Simultaneous determination of asarinin, ß-eudesmol, and wogonin in rats using ultraperformance liquid chromatography-tandem mass spectrometry and its application to pharmacokinetic studies following administration of standards and Gumiganghwal-tang.

Asarinin, ß-eudesmol, and wogonin have common antiangiogenic activities and have the potential for use in chemotherapy. Besides, they are multivalent substances that are combined in various herbal medicines. The purpose of this study was to develop a method for simultaneous analysis of asarinin, ß-eudesmol, and wogonin, which are representative pharmacological components of Asarum heterotropoides, Atractylodes lancea, and Scutellaria baicalensis, respectively, in rat biosamples using ultraperformance liquid chromatography-tandem mass spectrometry. The three components were separated using 5 mm aqueous ammonium acetate containing 0.1% formic acid and acetonitrile as a mobile phase, equipped with a KINETEX core-shell C18 column. The analysis was quantitated on a triple-quadrupole mass-spectrometer employing electrospray ionization, and operated in the multiple reaction monitoring mode. The chromatograms showed high resolution, sensitivity, and selectivity with no interference with plasma, urine, and feces constituents. The developed analytical method satisfied international guidance criteria and could be successfully applied to the pharmacokinetic (PK) studies evaluating oral bioavailability of asarinin, ß-eudesmol, and wogonin after oral and intravenous administration and their urinary and fecal excretion ratios after oral administration to rats. Furthermore, the analysis was extended to PK studies following oral administration of Gumiganghwal-tang. This study was the first simultaneous analysis of the aforesaid three constituents in rat plasma, urine, and feces that also determined their PK parameters.

Intestinal Absorption of Isoalantolactone and Alantolactone, Two Sesquiterpene Lactones from Radix Inulae, Using Caco-2 Cells.

BACKGROUND: Isoalantolactone and alantolactone are the main sesquiterpene lactones in Radix Inulae (dried root of Inula helenium L. or I. racemosa Hook. F.), which is a frequently utilized herbal medicine. They also occur in several plants and have various pharmacologic effects. However, they have been found to have poor oral bioavailability in rats. OBJECTIVES: To understand the intestinal absorptive characteristics of isoalantolactone and alantolactone as well specific influx and efflux transporters in their absorption. METHODS: Bidirectional permeabilities of isoalantolactone and alantolactone were investigated across Caco-2 cell monolayers. Transport assays were performed using different concentrations of two lactones and specific inhibitors of ATP-binding cassette transporters and influx transporters. RESULTS: The absorption permeability of isoalantolactone and alantolactone was high at the tested concentrations (5, 20 and 80 µmol/l), and the major permeation mechanism of both lactones was found to be passive diffusion with active efflux mediated by multidrug resistance-associated proteins (MRPs) and breast cancer resistance protein (BCRP). CONCLUSION: Our results demonstrated that the absorption permeability of isoalantolactone and alantolactone was good in the Caco-2 cell model. The isoalantolactone and alantolactone absorption elucidated in this study provides useful information for further pharmacokinetics studies. Since low intestinal absorption can now be ruled out as a cause, further studies are needed to explain the low oral bioavailability of the two sesquiterpene lactones.

Sesquiterpenes from the whole plants of Parasenecio roborowskii.

Six eremophilane-type (parasenolide A-F) and an eudesmane-type (parasenin) sesquiterpenoids, along with eight known sesquiterpenes, were isolated from the whole plants of Parasenecio roborowskii. The structures and absolute configurations of new compounds were elucidated using extensive spectroscopic analysis, including HRESIMS, 1D and 2D NMR experiments, the CD exciton chirality methods, and single-crystal X-ray crystallography. All isolated compounds were evaluated for cytotoxicity against five human cancer (HeLa, HepG2, K562, MDA231, and NCI-H460) cell lines and a murine melanoma B16 F10 cell line by MTT assay. Compounds 1-15 showed cytotoxic activities, especially compounds 3, 4, 8, 10, and 12. These five compounds showed broad spectrum activities against all the tested cancer cell lines with IC50 ranging from 9.2 to 35.5µM. The study supports that eremophilenolides and eudesmane-type sesquiterpenes occur mainly in the genus Parasenecio and can be used as a chemosystematic marker of the genus.

High body clearance and low oral bioavailability of alantolactone, isolated from Inula helenium, in rats: extensive hepatic metabolism and low stability in gastrointestinal fluids.

Alantolactone (ALA) is a major bioactive sesquiterpene lactone present in the roots of Inula helenium L. (Asteraceae) which has been used widely in traditional medicine against various diseases such as asthma, cancer and tuberculosis. The pharmacologic activities of alantolactone have been well characterized, yet information on the physicochemical and pharmacokinetic properties of alantolactone and their mechanistic elucidation are still limited. Thus, this study aims to investigate the oral absorption and disposition of alantolactone and their relevant mechanisms. Log P values of alantolactone ranged from 1.52 to 1.84, and alantolactone was unstable in biological samples such as plasma, urine, bile, rat liver microsomes (RLM) and simulated gastrointestinal fluids. The metabolic rate of alantolactone was markedly higher in rat liver homogenates than in the other tissue homogenates. A saturable and concentration-dependent metabolic rate profile of alantolactone was observed in RLM, and rat cytochrome P450 (CYP) 1 A, 2C, 2D and 3 A subfamilies were significantly involved in its hepatic metabolism. Based on the well-stirred model, the hepatic extraction ratio (HER) was estimated to be 0.890-0.933, classifying alantolactone as a drug with high HER. Moreover, high total body clearance (111 ± 41 ml/min/kg) and low oral bioavailability (0.323%) of alantolactone were observed in rats. Taken together, the present study demonstrates that the extensive hepatic metabolism, at least partially mediated by CYP, is primarily responsible for the high total body clearance of alantolactone, and that the low oral bioavailability of alantolactone could be attributed to its low stability in gastrointestinal fluids and a hepatic first-pass effect in rats. Copyright © 2016 John Wiley & Sons, Ltd.

Pharmacokinetics, tissue distribution and excretion of isoalantolactone and alantolactone in rats after oral administration of Radix Inulae extract.

Radix Inulae is endemic to China and has been used in traditional medicine to treat upper body pain, emesis and diarrhoea, and to eliminate parasites. Here, an UPLC-MS/MS method was developed and applied to study the pharmacokinetics, distribution and excretion of isoalantolactone and alantolactone, which are two main active sesquiterpene lactones in Radix Inulae, in Sprague-Dawley rats following oral administration of total Radix Inulae extract. Isoalantolactone, alantolactone and osthole (internal standard) were prepared using acetonitrile precipitation, and the separation of isoalantolactone and alantolactone was achieved by isocratic elution using water (containing 0.1% formic acid) and acetonitrile as the mobile phase using a ZORBAX Eclipse Plus C18 column. The total run time was 6.4 min. The present study showed poor absorption of isoalantolactone and alantolactone in vivo. The apparent Cmax, Tmax, T1/2 and total exposure (AUC0-12h) in rat plasma were 37.8 ng/mL, 120 min, 351.7 min and 6112.3 ng-min/mL for isoalantolactone and 25.9 ng/mL, 90 min, 321.0 min and 4918.9 ng-min/mL for alantolactone, respectively. It was shown that the highest concentration was achieved in the small intestine and feces clearance was shown to be the dominant elimination pathway of the lactones.

Simultaneous determination of sesquiterpene lactones isoalantolactone and alantolactone isomers in rat plasma by liquid chromatography with tandem mass spectrometry: application to a pharmacokinetic study.

A selective, sensitive, and accurate LC-MS/MS method for the simultaneous determination of isoalantolactone and alantolactone in rat plasma has been developed using psoralen as the internal standard. LC-MS/MS analysis was carried out on a Triple Quadrupole mass spectrometer using positive ion ESI and the selected reaction monitoring mode. The assays were linear in the range of 7.5-750 ng/mL for isoalantolactone and 5.5-550 ng/mL for alantolactone. The average recoveries in plasma samples both were better than 85%. The intra- and inter-day precision and accuracy values were found to be within the assay variability criteria limits according to the US FDA guidelines. The method was successfully applied to pharmacokinetic studies of the two structural isomers after an intravenous injection of Inula helenium formulation to rats.