (BC) patients based on the expression patterns of endothelial cell (EC) -related genes and constructed a diagnostic signature and an endothelial cell prognostic index (ECPI), which are useful for diagnosing BC patients, predicting the prognosis of BC and evaluating drug sensitivity. Differentially expressed genes in ECs were obtained from the Tumour Immune Single-Cell Hub database. Subsequently, a diagnostic signature, a tumour subtyping system and an ECPI were constructed using data from The Cancer Genome Atlas and Gene Expression Omnibus. Associations between the ECPI and the tumour microenvironment, drug sensitivity and biofunctions were assessed. The hub genes in the ECPI were identified as drug candidates by molecular docking. Subtype identification indicated that high EC levels were associated with a worse prognosis and immunosuppressive effect. The diagnostic signature and ECPI were used to effectively diagnose BC and accurately assess the prognosis of BC and drug sensitivity among patients. Three hub genes in the ECPI were extracted, and the three genes had the closest affinity for doxorubicin and curcumin. There was a close relationship between EC and BC. EC-related genes can help clinicians diagnose BC, predict the prognosis of BC and select effective drugs.

Gelatin/carboxymethylcellulose composite film combined with photodynamic antibacterial: New prospect for fruit preservation

Plastic packaging causes environmental pollution, and the development of simple and effective biodegradable active packaging remains a challenge. In this study, gelatin (G) and sodium carboxymethylcellulose (CMC) were used as film materials, with the addition of curcumin (Cur), a photosensitive substance, to investigate the changes in the physical and chemical properties of the film and its application in fruit preservation. The results demonstrated that Cur was compatible with the film. With the addition of Cur, the thickness of the film increased up to 1.3 times, while the moisture content was reduced to 12.10 %. The tensile strength (TS) and elongation at break (EAB) of the film can reach 8.84 MPa and 19.33 %, respectively. The photodynamic antibacterial experiment revealed that the film containing 0.5 % Cur exhibited the highest antibacterial rate, reaching 99.99 % against Staphylococcus aureus (S. aureus) and 95 % against Escherichia coli (E. coli). During storage, the grapes remained unspoiled for up to 9 days after being phototreated with the film and the microbial content of the skin was much lower than that of the control group. In addition, Cur provided antioxidant activity for the film, with a scavenging activity of 39.54 % against the 2,2-diphenyl-1-picrind radical (DPPH). Bananas exposed to the film-forming solution for a short period of time remained fresh for up to 6 days. During preservation, the weight of the treated bananas decreased more slowly than that of the control group. In addition, the activity of SOD on the 7th day was approximately 20 U/g higher than that of the control group, which helped to reduce oxidative stress during banana preservation. In summary, G-CMC/Cur film is an optional fruit-cling film that can be used in food packaging.

The synergistic effect of nanocurcumin and donepezil on Alzheimer's via PI3K/AKT/GSK-3β pathway modulating

Alzheimer's disease (AD) hallmarks include amyloid-βeta (Aβ) and tau proteins aggregates, neurite degeneration, microglial activation with cognitive impairment. Phosphatidylinositol-3-kinase/protein kinase B/Glycogen synthase kinase-3-beta (PI3K/AKT/GSK-3) pathway is essential for neuroprotection, cell survival and proliferation by blocking apoptosis. This study aimed to assess protective role of nanocurcumin (NCMN) as strong antioxidant and anti-inflammatory agent with elucidating its synergistic effects with Donepezil as acetylcholinesterase inhibitor on AD in rats via modulating PI3K/AKT/GSK-3β pathway. The experiment was performed on 70 male Wistar albino rats divided into seven groups (control, NCMN, Donepezil, AD-model, Donepezil co-treatment, NCMN only co-treatment, and NCMN+Donepezil combined treatment). Behavioral and biochemical investigations as cholinesterase activity, oxidative stress (malondialdehyde, reduced glutathione, nitric oxide, superoxidedismutase, and catalase), tumor necrosis factor-alpha, Tau, β-site amyloid precursor protein cleaving enzyme-1 (BACE-1), Phosphatase and tensin homolog (Pten), mitogen-activated protein kinase-1 (MAPK-1), Glycogen synthase kinase-3-beta (GSK-3β) and toll-like receptor-4 were evaluated. Treatment with NCMN improved memory, locomotion, neuronal differentiation by activating PI3K/AKT/GSK-3β pathway. These results were confirmed by histological studies in hippocampus.

Neuroprotective potentials of Lead phytochemicals against Alzheimer's disease with focus on oxidative stress-mediated signaling pathways: Pharmacokinetic challenges, target specificity, clinical trials and future perspectives

BACKGROUND

Alzheimer's diseases (AD) and dementia are among the highly prevalent neurological disorders characterized by deposition of beta amyloid (Aβ) plaques, dense deposits of highly phosphorylated tau proteins, insufficiency of acetylcholine (ACh) and imbalance in glutamatergic system. Patients typically experience cognitive, behavioral alterations and are unable to perform their routine activities. Evidence also suggests that inflammatory processes including excessive microglia activation, high expression of inflammatory cytokines and release of free radicals. Thus, targeting inflammatory pathways beside other targets might be the key factors to control- disease symptoms and progression.

PURPOSE

This review is aimed to highlight the mechanisms and pathways involved in the neuroprotective potentials of lead phytochemicals. Further to provide updates regarding challenges associated with their use and their progress into clinical trials as potential lead compounds.

METHODS

Most recent scientific literature on pre-clinical and clinical data published in quality journals especially on the lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin was collected using SciFinder, PubMed, Google Scholar, Web of Science, JSTOR, EBSCO, Scopus and other related web sources.

RESULTS

Literature review indicated that the drug discovery against AD is insufficient and only few drugs are clinically approved which have limited efficacy. Among the therapeutic options, natural products have got tremendous attraction owing to their molecular diversity, their safety and efficacy. Research suggest that natural products can delay the disease onset, reduce its progression and regenerate the damage via their anti-amyloid, anti-inflammatory and antioxidant potentials. These agents regulate the pathways involved in the release of neurotrophins which are implicated in neuronal survival and function. Highly potential lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin regulate neuroprotective signaling pathways implicated in neurotrophins-mediated activation of tropomyosin receptor kinase (Trk) and p75 neurotrophins receptor (p75NTR) family receptors.

CONCLUSIONS

Phytochemicals especially phenolic compounds were identified as highly potential molecules which ameliorate oxidative stress induced neurodegeneration, reduce Aβ load and inhibit vital enzymes. Yet their clinical efficacy and bioavailability are the major challenges which need further interventions for more effective therapeutic outcomes.

Nanoencapsulated Curcumin: Enhanced Efficacy in Reversing Memory Loss in An Alzheimer Disease Model

Investigating new drugs or formulations that target Alzheimer disease (AD) is critical for advancing therapeutic interventions. Therefore, this study aimed to assess the effectiveness of nanoencapsulated curcumin (NC Curc) in alleviating memory impairment, oxidative stress, and neuroinflammation in a validated AD model. Male Wistar rats were given bilateral intracerebroventricular injections of either saline or streptozotocin (STZ) (3 mg/3 µL/site) to establish the AD model (day 0). On day 22, daily oral administrations of curcumin (6 mg/kg), NC Curc (6 mg/kg), or a vehicle (unloaded NC) were initiated and continued for 14 days. NC Curc significantly reversed memory deficits in object recognition and inhibitory avoidance tests induced by STZ. Both formulations of curcumin attenuated elevated acetylcholinesterase activity caused by STZ. Importantly, NC Curc alone effectively mitigated STZ-induced oxidative stress. Additionally, NC Curc treatment normalized GFAP levels, suggesting a potential reduction in neuroinflammation in STZ-treated rats. Our findings indicate that NC Curc improves memory in an AD rat model, highlighting its enhanced therapeutic effects compared to unencapsulated curcumin. This research significantly contributes to understanding the therapeutic and neurorestorative potential of NC Curc in AD, particularly in reversing pathophysiological changes.

Theoretical studies on the photo protective mechanism of curcuminoids

In this work, the deactivation pathways of curcuminoids after photoexcitation was studied by employing density functional theory to explore their UVA radiation screening capacity. A comprehensive computational characterization of the excited-state processes of curcumin, demethoxycurcumin, and bis-demethoxycurcumin was done. The molecules exist in diketo and enol forms which are in equilibrium and interconvertible through keto-enol tautomerism. The enolic forms of each of the studied molecules have eight geometric cis-trans isomers as a result of torsion rotation about three different carbon-carbon double bonds across the aliphatic chain. For each geometric isomer, sixteen possible rotamers are found to exist due to rotation about five different carbon-carbon single bond rotations, also across the skeleton of the aliphatic chain. Upon photoexcitation, the studied molecules follow three main pathways of radiationless decay: (a) rotamerism and interconversion between rotamers of comparable energies which are in equilibrium, (b) interconversion between the cis-trans geometrical isomers where an efficient vibrational relaxation path is formed at ∼90° during torsion rotation about carbon-carbon double bond, and (c) excited state intramolecular proton transfer in a single O-H stretching vibration through a cyclic intramolecular hydrogen bonded ring formed at the centre of the molecule giving back the original structure. The absorption and emission spectra of the molecules were also simulated where the theoretically obtained absorption and emission maxima are close to the reported experimental values.

Curcumin in Cancer Prevention: Insights from Clinical Trials and Strategies to Enhance Bioavailability

Cancer remains a leading cause of death worldwide, and current cancer drugs often have high costs and undesirable side effects. Additionally, the development of drug resistance can reduce their effectiveness over time. Natural products have gained attention as potential sources for the treatment and prevention of various diseases. Curcumin, an extract from turmeric (Curcuma longa), is a natural phenolic compound with diverse pharmacological properties, including antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, antiprotozoal, antidiabetic, antivenom, antiulcer, anticarcinogenic, antimutagenic, anticoagulant, and antifertility activities. Given the increasing interest in curcumin for cancer prevention, this review aims to comprehensively examine clinical trials investigating the use of curcumin in different types of cancer. Additionally, effective techniques and approaches to enhance the bioavailability of curcumin are discussed and summarized. This review article provides insights into the properties of curcumin and its potential as a future anticancer drug.

Natural Activators of Autophagy

Autophagy is the process by which cell contents, such as aggregated proteins, dysfunctional organelles, and cell structures are sequestered by autophagosome and delivered to lysosomes for degradation. As a process that allows the cell to get rid of non-functional components that tend to accumulate with age, autophagy has been associated with many human diseases. In this regard, the search for autophagy activators and the study of their mechanism of action is an important task for treatment of many diseases, as well as for increasing healthy life expectancy. Plants are rich sources of autophagy activators, containing large amounts of polyphenolic compounds in their composition, which can be autophagy activators in their original form, or can be metabolized by the intestinal microbiota to active compounds. This review is devoted to the plant-based autophagy activators with emphasis on the sources of their production, mechanism of action, and application in various diseases. The review also describes companies commercializing natural autophagy activators.

Potential neuroprotective effect of nanomicellar curcumin on learning and memory functions following subacute exposure to bisphenol A in adult male rats

Bisphenol A (BPA) is an endocrine-disrupting chemical commonly utilized in the manufacture of plastics, which may cause damage to brain tissue. Curcumin is a phytochemical with protective effects against neurological and mental diseases. The purpose of this research was to evaluate whether nanomicellar curcumin (NmCur) might protect rats against BPA-induced learning and memory deficits. After determining the proper dose of BPA, the animals were randomly divided into 8 groups (8 rats in each group) receiving dextrose 5% (as vehicle of NmCur) (Dex), sesame oil (as vehicle of BPA) (Sea), Sea plus Dex, NmCur (50 mg/kg), BPA (50 mg/kg), and 50 mg/kg BPA plus 10, 25, and 50 mg/kg NmCur groups, respectively. Behavioral tests performed using passive avoidance training (PAT), open-field (OF), and Morris water maze (MWM) tests. The expression of oxidative stress markers, proinflammatory cytokines, oxidative stress-scavenging enzymes, glutamate receptors, and MAPK and memory-related proteins was measured in rat hippocampus and cortical tissues. BPA up-regulated ROS, MDA, TNF-α, IL-6, IL-1β, SOD, GST, p-P38, and p-JNK levels; however, it down-regulated GSH, GPx, GR, CAT, p-AKT, p-ERK1/2, p-NR1, p-NR2A, p-NR2B, p-GluA1, p-CREB, and BDNF levels. BPA decreased step-through latency (STL) and peripheral and total, but not central, locomotor activity. It increased the time to find the hidden platform, the mean of escape latency time, and the traveled distance in the target quadrant, but decreased the time spent in the target quadrant. The combination of BPA (50 mg/kg) and NmCur (25 and 50 mg/kg) reversed all of BPA's adverse effects. Therefore, NmCur exhibited neuroprotective effects against subacute BPA-caused learning and memory impairment.

Turmeric and Curcumin-Health-Promoting Properties in Humans versus Dogs

The growing popularity of the use of nutraceuticals in the prevention and alleviation of symptoms of many diseases in humans and dogs means that they are increasingly the subject of research. A representative of the nutraceutical that deserves special attention is turmeric. Turmeric belongs to the family Zingiberaceae and is grown extensively in Asia. It is a plant used as a spice and food coloring, and it is also used in traditional medicine. The biologically active factors that give turmeric its unusual properties and color are curcuminoids. It is a group of substances that includes curcumin, de-methoxycurcumin, and bis-demethoxycurcumin. Curcumin is used as a yellow-orange food coloring. The most important pro-health effects observed after taking curcuminoids include anti-inflammatory, anticancer, and antioxidant effects. The aim of this study was to characterize turmeric and its main substance, curcumin, in terms of their properties, advantages, and disadvantages, based on literature data.

Synthesis of a light-responsive platinum curcumin complex, chemical and biological investigations and delivery to tumor cells by means of polymeric nanoparticles

Platinum-based anticancer drugs are common in chemotherapy, but problems such as systemic toxicity and acquired resistance of some tumors hamper their clinical applications and therapeutic efficacy. It is necessary to synthesize Pt-based drugs and explore strategies to reduce side effects and improve pharmacokinetic profiles. Photo-responsive chemotherapeutics have emerged as an alternative strategy against several cancers, as photoactivation offers spatial selectivity and fewer side effects. Here, we combine chemical synthesis and nanotechnology to create a multifunctional platinum drug delivery system based on the novel metal complex [Pt(ppy)(curc)] (ppy = deprotonated 2-phenylpyridine, curc = deprotonated curcumin)] embodying the naturally occurring bioactive molecule, curcumin. The ultrasonication method coupled with the layer-by-layer technology was employed to produce nanocolloids, which demonstrated a good biocompatibility, higher solubility in aqueous solution, stability, large drug loading, and good biological activity in comparison with the free drug. In vitro release experiments revealed that the polymeric nanoformulation is relatively stable under physiological conditions (pH = 7.4 and 37 °C) but sensitive to acidic environments (pH = 5.6 and 37 °C) which would trigger the release of the loaded drug. Our approach modifies the bioavailability of this Pt-based drug increasing its therapeutic action in terms of both cytotoxic and anti-metastasis effects.

Effect of pulsed light on curcumin chemical stability and antioxidant capacity

Curcumin is the major bioactive component in turmeric with potent antioxidant activity. Little is known about how pulsed light (PL) technology (an emerging non-thermal food processing technology relying on high intensity short duration flashes of light) can affect the chemical stability and antioxidant capacity of curcumin. This study found that PL treatment of fluence levels from 0 to 12.75 J/cm2 produced a fluence-dependent reduction in curcumin content. These results paralleled the production of a tentative curcumin dimer, identified as a potential photochemical transformation product. PL-treated curcumin at relatively higher fluence levels decreased chemical-based ORAC and ABTS antioxidant capacity, relative to control (P < 0.05). This contrasted the effect observed to increase coincidently both intracellular antioxidant capacity (e.g., DCFH-DA (P < 0.05)) and GSH/GSSG ratio (P < 0.05), respectively, in cultured differentiated Caco-2 cells. In conclusion, the application of PL on curcumin results in photochemical transformation reactions, such as dimerization, which in turn, can enhance biological antioxidant capacity in differentiated Caco-2 cells.