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

Curcumin reverses the sunitinib resistance in clear cell renal cell carcinoma (ccRCC) through the induction of ferroptosis via the ADAMTS18 gene

Background

To explore the possible mechanism by which curcumin reverses the sunitinib resistance in clear cell renal cell carcinoma (ccRCC).

Methods

A sunitinib-resistant ccRCC cell model was established. The MTT assay was used to determine the half maximal inhibitory concentration (IC₅₀) and drug resistance (DR) index. The effects of curcumin plus sunitinib or sunitinib alone on drug-resistant cell lines were verified by the cell counting kit-8 (CCK-8)assay, colony formation assay, and apoptosis assay. The concentration of iron ions in the cell lines was analyzed using an Abcam Iron Assay Kit. The expressions of ADAMTS18 gene and ferroptosis-related proteins (NCOA4, FTH1 and p53) after curcumin plus sunitinib treatment were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. After transfection of curcumin plus sunitinib/sunitinib alone-treated drug-resistant cell lines with si-ADAMTS18, cell proliferation activity was assessed by the CCK-8 assay, and the protein expression levels of ADAMTS18, NCOA1, FTH1 and p53 were analyzed by Western blotting. After treatment with ferroptosis-1 (Fer-1; a ferroptosis inhibitor), the cell proliferation activity of drug-resistant cell lines treated with curcumin plus sunitinib/sunitinib alone was reassessed using the CCK-8 assay.

Results

Curcumin plus sunitinib inhibited the proliferation of sunitinib-resistant ccRCC cells (P<0.05). Curcumin significantly decreased the concentration of iron ions and increased the expression of ADAMTS18 gene, while significantly inhibited ferroptosis-related protein expression (P<0.05). After silencing the ADAMTS18 gene, there was no significant difference in cell proliferation or ferroptosis-related protein expression between curcumin plus sunitinib and sunitinib-treated drug-resistant cell lines (P>0.05). Ferroptosis inhibitors reversed the inhibitory effect of curcumin on sunitinib-resistant ccRCC cell lines.

Conclusions

Curcumin can reverse the sunitinib resistance in ccRCC, possibly by upregulating the expression of the ADAMTS18 gene to induce ferroptosis.

Curcumin encapsulation in functional PLGA nanoparticles: A promising strategy for cancer therapies

Nanoparticles have emerged as promising drug delivery systems for the treatment of several diseases. Novel cancer therapies have exploited these particles as alternative adjuvant therapies to overcome the traditional limitations of radio and chemotherapy. Curcumin is a natural bioactive compound found in turmeric, that has been reported to show anticancer activity against several types of tumors. Despite some biological limitations regarding its absorption in the human body, curcumin encapsulation in poly(lactic-co-glycolic acid) (PLGA), a non-toxic, biodegradable and biocompatible polymer, represents an effective strategy to deliver a drug to a tumor site. Furthermore, PLGA nanoparticles can be engineered with targeting moieties to reach specific cancer cells, thus enhancing the antitumor effects of curcumin. We herein aim to bring an up-to-date summary of the recently developed strategies for curcumin delivery to different types of cancer cells through encapsulation in PLGA nanoparticles, correlating their effects with those of curcumin on the biological capabilities acquired by cancer cells (cancer hallmarks). We discuss the targeting strategies proposed for advanced curcumin delivery and the respective improvements achieved for each cancer cell analyzed, in addition to exploring the encapsulation techniques employed. The conjugation of correct encapsulation techniques with tumor-oriented targeting design can result in curcumin-loaded PLGA nanoparticles that can successfully integrate the elaborate network of development of alternative cancer treatments along with traditional ones. Finally, the current challenges and future demands to launch these nanoparticles in oncology are comprehensively examined.

Progress in Colloid Delivery Systems for Protection and Delivery of Phenolic Bioactive Compounds: Two Study Cases-Hydroxytyrosol and Curcumin

Insufficient intake of beneficial food components into the human body is a major issue for many people. Among the strategies proposed to overcome this complication, colloid systems have been proven to offer successful solutions in many cases. The scientific community agrees that the production of colloid delivery systems is a good way to adequately protect and deliver nutritional components. In this review, we present the recent advances on bioactive phenolic compounds delivery mediated by colloid systems. As we are aware that this field is constantly evolving, we have focused our attention on the progress made in recent years in this specific field. To achieve this goal, structural and dynamic aspects of different colloid delivery systems, and the various interactions with two bioactive constituents, are presented and discussed. The choice of the appropriate delivery system for a given molecule depends on whether the drug is incorporated in an aqueous or hydrophobic environment. With this in mind, the aim of this evaluation was focused on two case studies, one representative of hydrophobic phenolic compounds and the other of hydrophilic ones. In particular, hydroxytyrosol was selected as a bioactive phenol with a hydrophilic character, while curcumin was selected as typical representative hydrophobic molecules.

Curcumin: Biological Activities and Modern Pharmaceutical Forms

Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione) is a natural lipophilic polyphenol that exhibits significant pharmacological effects in vitro and in vivo through various mechanisms of action. Numerous studies have identified and characterised the pharmacokinetic, pharmacodynamic, and clinical properties of curcumin. Curcumin has an anti-inflammatory, antioxidative, antinociceptive, antiparasitic, antimalarial effect, and it is used as a wound-healing agent. However, poor curcumin absorption in the small intestine, fast metabolism, and fast systemic elimination cause poor bioavailability of curcumin in human beings. In order to overcome these problems, a number of curcumin formulations have been developed. The aim of this paper is to provide an overview of recent research in biological and pharmaceutical aspects of curcumin, methods of sample preparation for its isolation (Soxhlet extraction, ultrasound extraction, pressurised fluid extraction, microwave extraction, enzyme-assisted aided extraction), analytical methods (FTIR, NIR, FT-Raman, UV-VIS, NMR, XRD, DSC, TLC, HPLC, HPTLC, LC-MS, UPLC/Q-TOF-MS) for identification and quantification of curcumin in different matrices, and different techniques for developing formulations. The optimal sample preparation and use of an appropriate analytical method will significantly improve the evaluation of formulations and the biological activity of curcumin.

Bulbus Fritillariae Cirrhosae as a Respiratory Medicine: Is There a Potential Drug in the Treatment of COVID-19?

Bulbus fritillariae cirrhosae (BFC) is one of the most used Chinese medicines for lung disease, and exerts antitussive, expectorant, anti-inflammatory, anti-asthmatic, and antioxidant effects, which is an ideal therapeutic drug for respiratory diseases such as ARDS, COPD, asthma, lung cancer, and pulmonary tuberculosis. Through this review, it is found that the therapeutic mechanism of BFC on respiratory diseases exhibits the characteristics of multi-components, multi-targets, and multi-signaling pathways. In particular, the therapeutic potential of BFC in terms of intervention of “cytokine storm”, STAT, NF-κB, and MAPK signaling pathways, as well as the renin-angiotensin system (RAS) that ACE is involved in. In the “cytokine storm” of SARS-CoV-2 infection there is an intense inflammatory response. ACE2 regulates the RAS by degradation of Ang II produced by ACE, which is associated with SARS-CoV-2. For COVID-19, may it be a potential drug? This review summarized the research progress of BFC in the respiratory diseases, discussed the development potentiality of BFC for the treatment of COVID-19, explained the chemical diversity and biological significance of the alkaloids in BFC, and clarified the material basis, molecular targets, and signaling pathways of BFC for the respiratory diseases. We hope this review can provide insights on the drug discovery of anti-COVID-19.

Curcumin, a potent therapeutic nutraceutical and its enhanced delivery and bioaccessibility by pickering emulsions

Curcumin is a biomolecule with functional moieties, which contribute to its anti-inflammatory, anticancer, and antioxidant properties. It has shown several therapeutic effects on treating inflammatory and neurodegenerative diseases and contributes to the reduction of oxidative stress and damage to body tissues. However, its low solubility and fast metabolism limit its absorption in the gastrointestinal (GI) tract and lead to its low bioavailability. Preparation of Pickering emulsions stabilized with mineral or biopolymer-based nanoparticles can be an effective strategy for enhancing the stability of curcumin against degradation, increasing its bioaccessibility in the GI tract, and achieving its controlled release at various locations based on changes in environmental conditions. Various nanoparticles prepared from minerals, proteins, and polysaccharides show potential for stabilizing the curcumin-loaded emulsions, and their wettability can be altered through complexation and formation of hybrid nanoparticles. Stabilization of Pickering emulsions with polysaccharide-based nanoparticles and their complexes can enhance the stability of the curcumin against degradation. Moreover, various protein-based nanoparticles and their conjugated forms with other proteins or polysaccharides can enable the preparation of high internal phase Pickering emulsions (HIPEs) with concomitant higher loading and bioaccessibility of the curcumin molecule. In light of the several therapeutic properties of curcumin, this review article aims to highlight recent studies and the strategies used for the preparation of curcumin Pickering emulsions stabilized by various nanoparticles for enhancing its bioaccessibility during metabolism. These may be useful in pharmaceutical and food industries for drug development and delivery and fortification of food products with this nutraceutical component.

Mechanism of enhancing the water-solubility and stability of curcumin by using self-assembled cod protein nanoparticles at an alkaline pH

Curcumin (Cur) is a bioactive phytochemical which is claimed to have several health-promoting benefits, whose applications are challenging due to its poor water-solubility, chemical instability, and low bioavailability. In this research, Cur was encapsulated in the cod protein (CP) using a pH-driven method to enhance its solubility and stability. The physicochemical and structural properties of cod protein-curcumin nanoparticles (CP-Cur) formed were characterized. Fluorescence spectroscopy (FL), ultraviolet spectroscopy (UV), circular dichroism (CD), and dynamic light scattering (DLS) results collectively suggest that the protein originally with a molten-globule state refolded into a more ordered structure after neutralization, during which Cur was incorporated. Fluorescence quenching and isothermal titration calorimetry (ITC) further showed that the CP/Cur binding was mainly driven by hydrophobic interactions, resulting in static fluorescence quenching and energy release. Up to 99.50% of Cur was loaded in the CP delivery system. Furthermore, the thermal stability and photostability of Cur were greatly improved due to the protection of the protein. The present study proved that cod protein could be a great potential edible carrier for encapsulating curcumin.

Safety of tetrahydrocurcuminoids from turmeric (Curcuma longa L.) as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on tetrahydrocurcuminoids from turmeric (Curcuma longa L.) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. Tetrahydrocurcuminoids are derivatives of curcuminoids, produced chemically by hydrogenation of curcuminoids extracted from the rhizomes of C. longa L. The NF consists of more than 95% of tetrahydrocurcuminoids. The applicant proposed to use the NF in food supplements at a maximum dose of 300 mg/day for adults excluding pregnant and lactating women. Taking into account the composition of the NF and the proposed conditions of use, consumption of the NF is not nutritionally disadvantageous. There are no concerns regarding genotoxicity of the NF. Based on a 90-day oral toxicity study and a reproduction/developmental toxicity screening test performed with the NF, the Panel derives a safe level of 2 mg/kg body weight per day. For the target population this level corresponds to 140 mg/day, which is lower than the use level as proposed by the applicant. The Panel concludes that the NF, tetrahydrocurcuminoids from turmeric (C. longa L.), is safe for the target population at 140 mg/day.

Curcumin protection against ultraviolet-induced photo-damage in Hacat cells by regulating nuclear factor erythroid 2-related factor 2

Curcumin suppressed ultraviolet (UV) induced skin carcinogenesis and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. However, whether curcumin protects skin injury caused by UV is still unknown. A vitro model was established and curcumin effects on Hacat cells were detected. Nrf2 was knocked down in Hacat cells to verify the Nrf2 role in the protective effect of curcumin. Results indicated that ultraviolet A (UVA) (or ultraviolet B (UVB)) irradiation would lead to decreased cell proliferation, increased cell apoptosis, decreased catalase, heme oxygenase 1, and superoxide dismutase expression, and increased levels of protein carbonylation and malondialdehyde (p < 0.05). These adverse events could be reversed by adding 5-μM curcumin. Meanwhile, we found that the application of curcumin effectively induced Nrf2 nuclear accumulation in Hacat cells. While in the Nrf2 knockdown cells, the protective effects of curcumin against UVA (or UVB) were attenuated. Conclusively, curcumin protects Hacat cells against UV exposure-induced photo-damage by regulating Nrf2 expression.

CD123-Targeted Nano-Curcumin Molecule Enhances Cytotoxic Efficacy in Leukemic Stem Cells

Acute myeloblastic leukemia (AML) is a disease with a high rate of relapse and drug resistance due to the remaining leukemic stem cells (LSCs). Therefore, LSCs are specific targets for the treatment of leukemia. CD123 is specifically expressed on LSCs and performs as a specific marker. Curcumin is the main active compound of a natural product with low toxicity for humans. It has been reported to inhibit leukemic cell growth. However, curcumin is practically insoluble in water and has low bioavailability. In this study, we aimed to formulate curcumin nanoparticles and conjugate with the anti-CD123 to overcome the low water solubility and improve the targeting of LSCs. The cytotoxicity of both curcumin-loaded PLGA/poloxamer nanoparticles (Cur-NPs) and anti-CD123-curcumin-loaded PLGA/poloxamer nanoparticles (anti-CD123-Cur-NPs) were examined in KG-1a cells. The results showed that Cur-NPs and Cur-NPs-CD123 exhibited cytotoxic effects on KG-1a cells with the IC₅₀ values of 74.20 ± 6.71 and 41.45 ± 5.49 µM, respectively. Moreover, anti-CD123-Cur-NPs induced higher apoptosis than Cur-NPs. The higher uptake of anti-CD123-Cur-NPs in KG-1a cells was confirmed by using flow cytometry. In conclusion, the anti-CD123-Cur-NPs formulation improved curcumin's bioavailability and specific targeting of LSCs, suggesting that it is a promising drug delivery system for improving the therapeutic efficacy against AML.

Curc-mPEG454, a PEGylated curcumin derivative, as a multi-target anti-fibrotic prodrug

Our previous studies demonstrated that Curc-mPEG454, a curcumin derivative modified with short-chain polyethylene glycol (PEG), not only increased the blood concentration of curcumin, but also retained its anti-inflammatory activity. Here, we aimed to evaluate the anti-fibrotic effect of Curc-mPEG454 on a rat liver fibrosis model induced by carbon tetrachloride (CCl₄), and to explore the underlying mechanisms by integrating our total liver RNA sequencing (RNA-seq) data with recent liver single-cell sequencing (scRNA-seq) studies. 50 mg/kg and 100 mg/kg Curc-mPEG454 treatment significantly reduced the elevation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) induced by CCl₄, and the incidence of liver cirrhosis decreased from 75% to 37% and 35%, respectively. RNA-seq analysis revealed that Curc-mPEG454 significantly upregulated aldehyde oxidase 1 (AOX1) while downregulated cytochrome p450 26A1 (CYP26A1) and cytochrome p450 26B1 (CYP26B1) resulting in restoring liver retinoic acid (RA) level, increased glutamate-cysteine ligase catalytic subunit (GCLC) and glutamate-cysteine ligase modifier subunit (GCLM) expression to synthesize hepatic glutathione (GSH), and inhibited liver inflammation via down-regulating the Prostaglandin E Synthase 2 (PTGES2)/prostacyclin E2 (PGE2) signaling. Integrating scRNA-seq data revealed that Curc-mPEG454 effectively inhibited the expansion of scar-associated macrophage subpopulation and scar-producing myofibroblasts in the damaged liver, and remodeled the fibrotic niche via regulation of ligand-receptor interactions including platelet-derived growth factor-B (PDGF-B)/platelet-derived growth factor receptor-α (PDGFR-α) signaling. As a multi-target prodrug, PEGylated curcumin deserves further attention and research.

Corn starch/polyvinyl alcohol based films incorporated with curcumin-loaded Pickering emulsion for application in intelligent packaging

The intelligent pH indicator films were prepared by incorporating curcumin-loaded Pickering emulsion with corn starch (CS) and polyvinyl alcohol (PVA) matrix. The mechanical properties, barrier properties and functional characteristics of the films were studied and the films were applied to monitor fish freshness. Fourier transform infrared (FTIR) spectroscopy and Scanning electron microscopy (SEM) showed that Pickering emulsion can form hydrogen bonds with CS and PVA. The antioxidant activity of the films was detected, which showed that Pickering emulsion could reduce the decomposition of curcumin during the process of preparation and storage. Bactericidal tests showed that the films can inhibit the growth of S. aureus, B. subtilis, and E. coli, and the effect of the films on Gram-positive (G⁺) bacteria is stronger than Gram-negative (G^-) bacteria. Application of the films presented here is supported by an activation test of Pangasius bocouti. With time changed, the color of films changed from yellow to red, and the color change of films prepared with curcumin-loaded Pickering emulsion was more evident than the films prepared with curcumin solution. Therefore, the films prepared with curcumin-loaded Pickering emulsion had better performance and can be used to indicate the quality of food.

Therapeutic Potential of Curcumin as an Antimycobacterial Agent

Curcumin is the principal curcuminoid obtained from the plant Curcuma longa and has been extensively studied for its biological and chemical properties. Curcumin displays a vast range of pharmacological properties, including antimicrobial, anti-inflammatory, antioxidant, and antitumor activity. Specifically, curcumin has been linked to the improvement of the outcome of tuberculosis. There are many reviews on the pharmacological effects of curcumin; however, reviews of the antitubercular activity are comparatively scarcer. In this review, we attempt to discuss the different aspects of the research on the antitubercular activity of curcumin. These include antimycobacterial activity, modulation of the host immune response, and enhancement of BCG vaccine efficacy. Recent advances in the antimycobacterial activity of curcumin synthetic derivatives, the role of computer aided drug design in identifying curcumin targets, the hepatoprotective role of curcumin, and the dosage and toxicology of curcumin will be discussed. While growing evidence supports the use of curcumin and its derivatives for tuberculosis therapy, further preclinical and clinical investigations are of pivotal importance before recommending the use of curcumin formulations in public health.

The Role of Curcumin in Cancer Treatment

Curcumin is a polyphenol extracted from the rhizomes of the turmeric plant, Curcuma longa which has anti-inflammatory, and anticancer properties. Chronic inflammation is associated with the development of cancer. Curcumin acts on the regulation of various immune modulators, including cytokines, cyclooxygenase-2 (COX-2), and reactive oxygen species (ROS), which partly explains its anticancer effects. It also takes part in the downregulation of growth factors, protein kinases, oncogenic molecules and various signaling pathways, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), c-Jun N-terminal kinase (JNK) and signal transducer and activator of transcription 3 (STAT3) signaling. Clinical trials of curcumin have been completed or are ongoing for various types of cancer. This review presents the molecular mechanisms of curcumin in different types of cancer and the evidence from the most recent clinical trials.

Inflammasomes and Colorectal Cancer

Inflammasomes are important intracellular multiprotein signaling complexes that modulate the activation of caspase-1 and induce levels of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18 in response to pathogenic microorganisms and molecules that originated from host proteins. Inflammasomes play contradictory roles in the development of inflammation-induced cancers. Based on several findings, inflammasomes can initiate and promote carcinogenesis. On the contrary, inflammasomes also exhibit anticancer effects by triggering pyroptosis and immunoregulatory functions. Herein, we review extant studies delving into different functions of inflammasomes in colorectal cancer development.

Mechanistic Insight into the Effects of Curcumin on Neuroinflammation-Driven Chronic Pain

Chronic pain is a persistent and unremitting condition that has immense effects on patients' quality of life. Studies have shown that neuroinflammation is associated with the induction and progression of chronic pain. The activation of microglia and astrocytes is the major hallmark of spinal neuroinflammation leading to neuronal excitability in the projection neurons. Excessive activation of microglia and astrocytes is one of the major contributing factors to the exacerbation of pain. However, the current chronic pain treatments, mainly by targeting the neuronal cells, remain ineffective and unable to meet the patients' needs. Curcumin, a natural plant product found in the Curcuma genus, improves chronic pain by diminishing the release of inflammatory mediators from the spinal glia. This review details the role of curcumin in microglia and astrocytes both in vitro and in vivo and how it improves pain. We also describe the mechanism of curcumin by highlighting the major glia-mediated cascades in pain. Moreover, the role of curcumin on inflammasome and epigenetic regulation is discussed. Furthermore, we discuss the strategies used to improve the efficacy of curcumin. This review illustrates that curcumin modulating microglia and astrocytes could assure the treatment of chronic pain by suppressing spinal neuroinflammation.

Pulmonary Delivery of Anticancer Drugs via Lipid-Based Nanocarriers for the Treatment of Lung Cancer: An Update

Lung cancer (LC) is the leading cause of cancer-related deaths, responsible for approximately 18.4% of all cancer mortalities in both sexes combined. The use of systemic therapeutics remains one of the primary treatments for LC. However, the therapeutic efficacy of these agents is limited due to their associated severe adverse effects, systemic toxicity and poor selectivity. In contrast, pulmonary delivery of anticancer drugs can provide many advantages over conventional routes. The inhalation route allows the direct delivery of chemotherapeutic agents to the target LC cells with high local concertation that may enhance the antitumor activity and lead to lower dosing and fewer systemic toxicities. Nevertheless, this route faces by many physiological barriers and technological challenges that may significantly affect the lung deposition, retention, and efficacy of anticancer drugs. The use of lipid-based nanocarriers could potentially overcome these problems owing to their unique characteristics, such as the ability to entrap drugs with various physicochemical properties, and their enhanced permeability and retention (EPR) effect for passive targeting. Besides, they can be functionalized with different targeting moieties for active targeting. This article highlights the physiological, physicochemical, and technological considerations for efficient inhalable anticancer delivery using lipid-based nanocarriers and their cutting-edge role in LC treatment.

The impact of curcumin derived polyphenols on the structure and flexibility COVID-19 main protease binding pocket: a molecular dynamics simulation study

The newly occurred SARS-CoV-2 caused a leading pandemic of coronavirus disease (COVID-19). Up to now it has infected more than one hundred sixty million and killed more than three million people according to 14 May 2021 World Health Organization report. So far, different types of studies have been conducted to develop an anti-viral drug for COVID-19 with no success yet. As part of this, silico were studied to discover and introduce COVID-19 antiviral drugs and results showed that protease inhibitors could be very effective in controlling. This study aims to investigate the binding affinity of three curcumin derived polyphenols against COVID-19 the main protease (Mpro), binding pocket, and identification of important residues for interaction. In this study, molecular modeling, auto-dock coupled with molecular dynamics simulations were performed to analyze the conformational, and stability of COVID-19 binding pocket with diferuloylmethane, demethoxycurcumin, and bisdemethoxycurcumin. All three compounds have shown binding affinity −39, −89 and −169.7, respectively. Demethoxycurcumin and bisdemethoxycurcumin showed an optimum binding affinity with target molecule and these could be one of potential ligands for COVID-19 therapy. And also, COVID-19 main protease binding pocket binds with the interface region by one hydrogen bond. Moreover, the MD simulation parameters indicated that demethoxycurcumin and bisdemethoxycurcumin were stable during the simulation run. These findings can be used as a baseline to develop therapeutics with curcumin derived polyphenols against COVID-19.

A Promising Anticancer Agent Dimethoxycurcumin: Aspects of Pharmacokinetics, Efficacy, Mechanism, and Nanoformulation for Drug Delivery

Curcumin is a well-known anticancer natural product with various significant bioactivities that has been well documented, but its widespread use is mainly hindered by insufficient ADME properties such as poor solubility and low metabolic stability. Dimethoxycurcumin (DiMC) is a kind of lipophilic compound derived from curcumin that maintains its anticancer potency and has greatly improved systematic bioavailability. Therefore, DiMC is regarded as a promising plant-derived anticancer agent that deserves to be well developed. Herein, we concentrate on the published work by those from original research groups concerned with the pharmacokinetics, efficacy, and mechanism of DiMC involved in the treatment of various tumors, as well as the nanoformulations for effective drug delivery.

“Nanomaterials of curcumin-hyaluronic acid”: their various methods of formulations, clinical and therapeutic applications, present gap, and future directions

Background

Nanomaterials of curcumin with hyaluronic acid have gained a lot of attention for potential therapeutic applications of curcumin and hyaluronic acid with or without other additional drugs. Overall studies of curcumin and hyaluronic acid show that nanomaterials of curcumin with hyaluronic acid accelerate the efficacy of curcumin in the treatment of various disorders like arthritis, cancer, hepatic fibrosis, neural disorders, wound healing, and skin regeneration, it is largely due to the combined effect of hyaluronic acid and curcumin. However, due to limited clinical trials and experiments on humans and animals, there is a substantial gap in research for the safety and efficacy of nanomaterials of curcumin-hyaluronic acid in the treatment of curcumin and hyaluronic acid targeted diseases and disorders.

Main body of the abstract

In this current review, we have first described various reported synthetic nanomaterials of curcumin-hyaluronic acid, then in the next section, we have described various fields, disorders, and diseases where these are being applied and in the final section of this review, we discussed the research gap, and future research directions needed to propose the fabricated nanocurcumin-hyaluronic acid biomaterials.

Short conclusion

There are substantial gaps in research for the safety and efficacy of nanomaterials of curcumin with hyaluronic acid due to limited available data of clinical trials and experiments of nanocurcumin-hyaluronic acid biomaterials on humans and animals. So, it entirely requires serious and committed efforts through the well-organized system of practical and clinical trials which provide results, data, and detections that lead to the formulation of the best drug from curcumin with hyaluronic acid for the treatment of curcumin and hyaluronic acid targeted diseases and disorders.

Nebulized curcumin protects neonatal lungs from antenatal insult in rats

Intrauterine growth restriction (IUGR) increases the risk of bronchopulmonary dysplasia (BPD), one of the major complications of prematurity. Antenatal low-protein diet (LPD) exposure in rats induces IUGR and mimics BPD-related alveolarization disorders. Peroxisome proliferator-activated receptor-γ (PPARγ) plays a key role in normal lung development and was found deregulated following LPD exposure. The objective of this article was to investigate the effects of nebulized curcumin, a natural PPARγ agonist, to prevent IUGR-related abnormal lung development. We studied rat pups antenatally exposed to an LPD or control diet (CTL) and treated with nebulized curcumin (50 mg/kg) or vehicle from postnatal (P) days 1 to 5. The primary readouts were lung morphometric analyses at P21. Immunohistochemistry (P21) and microarrays (P6 and P11) were compared within animals exposed to LPD versus controls, with and without curcumin treatment. Quantitative morphometric analyses revealed that LPD induced abnormal alveolarization as evidenced by a significant increase in mean linear intercept (MLI) observed in P21 LPD-exposed animals. Early curcumin treatment prevented this effect, and two-way ANOVA analysis demonstrated significant interaction between diet and curcumin both for MLI [F_(1,39) = 12.67, P = 0.001] and radial alveolar count at P21 [F_(1,40) = 6.065, P = 0.0182]. Immunohistochemistry for fatty acid binding protein 4 (FABP4), a major regulator of PPARγ pathway, showed a decreased FABP4⁺ alveolar cell density in LPD-exposed animals treated by curcumin. Transcriptomic analysis showed that early curcumin significantly prevented the activation of profibrotic pathways observed at P11 in LPD-exposed animals. Nebulized curcumin appears to be a promising strategy to prevent alveolarization disorders in IUGR rat pups, targeting pathways involved in lung development.

Carboxymethyl konjac glucomannan coating on multilayered emulsions for improved bioavailability and targeted delivery of curcumin

Curcumin was entrapped in multilayered emulsions to increase its stability and bioavailability. Curcumin emulsion stabilized by whey protein isolate (WPI) was coated with chitosan (CHI) or carboxymethyl konjac glucomannan (CMKGM) alone to form secondary emulsions and their combination in sequence to form the tertiary emulsion, in which, the polyelectrolyte concentrations were 1.0% WPI for the primary emulsion, 0.4% CMKGM for the secondary emulsion -CMKGM, 0.2% CHI for the secondary emulsion -CHI, and 0.1% CMKGM for the tertiary emulsion. The characteristics of the emulsions, including their particle size, ζ potential, microstructure, creaming stability, and biopolymer distribution, were investigated and their colon-targeted delivery potential was evaluated through both in vitro and in vivo studies as well. The curcumin-loaded secondary and tertiary emulsions were stable with a narrow size distribution and were generated by layer-by-layer assembly according to confocal laser scanning microscope observation. When CMKGM was located at the outermost layer, the corresponding secondary and tertiary emulsions showed a greatly reduced release of curcumin in the simulated gastric fluid, but exhibited increased release in the β-mannanase-containing simulated colonic fluid. In vivo evaluation in mice demonstrated that the bioavailability of curcumin in the CMKGM-coated secondary and tertiary emulsions was increased by about 4 folds compared with that of free curcumin and curcumin could be released in a sustainable manner. These results demonstrated that multilayered emulsions coated with CMKGM could promote curcumin absorption in the gastrointestinal tract and hence is a promising colon-targeted delivery system for curcumin.

Safety assessment of a highly bioavailable curcumin-galactomannoside complex (CurQfen) in healthy volunteers, with a special reference to the recent hepatotoxic reports of curcumin supplements: A 90-days prospective study

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CGM did not cause adverse effects or significant variations in clinical parameters.

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Liver and renal function markers were in normal range after CGM supplementation.

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CGM was proved to be devoid of adjuvants, synthetic curcumin and contaminants.

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CGM has 100 % natural clean label status comprising vegan, allergen-free ingredients.

Recently, there is a growing concern about the use of curcumin supplements owing to a few reported hepatotoxicity related adverse events among some of the long-term consumers. Even though no clear evidence was elucidated for the suspected toxicity, the addition of adjuvants that inhibits body’s essential detoxification pathways, adulteration with synthetic curcumin, and presence of contaminants including heavy metals, chromate, illegal dyes, non-steroidal anti-inflammatory agents, and pyrrole alkaloids were suggested as plausible reasons. Considering these incidences and speculations, there is a need to critically evaluate the safety of curcumin supplements for prolonged intake. The present study is an evaluation of the safety of curcumin-galactomannoside complex (CGM), a highly bioavailable curcumin formulation with demonstrated high free curcuminoids delivery. Twenty healthy human volunteers were evaluated for toxic manifestations of CGM when supplemented with 1000 mg per day (∼380 mg curcuminoids) for 90-days. CGM supplementation did not cause any adverse effects or clinically significant variations in the vital signs, hematological parameters, lipid profile and renal function markers of the volunteers, indicating its safety. Liver function enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT) and bilirubin were in the normal range after 90-day supplementation of CGM. In summary, no adverse effects were observed under the conditions of the study. CGM can be considered as a safe curcumin supplement for regular consumption and is devoid of any adulterants or contaminants.

The Novel Curcumin Derivative 1g Induces Mitochondrial and ER-Stress-Dependent Apoptosis in Colon Cancer Cells by Induction of ROS Production

Reactive oxygen species (ROS) play an important role in cellular metabolism. Many chemotherapeutic drugs are known to promote apoptosis through the production of ROS. In the present study, the novel curcumin derivative, 1g, was found to inhibit tumor growth in colon cancer cells both in vitro and in vivo. Bioinformatics was used to analyze the differentially expressed mRNAs. The mechanism of this effect was a change in mitochondrial membrane potential caused by 1g that increased its pro-apoptotic activity. In addition, 1g produced ROS, induced G1 checkpoint blockade, and enhanced endoplasmic reticulum (ER)-stress in colon cancer cells. Conversely, pretreatment with the ROS scavenging agent N-acetyl-l-cysteine (NAC) inhibited the mitochondrial dysfunction caused by 1g and reversed ER-stress, cell cycle stagnation, and apoptosis. Additionally, pretreatment with the p-PERK inhibitor GSK2606414 significantly reduced ER-stress and reversed the apoptosis induced by colon cancer cells. In summary, the production of ROS plays an important role in the destruction of colon cancer cells by 1g and demonstrates that targeted strategies based on ROS represent a promising approach to inhibit colon cancer proliferation. These findings reveal that the novel curcumin derivative 1g represents a potential candidate therapeutics for the treatment of colon cancer cells, via apoptosis caused by mitochondrial dysfunction and endoplasmic reticulum stress.

Calcium-Based Metal-Organic Frameworks and Their Potential Applications

Metal-organic frameworks (MOFs) built on calcium metal (Ca-MOFs) represent a unique subclass of MOFs featuring high stability, low toxicity, and relatively low density. Ca-MOFs show considerable potential for molecular separations, electronic, magnetic, and biomedical applications, although they are not investigated as extensively as transition metal-based MOFs. Compared to MOFs made of other groups of metals, Ca-MOFs may be particularly advantageous for certain applications such as adsorption and storage of light molecules because of their gravimetric benefit, and drug delivery due to their high biocompatibility. This review intends to provide an overview on the recent development of Ca-MOFs, including their synthesis, crystal structures, important properties, and related applications. Various synthetic methods and techniques, types of building blocks, structure and porosity features, selected physical properties, and potential uses will be discussed and summarized. Representative examples will be illustrated for each type of important applications with a focus on their structure-property relations.

Photoactive Thin-Film Structures of Curcumin, TiO2 and ZnO

Curcumin is known as a biologically active compound and a possible antimicrobial agent. Here, we combine it with TiO2 and ZnO semiconductors, known for their photocatalytic properties, with an eye towards synergistic photo-harvesting and/or antimicrobial effects. We deposit different nanoscale multi-layer structures of curcumin, TiO2 and ZnO, by combining the solution-based spin-coating (S-C) technique and the gas-phase atomic layer deposition (ALD) and molecular layer deposition (MLD) thin-film techniques. As one of the highlights, we demonstrate for these multi-layer structures a red-shift in the absorbance maximum and an expansion of the absorbance edge as far as the longest visible wavelength region, which activates them for the visible light harvesting. The novel fabrication approaches introduced here should be compatible with, e.g., textile substrates, opening up new horizons for novel applications such as new types of protective masks with thin conformal antimicrobial coatings.

An Overview on Dietary Polyphenols and Their Biopharmaceutical Classification System (BCS)

Polyphenols are natural organic compounds produced by plants, acting as antioxidants by reacting with ROS. These compounds are widely consumed in daily diet and many studies report several benefits to human health thanks to their bioavailability in humans. However, the digestion process of phenolic compounds is still not completely clear. Moreover, bioavailability is dependent on the metabolic phase of these compounds. The LogP value can be managed as a simplified measure of the lipophilicity of a substance ingested within the human body, which affects resultant absorption. The biopharmaceutical classification system (BCS), a method used to classify drugs intended for gastrointestinal absorption, correlates the solubility and permeability of the drug with both the rate and extent of oral absorption. BCS may be helpful to measure the bioactive constituents of foods, such as polyphenols, in order to understand their nutraceutical potential. There are many literature studies that focus on permeability, absorption, and bioavailability of polyphenols and their resultant metabolic byproducts, but there is still confusion about their respective LogP values and BCS classification. This review will provide an overview of the information regarding 10 dietarypolyphenols (ferulic acid, chlorogenic acid, rutin, quercetin, apigenin, cirsimaritin, daidzein, resveratrol, ellagic acid, and curcumin) and their association with the BCS classification.

Injectable supramolecular hydrogels based on custom-made poly(ether urethane)s and α-cyclodextrins as efficient delivery vehicles of curcumin

A strategy to enhance drug effectiveness while minimizing controversial effects consists in exploiting host-guest interactions. Moreover, these phenomena can induce the self-assembly of physical hydrogels as effective tools to treat various pathologies (e.g., chronic wounds or cancer). Here, two Poloxamers®/Pluronics® (P407/F127 and P188/F68) were utilized to synthesize various LEGO-like poly(ether urethane)s (PEUs) to develop a library of tunable and injectable supramolecular hydrogels for drug delivery. Three PEUs were synthesized by chain extending Poloxamer/Pluronic with 1,6-cyclohexanedimethanol or N-Boc serinol. Other two amino-functionalized and highly responsive polymers were obtained thorough Boc-group cleavage. For hydrogel design, the spontaneous self-assembly of the poly(ethylene oxide) domains of PEUs with α-cyclodextrins was exploited to form poly(pseudo)rotaxanes (PPRs). PPR-derived channel-like crystals were characterized by X-Ray powder diffraction, Infra-Red and Proton Nuclear Magnetic Resonance spectroscopies. Cytocompatible hydrogel formulations were designed at PEU concentrations between 1% and 5% w/v and α-cyclodextrin at 10% w/v. Supramolecular gels showed good mechanical performances (storage modulus up to 20 kPa) coupled with marked thixotropic and self-healing properties (mechanical recovery over 80% within 30 s after cyclic rupture) as assessed through rheology. Hydrogels exhibited stability and high responsiveness in watery environment up to 5 days: the release of less stable components as suitable drug carriers was coupled with high swelling (doubling the content of fluids with respect to their dry mass) and shape retention. Curcumin was encapsulated into the hydrogels at high concentration (80 μg ml^-1) through its complexation with α-cyclodextrins and delivery tests showed controllable and progressive release profiles up to four days.

Long non-coding RNAs in nasopharyngeal carcinoma: biological functions and clinical applications

Nasopharyngeal carcinoma (NPC) is one of the most common head and neck malignancies. It has obvious ethnic and regional specificity. Long non-coding RNAs (LncRNAs) are a class of non-protein coding RNA molecules. Emerging research shows that lncRNAs play a key role in tumor development, prognosis, and treatment. With the deepening of sequence analysis, a large number of functional LncRNAs have been found in NPC, which interact with coding genes, miRNAs, and proteins to form a complex regulatory network. However, the specific role and mechanism of abnormally expressed lncRNAs in the pathogenesis of NPC is not fully understood. This article briefly introduced the concept, classification, and functional mechanism of lncRNAs and reviewed their biological functions and their clinical applications in NPC. Specifically, we described lncRNAs related to the occurrence, growth, invasion, metastasis, angiogenesis, and cancer stem cells of NPC; discussed lncRNAs related to Epstein-Barr virus infection; and summarized the role of lncRNAs in NPC treatment resistance. We have also sorted out lncRNAs related to Chinese medicine treatment. We believe that with the deepening of lncRNAs research, tumor-specific lncRNAs may become a new target for the treatment and a biomarker for predicting prognosis.

Disposition of Dietary Polyphenols in Breast Cancer Patients' Tumors, and Their Associated Anticancer Activity: The Particular Case of Curcumin

SCOPE

Some polyphenol-derived metabolites reach human breast cancer (BC) tissues at concentrations that induce cell senescence. However, this is unknown for isoflavones, curcuminoids, and lignans. Here, their metabolic profiling in normal (NT) and malignant (MT) mammary tissues of newly-diagnosed BC patients and the tissue-occurring metabolites' anticancer activity are evaluated.

METHODS AND RESULTS

Patients (n = 26) consumed 3 capsules/day (turmeric, red clover, and flaxseed extracts plus resveratrol; 296.4 mg phenolics/capsule) from biopsy-confirmed diagnosis to surgery (5 ± 2 days) or did not consume capsules (n = 13). NT and MT, blood, and urine are analyzed by UPLC-QTOF-MS using targeted metabolomics. Anticancer activity was tested in MCF-7 and MDA-MB-231 BC cells. Mainly phase-II metabolites were detected (108, 84, 49, and 47 in urine, plasma, NT, and MT, respectively). Total metabolite concentrations reached 10.7 ± 11.1 and 2.5 ± 2.4 µmol L^-1 in NT and MT, respectively. Free curcumin, but not its glucuronide, was detected in the tissues (1.1 ± 1.8 and 0.2 ± 0.2 µmol L^-1 in NT and MT, respectively). Breast tissue-occurring metabolites' antiproliferation was mainly exerted in p53-wild-type MCF-7 cells by curcuminoids through cell cycle arrest, senescence, and apoptosis induction via p53/p21 induction, while isoflavone-derived metabolites exerted estrogenic-like activity.

CONCLUSION

Curcuminoids could be coadjuvants that might help fight BC upon regular consumption.

Experimental and clinical reports on anti-inflammatory, antioxidant, and immunomodulatory effects of Curcuma longa and curcumin, an updated and comprehensive review

Curcuma longa (C. longa) or turmeric is a plant with a long history of use in traditional medicine, especially for treating inflammatory conditions C. longa and its main constituent, curcumin (CUR), showed various pharmacological effects such as antioxidant and anti-microbial properties. The updated knowledge of anti-inflammatory, antioxidant, and immunomodulatory effects of C. longa and CUR is provided in this review article. Pharmacological effects of C. longa, and CUR, including anti-inflammatory, antioxidant, and immunomodulatory properties, were searched using various databases and appropriate keywords until September 2020. Various studies showed anti-inflammatory effects of C. longa and CUR, including decreased white blood cell, neutrophil, and eosinophil numbers, and its protective effects on serum levels of inflammatory mediators such as phospholipase A2 and total protein in different inflammatory disorders. The antioxidant effects of C. longa and CUR were also reported in several studies. The plant extracts and CUR decreased malondialdehyde and nitric oxide levels but increased thiol, superoxide dismutase, and catalase levels in oxidative stress conditions. Treatment with C. longa and CUR also improved immunoglobulin E (Ig)E, pro-inflammatory cytokine interleukin 4 (IL)-4, transforming growth factor-beta, IL-17, interferon-gamma levels, and type 1/type 2 helper cells (Th1)/(Th2) ratio in conditions with disturbance in the immune system. Therefore C. longa and CUR showed anti-inflammatory, antioxidant, and immunomodulatory effects, indicating a potential therapeutic effect of the plant and its constituent, CUR, for treating of inflammatory, oxidative, and immune dysregulation disorders.

Effects of Curcumin and Its Different Formulations in Preclinical and Clinical Studies of Peripheral Neuropathic and Postoperative Pain: A Comprehensive Review

Lesion or disease of the somatosensory system leads to the development of neuropathic pain. Peripheral neuropathic pain encompasses damage or injury of the peripheral nervous system. On the other hand, 10–15% of individuals suffer from acute postoperative pain followed by persistent pain after undergoing surgeries. Antidepressants, anticonvulsants, baclofen, and clonidine are used to treat peripheral neuropathy, whereas opioids are used to treat postoperative pain. The negative effects associated with these drugs emphasize the search for alternative therapeutics with better efficacy and fewer side effects. Curcumin, a polyphenol isolated from the roots of Curcuma longa, possesses antibacterial, antioxidant, and anti-inflammatory properties. Furthermore, the low bioavailability and fast metabolism of curcumin have led to the advent of various curcumin formulations. The present review provides a comprehensive analysis on the effects of curcumin and its formulations in preclinical and clinical studies of neuropathic and postoperative pain. Based on the positive outcomes from both preclinical and clinical studies, curcumin holds the promise of mitigating or preventing neuropathic and postoperative pain conditions. However, more clinical studies with improved curcumin formulations are required to involve its use as adjuvant to neuropathic and postoperative drugs.

Targeting Cancer using Curcumin Encapsulated Vesicular Drug Delivery Systems

Curcumin is a major curcuminoid present in turmeric. The compound is attributed to various therapeutic properties, which include anti-oxidant, anti-inflammatory, anti-bacterial, anti-malarial, and neuroprotection. Due to its therapeutic potential, curcumin has been employed for centuries in treating different ailments. Curcumin has been investigated lately as a novel therapeutic agent in the treatment of cancer. However, the mechanisms by which curcumin exerts its cytotoxic effects on malignant cells are still not fully understood. One of the main limiting factors in the clinical use of curcumin is its poor bioavailability and rapid elimination. Advancements in drug delivery systems such as nanoparticle-based vesicular drug delivery platforms have improved several parameters, namely, drug bioavailability, solubility, stability, and controlled release properties. The use of curcumin-encapsulated niosomes to improve the physical and pharmacokinetic properties of curcumin is one such approach. This review provides an up-to-date summary of nanoparticle-based vesicular drug carriers and their therapeutic applications. Specifically, we focus on niosomes as novel drug delivery formulations and their potential in improving the delivery of challenging small molecules, including curcumin. Overall, the applications of such carriers will provide a new direction for novel pharmaceutical drug delivery, as well as for biotechnology, nutraceutical, and functional food industries.

Application of starch nanoparticles as host materials for encapsulation of curcumin: Effect of citric acid modification

To encapsulate curcumin, absolute ethanolic curcumin solution with various content (300-1200 μg) was added to aqueous dispersion of citric acid-modified starch nanoparticles (M.SNPs) with various contents (0.5-2.5%), and then ethanol of the mixture was evaporated by nitrogen gas purge for 40 min (ethanol content decreased to 1%). SNPs (100 mg) could encapsulate 75.7 μg of curcumin in matrices of the composite, while 100 mg of M.SNPs could encapsulate 144.9 μg of curcumin. The XRD results revealed that curcumin was amorphously encapsulated in the composite, and hydrogen bond formation between M.SNPs and curcumin was one of the major driving forces for encapsulation as suggested by FT-IR. The composites had a spherical shape and mean particle size of the composites was increased from 136.3 to 255.3 nm with higher curcumin content in the matrices of composites. UV, pH, and thermal stability of curcumin significantly enhanced by the encapsulation, which was further increased when using M.SNPs and/or higher content of host materials. For the release of curcumin in simulated intestinal fluid digestion, release mechanism explained by Korsmeyer-Peppas model. For M.SNPs, k value was decreased from 13.097 to 2.938 as addition level of host material increased from 0.5 to 2.5%.

Brain regional pharmacokinetics following the oral administration of curcumagalactomannosides and its relation to cognitive function

OBJECTIVE

Though a number of bioavailable formulations of curcuminoids have been reported and available commercially as nutraceuticals for brain health, systematic informations on their blood-brain-barrier permeability and brain tissue distribution have not been reported. The present study was aimed to investigate the brain regional pharmacokinetics of curcuminoids following both single dose and repeated dose oral administration of a self-emulsifying food-grade formulation of curcuminoids using fenugreek galactomannan hydrogel scaffold as 'curcumagalactomannosides' (CGM), and its influence on cognitive functions in comparison with unformulated natural curcuminoids (NC) in Wistar rats.

METHODS

CGM was given to animals in single dose (100 mg curcuminoids/kg b. wt.) and repeated dose (100 mg curcuminoids/kg b. wt. for 28 days) and the concentration of total curcuminoids at various parts of brain was evaluated at different time points using Ultra-performance liquid chromatography/electrospray ionization triple quadruple tandem mass spectroscopy (UPLC-ESI-MS/MS) system. Another set of animals were also fed with CGM at single dose (100 mg curcuminoids/kg b. wt.) and repeated dose (100 mg curcuminoids/kg b. wt. for 28 days) and the behavioural studies were conducted using open field test and radial arm maze.

RESULTS

UPLC-ESI-MS/MS analyses of plasma revealed significant absorption of unconjugated (free) curcuminoids upon both single and repeated dose administration of CGM with maximum concentrations of 173.34 ± 27.12 ng/mL and 223.22 ± 32.73 ng/mL, respectively. Further analysis of brain tissues demonstrated significant blood-brain-barrier permeability. Brain regional pharmacokinetics (AUC, C_max and t_1/2) indicated a relative distribution order of hippocampus > striatum > cerebellum > cerebral cortex > brain stem. Supplementation of CGM for 28 days also offered significant (p  <  0.05) improvement in locomotor activity and reduction in spatial memory errors as compared to NC. The NC treatment also improved the behaviour better than the vehicle-treated group.

CONCLUSION

CGM could distribute significant amount of free curcuminoids, in brain especially in the hippocampus at both single and repeated dose administration with an elimination half-life of 2.6 h. CGM also showed a positive impact in behaviour of animals in comparison with normal unformulated curcuminoids.

Toll-like receptor 2 induced senescence in intervertebral disc cells of patients with back pain can be attenuated by o-vanillin

BACKGROUND

There is an increased level of senescent cells and toll-like teceptor-1, -2, -4, and -6 (TLR) expression in degenerating intervertebral discs (IVDs) from back pain patients. However, it is currently not known if the increase in expression of TLRs is related to the senescent cells or if it is a more general increase on all cells. It is also not known if TLR activation in IVD cells will induce cell senescence.

METHODS

Cells from non-degenerate human IVD were obtained from spine donors and cells from degenerate IVDs came from patients undergoing surgery for low back pain. Gene expression of TLR-1,2,4,6, senescence and senescence-associated secretory phenotype (SASP) markers was evaluated by RT-qPCR in isolated cells. Matrix synthesis was verified with safranin-O staining and Dimethyl-Methylene Blue Assay (DMMB) confirmed proteoglycan content. Protein expression of p16INK4a, SASP factors, and TLR-2 was evaluated by immunocytochemistry (ICC) and/or by enzyme-linked immunosorbent assay (ELISA).

RESULTS

An increase in senescent cells was found following 48-h induction with a TLR-2/6 agonist in cells from both non-degenerate and degenerating human IVDs. Higher levels of SASP factors, TLR-2 gene expression, and protein expression were found following 48-h induction with TLR-2/6 agonist. Treatment with o-vanillin reduced the number of senescent cells, and increased matrix synthesis in IVD cells from back pain patients. Treatment with o-vanillin after induction with TLR-2/6 agonist reduced gene and protein expression of SASP factors and TLR-2. Co-localized staining of p16INK4a and TLR-2 demonstrated that senescent cells have a high TLR-2 expression.

CONCLUSIONS

Taken together our data demonstrate that activation of TLR-2/6 induce senescence and increase TLR-2 and SASP expression in cells from non-degenerate IVDs of organ donors without degeneration and back pain and in cells from degenerating human IVD of patients with disc degeneration and back pain. The senescent cells showed high TLR-2 expression suggesting a link between TLR activation and cell senescence in human IVD cells. The reduction in senescence, SASP, and TLR-2 expression suggest o-vanillin as a potential disease-modifying drug for patients with disc degeneration and back pain.

Design of New Improved Curcumin Derivatives to Multi-targets of Cancer and Inflammation

BACKGROUND

Curcumin is a major active principle of Curcuma longa. There are more than 1700 citations in the Medline, reflecting various biological effects of curcumin. Most of these biological activities are associated with the antioxidant, anti-inflammatory and antitumor activity of the molecule. Several reports suggest various targets of natural curcumin that include growth factors, growth factor receptor, cytokines, enzymes and gene regulators of apoptosis. This review focuses on the improved curcumin derivatives that target the cancer and inflammation.

METHODOLOGY

In this present review, we explored the anticancer drugs with curcumin-based drugs under pre-clinical and clinical studies with critical examination. Based on the strong scientific reports of patentable and non-patented literature survey, we have investigated the mode of the interactions of curcumin-based molecules with the target molecules.

RESULTS

Advanced studies have added new dimensions of the molecular response of cancer cells to curcumin at the genomic level. However, poor bioavailability of the molecule seems to be the major limitation of the curcumin. Several researchers have been involved to improve the curcumin derivatives to overcome this limitation. Sufficient data of clinical trials to various cancers that include multiple myeloma, pancreatic cancer and colon cancer, have also been discussed.

CONCLUSION

The detailed analysis of the structure-activity relationship (SAR) and common synthesis of curcumin-based derivatives have been discussed in the review. Utilising the predictions of in silico coupled with validation reports of in vitro and in vivo studies have concluded many targets for curcumin. Among them, cancer-related inflammation genes regulating curcumin-based molecules are a very promising target to overcome hurdles in the multimodality therapy of cancer.

Study protocol of a phase 1 clinical trial establishing the safety of intrapleural administration of liposomal curcumin: curcumin as a palliative treatment for malignant pleural effusion (IPAL-MPE)

INTRODUCTION

This is a phase 1, open-label, single-centre, uncontrolled, dose-escalation study to evaluate the feasibility, tolerability and pharmacokinetic profiles of a single dose of liposomal curcumin, administered via an existing tunnelled indwelling pleural catheter (TIPC) directly to the tumour site in individuals with diagnoses of malignant pleural effusion. Primarily, we aim to determine a maximum tolerated dose of liposomal curcumin administered via this method.

METHODS AND ANALYSIS

We will use a 3+3 expanded cohort for predefined dose-escalation levels or until a predefined number of dose-limiting toxicities are reached. Participants will be administered a single dose of liposomal curcumin (LipoCurc, SignPath Pharma) via their existing TIPC as a sequential enrolling case series with the following dose cohorts: 100, 200 and 300 mg/m². Primary endpoints are determination of the maximum tolerated dose within the predetermined dose range, and determination of the feasibility of intrapleural administration of liposomal curcumin via an existing TIPC. Secondary endpoints include determination of the safety and tolerability of intrapleural administration of liposomal curcumin, median overall survival, effects on quality of life and on feelings of breathlessness, and the pharmacokinetics and concentrations of curcumin from the plasma and the pleural fluid. Important inclusion criteria include age ≥18 years, an existing TIPC, a pleural biopsy or pleural fluid cytology-proven diagnosis of malignant pleural effusion and for whom no antitumour therapy of proven benefit is available or has been previously declined, eastern cooperative group performance status <2.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Southern Adelaide Local Health Network Human Research Ethics Committee (HREC) (approval number: HREC/20/SAC/11). Study results will be published in peer-reviewed journals, and presented at conferences, in field of medical oncology and respiratory medicine.

TRIAL REGISTRATION NUMBER

ACTRN12620001216909.

PROTOCOL VERSION NUMBER

V.1.0.

Nanocurcumin improves Treg cell responses in patients with mild and severe SARS-CoV2

In Coronavirus disease 2019 (COVID-19), a decreased number of regulatory T (Treg) cells and their mediated factors lead to a hyperinflammatory state due to overactivation of the inflammatory cells and factors during the infection. In the current study, we evaluated the Nanocurcumin effects on the Treg cell population and corresponding factors in mild and severe COVID-19 patients. To investigate the Nanocurcumin effects, 80 COVID-19 patients (40 at the severe stage and 40 at the mild stage) were selected and classified into Nanocurcumin and placebo arms. In both the Nanocurcumin and placebo groups, the Treg cell frequency, the gene expression of Treg transcription factor forkhead box P3 (FoxP3), and cytokines (IL-10, IL-35, and TGF-β), as well as the serum levels of cytokines were measured before and after treatment. In both mild and severe COVID-19 patients, Nanocurcumin could considerably upregulate the frequency of Treg cells, the expression levels of FoxP3, IL-10, IL-35, and TGF-β, as well as the serum secretion levels of cytokines in the Nanocurcumin-treated group compared to the placebo group. The abovementioned factors were remarkably increased in the post-treatment with Nanocurcumin before pre-treatment conditions. By contrast, it has been observed no notable alteration in the placebo group. Our findings revealed the SinaCurcumin® effective function in a significant increase in the number of Treg cells and their mediated factors in the Nanocurcumin group than in the placebo group in both mild and severe patients. Hence, it would be an efficient therapeutic agent in rehabilitating COVID-19 infected patients.

Development, Characterization and Pharmacokinetic Profile of Chitosan-Sodium Tripolyphosphate Nanoparticles Based Drug Delivery Systems for Curcumin

Purpose: This study aimed to provide the method of preparation, characterization of curcumin-loaded chitosan-sodium tripolyphosphate (NaTPP) nanoparticle, and evaluate its pharmacokinetic profiles.

Methods: Curcumin-loaded chitosan-NaTPP nanoparticles were synthesized using ionic gelation methods. Curcumin was dissolved using surfactants and cosurfactants. Chitosan polymer was then mixed in the curcumin solution and dripped with NaTPP solution until nanoparticle formation. The mucoadhesive study was evaluated by measuring the fluorescence of curcumin within the prepared nanoparticles. The pharmacokinetic profiles of curcumin particles and nanoparticles were then assessed in rats by administering a single oral dose of 100 mg/kg BW. Blood samples were taken from nine predetermined time points, and curcumin plasma concentrations were then analyzed using UPLC-MS/MS.

Results: The particle size of the curcumin nanoparticles obtained were 11.5 nm. Entrapment efficiency (EE) of curcumin nanoparticles were exceeding 99.97%, and drug loading capacity (DLC) was 11.34%. The mucoadhesive properties of the nanoparticles were superior to that of curcumin particles. Pharmacokinetic evaluation in rats revealed that curcumin nanoparticles resulted in an increase of area under the curve (AUC), maximum concentration (Cmax), earlier time to reach maximum concentration (Tmax), and lower clearance (CL).

Conclusion: Curcumin-loaded chitosan-NaTPP nanoparticles is an effective formulation to improve curcumin plasma concentrations. Thus, enable its applications for the treatment of various diseases.

Chitosan-based nanocarriers for encapsulation and delivery of curcumin: A review

To overcome the poor aqueous solubility and bioavailability of curcumin, emphasize its functional features, and broaden its applications in the food and pharmaceutical industries, many nanoscale systems have been widely applied for its encapsulation and delivery. Over many decades, chitosan as a natural biopolymer has been extensively studied due to its polycationic nature, biodegradability, biocompatibility, non-toxicity, and non-allergenic. Various chitosan-based nanocarriers with unique properties for curcumin delivery, including but not limited to, self-assembled nanoparticles, nanocomposites, nanoemulsions, nanotubes, and nanofibers, have been designed. This review focuses on the most-recently reported fabrication techniques of different types of chitosan-based nanocarriers. The functionalities of chitosan in each formulation which determine the physicochemical properties such as surface charge, morphology, encapsulation driving force, and release profile, were discussed in detail. Moreover, the current pharmaceutical applications of curcumin-loaded chitosan nanoparticles were elaborated. The role of chitosan in facilitating the delivery of curcumin and improving the therapeutic effects on many chronic diseases, including cancer, bacterial infection, wound healing, Alzheimer's diseases, inflammatory bowel disease, and hepatitis C virus, were illustrated. Particularly, the recently discovered mechanisms of action of curcumin-loaded chitosan nanoparticles against the abovementioned diseases were highlighted.