Pleiotropic Chemotherapy to Abrogate Glioblastoma Multiforme Migration/Invasion.

Current clinical failure to cure primary glioblastoma multiforme in virtually all adult patients is due to genetic aberrations, molecular heterogeneity, and clonal evolution of tumor stem and differentiated cells within the core tumor, leading to their migration, invasion and proliferation in normal surrounding and in distant cerebral tissue sites. These factors are the causes of targeted drug resistance, inadequate surgical removal, and inadequate radio-therapeutic interventions. Resolution of this clinical conundrum may be found in administration of Withaferin A alone or in combination with pleiotropic drugs which address aberrant molecules and pathways promoting tumor cell motility, migration, invasion and proliferation.

Radiation-induced Demyelination and Remyelination in the Central Nervous System: A Literature Review.

Therapeutic radiation applied to the central nervous system concomitant with or followed by surgery and chemotherapy induces significant pathologic demyelination depending upon tumor volume, dosage, field of treatment, and age of patient, with consequent exacerbation of significant impairment of mental function including personality change, memory deficiencies, confusion, learning difficulties and dementia. These adverse clinical events may be ameliorated by the application of remyelinating measures including nutrition, supplements and pharmaceuticals prophylactically, concomitant with radiation or post-radiation treatment.

Distribution and Metabolism of Lipocurc™ (Liposomal Curcumin) in Dog and Human Blood Cells: Species Selectivity and Pharmacokinetic Relevance.

BACKGROUND/AIM: The aim of this study was to investigate the distribution of curcumin (in the form of Lipocurc™) and its major metabolite tetrahydrocurcumin (THC) in Beagle dog and human red blood cells, peripheral blood mononuclear cells (PBMC) and hepatocytes. MATERIALS AND METHODS: Lipocurc™ was used as the source of curcumin for the cell distribution assays. In vitro findings with red blood cells were also compared to in vivo pharmacokinetic data available from preclinical studies in dogs and phase I clinical studies in humans. RESULTS: High levels of curcumin were measured in PBMCs (625.5 ng/g w.w. cell pellet or 7,297 pg/106 cells in dog and 353.7 ng/g w.w. cell pellet or 6,809 pg/106 cells in human) and in hepatocytes (414.5 ng/g w.w. cell pellet or 14,005 pg/106 cells in dog and 813.5 ng/g w.w. cell pellet or 13,780 pg/106 cells in human). Lower curcumin levels were measured in red blood cells (dog: 78.4 ng/g w.w. cell pellet or 7.2 pg/106 cells, human: 201.5 ng/g w.w. cell pellet or 18.6 pg/106 cells). A decrease in the medium concentration of curcumin was observed in red blood cells and hepatocytes, but not in PBMCs. Red blood cell levels of THC were ~5-fold higher in dog compared to human and similar between dog and human for hepatocytes and PBMCs. The ratio of THC to curcumin found in the red blood cell medium following incubation was 6.3 for dog compared to 0.006 for human, while for PBMCs and hepatocytes the ratio of THC to curcumin in the medium did not display such marked species differences. CONCLUSION: There was an excellent correlation between the in vitro disposition of curcumin and THC following incubation with red blood cells and in vivo plasma levels of curcumin and THC in dog and human following intravenous infusion. The disposition of curcumin in blood cells is, therefore, species-dependent and of pharmacokinetic relevance.

The Kynurenine Pathway: A Primary Resistance Mechanism in Patients with Glioblastoma.

The failure of chemotherapy and radiation therapy to achieve long-term remission or cure in patients with glioblastoma (GBM) is, in a large part, due to the suppression of the immune system induced by the tumors themselves. These tumors adapt to treatment with chemotherapy or radiation therapy by stimulating secretion of molecules that cause tryptophan metabolism to be disrupted. Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) are produced, accelerating metabolism along the kynurenine pathway and resulting in excess levels of quinolinic acid, 3-hydroxyanthranilic acid and other neurotoxic molecules. IDO and TDO also act as checkpoint molecules that suppress T-cell function. GBM is particularly associated with severe immunosuppression, and this tumor type might be thought to be the ideal candidate for checkpoint inhibitor therapy. However, treatment with checkpoint inhibitors now in clinical use for peripheral solid tumors, such as those inhibiting cytotoxic T-lymphocyte-associated protein-4 (CTLA4) or programmed cell death-1 (PD1) receptors, results in further abnormalities of tryptophan metabolism. This implies that to obtain optimal results in the treatment of GBM, one may need to add an inhibitor of the kynurenine pathway to therapy with a CTLA4 or PD1 inhibitor, or use agents which can suppress multiple checkpoint molecules.

In Vitro Study of a Liposomal Curcumin Formulation (Lipocurc™): Toxicity and Biological Activity in Synovial Fibroblasts and Macrophages.

BACKGROUND/AIM: The polyphenol curcumin is produced in the rhizome of Curcuma longa and exhibits potent anti-inflammatory, antioxidant, and chemopreventive activities. Due to the fact that curcumin is poorly soluble in water, many delivery systems have been developed to improve its solubility and bioavailability achieving optimum therapeutic application. In this study, we evaluated the biological effects of a liposomal curcumin formulation (Lipocurc™) on human synovial fibroblasts (SW982) and mouse macrophages (RAW264). MATERIAL AND METHODS: Cellular uptake of liposomes was studied using calcein-loaded liposomes. Effects of Lipocurc™ on cell viability and proliferation were determined with Celltox green cytotoxicity assay and 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay, respectively. To induce cytokine/chemokine expression, the cells were stimulated with interleukin (IL)1ß or lipopolysaccharide (LPS). The release of IL6, IL8, and tumor necrosis factor-alpha (TNFα) was quantified by enzyme-linked immunosorbent assay (ELISA). RESULTS: Data showed that the liposomal curcumin formulation Lipocurc™ was significantly less toxic to synovial fibroblasts and macrophages compared to non-encapsulated, free curcumin. Furthermore, Lipocurc™ effectively reduced pro-inflammatory cytokine/chemokine expression in synovial fibroblasts as well as in macrophages without affecting cell viability, suggesting that this curcumin nanoformulation might be a promising tool for the treatment of inflammatory diseases.

Curcumin-ER Prolonged Subcutaneous Delivery for the Treatment of Non-Small Cell Lung Cancer.

Non-small-cell lung cancer therapy is a challenge due to poor prognosis and low survival rate. There is an acute need for advanced therapies having higher drug efficacy, low immunogenicity and fewer side effects which will markedly improve patient compliance and quality of life of cancer patients. The purpose of this study was to develop a novel hybrid curcumin nanoformulation (Curcumin-ER) and evaluate the therapeutic efficacy of this formulation on a non-small cell lung cancer xenograft model. Use of curcumin, a natural anticancer agent, is majorly limited due to its poor aqueous solubility and hence it's low systemic bioavailability. In this paper, we carried out the nanoformulation of Curcumin-ER, optimized the formulation process and determined the anticancer effects of Curcumin-ER against human A549 non-small cell lung cancer using in vitro and in vivo studies. Xenograft tumors in nude mice were treated with 20 mg/kg subcutaneous injection of Curcumin-ER and liposomal curcumin (Lipocurc) twice a week for seven weeks. Results showed that tumor growth was suppressed by 52.1% by Curcumin-ER treatment and only 32.2% by Lipocurc compared to controls. Tumor sections were isolated from murine xenografts and histology and immunohistochemistry was performed. A decrease in expression of NFκB-p65 subunit and proliferation marker, Ki-67 was observed in treated tumors. In addition, a potent anti-angiogenic effect, characterized by reduced expression of annexin A2 protein, was observed in treated tumors. These results establish the effectiveness of Curcumin-ER in regressing human non-small cell lung cancer growth in the xenograft model using subcutaneous route of administration. The therapeutic efficacy of Curcumin-ER highlights the potential of this hybrid nanoformulation in treating patients with non-small cell lung cancer.

Use of basic mobile phase to improve chromatography and boost sensitivity for quantifying tetrahydrocurcumin in human plasma by LC-MS/MS.

Tetrahydrocurcumin (THC), a major metabolite of curcumin, is often quantified by LC-MS or LC-MS/MS using acidic mobile phases due to the concern of its instability in a basic medium. However, acidic mobile phases often lead to poor chromatography (e.g. split or double peaks) and reduced detection sensitivity in the commonly used negative ionization mode. To overcome these shortcomings, a basic mobile phase was used for the first time in the LC-MS/MS quantification of THC. In comparison with the acidic mobile phases, a single symmetrical chromatographic peak was obtained and the sensitivity increased by 7-fold or more under the equivalent conditions. The new LC-MS/MS method using the basic mobile phase has been successfully validated for the quantification of THC in human EDTA plasma over the concentration range of 5-2500ng/ml. The within-batch accuracy (% nominal concentration) was between 88.7 and 104.9 and the between-batch accuracy ranged from 96.7 to 108.6. The CVs for within- and between-batch precisions were equal to or less than 5.5% and 9.1%, respectively. No significant matrix interference or matrix effect was observed from normal or lipemic and hemolytic plasma matrices. In addition, the common stabilities with adequate durations were established, including up to 5days of post-preparative stability. Furthermore, when the validated method was applied to a clinical study, the passing rate of ISR samples was 83%, indicating the good reproducibility of the method. The success of the unconventional approach presented in this article demonstrates that a mobile phase could be selected based mainly on its merits to facilitate LC separation and/or MS detection. There is no need for excessive concern about the stability of the compound(s) of interest in the selected mobile phase because the run time of modern LC-MS or LC-MS/MS methods is typically only a few minutes.

Bifunctional role of pro-inflammatory cytokines after traumatic brain injury.

BACKGROUND: Pro-inflammatory cytokines play an essential role in maintenance of normal brain function as well as in repair after traumatic brain injuries (TBI). However, massive and uncontrolled release of these cytokines, particularly interleukin (IL)-1ß, IL-6 and tumour necrosis factor (TNF)-α, can also result in a great deal of additional brain damage. Levels of these cytokines may increase in the brain thousands of times more than do the corresponding levels in serum. RESEARCH DESIGN: Narrative literature review. Outcome and conclusions: Strategies to control the levels of these pro-inflammatory cytokines and to reduce the cytokine-induced brain damage are discussed. There is extensive evidence from experiments in animal models that suppression of cytokines is effective in ameliorating neurologic damage after TBI. However, the efficacy of this approach remains to be proven in patient trials.

Sphingosine Kinase Inhibitors as Maintenance Therapy of Glioblastoma After Ceramide-Induced Response.

Ceramide and sphingosine 1-phosphate (S1P) are sphingolipid metabolites with important signaling functions. Ceramides promote apoptosis, whereas S1P favors proliferation, angiogenesis and cell survival. The balance between these opposing signaling functions is referred to as the sphingolipid rheostat. A shift in this balance toward S1P is seen in glioblastoma (GBM) and other cancers, and results in tumor cell survival and resistance to chemotherapy. Sphingosine kinase (SK), the enzyme responsible for transforming sphingosine into S1P, plays the critical role in modulating the balance between S1P and ceramides. Chemotherapeutic agents or radiation therapy may induce short-term responses in GBM patients by increasing ceramide levels. However, we believe that the enzyme SK may cause the increased ceramide to be metabolized to S1P, restoring the abnormally high S1P to ceramide balance, and that this may be part of the reason for the near-100% recurrence rate of GBM. The use of maintenance therapy with an SK inhibitor, in patients with GBM who have tumor reduction or stable disease after therapy, should be investigated.

Curcumin for the Treatment of Glioblastoma.

Glioblastoma multiforme is a highly aggressive primary cancer of the brain associated with a poor prognosis. Modest increases in survival can sometimes be achieved with the use of temozolomide and radiation therapy after surgery, but second-line therapy after recurrence has a limited efficacy. Curcumin has demonstrated promising results against this form of cancer in experimental models. The reported activity of curcumin against cancer stem cells, a major cause of glioblastoma resistance to therapy, and its ability to augment the apoptotic effects of ceramides, suggest it would have a synergistic effect with cytotoxic chemotherapy agents currently used in second-line therapy, such as lomustine.

Review: The Prolonged QT Interval: Role of Pro-inflammatory Cytokines, Reactive Oxygen Species and the Ceramide and Sphingosine-1 Phosphate Pathways.

Patients with QT prolongation have delayed cardiac repolarization and may suffer fatal ventricular arrhythmias. To determine the role of cytokines in causing this syndrome, we reviewed reports on patients with rheumatoid arthritis, psoriasis and other inflammatory conditions. These patients frequently have prolonged QT, which correlates with increases in tumor necrosis factor alpha, and interleukin-1ß and 6. Studies in experimental models have shown that these cytokines act through stimulation of reactive oxygen species. Our review of data on phospholipidosis and on QT-shortening agents suggests a key role in QT prolongation for the ceramide/sphingosine-1-phosphate rheostat. We conclude that the cause of prolonged QT in inflammatory conditions is cytokine induction of reactive oxygen species and then ceramides, and believe that QT-prolonging agents bypass initial steps of this pathway and directly affect ceramides. Since both pro-inflammatory cytokines and numerous medications cause QT prolongation and ventricular arrhythmias by this mechanism, extra caution is needed when using these agents in patients with inflammatory conditions.

Curcumin and cancer stem cells: curcumin has asymmetrical effects on cancer and normal stem cells.

Curcumin has been shown to have numerous cytotoxic effects on cancer stem cells (CSCs). This is due to its suppression of the release of cytokines, particularly interleukin (IL)-6, IL-8 and IL-1, which stimulate CSCs, and also to its effects at multiple sites along CSC pathways, such as Wnt, Notch, Hedgehog and FAK. In spite of its multiple actions targeting CSCs, curcumin has little toxicity against normal stem cells (NSCs). This may be due to curcumin's different effects on CSCs and NSCs.

Curcumin suppression of cytokine release and cytokine storm. A potential therapy for patients with Ebola and other severe viral infections.

BACKGROUND: The terminal stage of Ebola and other viral diseases is often the onset of a cytokine storm, the massive overproduction of cytokines by the body's immune system. MATERIALS AND METHODS: The actions of curcumin in suppressing cytokine release and cytokine storm are discussed. RESULTS: Curcumin blocks cytokine release, most importantly the key pro-inflammatory cytokines, interleukin-1, interleukin-6 and tumor necrosis factor-α. The suppression of cytokine release by curcumin correlates with clinical improvement in experimental models of disease conditions where a cytokine storm plays a significant role in mortality. CONCLUSION: The use of curcumin should be investigated in patients with Ebola and cytokine storm. Intravenous formulations may allow achievement of therapeutic blood levels of curcumin.

Safety, tolerability and pharmacokinetics of liposomal curcumin in healthy humans.

INTRODUCTION: Experimental studies have shown that liposomal curcumin can exert a reduction in tumor growth in pancreatic and colorectal cancer. In this phase I clinical trial we investigated the pharmacokinetics, safety, and tolerability of intravenously administered liposomal curcumin in healthy subjects. MATERIAL AND METHODS: 50 male and female participants were included in this randomized, placebo-controlled double-blind phase I dose escalation study. Subjects received a single dose of liposomal curcumin (10 - 400 mg/m2; n = 2 - 6 per group) or placebo over 2 hours intravenously. RESULTS: Dose-dependent increases in the plasma concentrations of curcumin and its metabolite tetrahydrocurcumin (THC) were detected. After the end of drug infusion, curcumin and THC plasma concentrations decreased within 6 - 60 minutes below the limit of quantification. Mean urinary excretion was ~ 0.1% of total systemic clearance. Liposomal curcumin was tolerated well, but a transient red blood cell echinocyte formation with concomitant increase in mean cellular volume was observed at dosages ≥ 120 mg/m2. CONCLUSION: Short-term intravenous dosing of liposomal curcumin appears to be safe up to a dose of 120 mg/m2. Changes in red blood cell morphology may represent a dose limiting sign of toxicity.

Liposomes ameliorate Crizotinib- and Nilotinib-induced inhibition of the cardiac IKr channel and QTc prolongation.

Crizotinib (Xalkori®) and nilotinib (Tasigna®) are tyrosine kinase inhibitors approved for the treatment of non-small cell lung cancer and chronic myeloid leukemia, respectively. Both have been shown to result in electrocardiogram rate-corrected Q-wave T-wave interval (QTc) prolongation in humans and animals. Liposomes have been shown to ameliorate drug-induced effects on the cardiac-delayed rectifier K(+) current (IKr, KV11.1), coded by the human ether-a-go-go-related gene (hERG). This study was undertaken to determine if liposomes would also decrease the effect of crizotinib and nilotinib on the IKr channel. Crizotinib and nilotinib were tested in an in vitro IKr assay using human embryonic kidney (HEK) 293 cells stably transfected with the hERG. Dose-responses were determined and the 50% inhibitory concentrations (IC50s) were calculated. When the HEK 293 cells were treated with crizotinib or nilotinib that were mixed with liposomes, there was a significant decrease in the IKr channel inhibitory effects of these two drugs. When isolated, rabbit hearts were exposed to crizotinib or nilotinib, there were significant increases in QTc prolongation. Mixing either of the drugs with liposomes ameliorated the effects of the drugs. Rabbits dosed intravenously (IV) with crizotinib or nilotinib showed QTc prolongation. When liposomes were injected prior to crizotinib or nilotinib, the liposomes decreased the effects on the QTc interval. The use of liposomal encapsulated QT-prolongation agents, or giving liposomes in combination with drugs, may decrease their cardiac liability.

Mitigating prolonged QT interval in cancer nanodrug development for accelerated clinical translation.

BACKGROUND: Cardiac toxicity is the foremost reason for drug discontinuation from development to clinical evaluation and post market surveillance [Fung 35:293-317, 2001; Piccini 158:317-326 2009]. The Food and Drug Administration (FDA) has rejected many potential pharmaceutical agents due to QT prolongation effects. Since drug development and FDA approval takes an enormous amount of time, money and effort with high failure rates, there is an increased focus on rescuing drugs that cause QT prolongation. If these otherwise safe and potent drugs were formulated in a unique way so as to mitigate the QT prolongation associated with them, these potent drugs may get FDA approval for clinical use. Rescuing these compounds not only benefit the patients who need them but also require much less time and money thus leading to faster clinical translation. In this study, we chose curcumin as our drug of choice since it has been shown to posses anti-tumor properties against various cancers with limited toxicity. The major limitations with this pharmacologically active drug are (a) its ability to prolong QT by inhibiting the hERG channel and (b) its low bioavailability. In our previous studies, we found that lipids have protective actions against hERG channel inhibition and therefore QT prolongation. RESULTS: Results of the manual patch clamp assay of HEK 293 cells clearly illustrated that our hybrid nanocurcumin formulation prevented the curcumin induced inhibition of hERG K+ channel at concentrations higher than the therapeutic concentrations of curcumin. Comparing the percent inhibition, the hybrid nanocurcumin limited inhibition to 24.8% at a high curcumin equivalent concentration of 18 µM. Liposomal curcumin could only decrease this inhibition upto 30% only at lower curcumin concentration of 6 µM but not at 18 µM concentration. CONCLUSIONS: Here we show a curcumin encapsulated lipopolymeric hybrid nanoparticle formulation which could protect against QT prolongation and also render increased bioavailability and stability thereby overcoming the limitations associated with curcumin.

Efficacy of liposomal curcumin in a human pancreatic tumor xenograft model: inhibition of tumor growth and angiogenesis.

BACKGROUND: Liposome-based drug delivery has been successful in the past decade, with some formulations being Food and Drug Administration (FDA)-approved and others in clinical trials around the world. The major disadvantage associated with curcumin, a potent anticancer agent, is its poor aqueous solubility and hence low systemic bioavailability. However, curcumin can be encapsulated into liposomes to improve systemic bioavailability. MATERIALS AND METHODS: We determined the antitumor effects of a liposomal curcumin formulation against human MiaPaCa pancreatic cancer cells both in vitro and in xenograft studies. Histological sections were isolated from murine xenografts and immunohistochemistry was performed. RESULTS: The in vitro (IC50) liposomal curcumin proliferation-inhibiting concentration was 17.5 µM. In xenograft tumors in nude mice, liposomal curcumin at 20 mg/kg i.p. three-times a week for four weeks induced 42% suppression of tumor growth compared to untreated controls. A potent antiangiogenic effect characterized by a reduced number of blood vessels and reduced expression of vascular endothelial growth factor and annexin A2 proteins, as determined by immunohistochemistry was observed in treated tumors. CONCLUSION: These data clearly establish the efficacy of liposomal curcumin in reducing human pancreatic cancer growth in the examined model. The therapeutic curcumin-based effects, with no limiting side-effects, suggest that liposomal curcumin may be beneficial in patients with pancreatic cancer.

Effect of liposomal curcumin on red blood cells in vitro.

BACKGROUND: The anti-inflammatory and antiproliferative agent curcumin has poor oral bioavailability and solubility in plasma. Liposomal formulations have therefore been developed, but the toxicity of these preparations is not yet established. We investigated the influence of free and liposomally formulated curcumin on human red blood cell (RBC) morphology in vitro. MATERIALS AND METHODS: EDTA-buffered whole blood from two healthy individuals was incubated with different concentrations (1, 10, 100 µg/ml) of free or liposomal curcumin. RBC morphology and mean cellular volume (MCV) were examined at up to 4 hours of incubation. RESULTS: Dose-dependent echinocyte formation was observed after incubation with free, and liposomal curcumin, with a threshold concentration of 10 µg/ml and peak effect after 30 minutes. A concomitant increase in mean cellular volume was detectable. CONCLUSION: Curcumin and liposomal curcumin cause dose-dependent changes in the shape of RBCs. This effect may represent an early sign of dose-limiting toxicity following intravenous administration.

Polymeric curcumin nanoparticle pharmacokinetics and metabolism in bile duct cannulated rats.

The objective of this study was to compare the pharmacokinetics and metabolism of polymeric nanoparticle-encapsulated (nanocurcumin) and solvent-solubilized curcumin formulations in Sprague-Dawley (SD) rats. Nanocurcumin is currently under development for cancer therapy. Since free, unencapsulated curcumin is rapidly metabolized and excreted in rats, upon intravenous (i.v.) administration of nanocurcumin only nanoparticle-encapsulated curcumin can be detected in plasma samples. Hence, the second objective of this study was to utilize the metabolic instability of curcumin to assess in vivo drug release from nanocurcumin. Nanocurcumin and solvent-solubilized curcumin were administered at 10 mg curcumin/kg by jugular vein to bile duct-cannulated male SD rats (n = 5). Nanocurcumin increased the plasma Cmax of curcumin 1749 fold relative to the solvent-solubilized curcumin. Nanocurcumin also increased the relative abundance of curcumin and glucuronides in bile but did not dramatically alter urine and tissue metabolite profiles. The observed increase in biliary and urinary excretion of both curcumin and metabolites for the nanocurcumin formulation suggested a rapid "burst" release of curcumin. Although the burst release observed in this study is a limitation for targeted tumor delivery, nanocurcumin still exhibits major advantages over solvent-solubilized curcumin, as the nanoformulation does not result in the lung accumulation observed for the solvent-solubilized curcumin and increases overall systemic curcumin exposure. Additionally, the remaining encapsulated curcumin fraction following burst release is available for tumor delivery via the enhanced permeation and retention effect commonly observed for nanoparticle formulations.

Curcumin (diferuloylmethane) delivery methods: a review.

Curcumin interacts with a large number of extra- and intracellular targets in a biphasic dose-dependent manner. It controls inflammation, oxidative stress, cell survival, cell secretion, homeostasis, and proliferation. Its mechanisms of action are generally directed toward cells that exhibit disordered physiology or blatant mutation-based abnormal states. Optimizing preventative or therapeutic applications require delivering appropriate quantities of curcumin to lesioned cellular targets. Since diseased conditions anatomically are located from topical to systemic sites, efficient application of curcumin requires specific lesion-oriented delivery methods, representatives of which are here reviewed.