Cellular binding and uptake of fluorescent glucose analogs 2-NBDG and 6-NBDG occurs independent of membrane glucose transporters.

The classical methods for determining glucose uptake rates in living cells involve the use of isotopically labeled 2-deoxy-d-glucose or 3-O-methyl-d-glucose, which enter cells via well-characterized membrane transporters of the SLC2A and SLC5A families, respectively. These classical methods, however, are increasingly being displaced by high-throughput assays that utilize fluorescent analogs of glucose. Among the most commonly used of these analogs are 2-NBDG and 6-NBDG, which contain a bulky 7-nitro-2,1,3-benzoxadiazol-4-yl-amino moiety in place of a hydroxy group on d-glucose. This fluorescent group significantly alters both the size and shape of these molecules compared to glucose, calling into question whether they actually enter cells by the same transport mechanisms. In this study, we took advantage of the well-defined glucose uptake mechanism of L929 murine fibroblasts, which rely exclusively on the Glut1/Slc2a1 membrane transporter. We demonstrate that neither pharmacologic inhibition of Glut1 nor genetic manipulation of its expression has a significant impact on the binding or uptake of 2-NBDG or 6-NBDG by L929 cells, though both approaches significantly impact [3H]-2-deoxyglucose uptake rates. Together these data indicate that 2-NBDG and 6-NBDG can bind and enter mammalian cells by transporter-independent mechanisms, which calls into question their utility as an accurate proxy for glucose transport.

Variation in the pharmacokinetics of glucosamine in healthy individuals.

OBJECTIVES: Clinical trial data for the efficacy of glucosamine in OA are conflicting. Reportedly, Rotta-manufactured glucosamine products are more likely to be effective, and a possible explanation is greater bioavailability than other brands. Specifically, the aim was to compare the steady-state pharmacokinetics of Rotta- and non-Rotta-manufactured glucosamine products in healthy volunteers and examine the interindividual variability. METHODS: In a crossover design, healthy adult participants ingested 1500 mg/day of a Rotta (DONA powder sachets; imported by Mylan Health, Carole Park, QLD, Australia) and a non-Rotta (glucosamine sulphate 1500 mg one-a-day tablet; Blackmores, Warriewood, NSW, Australia) glucosamine product/brand individually for 6 days. Blood samples were collected immediately before and for 12 h after the ingestion of the last dose of each brand and analysed to determine plasma levels of glucosamine. The pharmacokinetic parameters at steady state [including the minimum (Css min) and maximum (Css max) plasma concentration of glucosamine, time to reach Css max post-dosing (Tss max) and area under the plasma concentration vs time curve (AUCss 0-12)] for each brand were calculated and statistically compared. RESULTS: Fourteen participants [mean age 35.5 years (s.d. 8.8)] were recruited (64.2% males). No significant differences were observed in the pharmacokinetic parameters between the two brands. However, for both brands, the coefficient of variation for Css min, Tss max and AUCss 0-12 exceeded 20%, indicating considerable differences in the parameters between participants. No significant association of the pharmacokinetic parameters was observed with various dosing- and participant-related variables. CONCLUSION: Substantial interindividual differences in the absorption and elimination of glucosamine could be a cause of variable clinical outcomes in OA. TRIAL REGISTRATION: The study was registered with the Australian New Zealand Clinical Trials Registry (http://www.ANZCTR.org.au/ACTRN12618000699268p.aspx), number ACTRN12618000699268p.

[Symptomatic slow-acting drugs in the treatment of osteoarthritis: focus on glucosamine preparations]. / Simptomaticheskie lekarstvennye sredstva zamedlennogo deistviya pri lechenii osteoartrita: fokus na preparaty glyukozamina.

The article discusses the place of symptomatic slow-acting drugs in current guidelines for the treatment of osteoarthritis. Special emphasis is put ot glucosamine preparations, the attitude towards which, until recently, was ambiguous. The results of experimental and clinical studies demonstrating the advantages of crystalline glucosamine sulfate over preparations/food additives of glucosamine hydrochloride are presented. The differences in the pharmacodynamics and pharmacokinetics of glucosamine sulfate and glucosamine hydrochloride, which may be the reason for the ineffectiveness of the latter in clinical trials, are discussed.

Synthesis, in vitro inhibitory activity, kinetic study and molecular docking of novel N-alkyl-deoxynojirimycin derivatives as potential α-glucosidase inhibitors.

A series of novel N-alkyl-1-deoxynojirimycin derivatives 25 ∼ 44 were synthesised and evaluated for their in vitro α-glucosidase inhibitory activity to develop α-glucosidase inhibitors with high activity. All twenty compounds exhibited α-glucosidase inhibitory activity with IC50 values ranging from 30.0 ± 0.6 µM to 2000 µM as compared to standard acarbose (IC50 = 822.0 ± 1.5 µM). The most active compound 43 was ∼27-fold more active than acarbose. Kinetic study revealed that compounds 43, 40, and 34 were all competitive inhibitors on α-glucosidase with Ki of 10 µM, 52 µM, and 150 µM, respectively. Molecular docking demonstrated that the high active inhibitors interacted with α-glucosidase by four types of interactions, including hydrogen bonds, π-π stacking interactions, hydrophobic interactions, and electrostatic interaction. Among all the interactions, the π-π stacking interaction and hydrogen bond played a significant role in a various range of activities of the compounds.

Variation in Plasma Levels of Glucosamine With Chronic Dosing: A Possible Reason for Inconsistent Clinical Outcomes in Osteoarthritis.

PURPOSE: Glucosamine is widely used by patients with osteoarthritis (OA) to provide symptomatic relief and to delay disease progression. However, clinical studies have reported inconsistent clinical outcomes. The current study hypothesized that the reported inconsistent clinical results could be, in part, due to variable bioavailability and elimination of glucosamine. This study therefore aimed to determine steady-state minimum plasma concentrations (Css min) of glucosamine to examine the variability among patients taking the supplement. METHODS: Patients with OA who had been taking glucosamine for at least 1 week were recruited. Patients' blood samples were collected 24 h after the ingestion of the previous dose to determine Observed Css min and after a 5-day washout period to determine the endogenous glucosamine levels (GlcNend). The Actual Css min was calculated by using the following equation: Actual Css min = Observed Css min - GlcNend. The glucosamine plasma concentrations were determined by using a previously developed HPLC method. FINDINGS: Ninety-one participants (age range, 42-89 years; mean [SD] age, 68.2 [7.6] years) were recruited (70% females). There was substantial (106-fold) variation, with a 45% coefficient of variation, between the Actual Css min levels (3-320 ng/mL) in participants. No significant association of Actual Css min was observed with various dose- and patient-related variables. IMPLICATIONS: The observed high variability in steady-state plasma concentrations indicates substantial inter-patient differences in the absorption and elimination of glucosamine, which could be a cause for inconsistent clinical outcomes in patients with OA.

Comparative Analyses of Pharmaceuticals or Food Supplements Containing Chondroitin Sulfate: Are Their Bioactivities Equivalent?

INTRODUCTION: Oral supplementation of chondroitin sulfate (CS) and glucosamine (GlcN), symptomatic slow-acting molecules, is recommended by European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis and Musculoskeletal Diseases (ESCEO) and other European Union (EU) guidelines for the restoration of the articular cartilage surface in patients affected by osteoarthritis (OA). They are commercialized as pharmaceutical grade products and as food supplements in combination with plant extracts hyaluronic acid, methylsulfonylmethane, and other components. Food supplements do not need to undergo the strict regulatory controls of pharmaceutical grade products; thus, composition and contaminants that could be present may not be evidenced before commercialization and these uncertainties may give rise to concerns about the bioactivity of these formulations. METHODS: In this paper 10 different food supplements (FS) from diverse European countries were analyzed in comparison with two pharmaceutical grade products (Ph) using updated analytical approaches and biochemical cell-based assays. The purity, the titer, and the origin of CS in Ph and FS samples were initially assessed in order to successively compare the biological function. Both food supplements and pharmaceutical formulations were tested in vitro, using the same final CS concentration, on primary chondrocytes and synoviocytes in terms of (i) cell viability, (ii) activation of the NF-κB-mediated inflammation pathway, (iii) cartilage oligomeric matrix protein (COMP-2), IL-6, and IL-8 production. RESULTS: All the FS presented a certain insoluble fraction; the CS and the GlcN contents were lower than the declared ones in 9/10 and 8/10 samples, respectively. All FS contained keratan sulfate (KS) at up to 50% of the total glycosaminoglycan amount declared on the label. Primary cells treated with the samples diluted to present the same CS concentration in the medium showed cytotoxicity in 7/10 FS while Ph preserved viability and reduced NF-κB, COMP-2, and secreted inflammatory cytokines. CONCLUSION: Among all samples tested, the pharmaceutical grade products demonstrated effective modulation of biomarkers counteracting the inflammation status and improving viability and the physiological condition of OA human primary chondrocyte and synoviocyte cells. In contrast to that, most FS were cytotoxic at the tested concentrations, and only 3/10 of them showed similarities to Ph sample behavior in vitro. FUNDING: This work was partially supported by PON01_1226 NUTRAFAST, MIUR Ministero dell'Università e della Ricerca Scientifica. Bioteknet financed two short-term grants for graduate technicians. The journal's Rapid Service and Open Access fees were funded by IBSA CH.

Differentiation of patented crystalline glucosamine sulfate from other glucosamine preparations will optimize osteoarthritis treatment.

Symptomatic slow-acting drugs for osteoarthritis (SYSADOAs) are recommended for the medium- to long-term management of knee osteoarthritis (OA) due to their abilities to control pain, improve function and delay joint structural changes. Among SYSADOAs, evidence is greatest for the patented crystalline glucosamine sulfate (pCGS) formulation (Mylan). Glucosamine is widely available as glucosamine sulfate (GS) and glucosamine hydrochloride (GH) preparations that vary substantially in molecular form, pharmaceutical formulation and dose regimen. Only pCGS is given as a highly bioavailable once-daily dose (1500 mg), which consistently delivers the plasma levels of around 10 µmol/L required to inhibit interleukin-1-induced expression of genes involved in the pathophysiology of joint inflammation and tissue destruction. Careful consideration of the evidence base reveals that only pCGS reliably provides a moderate effect size on pain that is higher than paracetamol and equivalent to non-steroidal anti-inflammatory drugs (NSAIDs), while non-crystalline GS and GH fail to reach statistical significance for pain reduction. Chronic administration of pCGS has disease-modifying effects, with a reduction in need for total joint replacement lasting for 5 years after treatment cessation. Pharmacoeconomic studies of pCGS demonstrate long-term reduction in additional pain analgesia and NSAIDs, with a 50% reduction in costs of other OA medication and healthcare consultations. Consequently, pCGS is the logical choice, with demonstrated medium-term control of pain and lasting impact on disease progression. Physician and patient education on the differentiation of pCGS from other glucosamine formulations will help to improve treatment selection, increase treatment adherence, and optimize clinical benefit in OA.

Glucosamine-paracetamol spray-dried solid dispersions with maximized intrinsic dissolution rate, bioavailability and decreased levels of in vivo toxic metabolites.

PURPOSE: This study is aimed at preparing and testing physicochemical, pharmacokinetic and levels of toxic metabolites of paracetamol and glucosamine solid dispersions intended for multiple deliveries via the parenteral or per oral route. METHODS: Solid dispersions were prepared using the spray drying technique at different molar ratios of paracetamol and glucosamine. Characterization of the solid dispersions was carried out using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), equilibrium solubility and intrinsic dissolution rate. In vivo pharmacokinetics and toxic metabolites of the prepared dispersions were evaluated and compared to those of pure drugs and physical mixtures. RESULTS: Instant water solubility and more than 7-fold increase in dissolution rate led to significantly high plasma drug concentration (>6.5-fold) compared to paracetamol alone. More than 2-fold increase in area under the curve from 0 to 24 h from the dispersions was noticed on the third day of oral dosing to animals. Lower number and concentration followed by the complete disappearance of toxic pathway metabolites were observed on second and third days of dosing with solid dispersions and physical mixtures, respectively. CONCLUSIONS: The spray-dried dispersions support safer and more effective delivery of multiple doses of paracetamol, leading to an acceleration of its analgesic actions. Synergism between the analgesic actions of paracetamol and joint protective actions of glucosamine in this combination is expected to facilitate effective treatment of persistent pain-related illnesses such as osteoarthritis.

Novel 99mTc-Labeled Glucose Derivative for Single Photon Emission Computed Tomography: A Promising Tumor Imaging Agent.

In this study, a d-glucosamine derivative with an isonitrile group (CN5DG) was synthesized and it was chosen to coordinate with 99mTc for preparing 99mTc-CN5DG. 99mTc-CN5DG could be readily obtained with high radiochemical purity (>95%) and had great in vitro stability and metabolic stability in urine. The radiotracer demonstrated a positive response to the administration of glucose and insulin in S180 and A549 tumor cells in vitro, suggesting the mechanism of 99mTc-CN5DG into tumor cells was related to glucose transporters. Biodistribution studies in mice bearing A549 xenografts showed 99mTc-CN5DG had a high tumor uptake and high tumor-to-background ratios. SPECT/CT images further supported its ability for tumor imaging. As a cheap, conveniently made and widely available probe, 99mTc-CN5DG would become a potential "working horse" and be a breakthrough in 99mTc-labeled radiopharmaceuticals for tumor detection.

Imaging cellular pharmacokinetics of 18F-FDG and 6-NBDG uptake by inflammatory and stem cells.

OBJECTIVES: Myocardial infarction (MI) causes significant loss of cardiomyocytes, myocardial tissue damage, and impairment of myocardial function. The inability of cardiomyocytes to proliferate prevents the heart from self-regeneration. The treatment for advanced heart failure following an MI is heart transplantation despite the limited availability of the organs. Thus, stem-cell-based cardiac therapies could ultimately prevent heart failure by repairing injured myocardium that reverses cardiomyocyte loss. However, stem-cell-based therapies lack understanding of the mechanisms behind a successful therapy, including difficulty tracking stem cells to provide information on cell migration, proliferation and differentiation. In this study, we have investigated the interaction between different types of stem and inflammatory cells and cell-targeted imaging molecules, 18F-FDG and 6-NBDG, to identify uptake patterns and pharmacokinetics in vitro. METHODS: Macrophages (both M1 and M2), human induced pluripotent stem cells (hiPSCs), and human amniotic mesenchymal stem cells (hAMSCs) were incubated with either 18F-FDG or 6-NBDG. Excess radiotracer and fluorescence were removed and a 100 µm-thin CdWO4 scintillator plate was placed on top of the cells for radioluminescence microscopy imaging of 18F-FDG uptake, while no scintillator was needed for fluorescence imaging of 6-NBDG uptake. Light produced following beta decay was imaged with a highly sensitive inverted microscope (LV200, Olympus) and an Electron Multiplying Charge-Couple Device (EM-CCD) camera. Custom-written software was developed in MATLAB for image processing. RESULTS: The average cellular activity of 18F-FDG in a single cell of hAMSCs (0.670±0.028 fCi/µm2, P = 0.001) was 20% and 36% higher compared to uptake in hiPSCs (0.540±0.026 fCi/µm2, P = 0.003) and macrophages (0.430±0.023 fCi/µm2, P = 0.002), respectively. hAMSCs exhibited the slowest influx (0.210 min-1) but the fastest efflux (0.327 min-1) rate compared to the other tested cell lines for 18F-FDG. This cell line also has the highest phosphorylation but exhibited the lowest rate of de-phosphorylation. The uptake pattern for 6-NBDG was very different in these three cell lines. The average cellular activity of 6-NBDG in a single cell of macrophages (0.570±0.230 fM/µm2, P = 0.004) was 38% and 14% higher compared to hiPSCs (0.350±0.160 fM/µm2, P = 0.001) and hAMSCs (0.490±0.028 fM/µm2, P = 0.006), respectively. The influx (0.276 min-1), efflux (0.612 min-1), phosphorylation (0.269 min-1), and de-phosphorylation (0.049 min-1) rates were also highest for macrophages compared to the other two tested cell lines. CONCLUSION: hAMSCs were found to be 2-3× more sensitive to 18F-FDG molecule compared to hiPSCs/macrophages. However, macrophages exhibited the most sensitivity towards 6-NBDG. Based on this result, hAMSCs targeted with 18F-FDG could be more suitable for understanding the mechanisms behind successful therapy for treating MI patients by gathering information on cell migration, proliferation and differentiation.

Enhancing the Intestinal Permeation of the Chondroprotective Nutraceuticals Glucosamine Sulphate and Chondroitin Sulphate Using Conventional and Modified Liposomes.

BACKGROUND: Liposomes are promising systems for the delivery of macromolecules and poorly absorbed drugs, owing to their ability to compartmentalize drugs, their biodegradability and biocompatibility. OBJECTIVE: The aim of the present study was to formulate and evaluate conventional and modified glucosamine sulphate (GluS) and chondroitin sulphate (CS) liposomal formulations, to enhance their oral permeation for the treatment of osteoarthritis (OA). METHOD: Liposomal formulations were prepared by the thin-film hydration method using two types of phospholipids; Epikuron 200© and Epikuron 200© SH, and three permeation enhancers; poloxamer 407, cetylpyridinium chloride, and sodium deoxycholate. In-vitro characterization of liposomal formulations was conducted in terms of entrapment efficiency, particle size, zeta potential, viscosity, physical stability and mucoadhesive strength. Surface morphology and vesicle shape, ex-vivo intestinal permeation, and histopathological studies were further carried out on the selected formulation. RESULTS: Results showed that the liposomal formulation containing sodium deoxycholate was the most optimum formula, showing high entrapment efficiency (60.11% for GluS and 64.10% for CS) with a particle size of 4.40 µm, zeta potential of -17.2 mV and viscosity of 2.50 cP. CONCLUSION: The aforementioned formula displayed the highest cumulative % permeated of GluS and CS through rabbit intestinal mucosa compared to the solution of drugs and other liposomal formulations (64.20% for GluS and 78.21% for CS) after 2 hours. There were no histopathological alterations in the intestinal tissue, suggesting the safety of the utilized liposomal formulation. In light of the above, liposomes can be considered promising oral permeation-enhancer system for GluS and CS, which is worthy of future bioavailability experimentation.

Effect of albumin on the fluorescence quantum yield of porphyrin -based agents for fluorescent diagnostics.

BACKGROUND: Among modern methods of tumor diagnosis, fluorescent methods are considered one of the most prospective. Diagnostic agents (DAs) spread throughout the body by the bloodstream, so, the DA molecules are often transported by albumins and can be affected by these proteins. In our study we evaluate the effect of complex formation between bovine serum albumin (BSA) and three fluorescence DA's (Photolon, Photoditazin and Dimegin) on their fluorescent quantum yields. METHODS: Electron absorption spectroscopy and fluorescence spectroscopy were carried out to calculate fluorescence quantum yields of the DAs using Rhodamine 6G as a standard fluorescent dye. RESULTS: For all three DA's dissolved in phosphate buffer with pH 7.5 (close to that of blood) the addition of albumin resulted in bathochromic shift of the Soret band as well as change of amplitudes of absorption bands. Similar changes were observed for fluorescence spectra of all DAs that are connected with complex formation between DA and albumin. The presence of isobestic point suggests that DA can present in the solution only in two states, free and BSA-bound. Chlorine-based DA's demonstrate about 1.5-times higher fluorescence quantum yield in PBS than Dimegin. Nevertheless, the addition of BSA to the solutions of all DA's decreases sharply their fluorescence quantum yield to approximately equal values. CONCLUSION: The complex formation between DA and albumin equalize fluorescence efficacies of all studied DAs, so the results of photodymanic diagnostics using the specific DA will depend on other factors.

Oral Supplementation of Glucosamine Fails to Alleviate Acute Kidney Injury in Renal Ischemia-Reperfusion Damage.

Acute kidney injury is a leading contributor to morbidity and mortality in the ageing population. Proteotoxic stress response pathways have been suggested to contribute to the development of acute renal injury. Recent evidence suggests that increased synthesis of N-glycan precursors in the hexosamine pathway as well as feeding of animals with aminosugars produced in the hexosamine pathway may increase stress resistance through reducing proteotoxic stress and alleviate pathology in model organisms. As feeding of the hexosamine pathway metabolite glucosamine to aged mice increased their life expectancy we tested whether supplementation of this aminosugar may also protect mice from acute kidney injury after renal ischemia and reperfusion. Animals were fed for 4 weeks ad libitum with standard chow or standard chow supplemented with 0.5% N-acetylglucosamine. Preconditioning with caloric restriction for four weeks prior to surgery served as a positive control for protective dietary effects. Whereas caloric restriction demonstrated the known protective effect both on renal function as well as survival in the treated animals, glucosamine supplementation failed to promote any protection from ischemia-reperfusion injury. These data show that although hexosamine pathway metabolites have a proven role in enhancing protein quality control and survival in model organisms oral glucosamine supplementation at moderate doses that would be amenable to humans does not promote protection from ischemia-reperfusion injury of the kidney.

Comparison of Glucosamine Absorption After Administration of Oral Liquid, Chewable, and Tablet Formulations to Dogs.

Glucosamine (GS) is commonly administered as a nutritional supplement to support joint function. Although many supplements are available, the effect of formulation on oral absorption in dogs is unknown. The purpose of this study was to determine the relative bioavailability of GS for liquid, chewable, and tablet formulations containing GS sulfate or hydrochloride and chondroitin sulfate. In a randomized cross-over design, supplements were administered daily for 8 days with a 1 wk washout period between treatments. Liquid or Tablet A was administered to four dogs, whereas Liquid or Tablet B was administered to four additional dogs. When nutraceutical exposure was normalized to the administered dose of GS free base, similar relative bioavailabilities were determined for all three formulations. However, the dose-normalized maximum plasma GS concentration was higher for the liquid supplement (5.5 ± 0.5 µg/mL) than for the two tablets (3.1 ± 0.6 and 2.1 ± 0.6 µg/mL, P < 0.001). Similarly, the time at which maximal plasma GS concentrations occurred was shorter for the liquid formulation (0.7 ± 0.5 hr) than for the two tablets (4.2 ± 0.6 and 5.0 ± 0.6 hr, P < 0.001). These data show that the formulation of joint supplements affects the oral absorption of GS in dogs.

Efficacy and safety of glucosamine sulfate in the management of osteoarthritis: Evidence from real-life setting trials and surveys.

The European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO) treatment algorithm recommends chronic symptomatic slow-acting drugs for osteoarthritis (SYSADOAs) including glucosamine sulfate (GS) and chondroitin sulfate (CS) as first-line therapy for knee osteoarthritis (OA). Numerous studies are published on the use of SYSADOAs in OA; however, the efficacy of this class is still called into question largely due to the regulatory status, labeling and availability of these medications which differ substantially across the world. Examination of the evidence for the prescription patented crystalline GS (pCGS) formulation at a dose of 1500mg once-daily demonstrates superiority over other GS and glucosamine hydrochloride (GH) formulations and dosage regimens. Thus, the ESCEO task force advocates differentiation of prescription pCGS over other glucosamine preparations. Long-term clinical trials and real-life studies show that pCGS may delay joint structural changes, suggesting potential benefit beyond symptom control when used early in the management of knee OA. Real-life pharmacoeconomic studies demonstrate a long-term reduction in the need for additional pain analgesia and non-steroidal anti-inflammatory drugs (NSAIDs) with pCGS, with a significant reduction of over 50% in costs associated with medications, healthcare consultations and examinations over 12 months. Furthermore, treatment with pCGS for at least 12 months leads to a reduction in the need for total joint replacement for at least 5 years following treatment cessation. Thus, pCGS (1500mg od) is a logical choice to maximize clinical benefit in OA patients, with demonstrated medium-term control of pain and lasting impact on disease progression.

Parallel microscope-based fluorescence, absorbance and time-of-flight mass spectrometry detection for high performance liquid chromatography and determination of glucosamine in urine.

A parallel microscope-based laser-induced fluorescence (LIF), ultraviolet-visible absorbance (UV) and time-of-flight mass spectrometry (TOF-MS) detection for high performance liquid chromatography (HPLC) was achieved and used to determine glucosamine in urines. First, a reliable and convenient LIF detection was developed based on an inverted microscope and corresponding modulations. Parallel HPLC-LIF/UV/TOF-MS detection was developed by the combination of preceding Microscope-based LIF detection and HPLC coupled with UV and TOF-MS. The proposed setup, due to its parallel scheme, was free of the influence from photo bleaching in LIF detection. Rhodamine B, glutamic acid and glucosamine have been determined to evaluate its performance. Moreover, the proposed strategy was used to determine the glucosamine in urines, and subsequent results suggested that glucosamine, which was widely used in the prevention of the bone arthritis, was metabolized to urines within 4h. Furthermore, its concentration in urines decreased to 5.4mM at 12h. Efficient glucosamine detection was achieved based on a sensitive quantification (LIF), a universal detection (UV) and structural characterizations (TOF-MS). This application indicated that the proposed strategy was sensitive, universal and versatile, and it was capable of improved analysis, especially for analytes with low concentrations in complex samples, compared with conventional HPLC-UV/TOF-MS.

Effects of glucosamine-chondroitin combination on synovial fluid IL-1beta, IL-6, TNF-alfa and PGE2 levels in internal derangements of temporomandibular joint

BACKGROUND: The aim of the present study was to evaluate the effects of glucosamine-chondroitin sulphate combination on internal derangements of temporomandibular joint in clinical and biochemical manners. MATERIAL AND METHODS: This randomized clinical study included 31 cases reporting joint tenderness, in which disc displacement was detected on MR imaging. In all patients, synovial fluid sampling was performed under local anesthesia. In the study group, the patients were prescribed a combination of 1500 mg glucosamine and 1200 mg chondroitin sulphate, while patients in the control group were only prescribed 50 mg tramadol HCl (twice daily) for pain control. After 8 weeks, synovial fluid sampling was repeated in the same manner. The levels of pain, maximum mouth opening (MMO), synovial fluid IL-1ß, IL-6, TNF-alfa and PGE2 measured before and after pharmacological intervention were compared. RESULTS: The reduction in pain levels was significant in both groups. There was no significant difference between two groups in terms of pain reduction. The improvement in MMO was significant in the study group but it was not in the control group. The MMO improvement was significantly higher in the study group compared to the control group. In the study group, significant decrease was observed in PGE2 level, while the decreases in IL-1beta, IL-6 and TNF-alfa levels were not significant. In the control group, no significant decrease was observed in any of the inflammatory cytokines after 8 weeks, moreover IL-1ß and IL-6 levels were increased. Alterations of IL-1ß and IL-6 levels were significant in study group while TNF-alfa and PGE2 levels were not, compared to control group. CONCLUSIONS: In conclusion, these results might suggest that glucosamine-chondroitin combination significantly increases the MMO and decreases the synovial fluid IL1beta and IL6 levels in internal derangements of TMJ compared to tramadol. The modifications of synovial fluid TNF-α and PGE2 levels do not reach statistical significance. This combination also provides efficient pain relief in similar level with tramadol, a narcotic analgesic

Fiber-optic system for dual-modality imaging of glucose probes 18F-FDG and 6-NBDG in atherosclerotic plaques.

BACKGROUND: Atherosclerosis is a progressive inflammatory condition that underlies coronary artery disease (CAD)-the leading cause of death in the United States. Thus, the ultimate goal of this research is to advance our understanding of human CAD by improving the characterization of metabolically active vulnerable plaques within the coronary arteries using a novel catheter-based imaging system. The aims of this study include (1) developing a novel fiber-optic imaging system with a scintillator to detect both 18F and fluorescent glucose probes, and (2) validating the system on ex vivo murine plaques. METHODS: A novel design implements a flexible fiber-optic catheter consisting of both a radio-luminescence and a fluorescence imaging system to detect radionuclide 18F-fluorodeoxyglucose (18F-FDG) and the fluorescent analog 6-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-6-Deoxyglucose (6-NBDG), respectively. Murine macrophage-rich atherosclerotic carotid plaques were imaged ex vivo after intravenous delivery of 18F-FDG or 6-NBDG. Confirmatory optical imaging by IVIS-200 and autoradiography were also performed. RESULTS: Our fiber-optic imaging system successfully visualized both 18F-FDG and 6-NBDG probes in atherosclerotic plaques. For 18F-FDG, the ligated left carotid arteries (LCs) exhibited 4.9-fold higher radioluminescence signal intensity compared to the non-ligated right carotid arteries (RCs) (2.6 × 10(4) ± 1.4 × 10(3) vs. 5.4 × 10(3) ± 1.3 × 10(3) A.U., P = 0.008). Similarly, for 6-NBDG, the ligated LCs emitted 4.3-fold brighter fluorescent signals than the control RCs (1.6 × 10(2) ± 2.7 × 10(1) vs. 3.8 × 10(1) ± 5.9 A.U., P = 0.002). The higher uptake of both 18F-FDG and 6-NBDG in ligated LCs were confirmed with the IVIS-200 system. Autoradiography further verified the higher uptake of 18F-FDG by the LCs. CONCLUSIONS: This novel fiber-optic imaging system was sensitive to both radionuclide and fluorescent glucose probes taken up by murine atherosclerotic plaques. In addition, 6-NBDG is a promising novel fluorescent probe for detecting macrophage-rich atherosclerotic plaques.

Oral chondroprotection with nutraceuticals made of chondroitin sulphate plus glucosamine sulphate in osteoarthritis.

Oral supplementation of chondroitin sulphate plus glucosamine helps repair the articular surface in osteoarthritis. Chondroitin-S reduces the concentration of the pro-inflammatory cytokines and transcription factor involved in inflammation. GlcN.S enhances cartilage specific matrix components and prevents collagen degeneration in chondrocytes by inhibiting hydrolytic enzymes, and preventing the oxidation of lipids and proteins. Chondroitin-S plus GlcN.S are slow-acting drugs that alleviate pain and partly restore joint function in OA patients. Orally administered pharmaceutical-grade chondroitin-S plus GlcN.S stabilize the joint space narrowing and significantly decrease the number of patients with new erosive OA. They are safe and no adverse events have ever been reported; they are recommended by EULAR and OARSI. The cost/effectiveness of the oral chondroitin-S plus GlcN.S therapy derives from the reduction of costs for physiotherapy, and for gastroprotective and non-steroidal drugs. The synergistic association of these two world-widely preferred nutraceuticals is a step forward in the management of OA.

Biodistribution and lymph node retention of polysaccharide-based immunostimulating nanocapsules.

The adjuvant properties of polyglucosamine/squalene-based nanocapsules (PG-nanocapsules) associated with different subunit antigens has been previously reported. Thus, the aim of the present study was to monitor the biodistribution of PG-nanocapsules and their affinity for the draining lymph nodes after subcutaneous (s.c.) injection. The nanocapsules were efficiently radiolabeled with indium-111 ((111)In) (labeling efficiency of 98%). The diameter and zeta potential values of the unlabeled nanocapsules was preserved after the radiolabeling process and only 20% of the (111)In dissociated from the nanocapsules after 48h of incubation in serum. The radiolabeled nanocapsules and the control (111)InCl3 in saline solution (18.5MBq (500µCi) in 100µL) were injected s.c. in New Zealand White rabbits. The γ-scintigraphy imaging analysis revealed a slow clearance of the nanocapsules from the injection site and their progressive accumulation in the popliteal lymph node over time (3.8%±1.2 of the injected dose at 48h). Indeed, the clearance rate of the nanocapsules from the injection site was significantly slower than that of the control (free (111)InCl3), which rapidly drained into systemic circulation and accumulated mainly in excretion organs (i.e. kidneys and liver). In contrast, the biodistribution of nanocapsules was preferably limited to the lymphatic circulation. These results suggest that the immune potentiating effect previously observed for PG-nanocapsules is mainly due to the formation of a depot at the injection site, which was followed by a slow drainage into the lymphatic system and a prolonged retention in the lymph nodes.