A novel UPLC-MS/MS method for simultaneous quantification of trigonelline, 4-hydroxyisoleucine, and diosgenin from Trigonella foenum-graecum extract: Application to pharmacokinetic study in healthy and type 2 diabetic rats.

Trigonelline (TR), 4-hydroxyisoleucine (4-HI), and diosgenin (DG) are the main bioactives of the purified standardized extract of the popular plant Trigonella foenum-graecum L. (TFG), and it has been proven effective for the treatment of various diseases. However, to the best of our knowledge, no study has investigated the pharmacokinetic parameters of purified standardized T. foenum-graecum extract in normal and diabetic Wistar rats. The present study has developed and validated a rapid, reliable, and sensitive simultaneous ultra-performance liquid chromatography MS method to estimate these bioactives. The chromatographic separation was achieved using methanol, acetonitrile, and 0.1% formic acid with the ideal gradient flow system on a BEH Shield RP 18 column. A positive electrospray ionization mode was selected to estimate m/z values of TR (138.14 > 94.63), 4-HI (148.19 > 74.08), and DG (415.54 > 271.33). The method was robust and reproducible over the linearity range of 60-5000, 6-5000, and 15-5000 ng/mL for TR, 4-HI, and DG, respectively. Using this novel validated method, we investigated the pharmacokinetic parameters of bioactives using Phoenix WinNonlin version 8.0 (Certera) in normal and diabetic rats. The assay was successfully applied for the estimation of pharmacokinetic parameters using noncompartmental analysis. This investigation shows that the absorption rate increased, whereas distribution and elimination processes slowed down in diabetic rats compared with normal rats.

Comparative pharmacokinetics, intestinal absorption and urinary excretion of six alkaloids from herb pair Phellodendri Chinensis cortex-Atractylodis Rhizoma.

Phellodendri Chinensis Cortex (PCC) and Atractylodis Rhizoma (AR) are frequently used as herb pair to treat eczema and gout owing to their synergistic effects. Alkaloids are the major ingredients from PCC and the effect of their combination on the in vivo processing of alkaloids remains unclear. In this study, a simple and reliable UPLC-MS/MS method for simultaneous determination of six alkaloids in rat plasma was developed. This method was applied to a comparative pharmacokinetic study between PCC and PCC-AR in rats. Effect of AR on absorption of alkaloids was investigated by a single-pass intestinal perfusion study. The effect of AR on urinary excretion of alkaloids was studied. Pharmacokinetic studies showed that the values of rea under the concentration-time curve of phellodendrine, magnoflorine and palmatine were greater in the PCC-AR group than in the PCC group. The intestinal absorptive parameters absorption rate constant and effective permeability of phellodendrine and jatrorrhizine in PCC-AR groups were higher than those in the PCC group. Urinary excretion studies revealed that the excreted amount of alkaloids in the PCC-AR group was lower than that in the PCC group. The results revealed that the combination of PCC and AR improves intestinal absorption of alkaloids and reduces their urinary excretion, which enhances their systemic exposure. This study may explain the synergetic effects of PCC and AR in clinical applications.

Anti-hyperlipidemic and anti-diabetic evaluation of ethanolic leaf extract of Catharanthus roseus alone and in combination therapy

The use of plants in disease treatment is cost effective and relatively safe. This study was designed to investigate anti-hyperlipidemic and anti-diabetic activity of ethanolic leaf extract of Catharanthus roseus alone and in combination therapy in hyperlipidemic & diabetic mice. Eight groups comprising five mice each were used. Group A was hyperlipidemic control, group B, C, D received atorvastatin (20 mg/kg), leaf extract (200 mg/kg) and leaf extract in combination with atorvastatin (200 mg/kg and 20 mg/kg) orally for 15 days. Group E was diabetic control. Group F, G, H received sitagliptin (40 mg/kg), leaf extract (200 mg/kg) and extract in combination with sitagliptin (200 mg/kg and 40 mg/kg) orally for 7 days. Blood cholesterol levels were measured at 1st, 5th, 10th and 15th day and fasting blood sugar levels were measured at 2, 12, 24, 72 and 168 hours during treatment. One-way ANOVA with tukey- kramer multiple comparison test was used. The chemical characterization of ethanolic extract of Catharanthus roseus leaves showed presence of alkaloids, saponins, tannins and flavonoids. Ethanolic extract of Catharanthus roseus has significant anti-hyperlipidemic & anti-diabetic effects (p<0.05, p<0.01) when compared with control but had not cause significantly increase in anti-hyperlipidemic effects of atorvastatin. While significantly increased the antidiabetic effect of sitagliptin (p<0.05)

Preparation of magnetic yolk-shell structured metal-organic framework material and its application in pharmacokinetics study of alkaloids.

In this study, a magnetic yolk-shell structured metal-organic framework material (Fe3O4@YS-UiO-66-NH2) is prepared by the directional etching of Co2+/peroxymonosulfate and in situ magnetization. The characteristic properties of the material were investigated by using field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometer, Brunauer-Emmett-Teller, and contact angle test. The Fe3O4@YS-UiO-66-NH2 shows the advantages of large surface area, good magnetic property, and satisfactory stability, as well as giving high affinity to alkaloids (ALs) via hydrophilic interaction, hydrogen bonding, and π-π interaction. The results of static adsorption experiment indicate that the Fe3O4@YS-UiO-66-NH2 possesses high adsorption capacity towards ALs and the adsorption behaviors are fitted with Langmuir adsorption isotherm model. Furthermore, a magnetic solid-phase extraction using Fe3O4@YS-UiO-66-NH2 and HPLC method was developed for the analysis of ALs in spiked samples with the recovery of 89.6-100.8%. In addition, the proposed method was successfully applied in the pharmacokinetics study of berberine, coptisine, and palmatine in the rat. In short, the developed method might be used for high-efficient recognition and determination of ALs in plasma sample, which would also provide a new way to fabricate magnetic functionalized metal-organic framework in separation science.

Pharmacokinetics of Synthetic Cathinones Found in Bath Salts in Mouse Brain and Plasma Using High-Pressure Liquid Chromatography-Tandem Mass Spectrometry.

BACKGROUND AND OBJECTIVES: Approximately 10 years ago, "bath salts" became popular as legal alternatives to the psychostimulants cocaine and the amphetamines. These products contained synthetic cathinones, including 3,4-methylenedioxypyrovalerone (MDPV), 4-methylmethcathinone (mephedrone), and 3,4-methylenedioxymethcathinone (methylone). Most preclinical investigations have only assessed the effects of these synthetic cathinones independently; however, case reports and Drug Enforcement Administration (DEA) studies indicate that bath salts contain mixtures of these substances. In this study, we examine the pharmacokinetic interactions of the drug combination. We hypothesized that combined exposure to MDPV, mephedrone, and methylone would result in increased drug concentrations and enhanced total drug concentrations when compared to individual administration. METHODS: Adolescent male Swiss-Webster mice were injected intraperitoneally with either 10 mg/kg MDPV, 10 mg/kg mephedrone, 10 mg/kg methylone, or 10 mg/kg combined MDPV, mephedrone, and methylone. Following injection, brains and plasma were collected at 1, 10, 15, 30, 60, and 120 min. Drugs were extracted via solid-phase extraction, and concentrations were determined using a previously published high-pressure liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. RESULTS: All drugs crossed the blood-brain barrier quickly. For methylone, the maximal concentration (Cmax) and the total drug exposure [as represented by the area under the concentration-time curve (AUC)] were significantly higher when combined with mephedrone and MDPV in both matrices (2.89-fold increase for both Cmax and AUC with combined treatment). For mephedrone, the Cmax was unchanged, but the AUC in brain was increased when in combination by approximately 34%. Interestingly, for MDPV, the Cmax was unchanged, yet the AUC was higher when MDPV was administered individually (there was a 62% decrease in AUC with combined treatment). CONCLUSIONS: The pharmacokinetics of methylone, mepedrone, and MDPV are altered when the drugs are used in combination. These data provide insight into the consequences of co-exposure to synthetic cathinones in popular bath salt products.

Simultaneous LC-MS/MS bioanalysis of alkaloids, terpenoids, and flavonoids in rat plasma through salting-out-assisted liquid-liquid extraction after oral administration of extract from Tetradium ruticarpum and Glycyrrhiza uralensis: a sample preparation strategy to broaden analyte coverage of herbal medicines.

Herbal medicines have historically been practiced in combinatorial way, which achieves therapeutic efficacy by integrative effects of multi-components. Thus, the accurate and precise measurement of multi bioactive components in matrices is inalienable to understanding the metabolism and disposition of herbal medicines. In this study, aiming to provide a strategy that improves analyte coverage, evaluation of six protocols employing sample pretreatment methods- protein precipitation (PPT), liquid-liquid extraction (LLE), sugaring-out-assisted liquid-liquid extraction (SULLE), and salting-out-assisted liquid-liquid extraction (SALLE)- was performed by LC-MS/MS using rat plasma and a mixture of alkaloid (evodiamine, rutaecarpine, dehydroevodiamine), terpenoid (limonin, rutaevin, obacunone), and flavonoid (liquiritin, isoliquiritin, liquiritigenin) standards isolated from Tetradium ruticarpum and Glycyrrhiza uralensis. These protocols were as follows: (1) PPT with methanol, (2) PPT with acetonitrile, (3) LLE with methyl tertiary-butyl ether-dichloromethane, (4) LLE with ethyl acetate-n-butanol, (5) SALLE with ammonium acetate, (6) SULLE with glucose. The results suggested that SALLE produced broader analyte coverage with satisfactory reproducibility, acceptable recovery, and low matrix interference. Then, sample preparation procedure of SALLE, chromatographic conditions, and mass spectrometric parameters were optimized, followed by method validation, showing that good sensitivity (LLOQ ≤ 1 ng mL-1), linearity (r ≥ 0.9933), precision (RSD ≤ 14.45%), accuracy (89.54~110.87%), and stability could be achieved. Next, the developed method was applied successfully to determine the pharmacokinetic behavior of the nine compounds in rat plasma after intragastric administration with an extract from Tetradium ruticarpum and Glycyrrhiza uralensis (Wuzhuyu-Gancao pair). Based on an extensive review and experiments, a sample preparation procedure that matches with LC-MS/MS technique and can get wider analyte coverage was outlined. The developed SALLE method is rapid, reliable, and suitable for bioanalysis of analytes with diverse polarity, which was expected to be a promising strategy for the pharmacokinetic studies of herbal medicines. Graphical abstract.

Detection of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in blood in a forensic case using liquid chromatography-electrospray ionization linear ion trap mass spectrometry.

We present a case of fatal poisoning by 4-F-methcathinone (4-FMC; also called flephedrone), 4-methoxy-α-pyrrolidinopentiophenone (4-MeO-α-PVP), 4-fluoro-α-pyrrolidinopentiophenone (4-F-α-PVP), and α-pyrrolidinohepatanophenone (PV8). In this study, we compared the mass spectra of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, PV8, and α-pyrrolidinohexanophenone between LC-ESI-LIT-MS and GC-EI-MS analyses. Subsequently, we applied LC-ESI-LIT-MS for detection and quantification analyses of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in human authentic whole blood samples. More specific mass spectra for the target compounds were obtained with the LC-ESI-LIT-MS qualitative analyses than with the GC-EI-MS analyses, indicating that LC-ESI-LIT-MS was more suitable for the qualitative analysis of cathinones. The LC-ESI-LIT-MS validation data showed moderately good linearity and reproducibility for the compounds in the quantitative analyses at the range of 1-500 ng/mL. The detection limits of four cathinones ranged from 0.1 to 1 ng/mL. The concentrations of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in heart whole blood samples were 365, 449, 145, and 218 ng/mL, respectively. Those of the 4 cathinones in femoral vein whole blood samples were 397, 383, 127, and 167 ng/mL, respectively. We can then assume that the cause of death was acute poisoning by a combination of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8. In this article, we present a detailed LC-ESI-LIT-MS procedure for detection and quantification analyses of 4-FMC, 4-MeO-α-PVP, 4-F-α-PVP, and PV8 in authentic human whole blood samples.

Characterization of chemical constituents and metabolites in rat plasma after oral administration of San Miao Wan by ultra-high performance liquid chromatography tandem Q-Exactive Orbitrap mass spectrometry.

San Miao Wan (SMW), composed of Phellodendri Chinensis Cortex, Atractylodis Lanceae Rhizoma and Achyranthis Bidentatae Radix, is widely used for the treatment of gout, hyperuricemia and other diseases. In the present study, an overall identification strategy based on ultra-high performance liquid chromatography tandem Q-Exactive Orbitrap mass spectrometry (UPLC-Q-Exactive Orbitrap/MS) method was established to characterize the multiple chemical constituents of SMW and its metabolites in rat plasma after oral administration of SMW. A total of 76 constituents including alkaloids, organic acids, lactones, terpenes, saponins, sterones and others types of components were identified in the extract of SMW. After the oral administration of SMW, 47 prototype constituents and 66 metabolites were identified in rat plasma samples. The related metabolic pathways mainly involved reduction, demethylation, hydroxylation, methylation and glucuronide conjunction. The proposed method could be a useful approach to identify the chemical constituents of SMW and its metabolic components. Our study provide a universal strategy for the analysis of the components and metabolites of the traditional Chinese medicine prescription (TCP) extracts and plasma after administration using UPLC-Q-Exactive Orbitrap/MS method. It will assist with clarifying the substance basis of effective components in SMW. It also provides a rapid method for overall analysis of chemical constituents and metabolites of SMW.

Rapid detection of nine synthetic cathinones in blood and urine by direct analysis in real-time-tandem mass spectrometry.

RATIONALE: Designer drugs of cathinone, a kind of hallucinogen, were abused in the recent years. They were also known as bath salts, plant fertilizers, and zombie potions in drug market. The abuse of synthetic cathinones caused many bad effects on social order. Rapid detection of synthetic cathinones became an important subject of study in forensic science. METHODS: Direct analysis in real-time-tandem mass spectrometry (DART-MS/MS) was used to develop an effective method on nine synthetic cathinones in human whole blood and urine. The reference materials with 100 ng/mL were prepared for mass spectrometry optimization with electrospray ionization (ESI) probe tandem QTRAP 4000 mass spectrometer. The temperature of DART ion source was optimized to 400°C. The volumes of 4/1 (v/v) MeCN/MeOH with 0.69 mL were selected for the preparation of 0.31 mL blood and urine samples, respectively. Then the spiked analytes were prepared for detection by the DART 12Dip-it autosampler module. RESULTS: The results showed that the linearities range between 0.1 and 5 µg/mL, the correlation coefficients (r2 ) ranged from 0.99 to 1, the limits of detection (LODs) were all between 0.5 and 50 ng/mL, and the relative standard deviations (RSDs) of repeatability, intra-day and inter-day precisions were all below 13% and 14% in blood and urine, respectively. CONCLUSION: The results indicated that the method could meet the needs of rapid screening of samples that may contain synthetic cathinones. In addition, the method developed has many advantages, such as efficient, fast sample preparation, and environmental protection. Therefore, the DART-MS/MS method would provide effective data support for rapid screening of synthetic cathinones in forensic science.

Pepper Alkaloids and Processed Meat Intake: Results from a Randomized Trial and the European Prospective Investigation into Cancer and Nutrition (EPIC) Cohort.

SCOPE: Processed meat intake has been associated with adverse health outcomes. However, little is known about the type of processed meat more particularly responsible for these effects. This study aims to identify novel biomarkers for processed meat intake. METHODS AND RESULTS: In a controlled randomized cross-over dietary intervention study, 12 healthy volunteers consume different processed and non-processed meats for 3 consecutive days each. Metabolomics analyses are applied on post-intervention fasting blood and urine samples to identify discriminating molecular features of processed meat intake. Nine and five pepper alkaloid metabolites, including piperine, are identified as major discriminants of salami intake in urine and plasma, respectively. The associations with processed meat intake are tested for replication in a cross-sectional study (n = 418) embedded within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Three of the serum metabolites including piperine are associated with habitual intake of sausages and to a lesser extent of total processed meat. CONCLUSION: Pepper alkaloids are major discriminants of intake for sausages that contain high levels of pepper used as ingredient. Further work is needed to assess if pepper alkaloids in combination with other metabolites may serve as biomarkers of processed meat intake.

Pharmacokinetics and Pharmacodynamic Herb-Drug Interaction of Piperine with Atorvastatin in Rats.

Herbals that are widely consumed as therapeutic alternatives to conventional drugs for cardiovascular diseases, may lead to herb-drug interactions (HDIs). Atorvastatin (ATR) is drug of choice for hyperlipidemia and is extensively metabolized through CYP3A4 enzyme. Thus, we postulate that concomitant administration of ATR with piperine (PIP, potent inhibitor of CYP3A4 enzyme)/ridayarishta (RID, cardiotonic herbal formulations containing PIP) may lead to potential HDI. A simple, accurate, sensitive high-performance liquid chromatography-photodiode array detection method using Kromasil-100 C18 column, mobile phase acetonitrile: 30 mM phosphate buffer (55:45 v/v) pH 4.5 with flow rate gradient programming was developed to study the potential HDI in rats. Method was found to be linear (2-100 ng/mL) with Lower Limit of Detection (LLOD) 2 ng/mL. The precision (%CV < 15%), accuracy (-1.0 to -10% R.E) with recoveries above 90% from rat plasma of ATR and IS were obtained. The pharmacokinetic (PK) interactions studies on co-administration of ATR (8.4 mg/kg, p.o.) with PIP (35 mg/kg, p.o.), demonstrated a threefold increase in Cmax of ATR (P < 0.01) with significant increase in AUC0-t/AUC0-∞ compared to ATR alone indicating potential PK-HDI. However co-administration of RID (4.2 mL/kg, p.o.) showed less significant changes (P > 0.05) indicating low HDI. The pharmacodynamic effects/interactions study (TritonX-100 induced hyperlipidemic model in rats) suggested no significant alterations in the lipid profile on co-administration of PIP/RID with ATR, indicating that there may be no significant pharmacodynamic interactions.

A sensitive HPLC-MS/MS method for the detection, resolution and quantitation of cathinone enantiomers in horse blood plasma and urine.

Resolution of cathinone enantiomers in equine anti-doping analysis is becoming more important to distinguish the inadvertent ingestion of plant-based products from those of deliberate administration of designer synthetic analogs. With this in mind, a rapid and sensitive method was developed and validated for the detection, resolution and quantitative determination of cathinone enantiomers in horse blood plasma and urine. The analytes were recovered from the blood plasma and urine matrices by using a liquid-liquid extraction after adjusting the pH to 9. The recovered analytes were derivatized with Nα-(2,4-dinitro-5-fluorophenyl)-L-valinamide, a chiral derivatizing agent analogous to Marfey's reagent. The resulting diastereoisomers were baseline resolved under a reversed-phase liquid chromatographic condition. Derivatization of the analytes not only allowed the separation of the enantiomers using cost-effective traditional liquid chromatography conditions and reversed-phase columns but also increased the sensitivity, at least to an order of magnitude, when tandem mass spectrometry is used for the detection. A limit of detection of 0.05 ng/mL was achieved for cathinone enantiomers for both matrices. Acceptable intraday and interday precision and accuracy along with satisfactory dilution accuracy and precision were observed during the method validation. The method suitability was tested using the post administration urine samples collected after single doses of cathinone and ephedrine as single-enantiomeric form and methcathinone as racemic form. Finally, a proof of concept of the isomeric ratio in urine samples to distinguish the presence of cathinone as a result of accidental ingestion of plant-based product from that of an illicit use of a designer product is demonstrated. To the best of our knowledge, this is the first such work where cathinone enantiomers were resolved and quantified in horse blood plasma and urine at sub nanogram levels.

Simultaneous determination of five bioactive components of XiaoJin Capsule in normal and mammary gland hyperplasia rat plasma using LC-MS/MS and its application to a pharmacokinetic study.

XiaoJin Capsule (XJC) is a classic Traditional Chinese Medicine formula for clinical treatment of thyroid nodules, mammary gland hyperplasia and breast cancer. For the specification and rational application of XJC in the future, an accurate and specific LC-MS/MS method was developed and validated for quantitative determination of five components in rat plasma after oral administration of XJC. The collected plasma samples were extracted by protein precipitation with methanol-acetonitrile (1:3, v/v) mixture solvent and separated on a C18 column using a gradient elution system. Mass spectrometry was performed on a triple quadrupole mass spectrometer, and samples were detected in positive ionization and multiple reactions monitoring mode. The method was properly validated in terms of linearity, precision, accuracy, recovery, matrix effect and stability. All calibration curves showed good linearity (r2 > 0.9910) over their concentration ranges. The intra- and inter-day precisions (RSD) were within 11.0%, and the LLOQ was 0.1, 0.2, 0.5, 7.5 and 7.5 ng/ml for aconine, songorine, neoline, 3-acetyl-11-keto-ß-boswellic acid and 11-keto-ß-boswellic acid, respectively. Extraction recovery, matrix effect and stability were satisfactory in rat plasma. This established method was successfully applied to a pharmacokinetics study of five compounds after oral administration of XJC to normal and mammary gland hyperplasia model rats.

Near-fatal poisoning after ricin injection.

OBJECTIVE: To report a near-fatal poisoning after intentional injection of ricin from a castor bean (Ricinus communis) extract. CASE REPORT: A 21 year-old man self-injected ∼3 mL of a castor bean extract intramuscularly and subcutaneously in the left antecubital fossa. Upon admission to our ED (1 h post-exposure; day 1, D1) he was awake and alert, but complained of mild local pain and showed slight local edema and erythema. He evolved to refractory shock (∼24 h post-exposure) that required the administration of a large volume of fluids and high doses of norepinephrine and vasopressin, mainly from D2 to D4. During this period, he developed clinical and laboratory features compatible with systemic inflammatory response syndrome, multiple organ dysfunction, capillary leak syndrome, rhabdomyolysis, necrotizing fasciitis and possible compartment syndrome. The patient underwent forearm fasciotomy on D4 and there was progressive improvement of the hemodynamic status from D7 onwards. Wound management involved several debridements, broad-spectrum antibiotics and two skin grafts. Major laboratory findings within 12 days post-exposure revealed hypoalbuminemia, proteinuria, thrombocytopenia, leukocytosis and increases in cytokines (IL-6, IL-10 and TNF-α), troponin and creatine kinase. Ricin A-chain (ELISA) was detected in serum up to D3 (peak at 24 h post-exposure), with ∼79% being excreted in the urine within 64 h post-exposure. Ricinine was detected in serum and urine by LC-MS up to D5. A ricin A-chain concentration of 246 µg/mL was found in the seed extract, corresponding to the injection of ∼738 µg of ricin A-chain (∼10.5 µg/kg). The patient was discharged on D71, with limited range of motion and function of the left forearm and hand. CONCLUSION: Ricin injection resulted in a near-fatal poisoning that evolved with septic shock-like syndrome, multiple organ dysfunction and necrotizing fasciitis, all of which were successfully treated with supportive care.

Blood concentrations of synthetic cathinones.

INTRODUCTION: Synthetic cathinones are the second most frequently seized group of new psychoactive substances. They are sold as replacements for controlled stimulants such as amphetamine, cocaine and MDMA. Synthetic cathinones are often determined in biological material collected from both living people and fatally intoxicated with these substances. The interpretation of analytical results usually requires a comparison to previously published cases, therefore, a referenced compilation of concentration ranges would be useful. MATERIAL AND METHODS: Data collection was based on a search of PubMed and Google search engine. All the available data from articles where synthetic cathinones concentrations have been measured in whole blood, serum or plasma were included in the data analysis. RESULTS: Presented table lists the observed concentrations in fatal and non-fatal cases involving 47 synthetic cathinones. A reference list with original papers has been added for each compound, which makes it easy to find the source data. CONCLUSION: Conclusions regarding cause of death should be based upon the concentrations and knowledge of the clinical situation. Where there is clinical suspicion of death due to synthetic cathinones, postmortem blood concentrations >1 µg/mL (in person without developed tolerance) can be cautiously considered as lethal concentrations, however the exact ranges cannot be established.

Stability of synthetic cathinones in clinical and forensic toxicological analysis-Where are we now?

Understanding the stability of analyzed drugs in biological samples is a crucial part for an appropriate interpretation of the analytical findings. Synthetic cathinones, as psychoactive stimulants, belong to a major class of new psychoactive substances. As they are subject to several degradation pathways, they are known to clinical and forensic toxicologists as unstable analytes in biological samples. When interpreting analytical data of synthetic cathinones in biological samples, analysts must be aware that the concentration of analytes may not accurately reflect the levels at the time they were acquired owing to many factors. This review provides (i) an overview of the current scientific knowledge on the stability of synthetic cathinones and/or metabolites in various human biological samples with a focus on factors that may deteriorate their stability-such as storage temperature, length of storage, matrix, pH, type of preservatives, concentration of analytes, and the chemistry of the analytes-and (ii) possible solutions on how to avoid such degradation. The PubMed database as well as Google Scholar was thoroughly searched to find published studies on the stability of synthetic cathinones since 2007 by searching specific keywords. A total of 23 articles met the inclusion criteria and were included in this review. Synthetic cathinones that carry methylenedioxy or N-pyrrolidine ring showed higher degradation resistance over other substituted groups. Acidification of samples pH plays a crucial role at increasing the stability of cathinones even with analytes that were frequently considered as poorly stable. This review also provides several recommendations for best practice in planning the experimental design, preservation, and storage conditions in order to minimize synthetic cathinones' degradation in human biological samples.

Analysis of curcumin and piperine in biological samples by reversed-phase liquid chromatography with multi-wavelength detection.

Widely accessible food phytochemicals such as curcumin have been reported to have anti-inflammatory and anticarcinogenic properties. However, curcumin has poor absorption in the gut, and piperine has been of interest as a dietary compound that can enhance curcumin bioavailability. The aim of this study was to develop and optimize a technique using reversed-phase chromatography with multi-wavelength detection for the simultaneous measurement of curcumin and piperine in various biological matrices. Emodin was used as an internal standard. Protein precipitation and liquid-liquid extraction based on acetonitrile provided good recovery of these analytes. A 150 mm × 4.6 mm I.D. Luna C18 column was used under isocratic conditions to separate curcumin, piperine, and emodin with baseline resolution, and with good separation from other sample components, in as little as 4 min. The detection limits for curcumin and piperine were 3 and 7 ng/mL, respectively. This method has been used to quantitate these compounds in samples such as human intestinal epithelial cell lysates and mouse plasma or GI tissues in research aimed at examining the bioavailability of curcumin in the presence of piperine.

Association of caffeine and related analytes with resistance to Parkinson disease among LRRK2 mutation carriers: A metabolomic study.

OBJECTIVE: To identify markers of resistance to developing Parkinson disease (PD) among LRRK2 mutation carriers (LRRK2+), we carried out metabolomic profiling in individuals with PD and unaffected controls (UC), with and without the LRRK2 mutation. METHODS: Plasma from 368 patients with PD and UC in the LRRK2 Cohort Consortium (LCC), comprising 118 LRRK2+/PD+, 115 LRRK2+/UC, 70 LRRK2-/PD+, and 65 LRRK2-/UC, and CSF available from 68 of them, were analyzed by liquid chromatography with mass spectrometry. For 282 analytes quantified in plasma and CSF, we assessed differences among the 4 groups and interactions between LRRK2 and PD status, using analysis of covariance models adjusted by age, study site cohort, and sex, with p value corrections for multiple comparisons. RESULTS: Plasma caffeine concentration was lower in patients with PD vs UC (p < 0.001), more so among LRRK2+ carriers (by 76%) than among LRRK2- participants (by 31%), with significant interaction between LRRK2 and PD status (p = 0.005). Similar results were found for caffeine metabolites (paraxanthine, theophylline, 1-methylxanthine) and a nonxanthine marker of coffee consumption (trigonelline) in plasma, and in the subset of corresponding CSF samples. Dietary caffeine was also lower in LRRK2+/PD+ compared to LRRK2+/UC with significant interaction effect with the LRRK2+ mutation (p < 0.001). CONCLUSIONS: Metabolomic analyses of the LCC samples identified caffeine, its demethylation metabolites, and trigonelline as prominent markers of resistance to PD linked to pathogenic LRRK2 mutations, more so than to idiopathic PD. Because these analytes are known both as correlates of coffee consumption and as neuroprotectants in animal PD models, the findings may reflect their avoidance by those predisposed to develop PD or their protective effects among LRRK2 mutation carriers.

Influence of Different Dosage Forms on Pharmacokinetics of 6 Alkaloids in Raw Aconiti Kusnezoffii Radix (Caowu) and Chebulae Fructus- (Hezi-) Processed Caowu by UPLC-MS/MS.

PURPOSE: To study the pharmacokinetics of the 6 alkaloids (aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine, and benzoylhypaconine) in raw Aconiti Kusnezoffii Radix (Caowu) (RC) and Chebulae Fructus- (Hezi-) processed Caowu (HC) in the rats being, respectively, administrated with RC and HC in the dosage forms of powder and decoction and to demonstrate the mechanism of detoxification of HC. METHODS: The rats were randomly divided into 4 groups and, respectively, given RC powder, HC powder, RC decoction, and HC decoction by intragastric administration. The contents of the 6 alkaloids in the plasma of the rats were detected at different time points by the UPLC-MS/MS method, and DAS 3.2.7 software was used to calculate, compare, and analyze the detected pharmacokinetic parameters. RESULTS: Compared with those of the RC powder, the values of AUC0-t and C max of the HC powder were all reduced, whereas the values of t 1/2z and T max were mostly increased. Compared with those of the RC powder, the values of AUC0-t , C max, and t 1/2z of the RC decoction were decreased and the value of T max of the RC decoction was increased. Compared with those of the RC decoction, the values of AUC0-t , t 1/2z , and C max of the diester diterpenoid alkaloids of the HC decoction were all increased. However, there was no marked difference between the pharmacokinetic parameters of the HC powder and the HC decoction. CONCLUSIONS: A decrease in the level of absorption and in the rate of elimination of the alkaloids can be detected when HC is administrated in the dosage form of the powder, explaining that in traditional Mongolian medicine (TMM), the purpose of using HC in the dosage forms of pills and powder is for decreasing the toxicity and prolonging the efficacy duration of HC. Decocting can greatly decrease the plasma concentration of the diester diterpenoid alkaloids in RC and increase their rate of elimination. The influence of decocting on RC is greater than that on HC, explaining the rationality of the steaming and boiling methods for processing Caowu and the rationality of boiling Caowu for a longer time beforehand in preparing an herb decoction containing Caowu in TCM.

GC-MS analysis of underivatised new psychoactive substances in whole blood and urine.

Herein a method was develop and validated for the detection and quantification of five new psychoactive substances (NPS) belonging to three categories: synthetic cathinones (mephedrone, 3,4-MDPV), opioids (AH-7921) and cannabinoids (JWH-018, AM-2201) by EI GC-MS. Target analytes were quantified in whole blood; in urine the same compounds plus methylone were detected. Liquid-liquid extraction by MTBE - butyl acetate (1:1, v/v) in blood and butyl acetate in urine was applied for the recovery of analytes, while no derivatization was necessary for their sensitive detection and quantification. The method showed good linearity for all analytes within a concentration range from 0.25 to 2 µg/mL for mephedrone, from 0.02 to 0.16 µg/mL for 3,4-MDPV and AH-7921 and from 0.005 to 0.04 µg/mL for JWH-018 and AM-2201. LOD ranged from 0.002 µg/mL (JWH-018 and AM-2201 in blood and urine), to 0.08 µg/mL (mephedrone in urine). LOQ in blood ranged from 0.005 µg/mL for JWH-018 and AM-2201 to 0.25 µg/mL for mephedrone. Accuracy was within acceptable limits with % bias ranging from +20% to -17.98% for intra-assay study and from +18.87% to -11.16% for inter-assay study. Precision was found to be between 2.60% and 17.17% (CV%) for intra-assay study and from 6.03% to 13.72% (CV%) for inter-assay study. An intra laboratory comparison provided proof of the method robustness. The developed method can be used for the reliable and fast quantification of five NPS in blood and the detection of six NPS in urine within the practice of a clinical or forensic toxicology laboratory.