Seco-neferine A-F, three new pairs of benzyltetrahydroisoquinoline alkaloid epimers from Plumula Nelumbinis and their activity.

Three new pairs of benzyltetrahydroisoquinoline (BIQ) alkaloid epimers, Seco-neferine A-F (1-6), were isolated from an EtOH extract of Plumula Nelumbinis. The structures of these compounds were identified by a combination of NMR, HR-ESI-MS, circular dichroism, UV spectroscopic analyses and specific rotations. The structure of compounds 1-6 possesses high similarity with neferine, because these three pairs of epimers have the same skeleton as neferine. Compounds 1,2 and 5,6 are open-loop compounds of position 1' and 1 of neferine respectively. The H connects with position 2' N of compounds 1,2 is replaced by methyl, forming the structure of compounds 3,4. Moreover, six compounds were tested for cytotoxicity against MDA-MB-231 breast cancer cell. Compound 6 displayed moderate inhibitory effects on breast cancer with IC50 of 38.96 µM, while compounds 2,3,4 show certain inhibitory effects.

The Cholinesterase Inhibitory Properties of Stephaniae Tetrandrae Radix.

Stephaniae tetrandrae radix (STR) is a commonly used traditional Chinese medicine in alleviating edema by inducing diuresis. In the clinic, STR extracts or its components are widely used in the treatment of edema, dysuria, and rheumatism for the regulation of water metabolism. Furthermore, STR has been used in treating emotional problems for years by combining with other Chinese herbs. However, the material basis and mechanism of STR on the nervous system have not been revealed. Here, the main components of STR extracts with different extracting solvents were identified, including three major alkaloids, i.e., cyclanoline, fangchinoline, and tetrandrine. The cholinesterase inhibitory activity of STR extracts and its alkaloids was determined using the Ellman assay. Both cyclanoline and fangchinoline showed acetylcholinesterase (AChE) inhibitory activity, demonstrating noncompetitive enzyme inhibition. In contrast, tetrandrine did not show enzymatic inhibition. The synergism of STR alkaloids with huperzine A or donepezil was calculated by the median-effect principle. The drug combination of fangchinoline-huperzine A or donepezil synergistically inhibited AChE, having a combination index (CI) < 1 at Fa = 0.5. Furthermore, the molecular docking results showed that fangchinoline bound with AChE residues in the peripheral anionic site, and cyclanoline bound with AChE residues in the peripheral anionic site, anionic site, and catalytic site. In parallel, cyclanoline bound with butyrylcholinesterase (BChE) residues in the anionic site, catalytic site, and aromatic site. The results support that fangchinoline and cyclanoline, alkaloids derived from STR, could account for the anti-AChE function of STR. Thus, STR extract or its alkaloids may potentially be developed as a therapeutic strategy for Alzheimer's patients.

Neferine, a bisbenzylisoquinoline alkaloid of Nelumbo nucifera, inhibits glutamate release in rat cerebrocortical nerve terminals through 5-HT1A receptors.

Neferine, a bisbenzylisoquinoline alkaloid present in Nelumbo nucifera, has been reported to exhibit neuroprotective effects. Because reduced glutamatergic transmission through inhibition of glutamate release has been proposed as a mechanism of neuroprotection, we investigated whether and how neferine inhibits glutamate release in the nerve terminals of the cerebral cortex of rats. The results demonstrated that neferine inhibits the glutamate release that is evoked by the potassium channel blocker 4-aminopyridine, doing so in a dose-dependent manner. This effect was prevented by removing extracellular calcium and blocking vesicular transporters or N- and P/Q-type calcium channels but not by blocking glutamate transporters. Neferine decreased the 4-aminopyridine-stimulated elevation in intrasynaptosomal calcium concentration; however, it had no effect on the synaptosomal membrane potential. The inhibition of glutamate release by neferine was also eliminated by the selective 5-hydroxytryptamine 1A (5HT1A) receptor antagonist WAY100635, Gi/o protein inhibitor pertussis toxin, adenylyl cyclase inhibitor MDL12330A, and protein kinase A inhibitor H89. Moreover, immunocytochemical analysis revealed the presence of 5-HT1A receptor proteins in the vesicular transporter of glutamate type 1 positive synaptosomes. The molecular docking study also demonstrated that neferine exhibited the highest binding affinity with 5-HT1A receptors (Autodock scores for 5-HA1A = -11.4 kcal/mol). Collectively, these results suggested that neferine activates 5-HT1A receptors in cortical synaptosomes, which decreases calcium influx and glutamate release through the activation of Gi/o protein and the inhibition of adenylyl cyclase/cAMP/protein kinase A cascade.

Speed of action and stage specificity of Bencha-loga-wichian, a Thai traditional antipyretic formulation, against Plasmodium falciparum and the chloroquine-potentiating activity of its active compounds, tiliacorinine and yanangcorinine.

ETHNOPHARMACOLOGICAL RELEVANCE: Bencha-loga-wichian (BLW), a Thai traditional antipyretic formulation, has been reported to have promising antiplasmodial activity, and it was previously revealed that tiliacorinine and yanangcorinine, isolated from Tiliacora triandra, were the active compounds. However, the mechanisms of action of BLW have not been investigated. In addition, these active compounds are bisbenzylisoquinoline alkaloids, many compounds of which have been reported to potentiate the efficacy of chloroquine. AIMS OF THE STUDY: To investigate the antiplasmodial mechanisms of action of BLW and evaluate the effects of chloroquine combined with tiliacorinine or yanangcorinine. MATERIALS AND METHODS: Chloroquine-resistant Plasmodium falciparum (PfW2) strains at the ring, trophozoite, and schizont stages were exposed to the extracts or compounds for 2, 4, 6, 8, 10, 12, 24 or 48 h. The percentages of parasitemia were determined by flow cytometry, and their morphologies were examined by Giemsa-stained smear to evaluate the speed of action and stage specificity. For the drug combination assay, a modified fixed-ratio isobologram method was used. RESULTS: The antiplasmodial activity of BLW possessed a slow onset of action and was the most effective against ring-stage parasites. After 48 h of extracts or compounds exposure, most of the treated parasites, at all stages, turned to the pyknotic form and could not recover even after extracts or compounds removal. The results suggested that these extracts and compounds could kill the parasites or possess parasiticidal effects. In addition, the combination of chloroquine with tiliacorinine or yanangcorinine demonstrated a synergistic effect, indicating that these compounds could potentiate chloroquine efficacy against chloroquine-resistant parasites. CONCLUSION: The antiplasmodial mechanisms of action of BLW appeared to differ from that of chloroquine and other current antimalarial drugs. In addition, tiliacorinine and yanangcorinine, the active compounds of BLW, could potentiate the efficacy of chloroquine. Accordingly, BLW was shown to be a good candidate for development as a new antimalarial and useful for drug combination therapy.

Thalictrum foliolosum: A lesser unexplored medicinal herb from the Himalayan region as a source of valuable benzyl isoquinoline alkaloids.

ETHNOPHARMACOLOGICAL RELEVANCE: Thalictrum foliolosum DC (Ranunculaceae) is a perennial flowering herb traditionally used as a tonic, antiperiodic, diuretic, febrifuge, purgative and stomachic and for the treatment of snakebite, jaundice, and rheumatism. AIM OF THE STUDY: To provide a critical assessment of the state-of-the-art related to the traditional uses, phytochemistry, and pharmacology of T. foliolosum with the ultimate objective of providing further research strategies to facilitate the exploitation of the therapeutic potential of T. foliolosum for the treatment of human disorders. MATERIALS AND METHODS: Exhaustive bibliographic research related to T. foliolosum plant was carried out using scientific research engines and databases such as Google Scholar, PubMed, Web of Science covering all retrieved relevant manuscripts written in English. RESULTS: Several alkaloids such as berberine, jatrorrhizine, palmatine, thalrugosidine, thalrugosaminine, thalisopine (thaligosine), thalirugidine, thalirugine, 8-oxyberberine (berlambine), noroxyhydrastinine, N,O,O-trimethylsparsiflorine, thalicarpine, thalidasine, thalfoliolosumines A and thalfoliolosumines B were reported from T. foliolosum. Ethnomedicinal studies revealed much wider scope of T. foliolosum in developing various drugs to solve multiple challenges in the health sector. Therapeutic effects were attributed to the bioactivities of the secondary metabolites present in T. foliolosum. CONCLUSIONS: T. foliolosum is rich in berberine and other benzylisoquinoline alkaloids. T. foliolosum can be used as an excellent and effective herbal remedy for various human ailments since there are no reports on the toxicity of this herb.

Molecular mechanisms involved in drug-induced liver injury caused by urate-lowering Chinese herbs: A network pharmacology study and biology experiments.

As an important part of the comprehensive treatment methods, the urate-lowering Chinese herbs could provide favorable clinical effects on hyperuricemia in its ability to invigorate spleen and remove dampness. Owing to the long-term duration, it brought up the potential adverse reactions (ADRs) and concerns about the drug-induced liver injury from these herbs. To address this problem, the bioinformatics approaches which combined the network pharmacology, computer simulation and molecular biology experiments were undertaken to elucidate the underlying drug-induced liver injury molecular mechanisms of urate-lowering Chinese herbs. Several electronic databases were searched to identify the potential liver injury compounds in published research. Then, the putative target profile of liver injury was predicted, and the interaction network was constructed based on the links between the compounds, corresponding targets and core pathways. Accordingly, the molecular docking simulation was performed to recognize the representative compounds with hepatotoxicity. Finally, the cell experiments were conducted to investigate the biochemical indicators and expression of the crucial protein that were closely associated with liver injury. In conclusion, the current research revealed that the compounds with potential liver injury including diosgenin, baicalin, saikosaponin D, tetrandrine, rutaecarpine and evodiamine from urate-lowering Chinese herbs, could lead to decline the survival rate of L-02 cell, increase the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) in cell-culture medium, enhance the expression of p-p38/p38, while the p38 inhibitor could achieve the trend of regulating and controlling liver injury. These research findings bring further support to the growing evidence that the mechanism of the liver injury induced by the compounds from urate-lowering Chinese herbs may be associated with the activation of p38α.

Quantification of natural products in herbal supplements: A combined NMR approach applied on goldenseal.

Authentication of natural products is of major relevance in the context of manufactured drugs or herbal supplements since such active products generate a lucrative market. The analytical method to identify and quantify valuable natural products is critical for quality control and product assignment of herbal supplements. In this framework, we propose to apply a recently developed quantitative 2D NMR approach called Q QUIPU (Quick QUantItative Perfected and pUre shifted) in combination with 1D 1H NMR capable to access the concentration of three major alkaloids, berberine, ß-hydrastine and canadine, in the root extract of goldenseal (Hydrastis canadensis), one of the 20 most popular herbal supplements used worldwide. We highlight the complementarity of 1D and 2D quantitative NMR to accurately assess the amount of alkaloids with different range of concentrations and stability within extracts. In particular, unstable natural products having non-overlapped signals like berberine could only be quantified by sensitive and fast 1D 1H, while overlapped signals of ß-hydrastine and low intense ones of canadine could only be quantified with the recent 2D Q QUIPU HSQC. Results obtained from this combined approach have led to a good accuracy (<10%) as compared with coupled UHPLC-MS/UV techniques. This quantitative NMR approach paves the way to numerous applications where the accurate quantification of targeted compounds in complex mixtures is required, for instance in agricultural, food and pharmaceuticals products.

Neferine, a Bisbenzylisoquinoline Alkaloid, Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis.

Both the incidence and prevalence of ulcerative colitis (UC) are increasing throughout the world. Neferine, a natural alkaloid, demonstrated a variety of biological activities. In this study, the anti-inflammatory effect of neferine was investigated. Raw264.7 cells were stimulated with lipopolysaccharide (LPS) or LPS plus Z-VAD-fmk (Z-VAD). The inhibitory effect of neferine on secretion of nitrite, cytokines tumor necrosis factor alpha (TNF-[Formula: see text]) and interleukin 6 (IL-6), expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was determined. The protective effect of neferine was investigated in dextran sulfate sodium (DSS)-induced UC mouse model. Neferine significantly inhibited LPS and LPS plus Z-VAD induced secretion of nitrite, cytokines, and expression of iNOS and COX-2. Oral administration of neferine (10[Formula: see text]mg/kg and 25[Formula: see text]mg/kg) significantly reduced DSS-induced mouse weight loss, decreased disease activity index (DAI) scores, improved colon pathological changes, and decreased plasma cytokines. In addition, neferine significantly inhibited the protein expression of iNOS, COX-2, receptor-interacting protein 1 (RIP1), RIP3, mixed lineage kinase domain-like protein (MLKL), and increased the protein expression of caspase-8 in colon tissues. These data suggest that neferine was a potent anti-inflammatory agent against LPS and DSS induced inflammation both in vitro and in vivo.

The norpurpureine alkaloid from Annona purpurea inhibits human platelet activation in vitro.

BACKGROUND: The leaves of Annona purpurea have yielded several alkaloids with anti-aggregation activities against rabbit platelets. This is promising in the search for agents that might act against platelets and reduce the incidence of cardiovascular diseases. Since significant differences in platelet function have been reported between human and animal platelets, a study focusing on the effect of A. purpurea extracts against human platelet activation is necessary. METHODS: The compounds in an A. purpurea ethanolic extract underwent bio-guided fractionation and were used for in vitro human platelet aggregation assays to isolate the compounds with anti-platelet activity. The bioactive compounds were identified by spectroscopic analysis. Additional platelet studies were performed to characterize their action as inhibitors of human platelet activation. RESULTS: The benzylisoquinoline alkaloid norpurpureine was identified as the major anti-platelet compound. The IC50 for norpurpureine was 80 µM against platelets when stimulated with adenosine 5'-diphosphate (ADP), collagen and thrombin. It was pharmacologically effective from 20 to 220 µM. Norpurpureine (220 µM) exhibited its in vitro effectiveness in samples from 30 healthy human donors who did not take any drugs during the 2 weeks prior to the collection. Norpurpureine also gradually inhibited granule secretion and adhesion of activated platelets to immobilized fibrinogen. At the intra-platelet level, norpurpureine prevented agonist-stimulated calcium mobilization and cAMP reduction. Structure-activity relationship analysis indicates that the lack of a methyl group at the nitrogen seems to be key in the ability of the compound to interact with its molecular target. CONCLUSION: Norpurpureine displays a promising in vitro pharmacological profile as an inhibitor of human platelet activation. Its molecular target could be a common effector between Ca2+ and cAMP signaling, such as the PLC-PKC-Ca2+ pathway and PDEs. This needs further evaluation at the protein isoform level.

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.

Pharmacological benefits of neferine - A comprehensive review.

This article recapitulates the existing in vitro and in vivo studies focusing on the effects of neferine-an alkaloid derivative of lotus plant, in various disease models and its effects on key signaling molecules. The review also compiles a large number of research studies that demonstrate methods for isolation and extraction, biosynthetic pathway, pharmacological activity and mode of action of neferine and their underlying mechanisms at cellular level. Neferine is a unique bis-benzylisoquinoline alkaloid that possesses a number of therapeutic effects such as anti-cancer, anti-diabetic, anti-aging, anti-microbial, anti-thrombotic, anti-arrhythmic, anti-inflammatory and even anti-HIV. It also enhances the anti-cancer properties of other anti-cancer drugs like cisplatin, adriamycin, taxol, etc. It is also reported to reverse chemo-resistance and enhance sensitivity of the cancer cells towards anti-cancer drugs. The underlying mechanisms for its activities mainly include apoptosis, autophagy and G1 arrest. Neferine protects them against the effect of drugs like cisplatin. The therapeutic properties of neferine is widely diverse, while it shows toxicity to cancer it also shows cyto-protective effects against cardio-vascular diseases, pulmonary disease, and is also effective against Alzheimer's disease and elicits anti-oxidative effect in many cellular systems. This article thus is the first ever attempt to review the therapeutic activities of neferine established in in vitro and in vivo models and to compile all the fragmented data available on the omnipotent activities of neferine.

Isolation and identification of a tribenzylisoquinoline alkaloid from Nelumbo nucifera Gaertn, a novel potential smooth muscle relaxant.

A new skeleton benzylisoquinoline (BI) named neoliensinine (1) was isolated from embryos of lotus seed (Nelumbo nucifera Gaertn.), a traditional Chinese herb. The tribenzylisoquinoline (TBI) structure of 1 was confirmed by interpreting spectroscopic data of UV, IR, MS, 1D and 2D NMR. The stereo-configurations of the new compound, together with two known bisbenzylisoquinolines (BBI), neferine and isoliensinine were established by analyzing 1H NMR and 13C NMR spectra. The relaxation of 1, neferine, isoliensinine and liensinine in isolated mesenteric vascular smooth muscle (VSM) was evaluated. All the four BIs could efficiently inhibit MVSM contraction induced by 124mM KCl, with IC50 values of 2.407µM (1), 1.169µM (neferine), 3.504µM (isoliensinine) and 3.583µM (liensinine), respectively, suggesting that they were all potential relaxants for abnormal smooth muscle contractions. Interestingly, VSM treated by the three BBIs could re-contract when being stimulated by KCl after the drugs were removed, while VSM dealt with the TBI couldn't. It indicated that 1 has much high affinity with the molecular targets on relaxation of VSM contraction, which may relate to the unique skeleton with three BI groups.

Defense-related Proteins from Chelidonium majus L. as Important Components of its Latex.

The aim of this review is to cover most recent research on plant pathogenesis- and defenserelated proteins from latex-bearing medicinal plant Chelidonium majus (Papaveraceae) in the context of its importance for latex activity, function, pharmacological activities, and antiviral medicinal use. These results are compared with other latex-bearing plant species and recent research on proteins and chemical compounds contained in their latex. This is the first review, which clearly summarizes pathogenesisrelated (PR) protein families in latex-bearing plants pointing into their possible functions. The possible antiviral function of the latex by naming the abundant proteins present therein is also emphasized. Finally latex-borne defense system is hypothesized to constitute a novel type of preformed immediate defense response against viral, but also non-viral pathogens, and herbivores.

Identification of Alkaloids in Stephania hainanensis by Liquid Chromatography Coupled with Quadrupole Time-of-flight Mass Spectrometry.

INTRODUCTION: Plants in the genus Stephania can produce diverse bioactive alkaloids. Stephania hainanensis is a medicinal plant that contains effective alkaloids. However, only 10 alkaloids have been reported in this species. OBJECTIVE: To characterise the alkaloids in Stephania hainanensis using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS). METHODS: An LC-QTOF-MS/MS method was developed for structural characterisation of the alkaloids in Stephania hainanensis. The chromatographic separation was performed on a phenyl column with gradient elution, and the tandem mass spectra were obtained by using an electrospray ionisation (ESI) interface in positive ionisation mode. Compound identification was based on the exact masses, fragmentation pathways, retention behaviours and related botanical biogenesis. RESULTS: A total of 37 tetrahydroprotoberberine-, quaternary protoberberine-, aporphine-, proaporphine-, benzylisoquinoline- or bisbenzylisoquinoline-type alkaloids were identified or tentatively identified in a single LC run. Twenty-seven of these alkaloids, including the benzylisoquinoline-type of alkaloids, have not been previously reported in Stephania hainanensis. The possible fragmentation pathways of different types of alkaloids were proposed. Besides the general fragmentations, the characteristic losses of CH3 N = CH2 were observed for the benzylisoquinoline and aporphine alkaloids with two methyl groups on the nitrogen. CONCLUSION: The LC-QTOF-MS/MS method enabled profiling and rational, but tentative, identification of diverse alkaloids in Stephania hainanensis. The results obtained may be helpful for understanding the bioactivity of S. hainanensis and evaluating the quality of this plant. Copyright © 2016 John Wiley & Sons, Ltd.

Two new benzylisoquinoline alkaloids from Thalictrum foliolosum and their antioxidant and in vitro antiproliferative properties.

Two novel rare chloro-containing benzylisoquinoline alkaloids, thalfoliolosumines A (1) and B (2), along with eight known isoquinoline alkaloids (3-10) were isolated from the whole plant of Thalictrum foliolosum. The structures of these compounds were elucidated by spectral analyses, including 1D and 2D NMR (COSY, HSQC, HMBC and NOESY) experiments. The antiproliferative effects of all the isolated compounds were evaluated by MTT method against MCF-7, PC-3, and U937 cells, and trypan blue method against HL-60 cells. New compounds 1 and 2 exhibited moderate in vitro antiproliferative activity against MCF-7, PC-3, and HL-60 cells, and good inhibitory effects against U937 cells with IC50 values of 7.50 and 6.97 µM, respectively. Compounds 7 and 10 showed the strongest in vitro antiproliferative with IC50 values of 0.93 and 1.69 µM against HL-60 cell line. The antioxidant properties were also measured, bisbenzyltetrahydroisoquinoline alkaloids 3-6 showed the strongest antioxidant activities in ABTS assay.

Serotonergic mechanisms are involved in antidepressant-like effects of bisbenzylisoquinolines liensinine and its analogs isolated from the embryo of Nelumbo nucifera†Gaertner seeds in mice.

OBJECTIVES: We attempted to ascertain if bisbenzylisoquinoline alkaloids, liensinine and isoliensinine from Nelumbo nucifera Gaertner have antidepressant-like effects and compare the effects with those previously obtained by their analogue neferine. METHODS: Using mice, the forced swimming test (FST) was carried out after treatment with liensinine, isoliensinine and neferine. KEY FINDINGS: Liensinine and isoliensinine elicited antidepressant-like effects in mice after the FST. Anti-immobility effects of liensinine and isoliensinine were antagonized by the 5-hydroxytryptamine1 A (5-HT1 A ) receptor antagonist WAY 100635, but not by the α1 -adrenoceptor antagonist prazosin. The anti-immobility effects of liensinine, isoliensinine and neferine were blocked by pretreatment with p-chlorophenylalanine (PCPA), which depletes serotonin (5-HT). CONCLUSIONS: These data suggest that liensinine and isoliensinine from Nelumbo nucifera Gaertner have antidepressant-like effects and that antidepressant-like effects of liensinine and its analogues are closely related to serotonergic mechanisms.

Pseudoxandra sclerocarpa maas, colombian medicinal plant: a review / Pseudoxandra sclerocarpa maas, planta medicinal colombiana: una revisión

The Annonaceae family is one of the largest, with 130 genre and 2500 species, consisting of trees, shrubs and a few vines. Within this family, the Pseudoxandra genus of neotropical distribution is found. In Colombia, there are endemic and native species, distributed in the Amazon region and along the valley of the Magdalena River in the Chocó. Of the total of 22 species that form the genus in Colombia, Pseudoxandra sclerocarpa Maas is exclusive of the Antioquia region, receiving the common name of garrapato or frisolo. From this tree, bisbenzylisoquinolinic alkaloids like antioquine, medellline, obaberine, among others, has been isolated. Also neolignans: dieugenol and dehydro-1-O-methydehydrodieugenol. It is used in traditional medicine as an antiparasitic. From the pharmacological point of view, the alkaloids have shown activity against leishmaniasis and also have spasmolytic activity. Within the bisbenzylisoquinolinic alkaloids, antioquine has properties of being calcium antagonist.

La familia Annonaceae es uno de los más grandes, con 130 géneros y 2.500 especies, que consiste en árboles, arbustos y algunos bejucos. Dentro de esta familia, el género Pseudoxandra es de distribución neotropical. En Colombia existen especies endémicas y nativas, distribuidas en la región del Amazonas ya lo largo del valle del río Magdalena en el Chocó. Del total de 22 especies que forman el género en Colombia, Pseudoxandra sclerocarpa es exclusiva de la región de Antioquia, recibiendo el nombre común de garrapato o frisolo. De este árbol se ha aislado alcaloides bisbencilisoquinolínicos como antioquina, medelllina, obaberina, entre otros. También neolignanos: dieugenol y dehidro-1-O-metil-dehidrodieugenol. Se utiliza en la medicina tradicional como un antiparasitario. Desde el punto de vista farmacológico, los alcaloides han mostrado actividad contra la leishmaniasis y también tienen actividad espasmolítica. Dentro de los alcaloides bisbencilisoquinolínicos, antioquina tiene propiedades de ser antagonista del calcio.

Bisbenzylisoquinoline alkaloids from the roots of cyclea tonkinensis.

Cissampentine A (1), an enantiomer of cissampentin, three new cycleatjehenine-type bisbenzylisoquinoline alkaloids, cissampentine B-D (2-4), and five known alkaloids were isolated from the roots of Cyclea tonkinensis. Their structures were established by interpretation of NMR, high-resolution ESI-MS data, and CD spectra. In vitro studies indicated that compounds 1 and 4 exhibited cytotoxicity against the HCT-8 tumor cell line (IC50 values of 8.97 and 9.73 µM, respectively), and compound 4 was also active against the Bel-7402 tumor cell line (IC50 value of 5.36 µM).

Anti-fibrotic effects of neferine on carbon tetrachloride-induced hepatic fibrosis in mice.

The effects of neferine, a bisbenzylisoquinline alkaloid extracted from the seed embryo of the Chinese traditional medicine Nelumbo nucifera Gaertn, on carbon tetrachloride (CCl4)-induced hepatic fibrosis in mice were evaluated. Adult male Kunming mice were administered with CCl4 1 ml/kg via intraperitoneal injection twice a week for 8 weeks. At the beginning of the 9th week, mice were treated with normal saline, colchicine (0.1 mg/kg), and neferine (5, 10, 20 mg/kg) via intraperitoneal injection once a day for 2 weeks. The liver index and histological examination, plasma ALT/AST levels, hydroxyproline and TGF-ß1 content of liver tissue were examined. In the model group, the liver index, the hydroxyproline content of liver tissue and plasma ALT/AST levels were increased, and a high expression of TGF-ß1 was observed. The abnormal changes could be improved by neferine in a dose-dependent manner. Our data showed that neferine had an antifibrosis effect on CCl4-induced hepatic fibrosis in mice, possibly partly due to the decreased expression of TGF-ß1 in the liver.

Inhibitory Mechanisms of Human CYPs by Three Alkaloids Isolated from Traditional Chinese Herbs.

The three purified herbal compounds tetrahydropalmatine (Tet), neferine and berberine (Ber) were explored in vitro for basic inhibition mechanisms towards recombinant human CYP1A2, CYP2D6 and CYP3A4 metabolic activities. Phenacetin, dextromethorphan and testosterone, respectively, were used as CYP1A2, CYP2D6 and CYP3A4 substrates, and their metabolites were determined by validated HPLC methodologies. Positive inhibition controls were used. Mechanism-based (irreversible) inhibition was assessed by time-dependent and nicotinamide adenine dinucleotide phosphate-dependent and reversible inhibition by Lineweaver-Burk plot assessments. Inhibition mechanisms were also assessed by computerized interaction prediction by using the Discovery Studio CDOCKER software (Accelrys, San Diego, CA, USA). Tetrahydropalmatine showed a mechanism-based inhibition of both CYP1A2 and CYP2D6, and Ber of CYP2D6. Neferine and Ber both showed a nonmechanistic inhibition of CYP1A2. All compounds showed a similar and significant mechanism-based inhibition of CYP3A4. Tetrahydropalmatine and Ber demonstrated both reversible and irreversible inhibition of CYP2D6 and CYP3A4. Tetrahydropalmatine and Ber displayed H-bond and several Pi-bond connections with specific amino acid residues of CYP1A2, CYP2D6 and CYP3A4, giving further knowledge to the identified reversible and irreversible herb-drug interactions. Tetrahydropalmatine and Ber should be considered for herb-drug interactions in clinical therapy until relevant clinical studies are available.