Fe3O4-solamargine induces apoptosis and inhibits metastasis of pancreatic cancer cells.

Fe3O4-magnetic liposome (MLP) can deliver drugs to target tissues and can increase drug efficacy. The present study aimed to investigate the effects of solamargine (SM) and Fe3O4-SM in pancreatic cancer (PC). Cell viability was detected using a Cell Counting kit­8 assay. Apoptosis and cell cycle progression was tested using a flow cytometry assay. A scratch assay was used to examine cell metastasis. Quantitative polymerase chain reaction, western blot analysis or immunohistochemical analysis were performed to determine the expression of target factors. Magnetic resonance imagining (MRI) and terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling were conducted to detect tumor growth and apoptosis in vivo, respectively. It was demonstrated that Fe3O4-SM inhibited cancer cell growth via a slow release of SM over an extended period of time. SM was revealed to induce apoptosis and cell cycle arrest. Furthermore, SM decreased the expression of X-linked inhibitor of apoptosis, Survivin, Ki­67, proliferating cell nuclear antigen and cyclin D1, but increased the activity of caspase-3. It was also observed that SM inhibited tumor cell metastasis by modulating the expression of matrix metalloproteinase (MMP)-2 and TIMP metallopeptidase inhibitor-2. Furthermore, the phosphorylation of protein kinase B and mechanistic target of rapamycin was suppressed by SM. Notably, the effect of SM was enhanced by Fe3O4-SM. The malignant growth of PC was decreased by SM in vivo. Furthermore, the expression of Ki­67 was decreased by SM and Fe3O4-SM. Additionally, cell apoptosis was increased in the Fe3O4-SM group, compared with the SM group. The present study illustrated the antitumor effect and action mec-hanism produced by SM. Additionally, it was demonstrated that Fe3O4-SM was more effective than SM in protecting against PC.

An UPLC-MS/MS method for determination of solasonine in rat plasma and its application of a pharmacokinetic and bioavailability study.

Solasonine, a known glycoalkaloid, is a potential anti-cancer agent. In this work, a simple, sensitive and fast ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantitative determination of solasonine in rat plasma. Plasma samples were processed with a protein precipitation. The separation was achieved by an ACQUITY HSS T3 (100×2.1mm, 1.8µm) column with a gradient mobile phase consisting of 0.1% formic acid and acetonitrile. Detection was carried out using positive-ion electrospray tandem mass spectrometry via multiple reaction monitoring (MRM). The validated method had an excellent linearity in the range of 0.1-500ng/mL (R(2)>0.994) with a low limit of detection (0.1ng/mL) and lower limit of quantification (0.5ng/mL). The extraction recovery was in the range of 92.4-94.9% for solasonine and 91.9% for dendrobine (internal standard, IS). The intra- and inter-day precision was below 9.8% and accuracy was from 86.0% to 94.3%. No notable matrix effect and astaticism was observed for solasonine. The method has been successfully applied to a pharmacokinetic and bioavailability study of solasonine in rats for the first time, which provides the basis for the further development and application of solasonine.

Comparative study on pharmacokinetics of a series of anticholinergics, atropine, anisodamine, anisodine, scopolamine and tiotropium in rats.

The compound series of traditional anticholinergics [atropine (Atr), anisodamine (Ani), anisodine (AT3), and scopolamine (Sco)], naturally occurring belladonna alkaloid, have been approved for numerous therapeutic uses since 1970s. Tiotropium, a novel M receptor antagonist for the treatment of chronic obstructive pulmonary disease, was structurally modified based on atropine-like drugs. Clinical phenomena suggested that the changes of substituent group were related to the pharmacokinetic and pharmacodynamic characteristics of the agents. In an attempt to compare the pharmacokinetics of the series of anticholinergics and investigate the subsets motivating selective anticholinergic potencies, a sensitive LC-MS/MS method was established to analyze the differences of pharmacokinetic parameters. In this paper, we determined the pharmacokinetics of atropine, anisodamine, anisodine, scopolamine, and tiotropium after i.v. and i.g. single dose administration. After i.v. administration, the maximum drug plasma concentrations (C max) of Atr, Ani, AT3, and Sco were 274.25 ± 53.66, 267.50 ± 33.16, 340.50 ± 44.52, and 483.75 ± 78.13 ng/mL. Tiotropium had a slightly higher area under the curve with a significant increase of C max value. Because of their partial solubility, Atr, Ani, AT3, and Sco had different bioavailability in rats of 21.62, 10.78, 80.45 and 2.52 %, respectively. Following i.g. administration of tiotropium, the C max value below 20 ng/mL revealed the very low oral absorption. The urinary excretion rates of Atr, Ani, AT3, Sco and tiotropium were 11.33, 54.86, 32.67, 8.69 and 73.91 %. This work provided relatively comprehensive preclinical data on the series of anticholinergics, which may be used to explain the clinical adverse effects and applications.

Simultaneous determination of atropine, scopolamine, and anisodamine from Hyoscyamus niger L. in rat plasma by high-performance liquid chromatography with tandem mass spectrometry and its application to a pharmacokinetics study.

In order to investigate the pharmacokinetics of tropane alkaloids in Hyoscyamus niger L., a sensitive and specific high-performance liquid chromatography with tandem mass spectrometry method for the simultaneous determination of atropine, scopolamine, and anisodamine in rat plasma is developed and fully validated, using homatropine as an internal standard. The separation of the four compounds was carried out on a BDS Hypersil C18 column using a mobile phase consisting of acetonitrile and water (containing 10 mmol ammonium acetate). Calibration curves were linear from 0.2 to 40 ng/mL for atropine, scopolamine, and from 0.08 to 20 ng/mL for anisodamine. The precision of three analytes was <5.89% and the accuracy was between -1.04 to 2.94%. This method is successfully applied to rat pharmacokinetics analysis of the three tropane alkaloids after oral administration of H. niger extract. The maximum concentration of these three tropane alkaloids was reached within 15 min, and the maximum concentrations were 31.36 ± 7.35 ng/mL for atropine, 49.94 ± 2.67 ng/mL for scopolamine, and 2.83 ± 1.49 ng/mL for anisodamine. The pharmacokinetic parameters revealed areas under the curve of 22.76 ± 5.80, 16.80 ± 3.08, and 4.31 ± 1.21 ng/h mL and mean residence times of 2.08 ± 0.55, 1.19 ± 0.45, and 3.28 ± 0.78 h for atropine, scopolamine, and anisodamine, respectively.

Quantitative determination and pharmacokinetic study of solamargine in rat plasma by liquid chromatography-mass spectrometry.

A sensitive and simple liquid chromatography-mass spectrometry (LC-MS) method has been developed and validated for the quantification of solamargine, a steroidal glycoalkaloid, in rat plasma. Vincristine was selected as the internal standard. Sample preparation involved simple liquid-liquid extraction by ethyl acetate with high efficiency. The chromatographical separation was performed on a Shimadzu C(18) column (150mm×2.0mm, 5µm) with a gradient elution of acetonitrile and 0.02% (v/v) formic acid. The elutes were detected under positive electrospray ionization (ESI) and the target analytes quantified by selected ion monitoring (SIM) mode. The method was sensitive with the lowest limit of quantitation (LLOQ) at 0.5ng/mL in 50µL of rat plasma. Good linearity (r(2)=0.9996) was obtained covering the concentration of 0.5-2000.0ng/mL. The intra- and inter-day assay precision ranged from 2.87 to 3.60% and 0.52 to 6.81%, respectively. In addition, the stability, extraction recovery and matrix effect involved in the method were also validated. The practical utility of the aforementioned method was successfully confirmed in the pharmacokinetic evaluation of solamargine in Sprague-Dawley rats after intravenous administration.

Study of stereoselective pharmacokinetics of anisodamine enantiomers in rabbits by capillary electrophoresis.

The purpose of this study was to determine the pharmacokinetics of anisodamine enantiomers in plasma after oral and intravenous administration of racemic anisodamine in rabbits. A capillary electrophoresis method for the simultaneous separation of two pairs of enantiomers in plasma has been firstly developed and validated. Using a 75 mM phosphate buffer containing 25 mM carboxymethylated-gamma-cyclodextrin at pH 2.5, good resolution was achieved on a 45-cm uncoated fused-silica capillary at the voltage of 20 kV and 25 degrees C. The pharmacokinetics of individual anisodamine enantiomers were characterized using the CE assay, the sole method of enantiomeric separation for anisodamine. Pharmacokinetic analysis of results indicated that anisodamine enantiomers showed non-stereoselective disposition or stereoselective disposition in different rabbits. For the rabbits with non-stereoselective disposition, similar pharmacokinetic characteristics were observed between (6S, 2'S)- and (6R, 2'R)-, or (6S, 2'R)- and (6R, 2'S)-anisodamine. For the rabbits with stereoselective disposition, (6S, 2'S)- and (6R, 2'S)-anisodamine were below the established LOD, while the two remaining enantiomers also had similar pharmacokinetic profiles. Further investigations remain necessary to find out the underlying mechanism about the stereoselective disposition of (6S, 2'S)- and (6R, 2'S)-anisodamine.

[Studies on the determination of plasma level and pharmacokinetic parameters of anisodamine by micellar liquid chromatography].

Anisodamine is a tropane alkaloid isolated from the plant Anisodus tanguticus (Maxim) Pasch. It is an anticholine drug widely used in clinics. Micellar liquid chromatography is a new type of HPLC developed in the 1980's. Direct plasma injection technique is the application of micellar HPLC in bioanalyses. In this paper, a micellar HPLC method, which employs n-propanol as modifier, SDS as surfactant, atropine sulphate as internal standard, has been developed. By direct injection, this method was successfully applied to the measurement of plasma level of anisodamine. Application of this method to the study of anisodamine pharmacokinetics was investigated in human volunteers following a single intramuscular injection. The separation was performed in a Shim-pack CLC-CN column (150 mm x 6 mm ID, 5 microns) with a mobile phase of n-propanol-water (15:85) with 45 mmol/L SDS and total ion strength 70 mmol/L by adding phosphate, and detected at 205 nm. The standard curve was linear over the concentration range of 15-750 ng plasma level (r = 0.9972). The measurable lowest concentration was 10 ng/ml plasma (S/N = 3:1). The study of anisodamine pharmacokinetic in man was also described.

Determination of potato glycoalkaloids and their aglycone in blood serum by high-performance liquid chromatography. Application to pharmacokinetic studies in humans.

The development of a high-performance liquid chromatography (HPLC) method for the separation and quantification of potato glycoalkaloids and their aglycone solanidine in blood serum is reported. High selectivity was obtained by using solid-phase extraction followed by off-line dual-column HPLC. Injections were made via a sample enrichment column to achieve maximum sensitivity in the assay. The potato alkaloids in the HPLC effluents were detected by ultraviolet absorption at 200 nm. The detection limits were estimated to be 0.3 ng/ml of serum for each of the alkaloids. The method was used to study the pharmacokinetics of potato glycoalkaloids in humans. alpha-Solanine and alpha-chaconine were detected in all blood serum samples collected from seven volunteers 1-25 h after a meal of potatoes. Solanidine was detected in some samples, but there were no traces of the mono- or diglycosides. The average apparent biological half-lives for alpha-solanine and alpha-chaconine were 11 and 19 h, respectively.

Solasodine glycosides. In vitro preferential cytotoxicity for human cancer cells.

Solamargine [(22R,25R)-spiro-5-en-3 beta-yl-alpha-L-rhamnopyranosyl- (1----2glu)-O-alpha-L-rhamnopyranozyl (1----4glu)-beta-D-glucopyranoze], a glycoside of solasodine preferentially inhibits the uptake of tritiated thymidine by cancer cells. In contrast, solamargine at equivalent concentration, and the mono- and diglycosides of solasodine have a limited effect on the uptake of tritiated thymidine for other cell types, including unstimulated lymphocytes and lymphocytes stimulated with Con A. In contrast the solasodine glycosides do not inhibit the uptake of tritiated thymidine by lymphocytes stimulated with PHA or PWM. The inhibition of tritiated thymidine uptake by solamargine and the mono- and di-glycosides of solasodine are dependent upon their cellular uptake by endogenous endocytic lectins (EELs). The mode of action of the solasodine glycosides, in particular solamargine, appears to be the induction of cell lysis, as determined by morphological examination.