Roots Of Menispermum Dauricum Research Articles

Determination and pharmacokinetic study of dauricine in rat plasma by UPLC–MS/MS

Dauricine is the major bioactive component isolated from the roots of Menispermum dauricum D.C., a bisbenzylisoquinoline alkaloid derivative, and has shown multiple pharmacological properties. In this work, a sensitive and selective ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was developed for determination of dauricine in rat plasma and its application to pharmacokinetic study of dauricine after intravenous and oral administration in rats. After addition of daurisoline as an internal standard (IS), protein precipitation by acetonitrile was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification. Calibration plots were linear throughout the range 2–600 ng mL−1 for dauricine in rat plasma. Relative standard deviation (RSD) of intra-day and inter-day precision was less than 13%. The accuracy of the method was between 95.8% and 105.9%. Matrix effect of dauricine in rat plasma ranged from 88.0% to 90.3%. Mean recoveries of dauricine in rat plasma ranged from 91.5% to 95.1%. The method was successfully applied to pharmacokinetic study of dauricine after intravenous and oral administration in rats. The bioavailability of dauricine was found to be 55.4% for the first time.

P-glycoprotein inhibition increases the transport of dauricine across the blood-brain barrier

Dauricine is the major bioactive component isolated from the roots of Menispermum dauricum D.C. The aim of the present study was to investigate the role of P‑glycoprotein in the transport of dauricine across the blood‑brain barrier by pre‑treatment with the P‑glycoprotein inhibitor verapamil. Sprague Dawley rats were divided into a verapamil group (pretreated with verapamil at a dose of 20 mg/kg) and a control group (pretreated with the same volume of normal saline). After 90 min, the animals were injected intravenously with dauricine (10 mg/kg). At 15, 30 and 60 min after dauricine administration, the levels of dauricine in the blood and brain were detected by high‑performance liquid chromatography. Compared with the control group, the dauricine concentration in the brains of the rats in the verapamil group was significantly increased. Furthermore, the brain‑plasma ratio of dauricine in the rats pretreated with verapamil was significantly higher than that of the animals in the control group. However, there was no difference identified between dauricine levels in the plasma of the verapamil and the control groups. The results indicated that dauricine is able to pass the blood‑brain barrier, and that P‑glycoprotein has an important role in the transportation of dauricine across the blood‑brain barrier.

Inhibitory effects of a bisbenzylisoquinline alkaloid dauricine on HERG potassium channels

Ethnopharmacological relevanceThe roots of Menispermum dauricum have been widely used for the treatment of inflammation, allergy and arrhythmia in China for a long time. Dauricine (Dau), a bisbenzylisoquinline alkaloid from Menispermum dauricum, mainly contributes to the anti-arrhythmic effect and has received pharmacological attention. Dau can prolong the action potential duration (APD), which has been attributed to its ability to modulate Ca2+ and several K+ channels. However, its effects on human-ether-a-go-go-related gene (HERG) channels are unknown. Aim of the studyThe effects of Dau on HERG channels were investigated. Materials and methodsWhole-cell patch-clamp technique was used to record HERG current (IHERG) carried by recombinant HERG channels expressed in HEK293 cells. ResultsDau inhibited IHERG in a concentration-dependent manner with an IC50 of 3.5μM. Development of block and washout were fast. The inhibitory action of Dau was contingent on channel gating, showing significant voltage and time dependence. Dau inhibited IHERG in the open and inactivated states, but not in the closed states. The activation curve was shifted in a negative direction. ConclusionsDau inhibits HERG encoded potassium channels and this action might be a molecular mechanism for the previously reported APD prolongation with this drug.

Predictable and linear scale-up of four phenolic alkaloids separation from the roots of Menispermum dauricum using high-performance counter-current chromatography

This paper describes how distribution ratios were used for prediction of peak elution in analytical high-performance counter-current chromatography (HPCCC) to explore the method for separation and purification of bioactive compounds from the roots of Menispermum dauricum. Then important parameters related to HPCCC separations including solvent systems, sample concentration, sample loading volume and flow rate were optimized on an analytical Mini-DE HPCCC and finally linearly scaled up to a preparative Midi-DE HPCCC with nearly the same resolutions and separation time. Four phenolic alkaloids were for the first time obtained by HPCCC separation with a two-phase solvent system composed of petroleum ether–ethyl acetate–ethanol–water (1:2:1:2, v/v). This process produced 131.3 mg daurisolin, 197.1 mg dauricine, 32.4 mg daurinoline and 14.7 mg dauricicoline with the purity of 97.6%, 96.4%, 97.2% and 98.3%, respectively from 500 mg crude extract of the roots of M. dauricum in a one-step separation. The purities of compounds were determined by high-performance liquid chromatography (HPLC). Their structures were identified by electrospray ionization mass spectrometer (ESI-MS) and nuclear magnetic resonance (NMR).

Pulmonary Toxicity and Metabolic Activation of Dauricine in CD-1 Mice

Dauricine is the major bioactive component isolated from the roots of Menispermum dauricum D.C. and has shown promising pharmacological activities with a great potential for clinic use. However, the adverse effects and toxicity of the alkaloid are unfortunately ignored. The objective of the current study was to evaluate the toxicity of dauricine in vitro and in vivo. Mice (CD-1) were treated intraperitoneally with dauricine at various doses, and sera and lung lavage fluids were collected after 24 h of treatment. No changes in serum aspartate aminotransferase, alanine aminotransferase, and blood urea nitrogen were noticed, whereas a dose-dependent increase in lactate dehydrogenase activity was observed in lung lavage fluids. Ethidium-based staining studies showed that remarkable cells lost membrane integrity in the lungs of the animals treated with dauricine at 150 mg/kg. Histopathological evaluation of lungs of mice showed that dauricine at the same dose caused significant alveolar edema and hemorrhage. Exposure to dauricine at 40 muM for 24 h resulted in up to 60% cell death in human lung cell lines BEAS-2B, WI-38, and A549. Ketoconazole showed protective effect on the pulmonary injury in mice given dauricine. A quinone methide metabolite of dauricine was identified in mouse lung microsomal incubations, and the presence of ketoconazole in the microsomal incubations suppressed the formation of the quinone methide metabolite. In conclusion, dauricine produced pulmonary injury in CD-1 mice. The pulmonary toxicity appears to depend on the metabolism of dauricine mediated by CYP3A. The electrophilic quinone methide metabolite probably plays an important role in the pulmonary toxicity induced by dauricine.

Conversion of Dechlorodauricumine into Miharumine by a Cell-Free Preparation from Cultured Roots ofMenispermum dauricum

Dechlorodauricumine (5) and dechloroacutumine (6) were converted to miharumine (7) and dechloroacutumidine (8), respectively, by a cell-free preparation from cultured roots of Menispermum dauricum in the presence of FAD. The structures of 7 and 8 were elucidated on the basis of spectroscopic analyses and chemical conversion.

Dechlorodauricumine from cultured roots of Menispermum dauricum

Dechlorodauricumine, a possible organic substrate for biochlorination, was isolated from cultured roots of Menispermum dauricum, a rich source of chlorinated alkaloids. Its structure was established by spectroscopic and chemical methods.

A New 1,4-Phenanthraquinone from Menispermum Dauricum

A new 1,4-phenanthraquinone was isolated from the roots of Menispermum dauricum. The structure was elucidated as 7-hydroxy-3,6-dimethoxy-1,4-phenanthraquinone on the basis of spectral evidence.

Isoquinoline and isoindole alkaloids from Menispermum dauricum

Three isoquinoline alkaloids and an isoindole alkaloid, along with eight known compounds, were isolated from the roots of Menispermum dauricum (Menispermacese). The alkaloids were characterized as 7-hydroxy-6-methoxy-1(2 H)-isoquinolinone, 6,7-dimethoxy- N-methyl-3,4-dioxo-1(2 H)-isoquinolinone, 1-(4-hydroxybenzoyl)-7-hydroxy-6-methoxy-isoquinoline and 6-hydroxy-5-methoxy- N-methylphthalimide, on the basis of spectral evidence including 1D- and 2D-NMR and MS analyses.

Nitrotyrasacutuminine from Menispermum dauricum

Nitrotyrasacutuminine, an unusual nitrated morphine-type alkaloid was isolated from the roots of Menispermum dauricum . Its structure was determined by various 2D spectra and chemical methods.

Early Steps of Dauricine Biosynthesis in Cultured Roots ofMenispermum dauricum

Cultured roots of Menispermum dauricum, a rich source of the bisbenzylisoquinoline alkaloid dauricine (1), were fed with l-[U-(14)C] tyrosine, L-[3-(13)C] tyrosine, and [2-(13)C] tvramine independently, and the incorporation of possible early precursors into 1 was studied. The results demonstrated that 1 was composed of four molecules of tyrosine, and that tyramine was specifically incorporated into the isoquinoline portions of 1. The unusual chlorine-containing alkaloid acutumine (3), into which (14)C-labeled tyrosine was also incorporated, was identified as one of the main constituents in the alkaloid fraction from the roots.

Dauricine production in cultured roots of Menispermum dauricum

Root Cultures of Menispermum dauricum were established from adventitious roots formed on the leaf segments. These roots produce dauricine as a major constituent and the optimum conditions for dauricine production in cultured roots were investigated. A dauricine content of more than 0.5% dry weight was achieved in Gamborg's B5 medium containing 3% sucrose and 7.5 μM NAA. Tyrosine and tyramine, possible precursors of dauricine, increased dauricine formation. There was a positive correlation between dauricine content and root growth.