An alkaloid from Menispermum dauricum, dauricine mediates Ca2+ influx and inhibits NF-κB pathway to protect chondrocytes from IL-1ß-induced inflammation and catabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: Dauricine (DA) is a natural plant-derived alkaloid extracted from Menispermum dauricum. Menispermum dauricum has been used in traditional Chinese medicine as a classic remedy for rheumatoid arthropathy and is believed to be effective in alleviating swelling and pain in the limbs. AIM OF THE STUDY: Osteoarthritis (OA) is a classic degenerative disease involving chondrocyte death, and there is still a lack of effective therapeutic agents that can reverse the progression of the disease. Here we explored the therapeutic effects of DA against OA and further explored the mechanism. MATERIALS AND METHODS: The effect of DA on cell viability was assessed by CCK-8. IL-1ß-treated mouse chondrocytes were used as an in vitro model of OA, and apoptosis was detected by flow cytometry. QRT-PCR, western blotting, cell staining, and immunofluorescence were used to detect relevant inflammatory factors and cartilage-specific expression. RNA sequencing was used to identify pertinent signaling pathways. The therapeutic effect of DA was verified by micro-CT, histological analysis and immunohistochemical analysis in a mouse OA model. RESULTS: DA demonstrated a high safety profile on chondrocytes, significantly reversing the inflammatory response induced by IL-1ß, and promoting factors associated with cartilage regeneration. Moreover, DA exhibited a significant protective effect on the knee joints of mice undergoing ACLT-DMM, effectively preventing cartilage degeneration and subchondral bone tissue destruction. These positive therapeutic effects were achieved through the modulation of the NF-κB pathway and the Ca2+ signaling pathway by DA. CONCLUSION: Being derived from a traditional herb, DA exhibits remarkable therapeutic potential and safety in OA treatment, presenting a promising option for patients dealing with osteoarthritis.

Research Progress on Chemical Constituents and Pharmacological Activities of Menispermi Rhizoma.

Menispermi Rhizoma, the rhizome of Menispermum dauricum DC., is a traditional Chinese medicine, which has the effect of clearing away heat and detoxification, dispelling wind, and relieving pain. It is often used in the treatment of sore throat, enteritis, dysentery, and rheumatism. The chemical constituents of M. Rhizoma mainly include alkaloids, phenolic acids, quinones, cardiotonic glycosides, and so on. Modern pharmacological studies have proved that M. Rhizoma has the effects of anti-tumour, anti-inflammation, anti-oxidation, bacteriostasis, cardio-cerebrovascular protection, anti-depression and anti-Alzheimer's disease. In recent years, the chemical constituents of M. Rhizoma have been found continuously, and the pharmacological studies have deepened gradually. This paper reviews the research progress on the chemical composition and pharmacological effects of M. Rhizoma, to provide a basis for further research and development of its medicinal value.

Pharmacokinetics, tissue distribution and excretion of 6-O-demethylmenisporphine, a bioactive oxoisoaporphine alkaloid from Menispermi Rhizoma, as determined by a HPLC-MS/MS method.

6-O-demethylmenisporphine, a major active oxoisoaporphine alkaloid isolated from Menispermi Rhizoma, has been confirmed to possess significant bioactivities, including anti-cancer and anti-hypoxia effects. However, few researches on quantifying 6-O-demethylmenisporphine in biosamples have been performed. In this research, a sensitive HPLC-MS/MS approach for determining 6-O-demethylmenisporphine in various biological matrices (plasma, tissue, urine, bile and feces) of rat has been constructed. Carbamazepine was chosen as the internal standard (IS). All biosamples were prepared using a simple one-step acetonitrile precipitation. A Capcell Pak C18 column coupled with an isocratic mobile phase consisted of acetonitrile (0.1% formic acid)-water (90:10, v/v), was employed to separate 6-O-demethylmenisporphine from endogenous interferences. Peak responses were detected by multiple reaction monitoring (MRM) transitions with m/z 308.0 â†’ 264.9 for 6-O-demethylmenisporphine and m/z 237.0 â†’ 194.1 for IS in positive-ion mode. The approach exhibited perfect linearity over a range of 5-2000 ng/mL for plasma and 2-1000 ng/mL for various tissue, urine, bile and feces. The lower limit of quantification (LLOQ) for analyte among different biological samples ranged from 2 ng/mL to 5 ng/mL. The newly established method was simple, efficient and sensitive, which was successfully applied to investigate the absorption, distribution, and excretion of 6-O-demethylmenisporphine after oral dosing to rats. The results indicated that 6-O-demethylmenisporphine could be well absorbed into blood circulation and widely distributed in various tissues after oral dosing, the oral bioavailability was up to 51.52%. Meanwhile, it was widely metabolized in vivo and eliminated as the metabolites, the unconverted form was excreted mainly by feces route. The bioavailability, tissue distribution and excretion characteristics of 6-O-demethylmenisporphine were firstly revealed, which will provide references for further development of 6-O-demethylmenisporphine as an anti-tumor drug candidate.

Protective Effects of Total Alkaloids from Menispermum dauricum against Airway Inflammation in Asthmatic Mice.

Menispermum dauricum is widely used to treat respiratory inflammation, including laryngopharyngitis, tonsillitis, tracheitis, and bronchitis. Total alkaloids isolated from M. dauricum have shown a variety of beneficial bioactivities. However, available data on the effects of M. dauricum total alkaloids against allergic asthma has not been reported. In present study, the protective effect of M. dauricum total alkaloids was evaluated by using an ovalbumin-induced in vivo model of asthma. The asthma model was prepared by sensitizing and challenging mice with ovalbumin, and M. dauricum total alkaloids (100, 200, and 400 mg/kg) were administrated to asthmatic mice by gavage. Histopathological analysis of pulmonary changes was detected by hematoxylin and eosin, and periodic acid-schiff staining. Inflammatory cell counts were determined in bronchoalveolar lavage fluid. Total immunoglobulin E and ovalbumin-specific immunoglobulin E levels in serum, and T-helper 2 cytokines and chemokine levels in bronchoalveolar lavage fluid were detected by an ELISA. Histological results demonstrated that M. dauricum total alkaloids significantly attenuated pulmonary inflammation in asthmatic mice. M. dauricum total alkaloid treatment exhibited marked effects on asthmatic mice in reducing inflammatory cell counts, decreasing interleukin-4, interleukin-5, and interleukin-13 concentrations, and downregulating TNF-α and eotaxin levels in bronchoalveolar lavage fluid. In addition, M. dauricum total alkaloids could also inhibit the elevated serum levels of total immunoglobulin E and ovalbumin-specific immunoglobulin E. These findings confirmed that M. dauricum total alkaloids could suppress airway inflammation in ovalbumin-induced asthma through regulating the T-helper 2 response and chemokine level. M. dauricum total alkaloids may be a potential ethnopharmacological agent for asthmatic patients.

[Chemical constituents from rhizome of Menispermum dauricum and their anti-hypoxic activities].

To study the chemical constituents from the rhizome of Menispermum dauricum,fifteen compounds,N-methylcorydaldine( 1),thalifoline( 2),stepholidine( 3),acutumine( 4),daurisoline( 5),acutumidine( 6),dauricicoline( 7),bianfugecine( 8),6-O-demethylmenisporphine( 9),bianfugedine( 10),dauricoside( 11),eleutheroside D( 12),aristolactone( 13),aristoloterpenateⅠ( 14) and aristolochic acid( 15) were isolated from 75% ethanol extract of Menispermi Rhizoma by using thin layer chromatography and column chromatography methods. Their structures were identified based on their physicochemical properties and spectral data. Among them,compounds 12-15 were obtained from the genus Menispermum for the first time. Six alkaloids with higher contents were subjected to evaluate the anti-hypoxic activities by using MTT method. As a result,six alkaloids exhibited significant anti-hypoxia activities.

Chemical constituents from rhizome of Menispermum dauricum and their anti-hypoxic activities / 中国中药杂志

To study the chemical constituents from the rhizome of Menispermum dauricum,fifteen compounds,N-methylcorydaldine( 1),thalifoline( 2),stepholidine( 3),acutumine( 4),daurisoline( 5),acutumidine( 6),dauricicoline( 7),bianfugecine( 8),6-O-demethylmenisporphine( 9),bianfugedine( 10),dauricoside( 11),eleutheroside D( 12),aristolactone( 13),aristoloterpenateⅠ( 14) and aristolochic acid( 15) were isolated from 75% ethanol extract of Menispermi Rhizoma by using thin layer chromatography and column chromatography methods. Their structures were identified based on their physicochemical properties and spectral data. Among them,compounds 12-15 were obtained from the genus Menispermum for the first time. Six alkaloids with higher contents were subjected to evaluate the anti-hypoxic activities by using MTT method. As a result,six alkaloids exhibited significant anti-hypoxia activities.

Anti-tumor effects of phenolic alkaloids of menispermum dauricum on gastric cancer in vivo and in vitro.

AIM: This study was conducted to investigate the anti-tumor effects of the Chinese traditional herb phenolic alkaloids of menispermum dauricum (PAMD) on gastric cancer both in vitro and in vivo. MATERIALS AND METHODS: Cell apoptosis was detected in cultured SGC-7901 cells after administration of a different dose of PAMD. Gastric cancer model was established by single i.p. injection of SGC-7901 cells in the mice (n = 60). Then, animals were received high dose (20 mg/kg), medial dose (10 mg/kg), and low dose (5 mg/kg) of PAMD. Mice received 5-floxuridine was set as positive controls and received normal saline was as blank controls. Effects of PAMD on tumor growth were evaluated by tumor inhibition rate. Tumor tissues were collected from mice and detected for the expression of several genes P53, B-cell CLL/lymphoma 2 (BCL-2), BCL-2-associated X protein (BAX), CASPASE-3, K-RAS by real-time polymerase chain reaction, and Western blot. In addition, tumor cell changes were observed under transmission electron microscopy. RESULTS: The apoptosis index in PAMD at high- and medial-dose group was significantly higher than that in blank control group (P < 0.01). PAMD at different dose could significantly decrease the tumor weight compared to the blank control group (P < 0.01). In addition, PAMD could obviously increase BAX and caspase-3 expression as well as decrease K-RAS expression when compared to the blank control treatment (P < 0.01). Furthermore, PAMD could induce tumor cell morphology changes. CONCLUSIONS: PAMD could suppress gastric tumor growth in vivo, possibly through increasing the expression of pro-apoptotic genes expression then leading to cell apoptosis and inhibiting oncogenic K-RAS expression.

Dauricine combined with clindamycin inhibits severe pneumonia co-infected by influenza virus H5N1 and Streptococcus pneumoniae in vitro and in vivo through NF-κB signaling pathway.

Dauricine, isolated from Menispermum dauricum, has been widely used for treatment of various diseases, including cardiac ischemia and inflammation-related diseases. However, little is known regarding to the effect of dauricine on severe pneumonia. Therefore, the aim was to investigate the effect of dauricine on severe pneumonia and its mechanism during progress. Herein, H5N1 and Streptococcus pneumoniae (D39) were conducted to induce severe pneumonia in both BEAS-2B cells and mice. In vitro, dauricine reversed the protein and mRNA expressions of TNF-α, IL-6 and IL-1ß, examined by ELISA and qRT-PCR assay, respectively. In addition, the nuclear translocation of NF-κB/p65 and the phosphorylation expressions of IκBα and IKKα/ß, examined by western blotting, were dose-dependently dropped by dauricine. However, dauricine had no significant effect on MAPKs, including JNK, ERK and p38. In vivo, dauricine significantly decreased MPO activity, the lung wet/dry weight ratio, the protein and mRNA expression of TNF-α, IL-6 and IL-1ß, the expressions of NF-κB/p65, and attenuated the lung histological alterations. Besides, compared to dauricine alone, combined with clindamycin had more remarkably effects on severe pneumonia in vitro. Overall, the results suggested that dauricine, a relatively drug that targets NF-κB, in combination with clindamycin, maybe a novel therapeutic strategy for severe pneumonia.

Intestinal anti-inflammatory effect of the rhizome extracts of Menispermum dauricum DC. on trinitrobenzene sulfonic acid induced ulcerative colitis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Menispermum dauricum DC., commonly known as "Bei Dou Gen" (BDG) in China, has been used extensively in folk medicine to treat inflammatory diseases, especially intestinal inflammations such as enteritis and dysentery, and in pharyngitis, tonsillitis, rheumatism and bronchitis. Although previous studies showed that BDG has anti-inflammatory activities, its effects on ulcerative colitis (UC) have not yet been explored. AIM OF THE STUDY: To investigate the intestinal anti-inflammatory effect of the rhizome extracts of Menispermum dauricum DC. on UC model induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in mice. MATERIALS AND METHODS: UC in mice was induced by colonic administration with TNBS. BDG (100, 200 and 400mg/kg/day) and sulfasalazine (500mg/kg/day) were administered orally for 7 consecutive days. The inflammatory degree was assessed by gross appearance, macroscopic and histological analysis, and accumulation of myeloperoxidase (MPO) activity. Pro-inflammatory mediators, including tumor necrosis factor (TNF)-α, interleukin (IL)-1ß and IL-6, were determined by enzyme-linked immunoassay. The expression of cyclooxygenase (COX)-2 was assessed by immunohistochemical analysis. RESULTS: Treatment with different doses of BDG significantly ameliorated macroscopic damage and histological changes, reduced the accumulation of MPO activity, depressed serum and colonic tissue levels of TNF-α, IL-1ß and IL-6 in a dose-dependent manner. In addition, administration of BDG effectively reduced COX-2 overexpression in colon. CONCLUSION: We demonstrated for the first time that BDG possessed marked intestinal anti-inflammatory effect in TNBS induced colitis in mice, which might be related to the reduction of up-regulated productions and expressions of pro-inflammatory mediators, suggesting that it may have beneficial use for the treatment of inflammatory bowel disease.

Microwave-assisted extraction in combination with HPLC-UV for quantitative analysis of six bioactive oxoisoaporphine alkaloids in Menispermum dauricum DC.

A novel and reliable method based on microwave-assisted extraction (MAE) followed by HPLC-UV was developed and validated for the simultaneous quantification of six pharmacologically important oxoisoaporphine alkaloids in the total plants of Menispermum dauricum DC. The optimal MAE extraction condition was performed at 60°C for 11 min with ethanol-water (70:30, v/v) as the extracting solvent, and the solvent to solid ratio was 20:1. Chromatographic separation was achieved on a reversed-phase YMC C18 column (250 × 4.6 mm, i.d., 5 µm) with a gradient mobile phase consisting of A (1% aqueous formic acid) and B (acetonitrile containing 1% formic acid) at a flow rate of 1.5 mL/min. The detection wavelength was set at 422 nm. Excellent linearity over the investigated concentration ranges was observed with values of r >0.999 for all analytes. The method developed was validated with acceptable sensitivity, intra- and inter-day precision and extraction recoveries. It was successfully applied to the determination of six alkaloids in Menispermum dauricum DC from different sources and different parts of Menispermum dauricum DC. The results obtained indicated that the method is suitable for the quality control of Menispermum dauricum DC.

Identification of nuclear factor-κB inhibitors in the folk herb Rhizoma Menispermi via bioactivity-based ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry analysis.

BACKGROUND: Rhizoma Menispermi (RM) is the dried root of Menispermum dauricum DC, which is traditionally used to treat swelling and pain for sore throat, enteritis and rheumatic arthralgia in the clinic, but its bioactive compounds remain unclear. METHODS: In this study, RM extract was administered orally to ICR mice followed by challenging with an intratracheal Pseudomonas aeruginosa suspension. Then mortality, histological features of lung, and inflammatory cytokines were evaluated. RM treatment significantly ameliorated Pseudomonas aeruginosa-induced acute lung inflammation and reduced levels of inflammatory mediators. To screen for potential anti-inflammatory constituents of the RM extract, a simple and rapid method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS) coupled with a luciferase reporter assay system to detect nuclear factor-κB (NF-κB) activity was established. RESULTS: Using this system, seven potential NF-κB inhibitors were detected, including sinomenine, norsinoacutin, N-norsinoacutin-ß-D-glucopyranoside, 6-O-methyl-laudanosoline-13-O-glucopyranoside, magnoflorine, laurifloline and dauricinoline. Furthermore, IL-6 and IL-8 assays confirmed the anti-inflammatory effects of these potential NF-κB inhibitors, in which norsinoacutin, 6-O-methyl-laudanosoline-13-O-glucopyranoside laurifloline, dauricinoline and N-norsinoacutin-ß-D-glucopyranoside were revealed as new NF-κB inhibitors. CONCLUSION: This method of UPLC-Q/TOF coupled with the luciferase reporter assay system was initially applied to the study of RM and was demonstrated to represent a simple, rapid and practical approach to screen for anti-inflammatory compounds. This study provided useful results for further investigation on the anti-inflammatory mechanism of RM.

Induction of apoptosis in human cervical carcinoma Hela cells with active components of Menispermum dauricum.

Menispermum dauricum DC possesses a wide range of pharmacological effects. In this study, the mechanism of apoptosis induced by active components of M. dauricum was investigated in the human cervical carcinoma HeLa cell line. HeLa cells were treated with different M. dauricum concentrations over different time periods. The proliferation-inhibitory rate and cytotoxic effect of HeLa cells were measured by using the methyl thiazolyl tetrazolium (MTT) assay, and the apoptotic rate was detected by flow cytometry. Expressions of caspase-9, caspase-8, caspase-3, Bcl-2, and Fas proteins, in the apoptotic pathway, and the expression of nuclear factor-kappa B (NF-κB) were detected by SP immunocytochemistry. The MTT assay showed that active components of M. dauricum could significantly inhibit the growth of HeLa cells in a dose- and time-dependent manner (P<0.01). The Sub-Gl peak was found by flow cytometry, and the maximal apoptosis rate was 24.93%. Immunocytochemistry showed that after treatment with M. dauricum, the expressions of caspase-8, caspase-9, caspase-3, Fas protein, and NF-κB all increased, and the expression of the Bcl-2 protein decreased, with significant differences relative to the control group (P<0.01). Apoptosis in HeLa cells could be induced by active components of M. dauricum through the NF-κB signal transduction pathway and the caspase pathway, which was related to the downregulation of Bcl-2 expression and the upregulation of Fas expression.

Characterization and antitumor activities of a polysaccharide from the rhizoma of Menispermum dauricum.

The rhizome of Menispermum dauricum DC (Menispermaceae) is one of the most commonly used traditional Chinese medicines officially listed in Chinese Pharmacopeia. In present study, we purified a water-soluble polysaccharide (WMDP) from this plant and investigated its physicochemical properties. WMDP was a homogeneous polysaccharide, with an average molecular weight of approximately 3.5×10(4)Da, as determined by high-performance gel-permeation chromatography (HPGPC). Gas chromatography (GC) analysis identified that WMDP was composed of Glc, Gal, Xyl, Rha, Ara and Man in the ratio of 2.45:2.13:1.05:1.29:1.63:1.45. The interreaction between Gongo Red and WMDP in NaOH solutions resulted in the shift of maximum absorption, indicating WMDP had a triple-helix conformation. We also investigated the antitumor activities and mechanisms of WMDP in human ovarian carcinoma SKOV3 cells. The experimental evidence showed that WMDP significantly inhibited cell proliferation and DNA synthesis in SKOV3 cells in a concentration-dependent manner, due to a significant increase in the number of apoptotic cells. Furthermore, treatment with WMDP caused a rapid loss of intracellular glutathione (GSH) content and stimulation of reactive oxygen species (ROS). In addition, nuclear factor-kappa B (NF-κB) in SKOV3 cells received WMDP treatment was inactivated. Taken together, induction of apoptosis on SKOV3 cells by WMDP was mainly associated with ROS production, GSH depletion and NF-κB inactivation.

Dauricine can inhibit the activity of proliferation of urinary tract tumor cells.

OBJECTIVE: To explore the anti-tumor effects of asiatic moonseed rhizome extraction-dauricine on bladder cancer EJ cell strain, prostate cancer PC-3Mcell strain and primary cell culture system. METHODS: The main effective component-phenolic alkaloids ofMenispermum dauricum was extracted and separated from asiatic moonseed rhizome by chemical method. MTT method was used to detect dauricine anti-tumor effect. RESULTS: Dauricine had an obvious proliferation inhibition effect on the main tumor cells in urinary system. The minimum drug sensitivity concentration was between 3.81-5.15 µg/mL, and the inhibition ratio increased with the increase of concentration. CONCLUSIONS: Dauricine, the main effective component extracted from asiatic moonseed rhizome, had a good inhibition effect on tumor cells in urinary system. At the same time, Dauricine has certain inhibition effects on the primary cultured tumor cell.

Phenolic alkaloids from Menispermum dauricum rhizome protect against brain ischemia injury via regulation of GLT-1, EAAC1 and ROS generation.

Menispermum dauricum rhizome has been widely used in China to treat various cardiovascular and thrombosis disorders. Some studies have reported that the phenolic alkaloids of Menispermum dauricum rhizome (PAM) have protective effects against brain ischemia injury, but the mechanism of this action remains to be clarified. In the present study, we investigated the possible mechanisms of action of PAM on experimental brain ischemia injury. Oxygen and glucose deprivation (OGD) in rat primary cortical cultures and middle cerebral artery occlusion in rats were used to mimic ischemia-reperfusion injury, respectively. The results suggested that PAM protected rat primary cortical cultures against OGD-reoxygenation induced cytotoxicity. PAM decreased extracellular glutamate content and markedly prevented the effects induced by OGD on protein level of GLT-1 and EAAC1 glutamate transporters. In addition, it reduced intracellular ROS generation. In vivo, PAM significantly reduced cerebral infarct area and ameliorated neurological functional deficits at different time points. Our findings revealed that the possible mechanism of action of PAM protected against brain ischemia injury involves regulation of GLT-1, EAAC1 and ROS generation.

Inhibitory effects of a bisbenzylisoquinline alkaloid dauricine on HERG potassium channels.

ETHNOPHARMACOLOGICAL RELEVANCE: The 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 Ca(2+) and several K(+) channels. However, its effects on human-ether-a-go-go-related gene (HERG) channels are unknown. AIM OF THE STUDY: The effects of Dau on HERG channels were investigated. MATERIALS AND METHODS: Whole-cell patch-clamp technique was used to record HERG current (I(HERG)) carried by recombinant HERG channels expressed in HEK293 cells. RESULTS: Dau inhibited I(HERG) in a concentration-dependent manner with an IC(50) of 3.5 µM. 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 I(HERG) in the open and inactivated states, but not in the closed states. The activation curve was shifted in a negative direction. CONCLUSIONS: Dau inhibits HERG encoded potassium channels and this action might be a molecular mechanism for the previously reported APD prolongation with this drug.

Dauricine can inhibit the activity of proliferation of urinary tract tumor cells

OBJECTIVE@#To explore the anti-tumor effects of asiatic moonseed rhizome extraction-dauricine on bladder cancer EJ cell strain, prostate cancer PC-3Mcell strain and primary cell culture system.@*METHODS@#The main effective component-phenolic alkaloids ofMenispermum dauricum was extracted and separated from asiatic moonseed rhizome by chemical method. MTT method was used to detect dauricine anti-tumor effect.@*RESULTS@#Dauricine had an obvious proliferation inhibition effect on the main tumor cells in urinary system. The minimum drug sensitivity concentration was between 3.81-5.15 μg/mL, and the inhibition ratio increased with the increase of concentration.@*CONCLUSIONS@#Dauricine, the main effective component extracted from asiatic moonseed rhizome, had a good inhibition effect on tumor cells in urinary system. At the same time, Dauricine has certain inhibition effects on the primary cultured tumor cell.

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).

Daurisoline suppressed early afterdepolarizations and inhibited L-type calcium current.

Our previous studies have shown that daurisoline (DS) exerted antiarrhythmic effects on various experimental arrhythmias. In this study, the effects of DS on early afterdepolarizations (EADs) and its possible mechanisms have been investigated. Cardiac hypertrophy was induced in rabbits by coarctating the abdominal aorta. The effects of DS on action potential duration (APD) and the incidences of EADs were studied in hypertrophied papillary muscles of rabbits in the conditions of low external K(+) concentration ([K(+)]o) and dofetilide (dof) by using standard microelectrode technique. The whole-cell patch clamp was used to record the L-type calcium current (I(Ca-L)) in isolated left ventricular cells of rabbits. The results showed that in hypertrophied papillary muscles of rabbits with low [K(+)]o ([K(+)]o = 2.7 mM), 1 microM dof prolonged APD(50) and APD(90) markedly and the incidence of EADs was 66.7% (4/6, p < 0.01); when 15 microM DS was applied, the incidence of EADs was 0% (0/4, p < 0.01) and the prolonged APD was shortened (p < 0.01). In a single myocyte, DS could also inhibit EADs induced by dof, low [K(+)]o and low external Mg(2+) concentration ([Mg(2+)]o) ([Mg(2+)](o) = 0.5 mM). DS could decrease the triangulation. In a single myocyte, DS could make the I-V curve upward, shift the steady-state activation curves to the right and the steady-state inactivation curves to the left and prolong the tau value of recovery curve obviously. These results suggested that DS could inhibit EADs which may be associated with its blockade effects on I(Ca-L).

New bisbenzylisoquinolines, fatty acid amidic aporphines, and a protoberberine from Formosan Cocculus orbiculatus.

Two new bisbenzylisoquinoline alkaloids, (+)-coccuorbiculatine A (2) and (+)-10-hydroxyisotrilobine (3), two new amidic aporphines, a mixture of (+)-laurelliptinhexadecan-1-one (6) and (+)-laurelliptinoctadecan-1-one (7), and one new protoberberine (-)-4-methoxy-13,14-dihydrooxypalmatine (8) have been isolated from the stems of Taiwanese Cocculus orbiculatus. The structures were established on the basis of extensive analysis of spectroscopic data and by comparison with known related metabolites. Cytotoxicity of the isolated compounds was examined toward HepG2, Hep3B, MCF-7, and MDA-MB-231 cancer cell lines. Alkaloids 1 and (-)-sinococuline (9) showed significant inhibitory activity against the target cell lines.