A New Berberine Preparation Protects Pancreatic Islet Cells from Apoptosis Mediated by Inhibition of Phospholipase A2/p38 MAPK Pathway.

We studied an amorphous solid dispersion of berberine with absorption enhancer sodium caprate (Huang-Gui solid dispersion preparations, HGSD). A therapeutic effect of HGSD was revealed in mice with type 2 diabetes mellitus and palmitate-induced injury to MIN6 ß-cells. HGSD treatment (150 mg/kg) improved glucose metabolism and decreased ß-cell apoptosis in diabetic mice. Furthermore, the effective component of HGSD berberine significantly attenuated the palmitate-induced decrease in MIN6 ß-cells viability and insulin secretion. Moreover, molecular docking analysis and Western blotting showed that berberine decreased cell apoptosis and expression of group VIA phospholipase A2 (iPLA2), p38 mitogen-activated protein kinase (p38 MAPK), and caspase-3. These data suggest that HGSD treatment protected ß-cells via inhibiting the iPLA2/p38 MAPK pathway.

Micro-fabricated packed gas chromatography column based on laser etching technology.

In this work, a micro packed gas chromatograph column integrated with a micro heater was fabricated by using laser etching technology (LET) for analyzing environmental gases. LET is a powerful tool to etch deep well-shaped channels on the glass wafer, and it is the most effective way to increase depth of channels. The fabricated packed GC column with a length of over 1.6m, to our best knowledge, which is the longest so far. In addition, the fabricated column with a rectangular cross section of 1.2mm (depth) × 0.6mm (width) has a large aspect ratio of 2:1. The results show that the fabricated packed column had a large sample capacity, achieved a separation efficiency of about 5800 plates/m and eluted highly symmetrical Gaussian peaks.

Simultaneous separation and confirmation of amphetamine and related drugs in equine plasma by non-aqueous capillary-electrophoresis-tandem mass spectrometry.

A non-aqueous capillary electrophoresis-mass spectrometry (NACE-MS) method was developed for simultaneous separation and identification of 12 amphetamine and related compounds in equine plasma. Analytes were recovered from plasma by liquid-liquid extraction using methyl tertiary butyl ether (MTBE). A bare fused-silica capillary was used for separation of the analytes. Addition of sheath liquid to the capillary effluent allowed the detection of the analytes by positive electrospray ionization mass spectrometry using full scan data acquisition. The limit of detection (LOD) for the target analytes was 10-200 ng/mL and that of confirmation (LOC) was 50-1000 ng/mL in equine plasma. Capillary electrophoresis (CE) and mass spectrometry (MS) parameters were optimized for full CE separation and MS detection of the analytes. Separation buffer comprised 25 mM ammonium formate in acetonitrile/methanol (20: 80, v/v) plus 1 M formic acid. Sheath liquid was isopropanol-water-formic acid (50:50:0.5, v/v/v). Samples were hydrodynamically injected and separated at 25 kV. Analytes were electrokinetically separated and mass spectrometrically identified and confirmed. This simple, fast, inexpensive and reproducible method was successfully applied to post race equine plasma and research samples in screening for amphetamine and related drugs.

Simultaneous analysis of twenty-one glucocorticoids in equine plasma by liquid chromatography/tandem mass spectrometry.

A method for the simultaneous separation, identification, quantification and confirmation of the presence of 21 glucocorticoids (GCC) in equine plasma by liquid chromatography coupled with triple stage quadrupole tandem mass spectrometry (LC/TSQ-MS/MS) is described. Plasma sample augmented with the 21 GCC was extracted with methyl tert-butyl ether (MTBE) and analyzed by positive electrospray ionization. Desoxymetasone or dichlorisone acetate was used as the internal standard (IS). Quantification was performed by IS calibration. For each drug, one major product ion was chosen and used for screening for that drug. Analyte confirmation was performed by using the three most intense product ions formed from the precursor ion and the corresponding mass ratios. The recovery of the 21 GCC when spiked into blank plasma at 5 ng/mL was 45-200% with coefficient of variation (CV) from 0.3-18%. The limit of detection (LOD) and that of quantification (LOQ) for most of the analytes were 50-100 pg/mL and 1 ng/mL, respectively, whereas that of confirmation (LOC) was 100-300 pg/mL depending on the analyte. Intra- and inter-day precisions expressed as CV for quantification of 1 and 10 ng/mL was 1.0-17%, and 0.51-19%, respectively, and the accuracy was from 84-110%. The linear concentration range for quantification was 0.1-100 ng/mL (r(2) > 0.997). Estimated measurement uncertainty was from 11-37%. This study was undertaken to develop a method for simultaneous screening, identification, quantification and confirmation of these agents in post-race equine plasma samples. The method has been successfully applied to screening of a large number of plasma samples obtained from racehorses in competition and in pharmacokinetic studies of dexamethasone in the horse and concurrent changes in endogenous GCC, hydrocortisone and cortisone. The method is simple, sensitive, selective and reliably reproducible.

[A systematic screening and identification method for 29 central nervous system drugs in body fluid by high performance capillary electrophoresis].

A systematic screening method has been developed for the detection of 29 central nervous system (CNS) drugs in human plasma, urine and gastric juice by high performance capillary electrophoresis (HPCE). The first step is sample preparation. The patient's or normal human plasma (0.5 ml) spiked with CNS drugs was extracted with 2 x 4 ml dichloromethane, while 2 ml of patient's or spiked urine was extracted with 2 x 6 ml chloroform. The combined extract from plasma or urine was evaporated to dryness in a rotation evaporator at 35 degrees C. The residue was dissolved in 100 microliters methanol and subsequently 400 microliters of redistilled water was added. The patient gastric juice (3 ml) was centrifuged at 2,000 r.min-1 for 5 min. The supernatant was filtered through 0.45 micron microporous membrane for injection onto capillary columns. The second step was to perform CZE separation in acidic buffer composed of 30 mmol.L-1(NH4)3PO4(pH 2.50) and 10% acetonitrile (condition A). Most of the benzodiazepines (diazepam, nitrazepam, chlordiazepoxide, flurazepam, extazolam, alprazolam) and methaqualone were baseline separated and detected at 5-13 min, while thiodiphenylamines showed group peaks at 3-5 min and barbiturates migrate with electroosmotic fluid (EOF) together. The third step is to separate the drugs in basic buffer constituted of 70 mmol.L-1 Na2HPO4(pH 8.60) and 30% acetonitrile (condition B). The thiodiphenylamines and some other basic drugs could be well separated, which include thihexyphenidyl, imipramine, amitriptyline, diphenhydramine, chlorpromazine, doxepin, chlorprothixene, promethazine and flurazepam, while the rest of the CNS drugs did not interfere with the separation. The last step was to separate the drugs by micellar electrokinetic chromatography (MEKC) in such a buffer as 70 mmol.L-1 SDS plus 15 mmol.L-1 Na2HPO4 (pH 7.55) and 5% methanol (condition C). Barbiturates (barbital, phenobarbital, methylphenobarbital, amobarbital, thiopental, pentobarbital, secobarbital) and some hydrophobic drugs (glutethimide, alprazolam, clonazepam, carbamazepine, trifluoperazine, oxazepam) could be well separated. These drugs might be identified by both the relative migration time (rtm = tdrug/tEOF) and the ratios of peak heights (rh) monitored at different wavelength, since the ratios are characteristic of the spectrum of a drug. This method has been used in several real clinical samples of intoxication. For example, perphenazine and doxepin were detected in the gastric juice and phenobarbital in blood and gastric juice of an intoxicated patient.

GC/MS identification of tetramine in samples from human alimentary intoxication and evaluation of artificial carbonic kidneys for the treatment of the victims.

One day in July 1991, 78 people became victims of accidental alimentary intoxication in a factory in Hebei Province, China. Related samples, including rodenticide bait, the artificial carbonic kidneys used for the treatment of the victims, and the victims' blood, were analyzed by GC/MS. Tetramine [80-12-6], a highly toxic rodenticide, was identified as the toxicant. The effectiveness of artificial carbonic kidneys was evaluated. The analytical results revealed that detoxification of the patients was effective 48 hours after intoxication by percolating their blood through artificial carbonic kidneys.