Development of benzimidazole derivatives as efficient matrices for the analysis of acidic small-molecule compounds using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry in negative ion mode.

RATIONALE: With the development of matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry (MS) in spatial localisation omics research on small molecules, the detection sensitivity of the matrix must increase. However, the types of matrices suitable for detecting acidic small molecules in (-) MALDI-MS mode are very limited and are either not sensitive enough or difficult to obtain. METHODS: More than 10 commercially available benzimidazole and benzothiazole derivatives were selected as MALDI matrices in negative ion mode. MALDI-MS analysis was performed on 38 acidic small molecules and mouse serum, and the matrix effects were compared with those of the common commercial matrices 9-aminoacridine (9AA), 1,5-naphthalenediamine (DAN) and 3-aminoquinoline (3AQ). Moreover, the proton affinity (PA) of the selected potential matrix was calculated, and the relationships among the compound structure, PA value and matrix effect were discussed. RESULTS: In (-) MALDI-MS mode, a higher PA value generally indicates a better matrix effect. Amino-substituted 2-phenyl-1H-benzo[d]imidazole derivatives had well-defined matrix effects on all analytes and were generally superior to the commonly used matrices 9AA, DAN and 3AQ. Among them, 2-(4-(dimethylamino-phenyl)-1H-benzo[d]imidazole-5-amine (E-4) has the best sensitivity and versatility for detecting different analytes and has the best ability to detect fatty acids in mouse serum; moreover, the limit of detection (LOD) of some analytes can reach as low as ng/L. CONCLUSIONS: Compared to 9AA, DAN and 3AQ, matrix E-4 is more effective at detecting low-molecular-weight acidic compounds in (-) MALDI-MS mode, with higher sensitivity and better versatility. In addition, there is a clear correlation between compound structure, PA and matrix effects, which provides a basis for designing more efficient matrices.

Excellency of pyrimidinyl moieties containing α-aminophosphonates over benzthiazolyl moieties for thermal and structural stability of stem bromelain.

An efficient approach has been made for the synthesis of a series of novel di α-aminophosphonates by the reaction of terephthalaldehyde with various pyrimidine/benzthiazole amines and diethyl phosphite using sulfonated graphitic carbon nitride - SA@g-C3N4 as catalyst under room temperature and solvent free conditions. Later, the different effects of these newly synthesized α-aminophosphonates as a function of concentration gradient has been scrutinized on the thermal and structural stability of stem bromelain (SBM) through combining the results of various spectroscopic techniques like UV-vis, steady state fluorescence and circular dichroism (CD). Lastly the competitive and distinctive behaviour of α-aminophosphonates towards the stability of SBM has been envisaged using molecular docking simulations which suggest that nature of α-aminophosphonates plays a crucial role for their interactions with SBM. Molecular docking results clearly show that α-aminophosphonates with pyrimidine ring are having more number of hydrogen bonding interaction with amino acid residues of SBM than α-aminophosphonates with benzthiazolyl ring. Sequentially for thermal and structure stability of SBM, concentration of α-aminophosphonates plays an inexorable role and through these results it must be concluded that most of the α-aminophosphonates are stabilizing the SBM upto the 0. 1 mM concentration.

Ideal pharmacokinetic profile of dotinurad as a selective urate reabsorption inhibitor.

Dotinurad, a novel selective urate reabsorption inhibitor (SURI), has potent inhibitory effects at low doses on the uptake of urate by urate transporter 1 (URAT1, solute carrier family 22 member 12 [SLC22A12]), localized at the apical membrane of renal proximal tubular cells. This study sought to clarify the pharmacokinetic (PK) profile of dotinurad. In rats, monkeys, and humans, the apparent distribution volume (0.257, 0.205, and 0.182 L/kg, respectively) and oral clearance (0.054, 0.037, and 0.013 L·h-1·kg-1, respectively) of dotinurad were very low, whereas plasma and luminal concentrations were adequately maintained at high levels. In addition, species differences were scarcely observed with plasma protein binding of 99.4%. The main metabolite was dotinurad glucuronide (no specific metabolites in humans), and percentage excretion of unchanged dotinurad was low in all the investigated species. The risk of drug interaction with dotinurad was expected to be low, because it weakly inhibits metabolic enzymes such as cytochrome P450 (CYP). In conclusion, low-dose dotinurad exhibited excellent pharmacological effects as well as ideal PK properties as a SURI.

Effect of Food on the Pharmacokinetics of Quizartinib.

Quizartinib is an oral, highly potent, and selective type II FMS-like tyrosine kinase 3 inhibitor in development for acute myeloid leukemia. This parallel-group study evaluated potential food effects on quizartinib absorption in healthy subjects who received a single 30-mg dose after overnight fasting (n = 34) or a high-fat, high-calorie meal (n = 30). Blood samples were collected through 504 hours after dosing, and pharmacokinetic parameters calculated were maximum observed concentration (Cmax ) and area under plasma concentration-time curve from time 0 to last quantifiable concentration (AUClast ) and from time 0 to infinity (AUCinf ). Mean quizartinib pharmacokinetic profiles were similar under fasted and fed conditions. The geometric least squares means ratios (%) for fed/fasted and associated 90% confidence intervals (CIs) for Cmax , AUClast , and AUCinf were 91.58 (82.15-102.08), 105.39 (90.79-122.35), and 108.39 (91.54-128.34), respectively. The 90%CI for the ratio fell within the 80% to 125% limits for Cmax and AUClast , with 90%CI for AUCinf slightly outside the limits (ie, 128%). Food delayed quizartinib time to Cmax by 2 hours. All adverse events were either mild or moderate; no discontinuations due to adverse events occurred. Based on these results, quizartinib can be administered without regard to food.

Quantitative Analysis of Tozadenant Using Liquid Chromatography-Mass Spectrometric Method in Rat Plasma and Its Human Pharmacokinetics Prediction Using Physiologically Based Pharmacokinetic Modeling.

Tozadenant is one of the selective adenosine A2a receptor antagonists with a potential to be a new Parkinson's disease (PD) therapeutic drug. In this study, a liquid chromatography-mass spectrometry based bioanalytical method was qualified and applied for the quantitative analysis of tozadenant in rat plasma. A good calibration curve was observed in the range from 1.01 to 2200 ng/mL for tozadenant using a quadratic regression. In vitro and preclinical in vivo pharmacokinetic (PK) properties of tozadenant were studied through the developed bioanalytical methods, and human PK profiles were predicted using physiologically based pharmacokinetic (PBPK) modeling based on these values. The PBPK model was initially optimized using in vitro and in vivo PK data obtained by intravenous administration at a dose of 1 mg/kg in rats. Other in vivo PK data in rats were used to validate the PBPK model. The human PK of tozadenant after oral administration at a dose of 240 mg was simulated by using an optimized and validated PBPK model. The predicted human PK parameters and profiles were similar to the observed clinical data. As a result, optimized PBPK model could reasonably predict the PK in human.

Simultaneous determination of acetaminophen, pramipexole and carbamazepine by ZSM-5 nanozeolite and TiO2 nanoparticles modified carbon paste electrode.

In this present paper, a simple voltammetric method has been reported for the simultaneous determination of acetaminophen (AC), pramipexole (PRX) and carbamazepine (CBZ) using ZSM-5 nanozeolite-TiO2 nanoparticles composite modified carbon paste electrode (ZSM-5/TiO2/CPE). X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and N2 adsorption-desorption isotherm were used to characterize the structure of synthesized ZSM-5 nanozeolite. Also, cyclic voltammetry (CV), choronoamperometry and differential pulse voltammetry (DPV) were used to investigate the performance of the modified electrode. The oxidation peak currents of AC, PRX and CBZ at the surface of ZSM-5/TiO2/CPE were increased dramatically against CPE and their overpotentials decreased. Also, DPV method was used for the simultaneous determination of three drugs in ternary mixture. The effects of modifier amount, pH and scan rate were investigated on the electrochemical response of AC, PRX and CBZ oxidation. The diffusion coefficient, D, and the catalytic rate constant, kcat, were estimated for the oxidation of AC, PRX and CBZ at the surface of modified electrode. Under the optimized experimental conditions, AC, PRX and CBZ give linear response over the range of 2.5-110, 0.6-105 and 6.0-97 µM, respectively. The detection limits were found to be 0.58, 0.38 and 1.04 µM (S/N = 3) for AC, PRX and CBZ, respectively. The fabricated electrode showed good stability, reproducibility and repeatability as well as high recovery. The practical application of the modified electrode was demonstrated by measuring the concentration of spiked AC, PRX and CBZ in human plasma as real sample. The proposed method is simple, rapid and inexpensive and can be utilized as a valuable analytical tool in quality control of the pharmaceutical industry.

Exposure, respiratory symptoms, lung function and inflammation response of road-paving asphalt workers.

BACKGROUND: Controversy exists as to the health effects of exposure to asphalt and crumb rubber modified (CRM) asphalt, which contains recycled rubber tyres. OBJECTIVE: To assess exposures and effects on airway symptoms, lung function and inflammation biomarkers in conventional and CRM asphalt road pavers. METHODS: 116 conventional asphalt workers, 51 CRM asphalt workers and 100 controls were investigated. A repeated-measures analysis included 31 workers paving with both types of asphalt. Exposure to dust, nitrosamines, benzothiazole and polycyclic aromatic hydrocarbon (PAH) was measured in worksites. Self-reported symptoms, spirometry test and blood sampling were conducted prework and postwork. Symptoms were further collected during off-season for asphalt paving. RESULTS: Dust, PAHs and nitrosamine exposure was highly varied, without difference between conventional and CRM asphalt workers. Benzothiazole was higher in CRM asphalt workers (p<0.001). Higher proportions of asphalt workers than controls reported eye symptoms with onset in the current job. Decreased lung function from preworking to postworking was found in CRM asphalt workers and controls. Preworking interleukin-8 was higher in CRM asphalt workers than in the controls, followed by a decrement after 4 days of working. No differences in any studied effects were found between conventional and CRM asphalt paving. CONCLUSION: CRM asphalt workers are exposed to higher benzothiazole. Further studies are needed to identify the source of nitrosamines in conventional asphalt. Mild decrease in lung function in CRM asphalt workers and work-related eye symptoms in both asphalt workers were observed. However, our study did not find strong evidence for severe respiratory symptoms and inflammation response among asphalt workers.

Serum and Urine Thioflavin-T-Enhanced Fluorescence in Severe Preeclampsia.

Common features of amyloid-like proteotoxic aggregates are the ability to bind Congo red (congophilia) and to induce fluorescence of thioflavin-T (ThT). Based on the prior discovery that women with preeclampsia exhibit urine congophilia, we proposed that amyloid-like protein aggregates present in urine also circulate in the bloodstream and this feature is linked to disease severity and clinical phenotype. ThT fluorescence was investigated in 217 paired serum and urine samples from women with severe features of preeclampsia (n=101; median [interquartile range] gestational age [GA], 32 [29-35] weeks), mild features of preeclampsia (n=22; GA, 36 [36-37] weeks), chronic hypertension (n=15; GA, 38 [37-39] weeks), healthy pregnant controls (n=57; GA, 39 [38-39] weeks), and nonpregnant controls (n=22). Serum and urine fluorescence attributable to advanced glycation end products was measured in the same samples with correction for autofluorescence. There were no GA-related changes in ThT fluorescence, although near-term serum ThT fluorescence increased compared with nonpregnant state. Compared with healthy pregnant controls, serum and urine ThT fluorescence was increased in severe features of preeclampsia (P<0.001 for both) but not in mild features of preeclampsia or chronic hypertension. Except for chronic hypertension, advanced glycation end products-related fluorescence of serum or urine did not differ from controls. Urine congophilia had a stronger relationship with preeclampsia severity compared with either urine or serum ThT fluorescence. However, serum ThT fluorescence was independently associated with clinical features of hemolysis, elevated liver enzyme levels, and low platelet levels syndrome (P=0.003). We demonstrate that ThT fluorescence, a marker of amyloid-like aggregates, is increased in serum of women with preeclampsia and likely because of their cytotoxicity associated with hemolysis, elevated liver enzyme levels, and low platelet levels syndrome.

Method development for quantification of quizartinib in rat plasma by liquid chromatography/tandem mass spectrometry for pharmacokinetic application.

Quizartinib is a highly potent inhibitor of the fms-like tyrosine kinase receptor, which is one of the most commonly mutated genes in acute myeloid leukemia. Quizartinib has shown a significant antileukemic clinical influence among relapsed/refractory acute myeloid leukemia patients. This study aimed at developing and validating an analytical method for the measurement of quizartinib in rat plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was validated according to US Food and Drug Administration guidelines, and the results obtained in this work met the set criteria. Liquid-liquid extraction was used and chromatographic separation was achieved on a BEHTM C18 column. Detection of quizartinib was achieved in multiple reaction monitoring mode using positive-ion mode electrospray ionization. The MS/MS ion transitions at mass-to-charge ratios (m/z) of 561.129/114.09 and 441.16/84.03 were monitored for quizartinib and ibrutinib, respectively. The linear detection range was 2-1000 ng/mL (r > 0.998), with intra- and inter-day assay precisions ≤13.07 and 13.17%, respectively. This rapid, simple and sensitive method was validated and successfully applied to the pharmacokinetic study of quizartinib in rat samples.

Liquid chromatography-tandem mass spectrometric assay for the quantitative determination of the tyrosine kinase inhibitor quizartinib in mouse plasma using salting-out liquid-liquid extraction.

A bioanalytical assay for quizartinib -a potent, and selective FLT3 tyrosine kinase inhibitor- in mouse plasma was developed and validated. Salting-out assisted liquid-liquid extraction (SALLE), using acetonitrile and magnesium sulfate, was selected as sample pretreatment with deuterated quizartinib as internal standard. Separation was performed with reversed-phase liquid chromatography followed by detection with positive electrospray-triple quadrupole mass spectrometry in the selected reaction monitoring mode. The assay was successfully validated for mouse plasma in a 2-2000ng/ml calibration range with r2=0.9958±0.0028 (n=7) for linear regression with the inverse square of the concentration as a weighting factor. The within-run precision (n=18), between-run precision and accuracy were 2.9-6.0%, 4.5-8.9% and 91.7-109.4% respectively. The drug was stable under all relevant conditions. Finally, the assay was successfully applied in a pharmacokinetic pilot study in plasma of FVB/NRj mice treated with quizartinb orally.

Development and validation of a highly sensitive gradient chiral separation of pramipexole in human plasma by LC-MS/MS.

AIM: Development of a high-sensitivity chiral LC-MS/MS method was required to evaluate a combination of pramipexole (S-PPX) and its enantiomer dexpramipexole (R-PPX) in a proposed clinical trial. The previously available methods suffered from low sensitivity for the (S)-enantiomer in the presence of the more abundant (R)-enantiomer. Based on the projected dosing regimen in the clinical trial, a 5000-fold improvement in sensitivity was required for the (S)-enantiomer. METHODOLOGY: Spiked human plasma samples were extracted by liquid-liquid extraction using ethyl acetate and injected onto a CHIRALPAK ID column under pH gradient conditions. CONCLUSION: An improved analytical method was developed and validated with a final LLQ for (S)-PPX of 0.1 ng/ml in the presence of 2000 ng/ml of (R)-PPX.

Pramipexole Overdose Associated with Visual Hallucinations, Agitation and Myoclonus.

INTRODUCTION: Pramipexole is a dopamine D2 receptor agonist used to treat idiopathic Parkinson's disease and primary restless legs syndrome. There is limited information on pramipexole overdose. CASE REPORT: A 59-year-old male ingested 3 mg pramipexole, 2250 mg venlafaxine, 360 mg mirtazapine, with suicidal intent. He presented alert, had normal vital observations and normal pupillary reflexes. He was mildly agitated, reported visual hallucinations and was given 5 mg diazepam. He had a mildly elevated lactate of 1.7 mmol/L, but otherwise normal laboratory investigations. Overnight, he remained agitated with visual hallucinations and developed myoclonus while awake. He had increasing difficulty passing urine on a background of mild chronic urinary retention. On review, 14 h post-ingestion, he was hypervigilant, jittery and mildly agitated. He had pressured speech and difficulty focusing on questioning. He had a heart rate of 110 bpm, but had an otherwise normal examination, with no clonus or extrapyramidal effects. He was unable to mobilize due to dizziness and ataxia. Over the next few hours, he improved, the visual hallucinations and agitation resolved and he mobilized independently. Pramipexole was measured with liquid chromatography mass spectrometry. The initial plasma pramipexole concentration was 34.2 ng/mL (therapeutic range 0.2 to 7 ng/mL), 9 h post-overdose. Concentration time data fitted a one-compartment model with an estimated elimination half-life of 18 h. DISCUSSION: Pramipexole overdose with hallucination, agitation, and myoclonus is consistent with adverse effects reported with therapeutic toxicity, but mirtazapine and venlafaxine may have contributed. Pramipexole concentrations exceeded the therapeutic range for over 24 h. With the increasing use of pramipexole in restless legs syndrome, adult overdoses may become more common.

Quantification of highly selective sigma-1 receptor antagonist CM304 using liquid chromatography tandem mass spectrometry and its application to a pre-clinical pharmacokinetic study.

An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for quantification of CM304, a novel and highly selective sigma-1 receptor antagonist that has recently entered into human clinical trials. A structural analogue of CM304, SN56, was used as the internal standard (IS). Chromatographic separation was achieved on an Acquity UPLC™ BEH C18 (1.7 µm, 2.1 mm × 50 mm) column using a mobile phase [water:methanol (0.1%v/v formic acid; 50:50, %v/v)] at a flow rate of 0.2 mL/min. Mass spectrometric detection was performed in the positive ionization mode with multiple reaction monitoring (MRM) using m/z transitions of 337 > 238 for CM304 and 319 > 220 for the IS. The method was found to be linear and reproducible with a regression coefficient consistently >0.99 for the calibration range of 3 to 3000 ng/mL. The extraction recovery ranged from 91.5 to 98.4% from spiked (7.5, 300 and 2526 ng/mL) plasma quality control samples. The precision (%RSD; 1.1 to 2.9%) and accuracy (%RE; -1.9 to 1.8%) were within acceptable limit. The validated method was successfully applied to a single dose oral and intravenous (I.V.) pharmacokinetic study of CM304 in rats. Following I.V. administration, the compound exhibited adequate exposure along with high extravascular distribution and insignificant amount of extra hepatic metabolism. Copyright © 2016 John Wiley & Sons, Ltd.

Actinidia arguta supplementation protects aorta and liver in rats with induced hypercholesterolemia.

There are no published results focusing on the study of hardy kiwifruit as a supplementation to the atherogenic diet. We hypothesized that hardy kiwifruit (Actinidia arguta (A. arguta)) from Poland possess better pro-healthy action than two Asian varieties (Hayward and Bidan). We tested this hypothesis by measuring the metabolic reactions of rats loaded with 1% cholesterol and supplemented with 5% of hardy kiwifruit (A. arguta), Hayward, or Bidan in their diets. The experiment was performed on 71 male Wistar rats. Cholesterol showed a significant impact on the rise of liver somatic index, while lipid profile improved by decreasing the levels of TC, LDL-C, TC/HDL-C, AI, TG, and increasing HDL-C in the serum of rats (P<.05). Total plasma antioxidant capacity determined by ABTS, FRAP, and DPPH assays was increased. ALP in rat serum was higher in groups receiving cholesterol diets and kiwifruit. A decrease in fibrinogen as well as prolonged prothrombin time and a reduction of the MPO in serum were estimated. The smallest percentage of lesions in the aortic arch was in the ChGeneva, ChWeiki, and ChAnna. Similarly, the smallest fatty liver disease was recorded in the ChGeneva and ChAnna groups. The distribution of lipids in the liver from these groups had a character of "mosaic," in hardy/mini kiwifruit (Jumbo), Hayward, and Bidan was distributed uniformly. The longest villi were in ChWeiki, and significantly lower in ChHayward and ChBidan. The present results support our hypothesis that A. arguta showed better pro-health impacts in rats loaded with cholesterol than Hayward and Bidan kiwifruit, and, for the first time, the positive nutritional effects of supplemented A. arguta for hypercholesterolemia are noted.

Development of a selective and fast LC-MS/MS for determination of WSJ-537, an xanthine oxidase inhibitor, in rat plasma: Application to a pharmacokinetic study.

Gout is a common metabolic disorder caused by the deposition of monosodium urate crystals within joints. A new kind of xanthine oxidase inhibitor, WSJ-537, was developed as a potential drug. In order to investigate the pharmacokinetic behavior in vivo, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determination the concentration of WSJ-537 in rat plasma was developed. After extraction by protein precipitation method with acetonitrile, the chromatographic separation was accomplished on a Venusil ASB C18 column(2.1mm×50mm, 3mm)at a flow rate of 0.3mLmin(-1) with the mobile phase consisting of acetonitrile-ammonium acetate (33:67, v/v). An electrospray ionization (ESI) source was applied and operated in the positive ion mode. The plasma concentration was detected by multiple reactions monitoring (MRM) mode with the target fragment ions m/z 410.2→m/z 368.1 for WSJ-537 and m/z 244.1→m/z 185.0 for the IS. Good linearity was observed in the range of 20-800ngmL(-1) (r=0.9947). The recovery of WSJ-537 in rats plasma was more than 85%. This method was suitable for pharmacokinetic studies after oral administration of 10mg/kg WSJ-537 in rats.

Validated UHPLC-MS/MS method for the simultaneous determination of pramipexole and ropinirole in plasma of patients with Parkinson's disease.

A simple and validated ultra high pressure liquid chromatography-tandem mass spectrometry method was developed for the simultaneous determination of the dopaminergic agents pramipexole and ropinirole in plasma of patients with Parkinson's disease. Following liquid-liquid extraction with tert-butyl methyl ether from 250µL plasma, the separation of the analytes was achieved on a Gemini NX3 column using 10mM pH 6.0 ammonium formate and 10mM ammonium formate in methanol as binary gradient mobile phase at a flow rate of 0.3mL/min. The MS/MS ion transitions were 212.10→153.03 for pramipexole, 261.2→114.2 for ropinirole and 256.1→211 for the internal standard (lamotrigine). The lower limit of quantitation (LLOQ) for both analytes was 80pg/mL and the linearity was determined from 80 to 4000pg/mL for pramipexole and from 200 to 10000pg/mL for ropinirole. Mean recoveries were 94% for PRA and 73% for ROP. Both intra- and inter-assay precision and accuracy were ≤20% at LLOQ concentration and ≤15% at other concentrations. The proposed validated method was successfully applied to measure plasma concentrations of pramipexole and ropinirole in a series of patients with Parkinson's disease on chronic treatment. By grouping the two dopaminergic agents in the same assay, the method allows a large series of patient samples to be processed in a single analytical session.

The adrenergic α2 antagonist atipamezole alters the behavioural effects of pramipexole and increases pramipexole concentration in blood plasma.

Pramipexole is a dopaminergic agonist used in Parkinson's disease treatment. It is thought to exert its therapeutic and side effects through actions on dopamine D3 receptors. In a recent study, we found that at doses occupying D3 but not D2 receptors pramipexole reduced locomotion and operant responding for primary and conditioned reinforcement. These effects, however, were not blocked by a D3 receptor antagonist and were present in D3 knockout mice, suggesting non-D3 receptor mechanisms. Among the next highest affinity binding sites of pramipexole are adrenergic α2 receptors. Here we explored α2 receptor involvement in the behavioural effects of pramipexole. We found that the α2 antagonist atipamezole, which was itself behaviourally silent, counteracted pramipexole's reduction of locomotion, but not operant responding for water or a conditioned reinforcer. The resulting behavioural profile was similar to that of a higher dose of pramipexole, leading to the hypothesize that atipamezole mediates its behavioural effects by increasing pramipexole effective dose. In support of this hypothesis, we found that atipamezole increased pramipexole concentration in blood plasma. This is not likely due to an effect on drug metabolism since pramipexole is not known to undergo metabolic transformation. Future work should examine two alternative hypotheses; that pramipexole plasma concentration is elevated as the result of 1) competition with atipamezole for renal excretion, or 2) atipamezole blockade of peripheral α2 binding sites, thereby preventing pramipexole distribution to α2-rich tissues. The suggestion of adrenergic effects of pramipexole is important in light of recent interest in adrenergic pathophysiology in Parkinson's disease.

L-Carnitine supplementation improved clinical status without changing oxidative stress and lipid profile in women with knee osteoarthritis.

Considering the pathologic importance of oxidative stress and altered lipid metabolism in osteoarthritis (OA), this study aimed to investigate the effect of l-carnitine supplementation on oxidative stress, lipid profile, and clinical status in women with knee OA. We hypothesized that l-carnitine would improve clinical status by modulating serum oxidative stress and lipid profile. In this randomized double-blind, placebo-controlled trial, 72 overweight or obese women with mild to moderate knee OA were randomly allocated into 2 groups to receive 750 mg/d l-carnitine or placebo for 8 weeks. Dietary intake was evaluated using 24-hour recall for 3 days. Serum malondialdehyde (MDA), total antioxidant capacity (TAC) and lipid profile, visual analog scale for pain intensity, and patient global assessment of severity of disease were assessed before and after supplementation. Only 69 patients (33 in the l-carnitine group and 36 in the placebo group) completed the study. l-Carnitine supplementation resulted in significant reductions in serum MDA (2.46 ± 1.13 vs 2.16 ± 0.94 nmol/mL), total cholesterol (216.09 ± 34.54 vs 206.12 ± 39.74 mg/dL), and low-density lipoprotein cholesterol (129.45 ± 28.69 vs 122.05 ± 32.76 mg/dL) levels compared with baseline (P < .05), whereas these parameters increased in the placebo group. Serum triglyceride, high-density lipoprotein cholesterol, and TAC levels did not change significantly in both groups (P > .05). No significant differences were observed in dietary intake, serum lipid profile, MDA, and TAC levels between groups after adjusting for baseline values and covariates (P > .05). There were significant intragroup and intergroup differences in pain intensity and patient global assessment of disease status after supplementation (P < .05). Collectively, l-carnitine improved clinical status without changing oxidative stress and lipid profile significantly in women with knee OA.

LC-MS/MS analysis of pramipexole in mouse plasma and tissues: elimination of lipid matrix effects using weak cation exchange mode based solid-phase extraction.

Intranasal delivery is emerging as a promising alternative for oral or intravenous administration of central nervous system (CNS) drugs, such as pramipexole which is widely used for the treatment of Parkinson's disease. To evaluate the effectiveness of intranasal delivery of pramipexole, preclinical pharmacokinetic and tissue distribution studies following intranasal administration need to be investigated. In this paper, we developed and validated a robust and sensitive LC-MS/MS assay without matrix effect for accurate measurements of pramipexole in mouse plasma and tissue samples. Pramipexole and its stable isotope labeled internal standard (d3-pramipexole) were extracted from biological samples by protein precipitation (PPT) coupled with solid phase extraction (SPE) using weak cation exchange SPE cartridges. Matrix effects were studied using post-column infusion and post-extraction addition experiments by direct monitoring of typical phospholipids including glycerophosphocholines (GPChos) and lysoglycerophosphocholines (Lyso-GPChos). Chromatographic separation was achieved on a Welch Ultimate(®) XB-CN column using isocratic elution with a run time of 3.0 min. The assay was linear in the concentration range of 0.05-100 ng/mL and the intra- and inter-day precision and accuracy met the acceptance criteria. Compared with previous reported assays, the current sample preparation approach exhibited significant reduction of matrix effects due to the dramatically decreased levels of residual matrix components such as GPChos and Lyso-GPChos. This method has been successfully applied to pharmacokinetic and tissue distribution studies of pramipexole in mice following a single intravenous or intranasal dose of 50 µg/kg.

Tomato juice consumption improves blood antioxidative biomarkers in overweight and obese females.

BACKGROUND & AIMS: A few studies reported the beneficial effects of tomato juice on oxidative stress status. However, supporting data in obese subjects is scarce. This study aimed to determine the effects of tomato juice consumption on erythrocyte antioxidant enzymes, namely, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT), plasma total antioxidant capacity (TAC), and serum malondialdehyde (MDA) in overweight and obese females. METHODS: A randomized controlled clinical trial was conducted on 64 overweight or obese (BMI = 25 kg/m(2) or higher) female students of Shiraz University of Medical Sciences. Subjects randomly received tomato juice (n = 32, 330 ml/d) or water (n = 28) for 20 days. Daily dietary intake, anthropometric measures and blood antioxidant parameters were determined at the beginning and after 20 days intervention period. RESULTS: Plasma TAC and erythrocyte antioxidant enzymes increased and serum MDA decreased in the intervention group compared with baseline and with the control group (p < 0.05). In the intervention group, similar results were found in overweight, but not in obese, subjects. CONCLUSION: Our results suggest that tomato juice reduces oxidative stress in overweight (and possibly obese) females and, therefore, may prevent from obesity related diseases and promote health.