Spinal Stroke: Outcome Attenuation by Erythropoietin and Carbamylated Erythropoietin and Its Prediction by Sphingosine-1-Phosphate Serum Levels in Mice.

Spinal strokes may be associated with tremendous spinal cord injury. Erythropoietin (EPO) improves the neurological outcome of animals after spinal cord ischemia (SCI) and its effects on ischemia-induced endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are considered possible molecular mechanisms. Furthermore, sphingosin-1-phosphate (S1P) is suggested to correlate with SCI. In this study, the effect of recombinant human EPO (rhEPO) and carbamylated EPO (cEPO-Fc) on the outcome of mice after SCI and a prognostic value of S1P were investigated. SCI was induced in 12-month-old male mice by thoracic aortal cross-clamping after administration of rhEPO, cEPO-Fc, or a control. The locomotory behavior of mice was evaluated by the Basso mouse scale and S1P serum levels were measured by liquid chromatography-tandem mass spectrometry. The spinal cord was examined histologically and the expressions of key UPR proteins (ATF6, PERK, and IRE1a, caspase-12) were analyzed utilizing immunohistochemistry and real-time quantitative polymerase chain reaction. RhEPO and cEPO-Fc significantly improved outcomes after SCI. The expression of caspase-12 significantly increased in the control group within the first 24 h of reperfusion. Animals with better locomotory behavior had significantly higher serum levels of S1P. Our data indicate that rhEPO and cEPO-Fc have protective effects on the clinical outcome and neuronal tissue of mice after SCI and that the ER is involved in the molecular mechanisms. Moreover, serum S1P may predict the severity of impairment after SCI.

Intense Uptake of Liposomal Curcumin by Multiple Myeloma Cell Lines: Comparison to Normal Lymphocytes, Red Blood Cells and Chronic Lymphocytic Leukemia Cells.

BACKGROUND/AIM: Curcumin is being widely investigated for its anticancer properties and several studies in the literature suggest that curcumin is distributed to a higher degree in cancer cells compared to normal cells. The goal of this study was to investigate the disposition of curcumin in the form of Lipocurc™ in multiple myeloma (MM)-causing plasma cell lines and B-lymphocytes from healthy individuals and compare the uptake to previously published data for red blood cells (RBCs), peripheral blood mononuclear cells (PBMCs) from healthy individuals and PBMCs from patients with chronic lymphocytic leukemia (CLL-cells). MATERIALS AND METHODS: Two MM-producing cell lines were studied: RPMI-8266, an IgG lambda cell line, and NCL-H929, an IgA kappa line. The distribution of liposomal curcumin and its metabolism to the major stable metabolite tetrahydrocurcumin (THC) were measured in vitro in the cell lines and B-lymphocytes. The cells were incubated in plasma protein-supplemented media with liposomal curcumin (Lipocurc™) for 15 min at 37°C and the levels of curcumin and THC in cells and medium were determined by liquid chromatography tandem mass spectrometry. RESULTS: Extremely intense uptake was seen in both MM lines compared to that in B-lymphocytes and previously published data in RBCs, PBMCs and CLL cells. The levels of curcumin in RPMI-8266 and NCI-H929 cells were 14,225±847 and 12,723±500 pg/106 cells compared to 19±5,587±86 and 3,122±166 pg/106 cells in RBCs, PBMCs and CLL cells, respectively. Conversion of curcumin to THC was greatest in PBMCs, considerably less in CLL cells and minimal or absent in B-lymphocytes and MM cell lines. CONCLUSION: The extremely intense uptake of curcumin (as Lipocurc™) in both MM lines further suggests that Lipocurc™ should be investigated in the treatment of patients with this disease.

Pharmacokinetics of liposomal curcumin (Lipocurc™) infusion: effect of co-medication in cancer patients and comparison with healthy individuals.

PURPOSE: Investigation of the impact of co-medication on the plasma levels of curcumin and tetrahydrocurcumin (THC) in cancer patients and a comparison of the pharmacokinetics of curcumin and plasma levels of THC between cancer patients and healthy individuals following intravenous infusion of Lipocurc™ (liposomal curcumin). METHODS: Correlation analysis was used to determine the impact of co-medication on infusion rate normalized plasma levels of curcumin and THC in cancer patients and to compare the plasma levels of curcumin and THC at different infusion rates between cancer patients and healthy individuals. In vitro hepatocyte and red blood cell distribution experiments were conducted with Lipocurc™ to support clinical findings. Plasma concentration time data were analyzed by the non-compartmental method to determine and compare the pharmacokinetic parameters of curcumin in cancer patients and healthy individuals. RESULTS: Of 44 co-medications studied, three medications targeting the renin-angiotensin system, Lisinopril, Ramipril, and Valsartan elevated plasma levels of curcumin and THC in three cancer patients infused with Lipocurc™. Cell distribution experiments indicated that the disposition of curcumin in red blood cells may be a target for elevation of the plasma levels of curcumin. Plasma levels of curcumin in cancer patients increased to a greater extent with increased infusion rate compared to healthy individuals. Upon termination of infusion, the elimination phase for curcumin was shorter with a shorter terminal half-life and smaller volume of distribution for curcumin in cancer patients compared to healthy individuals. CONCLUSION: Either co-medications or health status, or both, can impact the pharmacokinetics of curcumin infusion (as Lipocurc™) in cancer patients.

A phase 1 dose-escalation study on the safety, tolerability and activity of liposomal curcumin (Lipocurc™) in patients with locally advanced or metastatic cancer.

PURPOSE: This study was conducted to investigate the safety and tolerability of increasing doses of liposomal curcumin in patients with metastatic cancer. Investigations of anti-tumor activity and of the pharmacokinetics of curcumin were secondary objectives. METHODS: In this phase I, single-center, open-label study in patients with metastatic tumors, liposomal curcumin was administered as a weekly intravenous infusion for 8 weeks. Dose escalation was started at 100 mg/m2 over 8 h and the dose increased to 300 mg/m2 over 6 h. RESULTS: 32 patients were treated. No dose-limiting toxicity was observed in 26 patients at doses between 100 and 300 mg/m2 over 8 h. Of six patients receiving 300 mg/m2 over 6 h, one patient developed hemolysis, and three other patients experienced hemoglobin decreases > 2 g/dL without signs of hemolysis. Pharmacokinetic analyses revealed stable curcumin plasma concentrations during infusion followed by rapid declines to undetectable levels after the infusion. Anti-tumor activity by RECIST V1.1 was not detected. Significant tumor marker responses and transient clinical benefit were observed in two patients. CONCLUSION: 300 mg/m2 liposomal curcumin over 6 h was the maximum tolerated dose in these heavily pretreated patients, and is the recommended starting dose for anti-cancer trials.

Distribution of Curcumin and THC in Peripheral Blood Mononuclear Cells Isolated from Healthy Individuals and Patients with Chronic Lymphocytic Leukemia.

Background/Aim: Curcumin is being widely investigated for its anticancer properties and studies in the literature suggest that curcumin distributes to a higher degree in tumor versus non-tumor cells. In the current study, we report on investigation of the distribution of curcumin and metabolism to THC in PBMC from healthy individuals and chronic lymphocytic leukemia (CLL) patients following exposure to Lipocurc™ (liposomal curcumin). Materials and Methods: The time and temperature-dependent distribution of liposomal curcumin and metabolism to tetrahydrocurcumin (THC) were measured in vitro in human peripheral blood mononuclear cells (PBMC) obtained from healthy individuals, PBMC HI (cryopreserved and freshly isolated PBMC) and CLL patients (cryopreserved PBMC) with lymphocyte counts ranging from 17-58×106 cells/ml (PBMCCLL,Grp 1) and >150×106 cells/ml (PBMCCLL,Grp 2). PBMC were incubated in plasma protein supplemented media with Lipocurc™ for 2-16 min at 37°C and 4°C and the cell and medium levels of curcumin determined by LC-MS/MS. Results: PBMC from CLL patients displayed a 2.2-2.6-fold higher distribution of curcumin compared to PBMC HI Curcumin distribution into PBMCCLL, Grp 1/Grp 2 ranged from 384.75 - 574.50 ng/g w.w. of cell pellet and was greater compared to PBMC HI that ranged from 122.27-220.59 ng/g w.w. of cell pellet following incubation for up to 15-16 min at 37°C. The distribution of curcumin into PBMCCLL,Grp 2 was time-dependent in comparison to PBMC HI which did not display a time-dependence and there was no temperature-dependence for curcumin distribution in either cell type. Curcumin was metabolized to THC in PBMC. The metabolism of curcumin to THC was not markedly different between PBMC HI (range=23.94-42.04 ng/g w.w. cell pellet) and PBMCCLL,Grp 1/Grp 2 (range=23.08-48.22 ng/g. w.w. cell pellet). However, a significantly greater time and temperature-dependence was noted for THC in PBMCCLL,Grp 2 compared to PBMC HI Conclusion: Curcumin distribution into PBMC from CLL patients was higher compared to PBMC from healthy individuals, while metabolism to THC was similar. The potential for a greater distribution of curcumin into PBMC from CLL patients may be of therapeutic benefit.

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.

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.

Erythropoietin preconditioning improves clinical and histologic outcome in an acute spinal cord ischemia and reperfusion rabbit model.

OBJECTIVE: This study examined effects and functional outcome of recombinant human erythropoietin (rhEPO) and carbamylated erythropoietin fusion protein (cEPO-FC) preconditioning in a rabbit model for spinal cord ischemia and resulting paraplegia. This model was chosen because only a small surgical effect is needed to cause paraplegia in rabbits, which facilitates postoperative observation of animals. METHODS: Anesthetized but spontaneously breathing New Zealand White rabbits randomly received cEPO-FC (50 µg/kg; n = 8), rhEPO (5000 IU/kg; n = 10), or vehicle (control; n = 10) 30 minutes before and after infrarenal aortic clamping. Ideal clamping time of 22 minutes was identified from preceding clamping tests (15-25 minutes). Postoperative observation time was 96 hours. Spinal cord function was assessed by neurologic evaluation of hind limb motor function every 12 hours using a modified Tarlov score. Spinal cord tissue damage was evaluated after 96 hours using hematoxylin and eosin, elastica van Gieson, Nissl, Masson-Goldner, and hemosiderin staining. Plasma levels of cell senescence markers stathmin, chitinase 1/3, elongation factor 1-α were determined. RESULTS: Rabbits that received rhEPO showed significant improvement of spontaneous lower limb movements until 36 hours of reperfusion and improved histologic scores upon examination of the lumbar spinal cord compared with the control group. In contrast, cEPO-FC treatment showed comparable outcome to the control group concerning movements of the lower limbs and histology. Senescence markers were elevated in the control group, but not in the treatment groups, except for chitinase 3 in the rhEPO group. Only stathmin showed no significant effect. Markers for senescence might increase after acute ischemic injury. Attenuation of senescence markers might not come alone from improvement of the spinal cord. CONCLUSIONS: Preconditioning with rhEPO attenuates ischemia/reperfusion injury of the spinal cord, whereas the carbamylated derivative (cEPO-FC) showed no positive effect on spinal cord function.

Comparison of pharmacokinetic and safety profiles between Bemfola(®) and Gonal-f(®) after subcutaneous application.

Recombinant human follicle stimulating hormone (r-hFSH) is effective and safe for controlled ovarian stimulation. Bemfola(®) (Finox AG, Burgdorf, Switzerland), a new biosimilar r-hFSH, has proven comparable non-clinical pharmacological profiles to those of the widely used Gonal-f(®) (Serono Pharma S.p.A., Bari, Italy). The objective of this study was to show that Bemfola(®) yields comparable clinical pharmacokinetic (PK) and safety profiles to Gonal-f(®) in healthy female subjects. In this randomized, Phase I trial conducted in healthy female volunteers (N = 32), a 2-period, balanced 2-treatment crossover design was used. A single subcutaneous dose of 225 IU Bemfola(®) or Gonal-f(®) was administered in each treatment period per sequence. Blood was collected for pharmacokinetic analysis until 10 days after each r-hFSH treatment. For down-regulation of endogenous FSH subjects were given a depot injection with leuprolide acetate prior to the study drug in either sequence. Pharmacokinetic data was available for 23 subjects. No appreciable differences in key PK parameters were detected between the r-hFSH products as per non-compartmental PK analysis [i.e. for Bemfola(®) and Gonal-f(®) respectively AUC0-192 424.90 and 432.75 IU h/L, C max 0.98 and 0.95 IU/L, T max 24.0 h (range 6.0-24.0) and 24.0 h (range 9.0-24.0), t 1/2 43.58 h [standard deviation (SD 14.17)] and 42.58 h (SD 16.47), and K e 0.0075 1/h (SD 0.003) and 0.0077 1/h (SD 0.002)]. Subgroup analysis for estradiol (E2) response was similar for Bemfola(®) and Gonal f(®) (AUC(0--120) p = 0.21 and C max p = 0.82). No major safety issues were identified and no immunogenic reaction to r-hFSH was observed. The results of this study indicate that a single dose of Bemfola(®) exhibits pharmacokinetic and safety profiles comparable to Gonal-f(®) in healthy young women.

Regulatory approval and a first-in-human phase I clinical trial of a monoclonal antibody produced in transgenic tobacco plants.

Although plant biotechnology has been widely investigated for the production of clinical-grade monoclonal antibodies, no antibody products derived from transgenic plants have yet been approved by pharmaceutical regulators for clinical testing. In the Pharma-Planta project, the HIV-neutralizing human monoclonal antibody 2G12 was expressed in transgenic tobacco (Nicotiana tabacum). The scientific, technical and regulatory demands of good manufacturing practice (GMP) were addressed by comprehensive molecular characterization of the transgene locus, confirmation of genetic and phenotypic stability over several generations of transgenic plants, and by establishing standard operating procedures for the creation of a master seed bank, plant cultivation, harvest, initial processing, downstream processing and purification. The project developed specifications for the plant-derived antibody (P2G12) as an active pharmaceutical ingredient (API) based on (i) the guidelines for the manufacture of monoclonal antibodies in cell culture systems; (ii) the draft European Medicines Agency Points to Consider document on quality requirements for APIs produced in transgenic plants; and (iii) de novo guidelines developed with European national regulators. From the resulting process, a GMP manufacturing authorization was issued by the competent authority in Germany for transgenic plant-derived monoclonal antibodies for use in a phase I clinical evaluation. Following preclinical evaluation and ethical approval, a clinical trial application was accepted by the UK national pharmaceutical regulator. A first-in-human, double-blind, placebo-controlled, randomized, dose-escalation phase I safety study of a single vaginal administration of P2G12 was carried out in healthy female subjects. The successful completion of the clinical trial marks a significant milestone in the commercial development of plant-derived pharmaceutical proteins.

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.

MABGEL 1: first phase 1 trial of the anti-HIV-1 monoclonal antibodies 2F5, 4E10 and 2G12 as a vaginal microbicide.

BACKGROUND: Monoclonal antibodies (mAbs) which potently neutralize a broad range of HIV isolates are potential microbicide candidates. To date, topical application of mAbs in humans and their stability in vaginal secretions has not been studied. OBJECTIVES: To assess the pharmacokinetics and safety of the mAbs 2F5, 4E10 and 2G12 when applied vaginally in women. DESIGN: A randomized, double-blind, placebo-controlled phase 1 trial. METHODS: Twenty-eight healthy, sexually abstinent women administered 2.5 g of gel daily for 12 days containing either 10 or 20 mg/g of each mAb (MABGEL) or placebo. Main clinical evaluations and sampling occurred at baseline, 1, 8, and 24 hours post-1st dose and 12 and 36 hours post-12th dose. RESULTS: After adjustment for dilution factors, median levels of 2F5, 4E10 and 2G12 in vaginal secretions at 1 hour post high-dose MABGEL were 7.74, 5.28 and 7.48 mg/ml respectively. Levels of 2F5 and 4E10 declined exponentially thereafter with similar estimated half-lives (4.6 and 4.3 hours). In contrast, 2G12 levels declined more rapidly in the first 8 hours, with an estimated half-life of 1.4 hours during this period. There was no evidence of systemic absorption. There were no significant differences in local or systemic adverse event rates or vaginal flora changes (by qPCR) between active and placebo gel arms. Whilst at least 1 adverse event was recorded in 96% of participants, 95% were mild and none were serious. CONCLUSIONS: Vaginal application of 50 mg of each mAb daily was safe over a 12 day period. Median mAb concentrations detected at 8 hours post dose were potentially sufficient to block HIV transmission.2G12 exhibited more rapid elimination from the human vagina than 4E10 and 2F5, likely due to poor stability of 2G12 in acidic human vaginal secretions. Further research is needed to develop mAb-based vaginal microbicides and delivery systems. TRIAL REGISTRATION: ISRCTN 64808733 UK CRN Portfolio 6470.

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.

The neuroprotective and neurorescue effects of carbamylated erythropoietin Fc fusion protein (CEPO-Fc) in a rat model of Parkinson's disease.

Parkinson's disease is characterized by progressive degeneration of dopaminergic neurons. Thus the development of therapeutic neuroprotection and neurorescue strategies to mitigate disease progression is important. In this study we evaluated the neuroprotective/rescue effects of erythropoietin Fc fusion protein (EPO-Fc) and carbamylated erythropoietin Fc fusion protein (CEPO-Fc) in a rat model of Parkinson's disease. Adult female Sprague-Dawley rats received intraperitoneal injection of EPO-Fc, CEPO-Fc or PBS. Behavioral evaluations consisted of rota-rod, cylinder and amphetamine-induced rotation tests. In the neuroprotection experiment, the CEPO-Fc group demonstrated significant improvement compared with the EPO-Fc group on the amphetamine-induced rotation test throughout the four-week follow-up period. Histologically, significantly more tyrosine hydroxylase (TH)-positive neurons were recognized in the substantia nigra (SN) pars compacta in the CEPO-Fc group than in the PBS and EPO-Fc groups. In the neurorescue experiment, rats receiving CEPO-Fc showed significantly better behavioural scores than those receiving PBS. The histological data concerning striatum also showed that the CEPO-Fc group had significantly better preservation of TH-positive fibers compared to the PBS and EPO-Fc groups. Importantly, there were no increases in hematocrit or hemoglobin levels in the CEPO-Fc group in either the neuroprotection or the neurorescue experiments. In conclusion, the newly developed CEPO-Fc might confer neuroprotective and neurorescue benefits in a rat model of Parkinson's disease without the side effects associated with polycythemia. CEPO-Fc might be a therapeutic tool for patients with Parkinson's disease.

Carbamylated erythropoietin-FC fusion protein and recombinant human erythropoietin during porcine kidney ischemia/reperfusion injury.

PURPOSE: To test the hypothesis that a carbamylated EPO-FC fusion protein (cEPO-FC) or recombinant human erythropoietin (rhEPO) would protect against kidney ischemia/reperfusion (I/R) injury in pigs with atherosclerosis. METHODS: Anesthetized and mechanically ventilated animals received cEPO-FC (50 µg kg(-1)), rhEPO (5,000 IU kg(-1)), or vehicle (n = 9 per group) prior to 120 min of aortic occlusion and over 4 h of reperfusion. During aortic occlusion, mean arterial pressure (MAP) was maintained at 80-120 % of baseline values by esmolol, nitroglycerin, and ATP. During reperfusion, noradrenaline was titrated to keep MAP at pre-ischemic levels. Blood creatinine and neutrophil gelatinase-associated lipocalin (NGAL) levels, creatinine clearance, fractional Na(+) excretion, and HE and PAS staining were used to assess kidney function and histological damage. Plasma interleukin-6, tumor necrosis factor-α, nitrate + nitrite and 8-isoprostane levels were measured to assess systemic inflammation, and nitrosative and oxidative stress. RESULTS: I/R caused acute kidney injury with reduced creatinine clearance, increased fractional Na(+) excretion and NGAL levels, moderate to severe glomerular and tubular damage and apoptosis, systemic inflammation and oxidative and nitrosative stress, but there were no differences between the treatment groups. Pre-ischemia nitrate + nitrite and 8-isoprostanes levels were lower and higher, respectively, than in healthy animals of a previous study, and immune histochemistry showed higher endothelial nitric oxide synthase and lower EPO receptor expression in pre-ischemia kidney biopsies than in biopsies from healthy animals. CONCLUSIONS: In swine with atherosclerosis, rhEPO and cEPO-FC failed to attenuate prolonged ischemia-induced kidney injury within an 8-h reperfusion period, possibly due to reduced EPO receptor expression resulting from pre-existing oxidative stress and/or reduced NO release.

Infusion pharmacokinetics of Lipocurc™ (liposomal curcumin) and its metabolite tetrahydrocurcumin in Beagle dogs.

Curcumin's instability and its metabolite, tetrahydrocurcumin (THC) pose a major issue for the establishment of dependable pharmacokinetics and excretion profiles. Additional pharmacokinetic variances are associated with durations of intravenous infusions. We found that stabilizing curcumin with phosphoric acid allows accurate quantitative determinations of curcuminoids in the plasma and bile, by preventing degradation during the analytical processes. Two male and two females dogs were infused with Lipocurc™ 10 mg/kg over two hours, and another four dogs (two males and two females) were infused with Lipocurc™ 10 mg/kg over eight hours. Plasma levels of curcumin and THC were determined during the infusions and at necropsy. THC levels were 6.3-9.6-fold higher than curcumin during both infusion rates, suggesting a combination of a high-rate of enzymatic curcumin metabolism and a comparatively slower rate of blood THC clearance. When levels of curcumin and THC were compared during infusion durations, the two-hour infusion levels were significantly higher than the eight-hour infusion. The plasma half-lives of both compounds following the two-hour infusion ranged from 0.4-0.7 hours, and was a consequence of both hepatic and renal clearance However, at higher plasma concentrations renal excretion predominated, particularly with THC. Enhanced clearance rates were noted during eight-hour infusions, which prevented achieving a steady state. These observations suggest that for leukemias and lymphomas, the two-hour infusion may be advantageous based upon higher concentration profiles, and unstimulated clearance rates, however data on curcumin penetration into circulating hematopoietic cancer cells and efficacy data are required in order to confirm these suggestions.

Tissue distribution of (Lipocurc™) liposomal curcumin and tetrahydrocurcumin following two- and eight-hour infusions in Beagle dogs.

This study interrogated whether different durations of intravenous infusions of lipocurc™ would alter curcumin metabolism, tissue distribution and whether treating necropsied tissues of Beagle dogs with phosphoric acid prior to measuring curcumin and its metabolite, tetrahydrocurcumin (THC), would stabilize the compounds allowing for accurate analytic measurements. Two cohorts comprising two male and two female dogs were infused each intravenously with 10 mg/kg lipocurc™, either over two hours or over eight hours. Tissue data from each cohort was averaged from four dogs. Curcumin and THC distributed among all 13 tissues were examined at necropsy. The highest curcumin level was observed in the lungs followed by the liver. Tissue levels of curcumin in the lung, spleen and liver increased substantially following the eight-hour infusion compared to the two-hour infusion. The pancreas, kidney and urinary bladder also contained relatively high curcumin levels. Tissue partition coefficients for curcumin and THC were also higher for the eight-hour infusion than the two-hour infusion. The tissue THC/curcumin ratio varied in a tissue-specific manner and was lower for the eight-hour compared to the two-hour infusion. In conclusion, this raised the possibility that prolonged infusion of curcumin may facilitate distribution into tissues via a transporter-dependent mechanism and elevated tissue concentrations of curcumin may inhibit or saturate a putative reductase enzyme converting curcumin to THC. The addition of phosphoric acid stabilized the levels of curcumin and THC in some but not all the examined tissues, raising issues of tissue-specific curcumin and THC stability.

Human pharmacokinetics of intravenous recombinant human Cu/Zn superoxide dismutase.

OBJECTIVE: Oxidative stress plays an important role in human disease, but antioxidant therapies are limited. Under physiological conditions superoxide is controlled by the enzyme superoxide dismutase. A recombinant human Cu/Zn superoxide dismutase (rhSOD) might open new therapeutic possibilities. METHODS: Safety profile and pharmacokinetics in plasma and urine were assessed in an open label phase I study with dose-escalation. 18 healthy male volunteers received a single intravenous 10-minute infusion of 150, 300, or 600 mg rhSOD, respectively (n = 6 per dose group). RESULTS: rhSOD was well tolerated. Peak plasma concentrations (cmax; mean ± SD) were reached at the end of infusion, with 32.96 ± 10.31, 51.60 ± 8.23, and 103.90 ± 19.02 µg/ ml, respectively. Non-compartmental halflife was 1.06 ± 0.37, 1.59 ± 0.64, and 1.63 ± 0.28 hours. Urinary excretion (10 h) showed dose-dependent relative increases with 11.28 ± 6.46 (7.5%), 54.93 ± 15.25 (18.3%), and 191.81 ± 104.60 mg (32.0%). CONCLUSIONS: Our results show a good safety profile and predictable pharmacokinetics of rhSOD, suggesting that therapeutic exploratory studies might be safely conducted in humans.

The effect of erythropoietin on platelet and endothelial activation markers: a prospective trial in healthy volunteers.

Erythropoietin (EPO) enhances formation of red blood cells and also affects thrombopoiesis and platelet function. We hypothesized that the effect of EPO may be reflected by changes in thromboxane B2 (TXB2) and endothelial cell function. Six male and six female subjects received recombinant human epoetin alpha (Erypo®) intravenously (300 U/kg). Biomarker levels were assessed at baseline and 4, 24, 48 and 72 hours after infusion. Epoetin alpha increased TXB2 levels by 140%, which reached significance at 48 hours (6.6 ± 5 ng/ml vs. 15 ± 9 ng/ml; p = 0.044) and remained at that level at 72 hours. In line, epoetin alpha increased E-selectin levels by 25% already at 24 hours (39 ± 21 ng/ml vs. 49 ± 26 ng/ml; p < 0.001) which stayed at this level until 72 hours (p < 0.001). The raise in platelet activation markers corresponded to an 88% increase in reticulocyte count (43 ± 10 × 10(9)/l vs. 81 ± 17 × 10(9)/l; p < 0.001) and a 9% increase in platelet count at 72 hours (224 ± 45 × 10(9)/l vs. 244 ± 52 × 10(9)/l; p = 0.005). Thrombomodulin and von Willebrand factor concentrations were not significantly altered by epoetin alpha. Interestingly, gender differences in the baseline levels of E-selectin and thrombomodulin were observed. E-selectin and thrombomodulin levels were doubled in men compared to women (51 ± 24 and 28 ± 10 ng/ml; p = 0.025 and 30 ± 5 ng/ml vs. 16 ± 5 ng/ml; p = 0.002, respectively). EPO increases TXB2 serum levels and soluble E-selectin. Further studies are needed to investigate whether these markers might be useful for estimation of thromboembolic risk during EPO-therapy and whether inhibition of thromboxane formation may lower thrombotic complications during EPO treatment: NCT01392612.

Comparison of carbamylated erythropoietin-FC fusion protein and recombinant human erythropoietin during porcine aortic balloon occlusion-induced spinal cord ischemia/reperfusion injury.

PURPOSE: Recombinant human erythropoietin (rhEPO) attenuated ischemia/reperfusion (I/R) injury-induced spinal cord damage. Since carbamylated EPO derivatives are stated to be devoid of rhEPO side effects, we tested the hypothesis that a newly developed carbamylated EPO-FC fusion protein (cEPO-FC) would compare favorably with rhEPO. METHODS: Anesthetized and mechanically ventilated pigs randomly received cEPO-FC (50 µg kg(-1)), rhEPO (5,000 IU kg(-1)) or vehicle (n = 9 per group) 30 min prior to 30 min of aortic occlusion and over the 4 h of reperfusion. During aortic occlusion, mean arterial pressure (MAP) was maintained at 80-120% of baseline values by esmolol, nitroglycerin, and adenosine-5'-triphosphate (ATP). During reperfusion, noradrenaline was titrated to keep MAP at pre-ischemic levels. Spinal cord function was assessed by motor evoked potentials (MEP) and lower limb reflexes. Tissue damage was evaluated using hematoxylin and eosin, Nissl, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining. Plasma levels of interleukin-6, tumor necrosis factor-α, and 8-isoprostanes were measured as markers of systemic inflammation and oxidative stress. RESULTS: While only cEPO-FC restored MEP amplitude to values close to pre-occlusion levels, both cEPO-FC and rhEPO comparably restored lower limb reflexes and reduced the percentage of damaged neurons. Infiltration of mononuclear inflammatory cells was moderate without intergroup difference; positive TUNEL staining was barely detectable in any group. I/R injury increased blood cytokine levels without intergroup difference, whereas both cEPO-FC and rhEPO significantly lowered 8-isoprostane levels. CONCLUSIONS: In a porcine model of aortic balloon occlusion-induced spinal cord I/R injury, cEPO-FC and rhEPO comparably protected against ischemic spinal cord dysfunction and neuronal damage. This effect coincided with attenuated oxidative stress.