Development and validation of a rapid and sensitive UPLC-MS/MS assay for simultaneous quantification of paclitaxel and cyclopamine in mouse whole blood and tissue samples.

The prominent stromal compartment surrounds pancreatic ductal adenocarcinoma and protects the tumor cells from chemo- or radiotherapy. We hypothesized that our nano formulation carrying cyclopamine (CPA, stroma modulator) and paclitaxel (PTX, antitumor agent) could increase the permeation of PTX through the stromal compartment and improve the intratumoral delivery of PTX. In the present study a sensitive, reliable UPLC-MS/MS method was developed and validated to quantify PTX and CPA simultaneously in mouse whole blood, pancreas, liver and spleen samples. Docetaxel was used as the internal standard. The method demonstrated a linear range of 0.5-2000 ng/mL for whole blood and tissue homogenates for both PTX and CPA. The accuracy and precision of the assay were all within ±15%. Matrix effects for both analytes were within 15%. Recoveries from whole blood, liver, spleen and pancreas homogenates were 92.7-105.2% for PTX and 72.8-99.7% for CPA. The stability was within ±15% in all test biomatrices. The validated method met the acceptance criteria according to US Food and Drug Administration regulatory guidelines. The method was successfully applied to support a pharmacokinetic and biodistribution study for PTX and CPA in mice biomatrices.

Hedgehog antagonists cyclopamine and dihydroveratramine can be mistaken for each other in Veratrum album.

A toxic plant, Veratrum album (ssp. viriscens), was found to have an inhibitory effect on Hedgehog (Hh), a developmental signaling pathway that has been shown to be active during development, in adult stem cells and in numerous human tumors. Based on earlier studies it was believed that the known Hh inhibitor cyclopamine was present in V. album (ssp. viriscens). Here we show that instead of cyclopamine, dihydroveratramine (DHV) was found in V. album (ssp. viriscens). These compounds are easily mistaken for each other, as both substances share the same molecular weight, and the same main MS/MS fragments. DHV was found to be a less potent Hh inhibitor compared to cyclopamine. This is the first reported occurrence of DVH in nature.

Accidental intoxication with Veratrum album.

A 49-year-old man consumed two glasses (approximately 2 x 20 mL) of a beverage containing yellow gentian (Gentiana lutea). Shortly after ingestion, he developed nausea, vomiting, and oral paraesthesia. On admission to the hospital he suffered from severe bradycardia (35 beats/min) and hypotension (50/30 mm Hg), and he was treated with activated charcoal, antiemetics (metoclopramide, ondansetron), atropine, and intravenous electrolytic solution. The initial suspicion of Veratrum poisoning could be confirmed by identifying protoveratrines A (ProA) and protoveratrine B (ProB) in a sample from the beverage as well as in the patients serum by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS). The yellow-colored beverage contained 25% ethanol (by headspace gas chromatography), 20.4 mg/L ProA, and 13.7 mg/L ProB. The serum concentration of ProA was 1162 ng/L and ProB was 402 ng/L. Veratridine, cevadine, and jervine were not detected, neither in the beverage nor in the serum sample. The lower limits of quantitation for all compounds is 10 microg/L (S/N > 10, beverage) and 100 ng/L (S/N > 10, serum). After treatment, the patient completely recovered from the symptoms within 24 h and was discharged from the hospital. The analytical method described was developed for the simultaneous identification and quantitation of five Veratrum alkaloids. The method is based on a liquid-liquid extraction followed by LC-MS-MS analysis. The time needed for analysis was 6 min.

Alkaloid profiling of crude and processed Veratrum nigrum L. through simultaneous determination of ten steroidal alkaloids by HPLC-ELSD.

Veratrum nigrum L., a traditional Chinese herb, has been used for treatment of hypertension, blood-stroke, excessive phlegm, epilepsy, etc. Steroidal alkaloids were well-known as both bioactive and toxic constituents of Veratrum species, the toxicity of which the traditional processing procedure can reduce. To reveal the mechanism of processing V. nigrum L., a high performance liquid chromatography (HPLC) with evaporative light scattering detector (ELSD) method was developed for the simultaneous determination of ten steroidal alkaloids in crude and processed V. nigrum L., comparison with ultrasound extract of crude V. nigrum L. With a Venusil XBP-C(18) analytical column, the analytes were separated efficiently using the mobile phase consisted of (A) 0.03% aqueous triethylamine (TEA) and (B) acetonitrile in a gradient program. The parameters for ELSD were set: S.C. (Spray Chamber)=35 degrees C, D.T. (Drift Tube)=70 degrees C, GAS=50 psi. All calibration curves showed good linear regression (gamma>or=0.9990) within the tested range. Additionally, reproducibility for the quantification of ten alkaloids in V. nigrum L. with intra- and inter-day variations of less than 5.0% was observed. The obtained alkaloid profiles performed by this newly established method, provided valuable information for the differentiation of crude and processed V. nigrum L. and for the explanation of the different toxicity.

[Determination of vetatramine in Veratrum nigrum by HPLC-ELSD].

OBJECTIVE: To develop an HPLC-ELSD method for determination of vetatramine. in Veratrum nigrum. METHOD: The analy fical column was Shim-pack ODS - C18 (4.6 mm x 250 mm, 4 microm) column, the mobile phase was acetonitrile-water (containing 0.1% triethylamine) (50:50), at a flow rate of 0.8 mL x min(-1). The temperature of drift tube was 90 degrees C and the gas flow was at the rate of 2.5 L x min(-1). RESULT: The calibration curve was linear in the range of 0.36-3.6 microg (r = 0.999 8). The average recovery was 100.9% (RSD 2.3%, n = 6). The contents of veratramine in Veratrum nigrum. from the ten different sources were determined. CONCLUSION: The method may be used as a accurate and reproducible way to determine the content of veratramine in V. nigrum.

[Determination of jervine and veratramine in Veratrum plants using high performance liquid chromatography coupled with evaporative light scattering detection].

A method of reversed-phase high performance liquid chromatography (HPLC) coupled with evaporative light scattering detection (ELSD) was developed for the determination of jervine and veratramine in veratrum plants. The extraction method of total active alkaloids from the raw material was also established. The separation and quantification were achieved using a Kromasil C8column (250 mm x 4.6 mm, 5 microm), and a mobile phase of acetonitrile and 0.1% trifluoroacetic acid with the following gradient elution: 20% acetonitrile at the first 5 mm, 20%-40% acetonitrile at the 5-30 mm, 40%-20% acetonitrile at the 30-40 mm, 20% acetonitrile at the 40-45 mm with a flow rate of 0.8 mL/min; column temperature of 35 t and monitored by an ELSD detector with the drift tube of 98 t and the nitrogen flow rate of 2.2 L/min. The calibration curves for jervine and veratramine were linear over the ranges of 42.05-980 mg/L and 43.52-1020 mg/L, respectively. The recoveries were 99.2% and 101.4% with relative standard deviations of 1.7% and 2.1% (n=6), respectively. The limits of detection for jervine and veratramine in raw material were 18.37 mg/kg and 21.50 mg/kg, respectively, with 3 times of the signal to noise ratio. This HPLC-ELSD method is rapid, simple, accurate and convenient. It can be used as one of the direct and reliable means for quantitative determination of the active alkaloids in veratrum plants.

Development of in vitro techniques for the important medicinal plant Veratrum californicum.

VERATRUM CALIFORNICUM (Liliaceae) is an important monocotyledonous medicinal plant which is the only source of the anticancer compound cyclopamine. An IN VITRO culture system for somatic embryogenesis and green plant regeneration of VERATRUM CALIFORNICUM was developed. Embryogenic calli were induced from mature embryos on induction medium. Five basal media supplemented with different growth regulators were evaluated for embryogenic callus induction, modified MS medium with 4 mg/L picloram showing the best result for embryogenic callus production. Fine suspension cell lines were established by employing friable embryogenic calli as starting material and AA medium and L2 medium as culture media. The suspension cell lines cultured in AA medium with 4 mg/L NAA appeared to be fresh yellow and fast growing. The suspension cells were cryopreserved successfully and recovered at a high rate. Green plants were regenerated from embryogenic calli maintained on solid medium with 73 % regeneration ability (green plants/100 calli) in 27-month-old culture. The IN VITRO plantlets contained the steroid alkaloids cyclopamine and veratramine. This IN VITRO system will form the basis for metabolic engineering of VERATRUM cells in the context of biotechnological production of pharmaceutically important secondary metabolites. DMSO:dimethyl sulfoxide fw:fresh weight NAA:naphthaleneacetic acid 2,4-D:2,4-dichlorophenoxyacetic acid picloram:4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid dicamba:3,6-dichloro-2-methoxybenzoic acid.

Development of an enzyme-linked immunosorbent assay for the veratrum plant teratogens: cyclopamine and jervine.

Veratrum californicum was responsible for large losses of sheep grazing high mountain ranges in central Idaho in the 1950s. Veratrum induces various birth defects including the cyclopic-type craniofacial defect (monkey-faced lambs) that is specifically induced in lambs after pregnant ewes grazed the plant on the 14th day of gestation. The steroidal alkaloids cyclopamine (1) and jervine (2) were isolated from Veratrum and shown to be primarily responsible for the malformations. Cyclopamine (1) and jervine (2) are potent teratogens that inhibit Sonic hedgehog (Shh) signaling during gastrulation-stage embryonic development, producing cyclopia and holoprosencephaly. Although losses to the sheep industry from Veratrum are now relatively infrequent, occasional incidents of toxicoses and craniofacial malformations are still reported in sheep and other species. However, the benefits to biomedical research using cyclopamine (1) as a tool to study human diseases have greatly expanded. A competitive inhibition enzyme-linked immunosorbent assay (ELISA) to detect and measure cyclopamine (1) and jervine (2) was developed using polyclonal antibodies produced in ewes. The limits of detection of the assay were 90.0 and 22.7 pg for cyclopamine (1) and jervine (2), respectively. This assay was used for the detection and measurement of cyclopamine (1) spiked into sheep blood. The simple extraction-ELISA methods developed in this study demonstrate the potential of using these techniques for the rapid screening of biological samples to detect the presence and concentration of cyclopamine (1) and jervine (2) and will be beneficial to pharmacological studies and livestock diagnostics.

Characterization of acetylcholinesterase-inhibition by itopride.

Itopride is a gastroprokinetic benzamide derivative. This agent inhibited both electric eel acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BuChE). The IC50 of itopride with AChE (2.04 +/- 0.27 microM) was, however, 100-fold less than that with BuChE, whereas in the case of neostigmine with AChE (11.3 +/- 3.4 nM), it was 10-fold less. The recovery of AChE activity inhibited by 10(-7) M neostigmine was partial, but that inhibited by up to 3 x 10(-5) M itopride was complete when the reaction mixture was subjected to ultrafiltration. Double reciprocal plots of the experimental data showed that both Km and Vmax were affected by itopride, suggesting that the inhibition is a "mixed" type, although primarily being an uncompetitive one. The inhibitory effect of itopride on cholinesterase (ChE) activity in guinea pig gastrointestine was much weaker than that on pure AChE. However, in the presence of a low dose of diisopropyl fluorophosphate, just enough to inhibit BuChE but not AChE, the IC50s of itopride against ChE activities were found to be about 0.5 microM. In conclusion, itopride exerts reversible and a "mixed" type of inhibition preferably against AChE. The IC50 of itopride for electric eel and guinea pig gastrointestinal AChE inhibition was 200 times and 50 times as large as that of neostigmine, respectively.

High-pressure liquid chromatography of steroidal alkaloids.

High-pressure liquid chromatography was used to separate the following steroidal alkaloids: tomatidine, solanidine, solasodine, rubijervine, veratramine and jervine. The method was used to prepare crystalline solanidine from a crude mixture of aglycones obtained from Solanum chacoense, and to separate radioactive solanidine from extracts of potato plants fed with [4-C]cholesterol.