Antiglioma activity of curcumin-loaded lipid nanoparticles and its enhanced bioavailability in brain tissue for effective glioblastoma therapy

Enhancing the therapeutic potential of curcumin: a novel nanoformulation for targeted anticancer therapy to colorectal cancer with reduced miR20a and miR21 expression

Curcumin (Cur) possesses remarkable pharmacological properties, including cardioprotective, neuroprotective, antimicrobial, and anticancer activities. However, the utilization of Cur in pharmaceuticals faces constraints owing to its inadequate water solubility and limited bioavailability. To overcome these hurdles, there has been notable focus on exploring innovative formulations, with nanobiotechnology emerging as a promising avenue to enhance the therapeutic effectiveness of these complex compounds. We report a novel safe, effective method for improving the incorporation of anticancer curcumin to induce apoptosis by reducing the expression levels of miR20a and miR21. The established method features three aspects that, to our knowledge, have not been formally verified: (1) use of a novel formula to incorporate curcumin, (2) use of all biocompatible biodegradable materials to produce this formula without leaving harmful residues, and (3) an incorporation process at temperatures of approximately 50 °C. The formula was prepared from lecithin (LE), and chitosan (CH) with an eco-friendly emulsifying agent and olive oil as the curcumin solvent. The formula was converted to nanoscale through ultrasonication and probe sonication at a frequency of 20 kHz. Transmission electron microscopy showed that the nano formula was spherical in shape with sizes ranging between 49.7 nm in diameter and negative zeta potentials ranging from 28 to 34 mV. Primers miR20a and miR21 were designed for molecular studies. Nearly complete curcumin with an encapsulation efficiency of 91.1% was established using a straight-line equation. The nano formula incorporated with curcumin was used to prepare formulations that exhibited anticancer activities. The apoptosis pathway in cancer cells was activated by the minimum inhibitory concentration of the nano formula. These findings suggest the potential of this nanoformulation as an effective and selective cancer treatment that does not affect the normal cells.

Improving the targeted delivery of curcumin to esophageal cancer cells via a novel formulation of biodegradable lecithin/chitosan nanoparticles with downregulated miR-20a and miR-21 expression

Nanoencapsulation, employing safe materials, holds substantial promise for enhancing bioactive compounds' delivery, stability, and bioactivity. In this study, we present an innovative and safe methodology for augmenting the incorporation of the anticancer agent, curcumin, thereby inducing apoptosis by downregulating miR20a and miR21 expression. Our established methodology introduces three pivotal elements that, to our knowledge, have not undergone formal validation: (1) Novel formulation: We introduce a unique formula for curcumin incorporation. (2) Biocompatibility and biodegradability: our formulation exclusively consists of biocompatible and biodegradable constituents, ensuring the absence of detrimental residues or undesirable reactions under varying conditions. (3) Low-temperature incorporation: Curcumin is incorporated into the formulation at temperatures approximating 50 °C. The formulation comprises lecithin (LE), chitosan (CH), an eco-friendly emulsifying agent, and olive oil as the solvent for curcumin. Nanoscale conversion is achieved through ultrasonication and probe sonication (20 kHz). Transmission electron microscopy (TEM) reveals spherical nanoparticles with diameters ranging from 29.33 nm and negative zeta potentials within the -28 to -34 mV range. Molecular studies involve the design of primers for miR20a and miR21. Our findings showcase a remarkable encapsulation efficiency of 91.1% for curcumin, as determined through a linear equation. The curcumin-loaded nanoformulation demonstrates potent anticancer activity, effectively activating the apoptosis pathway in cancer cells at the minimum inhibitory concentration. These results underscore the potential of our nanoformulation as a compelling, cancer-selective treatment strategy, preserving the integrity of normal cells, and thus, warranting further exploration in the field of cancer therapy.

Multimodal targeting of glioma with functionalized nanoparticles

The most common and aggressive primitive intracranial tumor of the central nervous system is the glioma. The blood–brain barrier (BBB) has proven to be a significant obstacle to the effective treatment of glioma. To effectively treat glioma, different ways have been used to cross the BBB to deliver drugs to the brain. Drug delivery through nanocarriers proves to be an effective and non-invasive technique for the treatment of glioma and has great potential in the treatment of glioma. In this review, we will provide an overview of nanocarrier-mediated drug delivery and related glioma therapy. Nanocarrier-mediated drug delivery techniques to cross the BBB (liposomes, micelles, inorganic systems, polymeric nanoparticles, nanogel system, and biomimetic nanoparticles) are explored. Finally, the use of nanotherapeutic approaches in the treatment of glioblastoma including chemotherapy, radiotherapy, photothermal therapy, gene therapy, glioma genome editing, immunotherapy, chimeric antigen receptor (CAR) T-cells, immune checkpoint modulators, immune photothermal therapy, vaccine-based immunotherapy, and combination therapy is summarized. Furthermore, this article offers various views on the clinical applicability of nanomedicine.

Nanoparticles as phytochemical carriers for cancer treatment: News of the last decade

INTRODUCTION

The development and application of novel therapeutic medicines for the treatment of cancer are of vital importance to improve the disease's outcome and survival rate. One noteworthy treatment approach is the use of biologically active compounds present in natural products. Even though these phytocompounds present anti-inflammatory, antioxidant, and anticancer properties, their use is limited essentially due to poor systemic delivery, low bioavailability, and water solubility concerns. To make full use of the anticancer potential of natural products, these limitations need to be technologically addressed. In this sense, nanotechnology emerges as a promising drug delivery system strategy.

AREAS COVERED

In this review, the benefits and potential of nanodelivery systems for natural products encapsulation as promising therapeutic approaches for cancer, which were developed during the last decade, are highlighted.

EXPERT OPINION

The nanotechnology area has been under extensive research in the medical field given its capacity for improving the therapeutic potential of drugs by increasing their bioavailability and allowing a targeted delivery to the tumor site. Thereby, the nanoencapsulation of phytocompounds can have a direct impact on the recognized therapeutic activity of natural products towards cancer.

Highlights in targeted nanoparticles as a delivery strategy for glioma treatment

Glioma is the most common type of Central Nervous System (CNS) neoplasia and it arises from glial cells. As glial cells are formed by different types of cells, glioma can be classified according to the cells that originate it or the malignancy grade. Glioblastoma multiforme is the most common and aggressive glioma. The high lethality of this tumor is related to the difficulty in performing surgical removal, chemotherapy, and radiotherapy in the CNS. To improve glioma treatment, a wide range of chemotherapeutics have been encapsulated in nanosystems to increase their ability to overcome the blood-brain barrier (BBB) and specifically reach the tumoral cells, reducing side effects and improving drug concentration in the tumor microenvironment. Several studies have investigated nanosystems covered with targeting ligands (e.g., proteins, peptides, aptamers, folate, and glucose) to increase the ability of drugs to cross the BBB and enhance their specificity to glioma through specific recognition by receptors on BBB and glioma cells. This review addresses the main targeting ligands used in nanosystems to overcome the BBB and promote the active targeting of drugs for glioma. Furthermore, the advantages of using these molecules in glioma treatment are discussed.

The potential of intranasal delivery of nanocrystals in powder form on the improvement of zaleplon performance: in-vitro, in-vivo assessment

OBJECTIVE

The present work focuses on improving zaleplon (ZAP) performance through nanosizing its insoluble particles which were then delivered intranasally in powder form.

SIGNIFICANCE

Since nanopowders have an exceptional ability to cross cell membrane, their absorption is facilitated in the solid form. Hence, delivering insoluble ZAP nanocrystals (NC) through intranasal route improves its bioavailability due to both nanosization and the escape of hepatic metabolism.

METHODS

Nanocrystals were prepared by anti-solvent precipitation followed by probe sonication in presence of Soluplus^®, Poloxamer-188 (0.25%), sodium lauryl sulfate (0.5%), and mannitol. Physicochemical evaluation of the prepared NC was done by DSC and XRPD. TGA was performed for stability detection. Ex vivo permeation study through isolated cattle nasal mucosal membrane, in addition to an in vivo bioavailability study was performed for assessment of the prepared NC.

RESULTS

Nanosization to 200 nm contributed to the enhancement in dissolution ∼100% within 30 min and reduced half-life to 1.63 min. Confirmation of adsorption of polymers over NC' surface was elucidated. TGA confirmed their thermal stability. Ex vivo permeation study showed a 2.7 enhancement ratio in favor of the prepared NC. Both the extent and rate of NC absorption through nasal mucosa of rabbits were significantly higher (p ˂ .05) than in case of oral tablets. The relative bioavailability of NC was increased 3.14 times as compared to the Sleep aid^® tablets.

CONCLUSION

The intranasal delivery of nanoscale ZAP powder proved to be a successful alternative to oral formulations that suffer poor absorption and limited bioavailability.

An Update on the Pharmacological Usage of Curcumin: Has it Failed in the Drug Discovery Pipeline?

The pharmacological propensities of curcumin have been reported in a plethora of pre-clinical and clinical studies. However, innate attributes account for extremely low oral bioavailability which impedes its development as a therapeutic agent. Regardless, these drawbacks have not deterred researchers from optimizing its potentials. This review discussed the pharmacokinetic properties of curcumin relative to its outlook as a lead compound in drug discovery. Also, we highlighted therapeutic strategies that have expedited improvements in curcumin oral bioavailability and delivery to target sites over the years. Recent implementations of these strategies were also covered. More research efforts should be directed towards investigating the pharmacokinetic impacts of these novel curcumin formulations in human clinical studies since inter-species disparities could limit the accuracies of animal studies. We envisaged that integrative-clinical research would help determine 'actual' improvements in curcumin pharmacokinetics coupled with suitable administrative routes, optimal dosing, and drug-enzyme or drug-drug interactions. In addition, this could help determine formulations for achieving higher systemic exposure of parent curcumin thereby providing a strong impetus towards the development of curcumin as a drug candidate in disease treatment.

Co-Administered Polymeric Nano-Antidotes for Improved Photo-Triggered Response in Glioblastoma

Polymer-based nanoparticles (NPs) are useful vehicles in treating glioblastoma because of their favorable characteristics such as small size and ability to cross the blood–brain barrier, as well as reduced immunogenicity and side effects. The use of a photosensitizer drug such as Verteporfin (BPD), in combination with a pan-vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI), Cediranib (CED), encapsulated in NPs will provide the medical field with new research on the possible ways to treat glioblastoma. Concomitant administration of BPD and CED NPs have the potential to induce dual photocytotoxic and cytostatic effects in U87 MG cells by (1) remotely triggering BPD through photodynamic therapy by irradiating laser at 690 nm and subsequent production of reactive oxygen species and (2) inhibiting cell proliferation by VEGFR interference and growth factor signaling mechanisms which may allow for longer progression free survival in patients and fewer systemic side effects. The specific aims of this research were to synthesize, characterize and assess cell viability and drug interactions for polyethylene-glycolated (PEGylated) polymeric based CED and BPD NPs which were less than 100 nm in size for enhanced permeation and retention effects. Synergistic effects were found using the co-administered therapies compared to the individual drugs. The major goal of this research was to investigate a new combination of photodynamic-chemotherapy drugs in nano-formulation for increased efficacy in glioblastoma treatment at reduced concentrations of therapeutics for enhanced drug delivery in vitro.

Nanocurcumin-Mediated Down-Regulation of Telomerase Via Stimulating TGFβ1 Signaling Pathway in Hepatocellular Carcinoma Cells

Background

Curcumin, extracted from turmeric, represents enormous potential to serve as an anticancer agent. Telomerase is viewed as a prominent molecular target of curcumin, and Transforming growth factor-β1 (TGFβ1) has proven to be a major inhibitory signaling pathway for telomerase activity. In the current study, we aimed to explore suppressive effects of nanocurcumin on telomerase expression through TGFβ1 pathway in a hepatocellular carcinoma cell line (Huh7).

Methods

MTT assay was used to determine the effect of nonocurcumin on viability of Huh7 cells. RT-PCR was used to analyze the gene expression patterns.

Results

MTT assay revealed that nanocurcumin acts in a dose- and time-dependent manner to diminish the cell viability. RT-PCR analysis indicated that nanocurcumin results in augmentation of TGFβ1 72 hours post treatment and leads to the reduction of telomerase expression 48 and 72 hours post exposure. Also, up-regulation of Smad3 and E2F1 and down-regulation of Smad7 confirmed the effect of nanocurcumin on intermediate components of TGFβ1 pathway. Furthermore, transfection of the proximal promoter of telomerase triggered a significant reduction in luciferase activity.

Conclusion

The data from the present study lead us to develop a deeper understanding of the mechanisms underlying nanocurcumin-mediated regulation of telomerase expression, thereby presenting a new perspective to the landscape of using nanocurcumin as a cancer-oriented therapeutic agent.

Nanoformulations of curcumin: an emerging paradigm for improved remedial application

Curcumin is a natural polyphenol and essential curcuminoid derived from the rhizome of the medicinal plant Curcuma longa (L.) is universally acknowledged as “Wonder drug of life”. It is a vital consumable and restorative herb, commonly keened for several ailments such as cancer, arthritis, pain, bruises, gastrointestinal quandaries, swelling and much more. Despite its enormous curative potential, the poor aqueous solubility and consequently, minimal systemic bioavailability with rapid degradation are some of the major factors which restrict the utilization of curcumin at medical perspective. However, to improve its clinically relevant parameters, nanoformulation of curcumin is emerging as a novel substitute for their superior therapeutic modality. It enhances its aqueous solubility and targeted delivery to the tissue of interest that prompts to enhance the bioavailability, better drug conveyance, and more expeditious treatment. Subsequent investigations are endeavored to enhance the bio-distribution of native curcumin by modifying with felicitous nano-carriers for encapsulation. In this review, we specifically focus on the recent nanotechnology based implementations applied for overcoming the innate constraints of native curcumin and additionally the associated challenges which restrict its potential therapeutic applications both in vivo and in-vitro studies, as well as their detailed mechanism of action, have additionally been discussed.

The Essential Medicinal Chemistry of Curcumin

Curcumin is a constituent (up to ∼5%) of the traditional medicine known as turmeric. Interest in the therapeutic use of turmeric and the relative ease of isolation of curcuminoids has led to their extensive investigation. Curcumin has recently been classified as both a PAINS (pan-assay interference compounds) and an IMPS (invalid metabolic panaceas) candidate. The likely false activity of curcumin in vitro and in vivo has resulted in >120 clinical trials of curcuminoids against several diseases. No double-blinded, placebo controlled clinical trial of curcumin has been successful. This manuscript reviews the essential medicinal chemistry of curcumin and provides evidence that curcumin is an unstable, reactive, nonbioavailable compound and, therefore, a highly improbable lead. On the basis of this in-depth evaluation, potential new directions for research on curcuminoids are discussed.

Phytosomal curcumin: A review of pharmacokinetic, experimental and clinical studies

Curcumin, a hydrophobic polyphenol, is the principal constituent extracted from dried rhizomes of Curcuma longa L. (turmeric). Curcumin is known as a strong anti-oxidant and anti-inflammatory agent that has different pharmacological effects. In addition, several studies have demonstrated that curcumin is safe even at dosages as high as 8g per day; however, instability at physiological pH, low solubility in water and rapid metabolism results in a low oral bioavailability of curcumin. The phytosomal formulation of curcumin (a complex of curcumin with phosphatidylcholine) has been shown to improve curcumin bioavailability. Existence of phospholipids in phytosomes leads to specific physicochemical properties such as amphiphilic nature that allows dispersion in both hydrophilic and lipophilic media. The efficacy and safety of curcumin phytosomes have been shown against several human diseases including cancer, osteoarthritis, diabetic microangiopathy and retinopathy, and inflammatory diseases. This review focuses on the pharmacokinetics as well as pharmacological and clinical effects of phytosomal curcumin.

Functionalized cell nucleus-penetrating peptide combined with doxorubicin for synergistic treatment of glioma

Clinical application of cell-penetrating peptides (CPPs) in cancer therapy is greatly restricted due to lack of tissue selectivity and tumor-targeting ability. CB5005, a rationally designed CPP that targets and inhibits intracellular NF-κB activation, is constituted by a unique membrane-permeable sequence (CB5005M) cascading to a NF-κB nuclear localization sequence (CB5005N). In vitro cellular evaluation confirmed that CB5005 was effectively taken up by brain capillary endothelial cell bEnd.3 and glioma cells U87. The intracellular localization analysis further demonstrated that CB5005 could not only penetrate into the cells but also enter into their nuclei. More interestingly, CB5005 permeated deeply into the tumor spheroids of U87 cell. In vivo imaging illustrated that the fluorescence-labeled CB5005 distributed itself into the brain and accumulated at the tumor site after intravenous injection. Given the important role of over expressed NF-κB in tumor growth and development, we further investigated CB5005 for its potential in treatment of glioma. When combined administration in vitro with doxorubicin (DOX), CB5005 exhibited a synergistic effect in killing U87 cells. In a nude mice xenograft model, CB5005 inhibited the growth of tumor when applied alone, and displayed a synergistic anti-tumor effect with DOX. In conclusion, CB5005 functioned simultaneously as a cell penetrating peptide and a tumor growth inhibitor, therefore can work as a potential synergist for chemotherapy of human tumor.

STATEMENT OF SIGNIFICANCE

Clinical application of cell-penetrating peptides in cancer therapy is restricted due to lack of tissue selectivity and tumor-targeting ability. In this manuscript, we reported a rationally designed peptide, named CB5005, which had an attractive capability of translocation into the cell nucleus and blocking nuclear translocation of endogenous NF-κB protein. CB5005 had unique affinity with brain and glioma, and could rapidly accumulate in these tissues after intravenous injection. Furthermore, CB5005 showed a synergistic effect on inhibiting gliomas when administrated with doxorubicin. This is the first literature report on this multi-functionalized peptide, which can work as a potential synergist for chemotherapy of tumor. This work should be of general interest to scientists in the fields of biomaterials, biology, pharmacy, and oncology.

"Squalenoylcurcumin" nanoassemblies as water-dispersible drug candidates with antileishmanial activity

Curcumin, a natural polyphenolic compound, showed antiparasitic potential, including trypanocidal and leishmanicidal activity, in several in vitro and in vivo models. The molecule is well tolerated in humans. However, it is insoluble in water and displays poor oral bioavailability as a result of low absorption. New derivatives of curcumin were prepared by esterification of one or two of its phenolic groups with 1,1',2-tris-norsqualenic acid. These "squalenoylcurcumins" were formulated as water-dispersible nanoassemblies of homogeneous size, and they proved to be stable. Squalenoylcurcumins were inactive against Trypanosoma brucei brucei trypomastigotes, even as nanoassemblies, in contrast with curcumin. However, against Leishmania donovani promastigotes, the activities of the squalenoylcurcumins and their nanoassemblies were enhanced relative to that of curcumin. In L. donovani axenic and intramacrophagic amastigotes, they showed activity in the range of miltefosine, with good selectivity indexes. In regard to their dispersibility in water and to the safety of curcumin, these nanoassemblies are promising candidates for preclinical study toward the treatment of visceral leishmaniasis.

FA-loaded lipid drug delivery systems: preparation, characterization and biological studies

The main purpose of this research was to prepare and to characterize ferulic acid-loaded nanostructured lipid carrier (FA-NLC) to evaluate the cytotoxic effect on human glioblastoma cancer U87MG cells. First of all, the influence of different materials on mean size and homogeneity of NLC prepared by a low energy organic solvent-free method was investigated. Technological characterization (encapsulation efficiency, mean particle size, homogeneity and in vitro release profile) was performed on the selected NLC in comparison to others lipid carriers, nanoemulsion and SLN. Furthermore, the thermal behavior of NLC and SLN was investigated using Differential Scanning Calorimetry (DSC) in order to evaluate their structure. Biological studies (MTT bioassay and caspase-3 cleavage) on the selected NLC showed no cytotoxic effects of the unloaded tested NLC. Besides, the effectiveness of FA-loaded NLC was higher compared to the free drug. Cells treated with FA or FA-loaded NLC showed a greater effect compared to idebenone (IDE) or IDE-loaded NLC, respectively. These results strongly support that FA-loaded NLC could be potentially used for the treatment of glioblastoma.

Nanotechnology: an effective tool for enhancing bioavailability and bioactivity of phytomedicine

To achieve the desired therapeutic objective, the drug product must deliver the active drug at an optimal rate and amount. By proper biopharmaceutic design, the rate and extent of drug absorption (also called as bioavailability) or the systemic delivery of drugs to the body can be varied from rapid and complete absorption to slow and sustained absorption depending upon the desired therapeutic objective. Phytomedicine have served as the foundation for a larger fraction of the current pharmacopeia. But the delivery of phytomedicine is always problematic due to poor aqueous solubility, poor permeation, low systemic availability, instability and extensive first pass metabolism. Current review will discuss in detail about how nanotechnology can enhance the bioavilability and bioactivity of the phytomedicine.

Nasal-nanotechnology: revolution for efficient therapeutics delivery

CONTEXT

In recent years, nanotechnology-based delivery systems have gained interest to overcome the problems of restricted absorption of therapeutic agents from the nasal cavity, depending upon the physicochemical properties of the drug and physiological properties of the human nose.

OBJECTIVE

The well-tolerated and non-invasive nasal drug delivery when combined with the nanotechnology-based novel formulations and carriers, opens the way for the effective systemic and brain targeting delivery of various therapeutic agents. To accomplish competent drug delivery, it is imperative to recognize the interactions among the nanomaterials and the nasal biological environment, targeting cell-surface receptors, drug release, multiple drug administration, stability of therapeutic agents and molecular mechanisms of cell signaling involved in patho-biology of the disease under consideration.

METHODS

Quite a few systems have been successfully formulated using nanomaterials for intranasal (IN) delivery. Carbon nanotubes (CNTs), chitosan, polylactic-co-glycolic acid (PLGA) and PLGA-based nanosystems have also been studied in vitro and in vivo for the delivery of several therapeutic agents which shown promising concentrations in the brain after nasal administration.

RESULTS AND CONCLUSION

The use of nanomaterials including peptide-based nanotubes and nanogels (NGs) for vaccine delivery via nasal route is a new approach to control the disease progression. In this review, the recent developments in nanotechnology utilized for nasal drug delivery have been discussed.

The critical role of didodecyldimethylammonium bromide on physico-chemical, technological and biological properties of NLC

Exploiting the experimental factorial design and the potentiality of Turbiscan AG Station, we developed and characterized unmodified and DDAB-coated NLC prepared by a low energy organic solvent free phase inversion temperature technique. A 22 full factorial experimental design was developed in order to study the effects of two independent variables (DDAB and ferulic acid) and their interaction on mean particle size and zeta potential values. The factorial planning was validated by ANOVA analysis; the correspondence between the predicted values of size and zeta and those measured experimentally confirmed the validity of the design and the equation applied for its resolution. The DDAB-coated NLC were significantly affected in their physico-chemical properties by the presence of DDAB, as showed by the results of the experimental design. The coated NLC showed higher physical stability with no particles aggregation compared to the unmodified NLC, as demonstrated by Turbiscan(®) AGS measurements. X-ray diffraction, Raman spectroscopy and Cryo-TEM images allowed us to assert that DDAB plays a critical role in increasing the lipids structural order with a consequent enhancement of the NLC physical stability. Furthermore, the results of the in vitro biological studies allow the revisiting of the role of DDAB to the benefit of glioblastoma treatment, due to its efficacy in increasing the NLC uptake and reducing the viability of human glioblastoma cancer cells (U87MG).

Overview of the role of nanotechnological innovations in the detection and treatment of solid tumors

Nanotechnology, although still in its infantile stages, has the potential to revolutionize the diagnosis, treatment, and monitoring of disease progression and success of therapy for numerous diseases and conditions, not least of which is cancer. As it is a leading cause of mortality worldwide, early cancer detection, as well as safe and efficacious therapeutic intervention, will be indispensable in improving the prognosis related to cancers and overall survival rate, as well as health-related quality of life of patients diagnosed with cancer. The development of a relatively new field of nanomedicine, which combines various domains and technologies including nanotechnology, medicine, biology, pharmacology, mathematics, physics, and chemistry, has yielded different approaches to addressing these challenges. Of particular relevance in cancer, nanosystems have shown appreciable success in the realm of diagnosis and treatment. Characteristics attributable to these systems on account of the nanoscale size range allow for individualization of therapy, passive targeting, the attachment of targeting moieties for more specific targeting, minimally invasive procedures, and real-time imaging and monitoring of in vivo processes. Furthermore, incorporation into nanosystems may have the potential to reintroduce into clinical practice drugs that are no longer used because of various shortfalls, as well as aid in the registration of new, potent drugs with suboptimal pharmacokinetic profiles. Research into the development of nanosystems for cancer diagnosis and therapy is thus a rapidly emerging and viable field of study.

Curcumin suppresses malignant glioma cells growth and induces apoptosis by inhibition of SHH/GLI1 signaling pathway in vitro and vivo

AIMS

To study the role of curcumin on glioma cells via the SHH/GLI1 pathway in vitro and vivo.

METHODS

The effects of curcumin on proliferation, migration, apoptosis, SHH/GLI1 signaling, and GLI1 target genes expression were evaluated in multiple glioma cell lines in vitro. A U87-implanted nude mice model was used to study the role of curcumin on tumor volume and the suppression efficacy of GLI1.

RESULTS

Curcumin showed cytotoxic effects on glioma cell lines in vitro. Both mRNA and protein levels of SHH/GLI1 signaling (Shh, Smo, GLI1) were downregulated in a dose- and time-dependent manner. Several GLI1-dependent target genes (CyclinD1, Bcl-2, Foxm1) were also downregulated. Curcumin treatment prevented GLI1 translocating into the cell nucleus and reduced the concentration of its reporter. Curcumin suppressed cell proliferation, colony formation, migration, and induced apoptosis which was mediated partly through the mitochondrial pathway after an increase in the ratio of Bax to Bcl2. Intraperitoneal injection of curcumin in vivo reduced tumor volume, GLI1 expression, the number of positively stained cells, and prolonged the survival period compared with the control group.

CONCLUSION

This study shows that curcumin holds a great promise for SHH/GLI1 targeted therapy against gliomas.

Curcumin nanoparticles attenuate neurochemical and neurobehavioral deficits in experimental model of Huntington's disease

Till date, an exact causative pathway responsible for neurodegeneration in Huntington's disease (HD) remains elusive; however, mitochondrial dysfunction appears to play an important role in HD pathogenesis. Therefore, strategies to attenuate mitochondrial impairments could provide a potential therapeutic intervention. In the present study, we used curcumin encapsulated solid lipid nanoparticles (C-SLNs) to ameliorate 3-nitropropionic acid (3-NP)-induced HD in rats. Results of MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay and succinate dehydrogenase (SDH) staining of striatum revealed a marked decrease in Complex II activity. However, C-SLN-treated animals showed significant increase in the activity of mitochondrial complexes and cytochrome levels. C-SLNs also restored the glutathione levels and superoxide dismutase activity. Moreover, significant reduction in mitochondrial swelling, lipid peroxidation, protein carbonyls and reactive oxygen species was observed in rats treated with C-SLNs. Quantitative PCR and Western blot results revealed the activation of nuclear factor-erythroid 2 antioxidant pathway after C-SLNs administration in 3-NP-treated animals. In addition, C-SLN-treated rats showed significant improvement in neuromotor coordination when compared with 3-NP-treated rats. Thus, the results of this study suggest that C-SLNs administration might be a promising therapeutic intervention to ameliorate mitochondrial dysfunctions in HD.

Free and nanoencapsulated curcumin suppress β-amyloid-induced cognitive impairments in rats: involvement of BDNF and Akt/GSK-3β signaling pathway

Alzheimer's disease (AD), a neurodegenerative disorder exhibiting progressive loss of memory and cognitive functions, is characterized by the presence of neuritic plaques composed of neurofibrillary tangles and β-amyloid (Aβ) peptide. Drug delivery to the brain still remains highly challenging for the treatment of AD. Several studies have been shown that curcumin is associated with anti-amyloidogenic properties, but therapeutic application of its beneficial effects is limited. Here we investigated possible mechanisms involved in curcumin protection against Aβ(1-42)-induced cognitive impairment and, due to its poor bioavailability, we developed curcumin-loaded lipid-core nanocapsules in an attempt to improve the neuroprotective effect of this polyphenol. Animals received a single intracerebroventricular injection of Aβ(1-42) and they were administered either free curcumin or curcumin-loaded lipid-core nanocapsules (Cur-LNC) intraperitoneally for 10days. Aβ(1-42)-infused animals showed a significant impairment on learning-memory ability, which was paralleled by a significant decrease in hippocampal synaptophysin levels. Furthermore, animals exhibited activated astrocytes and microglial cells, as well as disturbance in BDNF expression and Akt/GSK-3β signaling pathway, beyond tau hyperphosphorylation. Our findings demonstrate that administration of curcumin was effective in preventing behavioral impairments, neuroinflammation, tau hyperphosphorylation as well as cell signaling disturbances triggered by Aβ in vivo. Of high interest, Cur-LNC in a dose 20-fold lower presented similar neuroprotective results compared to the effective dose of free curcumin. Considered overall, the data suggest that curcumin is a potential therapeutic agent for neurocognition and nanoencapsulation of curcumin in LNC might constitute a promising therapeutic alternative in the treatment of neurodegenerative diseases such as AD.

Curcumin-loaded lipid-core nanocapsules as a strategy to improve pharmacological efficacy of curcumin in glioma treatment

In this study, we developed curcumin-loaded lipid-core nanocapsules (C-LNCs) in an attempt to improve the antiglioma activity of this polyphenol. C-LNC showed nanotechnological properties such as nanometric mean size (196 nm), 100% encapsulation efficiency, polydispersity index below 0.1, and negative zeta potential. The in vitro release assays demonstrated a controlled release of curcumin from lipid-core nanocapsules. In C6 and U251MG gliomas, C-LNC promoted a biphasic delivery of curcumin: the first peak occurred early in the treatment (1-3h), whereas the onset of the second phase occurred after 48 h. In C6 cells, the cytotoxicity of C-LNC was comparable to non-encapsulated curcumin only after 96 h, whereas C-LNCs were more cytotoxic than non-encapsulated curcumin after 24h of incubation in U251MG. Induction of G2/M arrest and autophagy were observed in C-LNC as well as in free-curcumin treatments. In rats bearing C6 gliomas, C-LNC (1.5mg/kg/day, i.p.) decreased the tumor size and malignance and prolonged animal survival when compared to same dose of non-encapsulated drug. In addition, serum markers of tissue toxicity and histological parameters were not altered. Considered overall, the data suggest that the nanoencapsulation of curcumin in LNC is an important strategy to improve its pharmacological efficacy in the treatment of gliomas.

Emerging role of nanocarriers to increase the solubility and bioavailability of curcumin

INTRODUCTION

Curcumin is a safe, affordable and natural bioactive molecule of turmeric (Curcuma longa). It has gained considerable attention in recent years for its multiple pharmacological activities. However, its optimum pharmaceutical potential has been limited by its lack of aqueous solubility and poor bioavailability. To mitigate the above limitations, recently various nanostructured water-soluble delivery systems were developed to increase the solubility and bioavailability of curcumin.

AREAS COVERED

Major reasons contributing to the low bioavailability of curcumin appear to be owing to its poor solubility, low absorption, rapid metabolism and rapid systemic elimination. The present review summarizes the strategies using curcumin in various nanocarrier delivery systems to overcome poor solubility and inconsistent bioavailability of curcumin and describes the current status and challenges for the future.

EXPERT OPINION

The development of various drug delivery systems to deliver curcumin will certainly provide a step up towards augmenting the therapeutic activity of curcumin thereby increasing the solubility and bioavailability of curcumin. However, the future of such delivery technology will be highly dependent on the development of safe, non-toxic and non-immunogenic nanocarriers.