Highly sensitive analysis of cyanogenic glycosides in cold-pressed flaxseed oil by employing cigarette filter fiber-based SPE coupled with ultra-performance liquid chromatography-tandem mass spectrometry.

In this study, a highly sensitive method for analysis of 4 cyanogenic glycosides (CNGs) in cold-pressed flaxseed oil was developed by using cigarette filter fiber-based SPE and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The cold-pressed flaxseed oil was diluted with 5% (v/v) isopropanol/n-hexane solution and loaded to a cigarette filters fiber-based SPE column for CNG enrichment and purification. Under optimized conditions, four CNGs could be detected with limits of detection ranging from 1.3 to 4.4 pg/mL. The linear range was 0.05-50 ng/ml with a linear correlation coefficient (r) > 0.9935. CNG recovery ranged from 113% to 133%, and the relative standard deviation was between 0.8% and 20.5%. Finally, the proposed method was applied to the determination of CNGs in nine cold-pressed flaxseed oils.

Electrospinning-based synthesis of highly ordered mesoporous silica fiber for lab-in-syringe enrichment of plasma peptides.

Silica fiber with highly ordered mesoporous structure and continuously long fibrous property was synthesized on a large-scale for the first time. It can be applied to the rapid (less than 3 min) and effective enrichment of endogenous peptides with a novel lab-in-syringe approach.

Determination of brain cytochrome P450 2E1 activity in rat with the probe of chlorzoxazone by liquid chromatography-mass spectrometry.

A simple and sensitive method was developed for the determination of cytochrome P450 2E1 (CYP2E1) activity based on the liquid chromatography-mass spectrometry (LC-MS) analysis of 6-hydroxychlorzoxazone generated by 6-hydroxylation of chlorzoxazone under specific catalysis of CYP2E1. In the proposed method, 2-benzoxazolinone was chosen as internal standard and isopropyl ether was used as extraction solvent for sample preparation. The inter-day and intra-day precisions at low, medium and high concentrations of 6-hydroxychlorzoxazone were below 20.0%, and the LOD (S/N=3) was 0.05 ng/mL. This method was applied to analyze the CYP2E1 activity of rat in different brain regions including frontal cortex (FC), cerebellum (CB), brain stem (BS), hippocampus (HC), striatum (ST), thalamus (TH), and olfactory bulb (OB). The results confirmed that chlorzoxazone was a suitable probe for the determination of CYP2E1 activity in brain regions and samples with low content of CYP2E1.

Determination of 5-hydroxymethylfurfural using derivatization combined with polymer monolith microextraction by high-performance liquid chromatography.

A simple and sensitive method for the determination of 5-hydroxymethylfurfural (HMF) in coffee, honey, beer, Coke, and urine by high-performance liquid chromatography (HPLC) is presented. This method is based on the formation of the 2,4-dinitrophenylhydrazone of HMF and subsequent polymer monolith microextraction (PMME) of this derivative. A poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EGDMA) monolithic capillary column was selected as the extraction medium. Several parameters affecting the derivatization of HMF with 2,4-dinitrophenylhydrazine (DNPH) followed by extraction of the derivative were optimized. The procedure is simple and offers high sensitivity and specificity since the derivative of HMF is well preconcentrated by PMME with poly(MAA-co-EGDMA) monolith and well separated from the other components of the samples under examination. The recoveries in coffee, honey, beer, Coke, and urine samples were in the range of 83.9-110.8% spiked at different levels with HMF. The inter- and intraday precisions were less than 10%. The LOD (S/N = 3) and LOQ (S/N = 10) for HMF were 1.0 ng/mL and 3.4 ng/mL, respectively.

[Study on the Chinese herbal formula for treatment of vaginitis and the antimicrobial activity in murine models].

OBJECTIVE: To study on the various proportions of Radix Sophorae Flavescentis, Cortex Phellodendri, Fructus Cnidii and pericarp of Zanthoxylum bungeanum Maxim in the formulas, whose antimicrobial effects on E. coli, S. aureus, P. aeruginosa and C. albicans under different pH values were compared in vitro. METHODS: According to Chinese ancient proved recipe, the K-B method and plate diluting method were adopted to measure antimicrobial activity, and orthogonal design to ascertain the herbal formula in vitro. Finally, murine models were established to test the antimicrobial activity in vivo through vaginal membrane irritancy experiment, negative rate of pathogeny and pathological grade of vaginal membrane. RESULTS: The results suggested that formulas with different proportions of the herbs had diverse antimicrobial activities, and the effect was shown to be most obvious when one milliliter drug contains 100 microl Fructus Cnidii-pericarp of Zanthoxylum bungeanum (2:1) co-extracted volatile oil and 50 microl Radix Sophorae Flavescentis and Cortex Phenodendri ethanol extraction respectively under pH6. The antimicrobial effect of the formula, which hardly had any membrane irritancy, was better than Jie Eryin in vitro and vivo. CONCLUSION: The fromula has few components and better effect, and adaptation to the pH value of vaginitis. It is a promising alternative for gynecological diseases.

Modulation of Kupffer cells on hepatic drug metabolism.

AIM: To observe the effects of Kupffer cells on hepatic drug metabolic enzymes. METHODS: Kunming mice were i.p. injected with GdCl310, 20, 40 mg/kg to decrease the number and block the function of kupffer cells selectively. The contents of drug metabolic enzymes, cytochrome P450, NADPH-cytochrom C redutase (NADPH-C), aniline hydroxylase (ANH), aminopyrine N-demethylase (AMD), erythromycin N-demethylase (EMD), and glutathione s-transferase (mGST) in hepatic microsome and S9-GSTpi, S9-GST in supernatant of 9 000 g were accessed 1 d after the injection. The time course of alteration of drug metabolic enzymes was observed on d 1, 3, and 6 treated with a single dose GdCl3. Mice were treated with Angelica sinensis polysaccharides (ASP) of 30, 60, 120 mg/kg, i.g., qd x 6 d, respectively and the same assays were performed. RESULTS: P450 content and NADPH-C, ANH, AMD, and EMD activities were obviously reduced 1 d after Kupffer cell blockade. However, mGST and S9-GST activities were significantly increased. But no relationship was observed between GdCl3 dosage and enzyme activities. With single dose GdCl3 treatment, P450 content, NADPH-C, and ANH activities were further decreased following Kupffer cell blockade lasted for 6 d, by 35.7%, 50.3%, 36.5% after 3 d, and 57.9%, 57.9%, 63.2% after 6 d, respectively. On the contrary, AMD, EMD, mGST, and S9-GST activities were raised by 36.5%, 71.9%, 23.1%, 35.7% after 3 d, and 155%, 182%, 21.5%, 33.7% after 6 d, respectively. Furthermore, the activities of drug metabolic enzymes were markedly increased after 30 mg/kg ASP treatment, and decreased significantly after 120 mg/kg ASP treatment. No change in activity of S9-GSTpi was observed in the present study. CONCLUSION: Kupffer cells play an important role in the modulation of drug metabolic enzymes. The changes of drug metabolic enzyme activities depend on the time of kupffer cell blockade and on the degree of Kupffer cells activated. A low concentration of ASP increases the activities of drug metabolic enzymes, but a high concentration of ASP decreases the activities of drug metabolic enzymes.