Nuciferine relaxes rat mesenteric arteries through endothelium-dependent and -independent mechanisms

Characterization and Molecular Engineering of a N-Methyltransferase from Edible Nelumbo nucifera Leaves Involved in Nuciferine Biosynthesis

Lotus leaf, traditionally used as both edible tea and herbal medicine in Asia, contains nuciferine, a lipid-lowering and weight-loss compoud. The biosynthetic pathways of nuciferine in Nelumbo nucifera remain unclear. We characterized a specific N-methyltransferase, NnNMT, which had a novel function and catalyzed only nuciferine synthesis from the aporphine-type alkaloid N-nornuciferine. The expression profile of NnNMT was in agreement with BIA accumulation patterns in four tissues from three varieties, suggesting that NnNMT is involved in nucleiferine biosynthesis in Nelumbo nucifera. Protein engineering based on molecular docking and dynamic simulations revealed key residues (Y98, H208, F256, Y81, F329, G260, P76, and H80) crucial for NnNMT activity, with the F257A mutant showing increased efficiency. These findings enhance our understanding of aporphine alkaloid biosynthesis and support the development of lotus-based functional foods and medicinal applications.

Nuciferine analogs block voltage-gated sodium, calcium and potassium channels to regulate the action potential and treat arrhythmia

Dysfunction of the Nav1.5, Cav1.2, and Kv channels could interfere with the AP and result in arrhythmias and even heart failure. We herein present a novel library of nuciferine analogs that target ion channels for the treatment of arrhythmias. Patch clamp measurements of ventricular myocytes revealed that 6a dramatically blocked both the INa and ICa without altering the currentvoltage relationship (including the activation potential and peak potential), accelerated the inactivation of Nav and Cav channels and delayed the resurrection of these channels after inactivation. Additionally, 6a significantly decreased the APA and RMP without affecting the APD30 or APD50. The IC50 values of 6a against Nav1.5 and Cav1.2 were 4.98 μM and 4.62 μM, respectively. Furthermore, 6a (10 μM) blocked IKs, IK1, and Ito with values of 17.01 %±2.54 %, 9.09 %±2.78 %, and 11.15 %±3.52 %, respectively. Surprisingly, 6a weakly inhibited hERG channels, suggesting a low risk of proarrhythmia. The cytotoxicity evaluation of 6a with the H9c2 cell line indicated that this compound was noncytotoxic. In vivo studies suggested that these novel nuciferine analogs could shorten the time of arrhythmia continuum induced by BaCl2 and normalize the HR, QRS, QT and QTc interval and the R wave amplitude. Moreover, 6a dose-dependently affected aconitine-induced arrhythmias and notably improved the cumulative dosage of aconitine required to evoke VP, VT, VF and CA in rats with aconitine-induced arrhythmia. In conclusion, nuciferine analogs could be promising ion channel blockers that could be further developed into antiarrhythmic agents.

Advances in the pharmacological effects and mechanisms of Nelumbo nucifera gaertn. Extract nuciferine

ETHNOPHARMACOLOGIC RELEVANCE

The leaves of Nelumbo nucifera Gaertn. Are recorded in the earliest written documentation of traditional Chinese medicinal as "Ben Cao Gang Mu", a medicinal herb for blood clotting, dysentery and dizziness. Nuciferine, one of N. nucifera Gaertn. leaf extracts, has been shown to possess several pharmacological properties, including but not limited to ameliorating hyperlipidemia, stimulating insulin secretion, inducing vasodilation, reducing blood pressure, and demonstrating anti-arrhythmic properties.

AIM OF THE STUDY

In light of the latest research findings on nuciferine, this article provides a comprehensive overview of its chemical properties, pharmacological activities, and the underlying regulatory mechanisms. It aims to serve as a dependable reference for further investigations into the pharmacological effects and mechanisms of nuciferine.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the literature on extraction, separation, structural analysis and pharmacological activity of nuciferine published before November 2023. The key words are "extraction", "isolation", "purification" and "pharmacological action" and "nuciferine".

RESULTS

Nuciferine has been widely used in the treatment of ameliorating hyperlipidemia and lose weight, Nuciferine is a monomeric aporphine alkaloid extracted from the leaves of the plant Nymphaea caerulea and Nelumbo nucifera Gaertn. Nuciferine has pharmacological activities such as relaxing smooth muscles, improving hyperlipidemia, stimulating insulin secretion, vasodilation, inducing hypotension, antiarrhythmic effects, and antimicrobial and anti-HIV activities. These pharmacological properties lay a foundation for the treatment of tumors, inflammation, hyperglycemia, lipid-lowering and weight-loss, oxidative stress and other diseases with nuciferine.

CONCLUSION

Nuciferine has been clinically used to treat hyperlipidemia and aid in weight loss due to its effects on lipid levels, insulin secretion, vasodilation, blood pressure reduction, anti-tumor properties, and immune enhancement. However, other potential benefits of nuciferine have not yet been fully explored in clinical practice. Future research should delve deeper into its molecular structure, toxicity, side effects, and clinical pharmacology to uncover its full range of effects and pave the way for its safe and expanded clinical use.

Natural aporphine alkaloids: A comprehensive review of phytochemistry, pharmacokinetics, anticancer activities, and clinical application

BACKGROUND

Cancer is the most common cause of death and is still a serious public health problem. Alkaloids, a class of bioactive compounds widely diffused in plants, especially Chinese herbs, are used as functional ingredients, precursors, and lead compounds in food and clinical applications. Among them, aporphine alkaloids (AAs), as an important class of isoquinoline alkaloids, exert a strong anticancer effect on multiple cancer types.

AIM OF REVIEW

This review aims to comprehensively summarize the phytochemistry, pharmacokinetics, and bioavailability of seven subtypes of AAs and their derivatives from various plants and highlight their anticancer bioactivities and mechanisms of action. Key Scientific Concepts of Review. The chemical structures and botanical diversity of AAs are elucidated, and promising results are highlighted regarding the potent anticancer activities of AAs and their derivatives, contributing to their pharmacological benefits. This work provides a better understanding of AAs and combinational anticancer therapies involving them, thereby improving the development of functional food containing plant-derived AA and the clinical application of AAs.

Structure-activity relationship, bioactivities, molecular mechanisms, and clinical application of nuciferine on inflammation-related diseases

Nuciferine aporphine alkaloid mainly exists in Nelumbo nucifera Gaertn and is a beneficial to human health, such as anti-obesity, lowering blood lipid, prevention of diabetes and cancer, closely associated with inflammation. Importantly, nuciferine may contribute to its bioactivities by exerting intense anti-inflammatory activities in multiple models. However, no review has summarized the anti-inflammatory effect of nuciferine. This review critically summarized the information regarding the structure-activity relationships of dietary nuciferine. Moreover, biological activities and clinical application on inflammation-related diseases, such as obesity, diabetes, liver, cardiovascular diseases, and cancer, as well as their potential mechanisms, involving oxidative stress, metabolic signaling, and gut microbiota has been reviewed. The current work provides a better understanding of the anti-inflammation properties of nuciferine against multiple diseases, thereby improving the utilization and application of nuciferine-containing plants across functional food and medicine.

Nuciferine improves random skin flap survival via TFEB-mediated activation of autophagy-lysosomal pathway

Due to their simplicity and reliability, random-pattern skin flaps are commonly utilized in surgical reconstruction to repair cutaneous wounds. However, the post-operative necrosis frequently happens because of the ischemia and high-level of oxidative stress of random skin flaps, which can severely affect the healing outcomes. Earlier evidence has shown promising effect of Nuciferine (NF) on preventing hydrogen peroxide (H₂O₂)-induced fibroblast senescence and ischemic injury, however, whether it can function on promoting ischemic flap survival remains unknown. In this work, using network pharmacology analysis, it was possible to anticipate the prospective targets of NF in the context of ischemia. The results revealed that NF treatment minimized H₂O₂-induced cellular dysfunction of human umbilical vein endothelial cells (HUVECs), and also improved flap survival through strengthening angiogenesis and alleviating oxidative stress, inflammation and apoptosis in vivo. These outcomes should be attributed to TFEB-mediated enhancement of autophagy-lysosomal degradation via the AMPK-mTOR signaling pathway, whilst the restriction of autophagy stimulation with 3MA effectively diminished the above advantages of NF treatment. The increased nuclear translocation of TFEB not only restored lysosome function, but also promoted autophagosome-lysosome fusion, eventually restoring the inhibited autophagic flux and filling the high energy levels. The outcomes of our research can provide potent proof for the application of NF in the therapy of vascular insufficiency associated disorders, including random flaps.

Nuciferine blocks MIB2-mediated CARD6 polyubiquitination and degradation in the amelioration of high fructose-induced liver lipid accumulation

Dietary alkaloid nuciferine isolated from the leaves of Nelumbo nucifera can ameliorate dyslipidemia and liver lipid accumulation, but the underlying mechanism remains unclear. Caspase recruitment domain protein family member 6 (CARD6) is suggested to play an important role in metabolic diseases. This study aimed to investigate the role and the upstream regulator of CARD6 in high fructose-induced liver lipid accumulation and whether and how the anti-lipid accumulation effect of nuciferine was related to CARD6. Herein, we found that high fructose decreased CARD6 expression and increased ASK1 and JNK1/2 phosphorylation in rat livers and hepatocytes, which were attenuated by nuciferine. Furthermore, after the transfection with HA-CARD6, CARD6 siRNA and MIB2 siRNA, the data showed that CARD6 overexpression blocked high fructose-induced upregulation of ASK1 and JNK1/2 phosphorylation as well as lipid accumulation in hepatocytes. CARD6 siRNA reversed the amelioration of nuciferine to high fructose-induced upregulation of ASK1 and JNK1/2 phosphorylation in hepatocyte lipid accumulation. Mechanistically, high fructose upregulated MIB2 expression by interacting with CARD6 and promoting K48-linked CARD6 polyubiquitination and degradation in high fructose-stimulated hepatocytes which were explored by immunoblotting, immunofluorescence, and immunoprecipitation. However, MIB2 siRNA reversed high fructose-induced downregulation of CARD6 and lipid accumulation in hepatocytes. Notably, nuciferine reduced MIB2 expression and thus decreased K48-linked CARD6 polyubiquitination and degradation in the amelioration of high fructose-induced lipid accumulation in hepatocytes. These results suggested that nuciferine exhibited a protective effect against high fructose-induced liver lipid accumulation through blocking MIB2-mediated CARD6 polyubiquitination and degradation.

Regulated extravascular microenvironment via reversible thermosensitive hydrogel for inhibiting calcium influx and vasospasm

Arterial vasospasm after microsurgery can cause severe obstruction of blood flow manifested as low tissue temperature, leading to tissue necrosis. The timely discovery and synchronized treatment become pivotal. In this study, a reversible, intelligent, responsive thermosensitive hydrogel system is constructed employing both the gel–sol transition and the sol–gel transition. The “reversible thermosensitive (RTS)” hydrogel loaded with verapamil hydrochloride is designed to dynamically and continuously regulate the extravascular microenvironment by inhibiting extracellular calcium influx. After accurate implantation and following in situ gelation, the RTS hydrogel reverses to the sol state causing massive drug release to inhibit vasospasm when the tissue temperature drops to the predetermined transition temperature. Subsequent restoration of the blood supply alleviates further tissue injury. Before the temperature drops, the RTS hydrogel maintains the gel state as a sustained-release reservoir to prevent vasospasm. The inhibition of calcium influx and vasospasm in vitro and in vivo is demonstrated using vascular smooth muscle cells, mice mesenteric arterial rings, and vascular ultrasonic Doppler detection. Subsequent animal experiments demonstrate that RTS hydrogel can promote tissue survival and alleviate tissue injury responding to temperature change. Therefore, this RTS hydrogel holds therapeutic potential for diseases requiring timely detection of temperature change.

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Proposing a new strategy for the discovery and treatment for diseases requiring timely detection of temperature change.

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Applying both the gel–sol transition and the sol–gel transition of PEG/PLGA triblock polymers.

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Realizing the dynamical and continuous regulation of the extravascular microenvironment.

Calcitriol Suppressed Isoproterenol-induced Proliferation of Cardiac Fibroblasts via Integrin β3/FAK/Akt Pathway

OBJECTIVE

Cardiac fibroblasts (CFs) proliferation and extracellular matrix deposition are important features of cardiac fibrosis. Various studies have indicated that vitamin D displays an anti-fibrotic property in chronic heart diseases. This study explored the role of vitamin D in the growth of CFs via an integrin signaling pathway.

METHODS

MTT and 5-ethynyl-2'-deoxyuridine assays were performed to determine cell viability. Western blotting was performed to detect the expression of proliferating cell nuclear antigen (PCNA) and integrin signaling pathway. The fibronectin was observed by ELISA. Immunohistochemical staining was employed to evaluate the expression of integrin β3.

RESULTS

The PCNA expression in the CFs was enhanced after isoproterenol (ISO) stimulation accompanied by an elevated expression of integrin beta-3 (β3). The blockade of the integrin β3 with a specific integrin β3 antibody reduced the PCNA expression induced by the ISO. Decreasing the integrin β3 by siRNA reduced the ISO-triggered phosphorylation of FAK and Akt. Both the FAK inhibitor and Akt inhibitor suppressed the PCNA expression induced by the ISO in the CFs. Calcitriol (CAL), an active form of vitamin D, attenuated the ISO-induced CFs proliferation by downregulating the integrin β3 expression, and phosphorylation of FAK and Akt. Moreover, CAL reduced the increased levels of fibronectin and hydroxyproline in the CFs culture medium triggered by the ISO. The administration of calcitriol decreased the integrin β3 expression in the ISO-induced myocardial injury model.

CONCLUSION

These findings revealed a novel role for CAL in suppressing the CFs growth by the downregulation of the integrin β3/FAK/Akt pathway.

Study on the vasodilatory activity of lotus leaf extract and its representative substance nuciferine on thoracic aorta in rats

Lotus (Nelumbo nucifera) leaves are widely used for both edible and medicinal applications. For its further utilization, we studied the vasodilatory activity of lotus leaf extract for the first time. In this study, we obtained the extracts using different ratios of water and ethanol, which was followed by polarity-dependent extraction. We found that the CH₂Cl₂ layer exhibited better vasodilatory activity (EC₅₀ = 1.21 ± 0.10 μg/ml). HPLC and ESI-HRMS analysis of the CH₂Cl₂ layer using the standard product as a control revealed that nuciferine (E_max = 97.95 ± 0.76%, EC₅₀ = 0.36 ± 0.02 μM) was the main component in this layer. Further research revealed that nuciferine exerts a multi-target synergistic effect to promote vasodilation, via the NO signaling pathway, K⁺ channel, Ca²⁺ channel, intracellular Ca²⁺ release, α and β receptors, etc. Nuciferine exhibits good vasodilatory activity, and it exhibits the potential to be utilized as a lead compound.

An eco-friendly extraction and purification method of nuciferine from Folium nelumbinis with p-sulfonatocalix[6]arenes

INTRODUCTION

Folium nelumbinis is used as vegetable, functional food and herbal medicine in Asia. p-Sulfonatocalix[6]arene (SC6A) is a water-soluble supramolecular macrocycle and has never been applied to the extraction of herbal products.

OBJECTIVE

In this study, SC6A-assisted extraction of nuciferine from Folium nelumbinis has been carried out to develop an eco-friendly extraction process with high extraction efficacy and easy operation.

METHODS

Single-factor experiments were adopted to obtain the optimal conditions for the SC6A-assisted extraction of nuciferine from Folium nelumbinis, and then nuciferine and SC6A were separated easily by one-step alkalization. The host-guest complexes between nuciferine and SC6A were analyzed by competitive fluorescence titration, DSC, FT-IR and ¹ H-NMR.

RESULTS

The optimal SC6A/Folium nelumbinis/solution ratio for extraction was 0.4:1:20 (g/g/mL), with a granulometric fraction below 180 μm and an extraction time of 1 h with soaking. The purity and recovery of nuciferine extracted with SC6A were increased 29.24 and 35.73 times compared with extraction with aqueous solution, respectively. Moreover, a good reusability of SC6A in the extraction of nuciferine was demonstrated. Competitive fluorescence titration, DSC, FT-IR and ¹ H-NMR characterization indicated that SC6A could form host-guest complexes with nuciferine at a ratio of 1:1.

CONCLUSION

The study provided an eco-friendly, safe and effective nuciferine extraction method, which can be used for the development of nutrition supplements containing nuciferine.

Vasorelaxant Activities and its Underlying Mechanisms of Magnolia Volatile Oil on Rat Thoracic Aorta Based on Network Pharmacology

Objective: Magnolia volatile oil (MVO) is a mixture mainly containing eudesmol and its isomers. This study was to investigate the vasorelaxant effects and the underlying mechanism of MVO in rat thoracic aortas.

Method: The present study combined gas chromatography–mass spectrometry (GC-MS) and network pharmacology analysis with in vitro experiments to clarify the mechanisms of MVO against vessel contraction. A compound–target network, compound–target–disease network, protein–protein interaction network, compound–target–pathway network, gene ontology, and pathway enrichment for hypertension were applied to identify the potential active compounds, drug targets, and pathways. Additionally, the thoracic aortic rings with or without endothelium were prepared to explore the underlying mechanisms. The roles of the PI3K-Akt-NO pathways, neuroreceptors, K⁺ channels, and Ca²⁺ channels on the vasorelaxant effects of MVO were evaluated through the rat thoracic aortic rings.

Results: A total of 29 compounds were found in MVO, which were identified by GC-MS, of which 21 compounds with a content of more than 0.1% were selected for further analysis. The network pharmacology research predicted that beta-caryophyllene, palmitic acid, and (+)-β-selinene might act as the effective ingredients of MVO for the treatment of hypertension. Several hot targets, mainly involving TNF, CHRM1, ACE, IL10, PTGS2, REN, and F2, and pivotal pathways, such as the neuroactive ligand–receptor interaction, the calcium signaling pathway, and the PI3K-Akt signaling, were responsible for the vasorelaxant effect of MVO. As expected, MVO exerted a vasorelaxant effect on the aortic rings pre-contracted by KCl and phenylephrine in an endothelium-dependent and non-endothelium-dependent manner. Importantly, a pre-incubation with indomethacin (Indo), N-nitro-L-arginine methyl ester, methylene blue, wortmannin, and atropine sulfate as well as 4-aminopyridione diminished MVO-induced vasorelaxation, suggesting that the activation of the PI3K-Akt-NO pathway and K_V channel were involved in the vasorelaxant effect of MVO, which was consistent with the results of the Kyoto Encyclopedia of Genes and the Genomes. Additionally, MVO could significantly inhibit Ca²⁺ influx resulting in the contraction of aortic rings, revealing that the inhibition of the calcium signaling pathway exactly participated in the vasorelaxant activity of MVO as predicted by network pharmacology.

Conclusion: MVO might be a potent treatment of diseases with vascular dysfunction like hypertension. The underlying mechanisms were related to the PI3K-Akt-NO pathway, K_V pathway, as well as Ca²⁺ channel, which were predicted by the network pharmacology and verified by the experiments in vitro. This study based on network pharmacology provided experimental support for the clinical application of MVO in the treatment of hypertension and afforded a novel research method to explore the activity and mechanism of traditional Chinese medicine.

Higenamine in Plants as a Source of Unintentional Doping

BACKGROUND

Higenamine is a β2 agonist of plant origin. The compound has been included in WADA's prohibited list since 2017. Higenamine may be detected in different plants and many food supplements of natural origin.

METHODS

Our literature search was conducted through PubMed, Science Direct, Google Scholar, and Web of Science studies investigating the presence of higenamine in plants that are used in traditional folk medicine or included in food supplements. Our study aimed to assess the risk of adverse analytical findings caused by higenamine-containing plants.

RESULTS

Based on our literature search, Nelumbo nucifera, Tinospora crispa, Nandina domestica, Gnetum parvifolium, Asarum siebodii,Asarum heterotropoides, Aconitum carmichaelii, and Aristolochia brasiliensis are higenamine-containing plants. Based on data from Eastern folk medicine, these plants can provide numerous health benefits. Professional athletes likely ingest these plants without knowing that they contain higenamine; these herbs are used in treatments for different conditions and various foods/food supplements in addition to folk medicine.

CONCLUSION

Athletes and their teams must be aware of the issues associated with the use of plant-based products. They should avoid consuming higenamine-containing plants during and outside of competition periods.

Phosphodiesterase 4D promotes angiotensin II-induced hypertension in mice via smooth muscle cell contraction

Hypertension is a common chronic disease, which leads to cardio-cerebrovascular diseases, and its prevalence is increasing. The cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway participates in multiple cardiovascular diseases. Phosphodiesterase (PDE) 4 has been shown to regulate PKA activity via cAMP specific hydrolysis. However, whether PDE4-cAMP-PKA pathway influences hypertension remains unknown. Herein, we reveal that PDE4D (one of PDE4 isoforms) expression is upregulated in the aortas of experimental hypertension induced by angiotensin II (Ang II). Furthermore, knockout of Pde4d in mouse smooth muscle cells (SMCs) attenuates Ang II-induced hypertension, arterial wall media thickening, vascular fibrosis and vasocontraction. Additionally, we find that PDE4D deficiency activates PKA-AMP-activated protein kinase (AMPK) signaling pathway to inhibit myosin phosphatase targeting subunit 1 (MYPT1)-myosin light chain (MLC) phosphorylation, relieving Ang II-induced SMC contraction in vitro and in vivo. Our results also indicate that rolipram, a PDE4 inhibitor, may be a potential drug for hypertension therapy.

Nuciferine, an active ingredient derived from lotus leaf, lights up the way for the potential treatment of obesity and obesity-related diseases

Obesity, is an increasingly global public health problem associated complications. However, the proven anti-obesity agents are inefficient with adverse side effects; hence attention is being paid to novel drugs from natural resources to manage obesity and obesity-related diseases. Nuciferine (NF) is a high-quality aporphine alkaloid present in lotus leaf. Unlike the chemical drugs, NF elicits anti-obesity, anti-dyslipidemia, anti-hyperglycemic, anti-hypouricemic, anti-inflammatory, and anti-tumor effects, and affinity to neural receptors, and protection against obesity-related diseases. The underlying mechanism of NF includes the regulation of targeted molecules and pathways related to metabolism, inflammation, and cancer and modulation of Ca²⁺ flux, gut microbiota, and ferroptosis. Besides, the clinical application, availability, pharmacokinetics, pharmaceutics, and security of NF have been established, highlighting the potential of developing NF as an anti-obesity agent. Therefore, this review provides a comprehensive summarization, which sheds light on future research in NF.

Natural Aporphine Alkaloids with Potential to Impact Metabolic Syndrome

The incidence and prevalence of metabolic syndrome has steadily increased worldwide. As a major risk factor for various diseases, metabolic syndrome has come into focus in recent years. Some natural aporphine alkaloids are very promising agents in the prevention and treatment of metabolic syndrome and its components because of their wide variety of biological activities. These natural aporphine alkaloids have protective effects on the different risk factors characterizing metabolic syndrome. In this review, we highlight the activities of bioactive aporphine alkaloids: thaliporphine, boldine, nuciferine, pronuciferine, roemerine, dicentrine, magnoflorine, anonaine, apomorphine, glaucine, predicentrine, isolaureline, xylopine, methylbulbocapnine, and crebanine. We particularly focused on their impact on metabolic syndrome and its components, including insulin resistance and type 2 diabetes mellitus, endothelial dysfunction, hypertension and cardiovascular disease, hyperlipidemia and obesity, non-alcoholic fatty liver disease, hyperuricemia and kidney damage, erectile dysfunction, central nervous system-related disorder, and intestinal microbiota dysbiosis. We also discussed the potential mechanisms of actions by aporphine alkaloids in metabolic syndrome.

Discovery of eight alkaloids with D1 and D2 antagonist activity in leaves of Nelumbo nucifera Gaertn. Using FLIPR assays

ETHNOPHARMACOLOGICAL RELEVANCE

Dopamine receptors are long-standing primary targets in the treatment of mental diseases and there is growing evidence that suggests relationships between obesity and the dopamine system, especially dopamine D1 and D2 receptors. Leaves of Nelumbo nucifera Gaertn. (lotus leaves) have been medically used for helping long-term maintenance of weight loss. Whether and how components of lotus leaves function through the dopamine receptors remains unclear.

AIM OF THE STUDY

This work aimed to discover dopamine receptor-active alkaloids isolated from the lotus leaves, to evaluate their potencies and to analyze their structure activity relationship.

MATERIALS AND METHODS

Dried lotus leaves were prepared and total extract was divided into alkaloids and flavones. Eight alkaloids were separated and characterized by a combination of high-performance liquid chromatography, quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance, and assayed by a fluorometric imaging plate reader platform. Human embryonic kidney 239 cell lines expressing dopamine D1, D2 and serotonin 2A (5-HT2A) receptors, respectively, were cultured and used in the assay.

RESULTS

Alkaloids in the lotus leaves were the bioactive phytochemicals and inhibited dopamine from accessing the D1 and D2 receptors. All eight compounds functioned as D1-receptor antagonists and except N-nornuciferine, seven alkaloids functioned as D2-receptor antagonists. (S)-coclaurine and (R)-coclaurine are optical isomers and antagonized both D1 and D2 with equivalent potencies, suggesting that the optical rotation of the methylene linker in the monobenzyl isoquinoline backbone did not influence their activity. Among the eight alkaloids, O-nornuciferine was the potent antagonist to both receptors (the lowest IC₅₀ values, D1: 2.09 ± 0.65 μM and D2: 1.14 ± 0.10 μM) while N-nornuciferine was found to be the least potent as it moderately antagonized D1 and was inactive on D2. O-nornuciferine was also a 5-HT2A antagonist (IC₅₀~20 μM) while N-nornuciferine had no activity. These hinted the importance of a methyl group attached to the nitrogen atom in the aporphine backbone. Armepavine showed a nearly 10-fold selectivity to D2.

CONCLUSIONS

In this work, eight alkaloids were isolated from the leaves of Nelumbo nucifera Gaertn. and assayed on the D1 and D2 receptors. They were D1/D2 antagonists with IC₅₀ values in the mid- to low-micromolar range and O-nornuciferine was the most potent alkaloid among the eight. This family of alkaloids was biochemically evaluated on the dopamine receptors by the same platform for the first time.

Comparative Analysis of Chemical Constituents in Different Parts of Lotus by UPLC and QToF-MS

Six parts of lotus (seeds, leaves, plumule, stamens, receptacles and rhizome nodes) are herbal medicines that are listed in the Chinese Pharmacopoeia. Their indications and functions have been confirmed by a long history of clinical practice. To fully understand the material basis of clinical applications, UPLC-QToF-MS combined with the UNIFI platform and multivariate statistical analysis was used in this study. As a result, a total of 171 compounds were detected and characterized from the six parts, and 23 robust biomarkers were discovered. The method can be used as a standard protocol for the direct identification and prediction of the six parts of lotus. Meanwhile, these discoveries are valuable for improving the quality control method of herbal medicines. Most importantly, this was the first time that alkaloids were detected in the stamen, and terpenoids were detected in the cored seed. The stamen is a noteworthy part because it contains the greatest diversity of flavonoids and terpenoids, but research on the stamen is rather limited.

UPLC-Q-TOF/MS-Based Serum Metabolomics Reveals the Anti-Ischemic Stroke Mechanism of Nuciferine in MCAO Rats

Nuciferine is an aporphine alkaloid monomer that is extracted from the leaves of the lotus species Nymphaea caerulea and Nelumbo nucifera Gaertn. Nuciferine was reported to treat cerebrovascular diseases. However, the potential mechanism of the neuroprotective effects of nuciferine at the metabolomics level is still not unclear. The present research used neurological score, infarct volume, cerebral water content, and ultraperformance liquid chromatography to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS)-based serum metabolomics to elucidate the anti-ischemic stroke effect and mechanisms of nuciferine. The results showed that nuciferine significantly improved neurological deficit scores and ameliorated cerebral edema and infarction. Multivariate data analysis methods were used to examine the differences in serum endogenous metabolism between groups, and the biomarkers of nuciferine on ischemic stroke were identified. Approximately 19 metabolites and 7 metabolic pathways associated with nuciferine on treatment of stroke were found, which indicated that nuciferine exerted a positive therapeutic action on cerebral ischemic by regulating metabolism. These results provided some data support for the study of anti-stroke effect of nuciferine from the perspective of metabolomics.

The genus Uncaria: A review on phytochemical metabolites and biological aspects

The genus Uncaira (Rubiaceae) comprises of 34 species, many of which are usually used as traditional Chinese medicines (TCMs) to treat hypertension, fever, headache, gastrointestinal illness, and fungal infection. Over the past twenty years, Uncaira species have been paid the considerable attentions in phytochemical and biological aspects, and about 100 new secondary metabolites, including alkaloids, triterpenes, and flavonoids, have been elucidated. This review aims to present a comprehensive and up-to date overview of the biological source, structures and their biosynthetic pathways, as well as the pharmacological of the compounds reported in the genus Uncaria for the past two decades. It would provide an insight into the emerging pharmacological applications of the genus Uncaria.

Stimulation of Epithelial Sodium Channels in Endothelial Cells by Bone Morphogenetic Protein-4 Contributes to Salt-Sensitive Hypertension in Rats

Previous studies have shown that high salt induces artery stiffness by causing endothelial dysfunction via increased sodium influx. We used our unique split-open artery technique combined with protein biochemistry and in vitro measurement of vascular tone to test a hypothesis that bone morphogenetic protein 4 (BMP4) mediates high salt-induced loss of vascular relaxation by stimulating the epithelial sodium channel (ENaC) in endothelial cells. The data show that high salt intake increased BMP4 both in endothelial cells and in the serum and that exogenous BMP4 stimulated ENaC in endothelial cells. The data also show that the stimulation is mediated by p38 mitogen-activated protein kinases (p38 MAPK) and serum and glucocorticoid-regulated kinase 1 (Sgk1)/neural precursor cell expressed developmentally downregulated gene 4-2 (Nedd4-2) (Sgk1/Nedd4-2). Furthermore, BMP4 decreased mesenteric artery relaxation in a benzamil-sensitive manner. These results suggest that high salt intake stimulates endothelial cells to express and release BMP4 and that the released BMP4 reduces artery relaxation by stimulating ENaC in endothelial cells. Therefore, stimulation of ENaC in endothelial cells by BMP4 may serve as another pathway to participate in the complex mechanism of salt-sensitive (SS) hypertension.

Periplocymarin Plays an Efficacious Cardiotonic Role via Promoting Calcium Influx

Periplocymarin, which belongs to cardiac glycosides, is an effective component extracted from Periplocae Cortex. However, its cardiovascular effects remain unidentified. In the present study, injection of periplocymarin (5 mg/kg) through external jugular vein immediately increased the mean arterial pressure (MAP) in anesthetized C57BL/6 mice. Ex vivo experiments using mouse mesenteric artery rings were conducted to validate the role of periplocymarin on blood vessels. However, periplocymarin failed to induce vasoconstriction directly, and had no effects on vasoconstriction induced by phenylephrine (Phe) and angiotensin II (Ang II). In addition, vasodilatation induced by acetylcholine (Ach) was insusceptible to periplocymarin. Echocardiography was used to evaluate the effects of periplocymarin on cardiac function. The results showed that the injection of periplocymarin significantly increase the ejection fraction (EF) in mice without changing the heart rate. In vitro studies using isolated neonatal rat ventricular myocytes (NRVMs) revealed that periplocymarin transiently increased the intracellular Ca²⁺ concentration observed by confocal microscope. But in Ca²⁺-free buffer, this phenomenon vanished. Besides, inhibition of sodium potassium-activated adenosine triphosphatase (Na⁺-K⁺-ATPase) by digoxin significantly suppressed the increase of MAP and EF in mice, and the influx of Ca²⁺ in cardiomyocytes, mediated by periplocymarin. Collectively, these findings demonstrated that periplocymarin increased the contractility of myocardium by promoting the Ca²⁺ influx of cardiomyocytes via targeting on Na⁺-K⁺-ATPase, which indirectly led to the instantaneous rise of blood pressure.

Endothelial cell prostaglandin E2 receptor EP4 is essential for blood pressure homeostasis

Prostaglandin E2 and its cognate EP1-4 receptors play important roles in blood pressure (BP) regulation. Herein, we show that endothelial cell-specific (EC-specific) EP4 gene-knockout mice (EC-EP4-/-) exhibited elevated, while EC-specific EP4-overexpression mice (EC-hEP4OE) displayed reduced, BP levels compared with the control mice under both basal and high-salt diet-fed conditions. The altered BP was completely abolished by treatment with l-NG-nitro-l-arginine methyl ester (l-NAME), a competitive inhibitor of endothelial nitric oxide synthase (eNOS). The mesenteric arteries of the EC-EP4-/- mice showed increased vasoconstrictive response to angiotensin II and reduced vasorelaxant response to acetylcholine, both of which were eliminated by l-NAME. Furthermore, EP4 activation significantly reduced BP levels in hypertensive rats. Mechanistically, EP4 deletion markedly decreased NO contents in blood vessels via reducing eNOS phosphorylation at Ser1177. EP4 enhanced NO production mainly through the AMPK pathway in cultured ECs. Collectively, our findings demonstrate that endothelial EP4 is essential for BP homeostasis.

PPARδ agonist prevents endothelial dysfunction via induction of dihydrofolate reductase gene and activation of tetrahydrobiopterin salvage pathway

BACKGROUND AND PURPOSE

Impaired endothelium-dependent relaxation (EDR) is a hallmark of endothelial dysfunction. A deficiency of tetrahydrobiopterin (BH4 ) causes endothelial NOS to produce ROS rather than NO. PPARδ is an emerging target for pharmacological intervention of endothelial dysfunction. Thus, the present study examined the role of PPARδ in the regulation of dihydrofolate reductase (DHFR), a key enzyme in the BH4 salvage pathway.

EXPERIMENTAL APPROACH

Gene expression was measured by using qRT-PCR and western blotting. Biopterins and ROS were determined by using HPLC. NO was measured with fluorescent dye and electron paramagnetic resonance spectroscopy. Vasorelaxation was measured by Multi Myograph System.

KEY RESULTS

The PPARδ agonist GW501516 increased DHFR and BH4 levels in endothelial cells (ECs). The effect was blocked by PPARδ antagonist GSK0660. Chromatin immunoprecipitation identified PPAR-responsive elements within the 5'-flanking region of the human DHFR gene. The promoter activity was examined with luciferase assays using deletion reporters. Importantly, DHFR expression was suppressed by palmitic acid (PA, a saturated fatty acid) but increased by docosahexaenoic acid (DHA, a polyunsaturated fatty acid). GSK0660 prevented DHA-induced increased DHFR expression. Conversely, the suppressive effect of PA was mitigated by GW501516. In mouse aortae, GW501516 ameliorated the PA-impaired EDR. However, this vasoprotective effect was attenuated by DHFR siRNA or methotrexate. In EC-specific Ppard knockout mice, GW501516 failed to improve vasorelaxation.

CONCLUSION AND IMPLICATIONS

PPARδ prevented endothelial dysfunction by increasing DHFR and activating the BH4 salvage pathway. These results provide a novel mechanism for the protective roles of PPARδ against vascular diseases.

Marsdenia tenacissima extract dilated small mesenteric arteries via stimulating endothelial nitric oxide synthase and inhibiting calcium influx

ETHNOPHARMACOLOGICAL RELEVANCE

Marsdenia tenacissima is a traditional Chinese medicine that is known to be effective in combating cancer as well as reducing blood pressure. The efficacy and mechanisms of Marsdenia tenacissima in treating cancer have been well described. However, the potential vasoactivities of Marsdenia tenacissima remain poorly known.

AIM OF THE STUDY

To determine the vasoactive effects of the water-soluble part of marsdenia tenacissima in mesenteric resistance arteries of the mice, and to explore the underlying mechanisms.

MATERIALS AND METHODS

Isometric vessel tension study was used to examine the effects of marsdenia tenacissima extract (MTE) on vasodilation of the mesenteric arteries of mice. KCl, phenylephrine (PE) and 9,11-Dideoxy-11α,9α-epoxymethanoprostaglandin F2α (U46619) were used as vasoconstrictors. Y27632, Nitro-L-arginine methyl ester hydrochloride (L-NAME) and indomethacin were used to explore the underlying mechanisms for the vasoactivities of MTE. Western blot and nitric oxide (NO) assay were used to evaluate the effects of MTE on the activities of endothelial nitric oxide synthase (eNOS).

RESULTS

MTE (5-50 mg/mL), but not vehicle, dose-dependently relaxed the mesenteric arteries constricted with KCl, PE or U46619, in which relaxations to KCl were more pronounced than that to PE or U46619. Pre-incubation of the vessels with MTE (40 mg/mL) reduced the vasoconstrictions caused by calcium influx. Decreasing calcium sensitivity by inhibition of Rho kinase (ROCK) significantly augmented the vasorelaxation of MTE. While, inhibition of endothelial cells by pre-incubation with L-NAME (300 μM) and indomethacin (10 μM) or denudating endothelial cells attenuated vasorelaxations of MTE to KCl, and with a larger potency, to U46619. In both human umbilical vein endothelial cells (HUVECs) and human heart microvascular endothelial cells (HMECs), the phosphorylations of eNOS and the production of NO were significantly enhanced after treatment of MTE for 2, 5, 10, 30 min.

CONCLUSIONS

MTE, the water-soluble part of marsdenia tenacissima, was effective in relaxing mesenteric resistance arteries via inhibiting calcium influx and stimulating eNOS activities.

Endothelial-Dependent and Independent Vascular Relaxation Effect of Tetrahydropalmatine on Rat Aorta

Tetrahydropalmatine (THP) is an active natural alkaloid isolated from Corydalis yanhusuo W.T. Wang which has been widely used for treating pain and cardiovascular disease in traditional Chinese medicine. Previous studies suggested THP have various pharmacological effects in neural and cardio tissue while the vascular reactivity of THP was not fully established. The present study found that THP relaxed rat aorta which contracted by phenylephrine (Phe), KCl, and U46619. The vascular relaxation effect of THP was partially attenuated by PI3K inhibitor wortmannin, Akt inhibitor IV, endothelial nitric oxide synthetase (eNOS) inhibitor L-NAME, guanylate cyclase inhibitors and the mechanical removal of endothelium. Also, the eNOS substrate L-arginine reversed the inhibition effect of L-NAME on THP-induced vascular relaxation. THP also induced intracellular NO production in human umbilical vein endothelial cells. However, Pre-incubation with β-adrenergic receptor blocker propranolol, angiotensin II receptor 1 (AT1) inhibitor losartan, angiotensin II receptor 2 (AT1) inhibitor PD123319 or angiotensin converting enzyme inhibitor enalapril enhanced the vascular relaxation effect of THP. THP did not affect the angiotensin II induced vascular contraction. Cyclooxygenase-2 (COX2) inhibitor indomethacin did not affect the vascular relaxation effect of THP. Furthermore, pre-treatment THP attenuated KCl and Phe induced rat aorta contraction in standard Krebs solution. In Ca²⁺ free Krebs solution, THP inhibited the Ca²⁺ induced vascular contraction under KCl or Phe stress and reduced KCl stressed Ca²⁺ influx in rat vascular smooth muscle cells. THP also inhibited intracellular Ca²⁺ release induced vascular contraction by blocking Ryr or IP3 receptors. In addition, the voltage-dependent K⁺ channel (Kv) blocker 4-aminopyridine, ATP-sensitive K⁺ channel (KATP) blocker glibenclamide and inward rectifying K⁺ channel blocker BaCl₂ attenuated THP induced vascular relaxation regardless of the Ca²⁺-activated K⁺ channel (KCa) blocker tetraethylammonium. Thus, we could conclude that THP relaxed rat aorta in an endothelium-dependent and independent manner. The underlying mechanism of THP relaxing rat aorta involved PI3K/Akt/eNOS/NO/cGMP signaling path-way, Ca²⁺ channels and K⁺ channels rather than COX2, β-adrenergic receptor and renin-angiotensin system (RAS). These findings indicated that THP might be a potent treatment of diseases with vascular dysfunction like hypertension.

Cardioprotection and improvement in endothelial-dependent vasodilation during late-phase of whole body hypoxic preconditioning in spontaneously hypertensive rats via VEGF and endothelin-1

The present study was designed to investigate the effect of late phase of whole body hypoxic preconditioning on endothelial-dependent vasorelaxation and cardioprotection from ischemia-reperfusion injury in spontaneously hypertensive rats (SHR). Hypoxic preconditioning was performed by subjecting rats to four episodes of alternate exposure to low O₂ (8%) and normal air O₂ of 10 min each. After 24 h, the mesenteric arteries and hearts were isolated to determine the vascular function and cardioprotection from ischemia-reperfusion (I/R) injury on the Langendorff apparatus. There was a significant impairment in acetylcholine-induced relaxation in norepinephrine precontracted arteries (endothelium-dependent function) and increase in I/R-induced myocardial injury in SHR in comparison to Wistar Kyoto rats (WKY). However, hypoxic preconditioning significantly restored endothelium-dependent relaxation in SHR and attenuated I/R injury in both SHR and WKY. Hypoxic preconditioning also led to an increase in the levels of endothelin-1 (not endothelin-2 or -3), vascular endothelial growth factor-A (VEGF-A) and HIF-1α levels. Pretreatment with bevacizumab (anti-VEGF-A) and bosentan (endothelin receptor blocker) significantly attenuated hypoxic preconditioning-induced restoration of endothelium-dependent relaxation and cardioprotection from I/R injury. These interventions also attenuated the levels of VEGF-A and HIF-1α without modulating the endothelin-1 levels. It may be concluded that an increase in the endothelin-1 levels with a subsequent increase in HIF-1α and VEGF expression may possibly contribute in improving endothelium-dependent vasorelaxation and protecting hearts from I/R injury in SHR during late phase of whole body hypoxic preconditioning.

Nuciferine ameliorates hepatic steatosis in high-fat diet/streptozocin-induced diabetic mice through a PPARα/PPARγ coactivator-1α pathway

BACKGROUND AND PURPOSE

Nuciferine, an alkaloid found in Nelumbo nucifera leaves, alleviates dyslipidemia in vivo. However, whether it improves liver injury in diabetic conditions and the underlying mechanism is unclear. The present study aimed to investigate the effects of nuciferine on lipid and glucose metabolism in a murine model of Type 2 diabetes mellitus (T2DM) and to determine the underlying mechanisms of these effects.

EXPERIMENTAL APPROACH

A murine model of T2DM was induced by high-fat diet (HFD) feeding combined with streptozocin (STZ) injections, and the diabetic mice were treated with nuciferine in their food. The underlying mechanism of the anti-steatotic effect of nuciferine was further explored in HepG2 hepatocytes cultured with palmitic acid. Major signalling profiles involved in fatty acid oxidation were then evaluated, using Western blot, RT-qPCR and si-RNA techniques, along with immunohistochemistry.

KEY RESULTS

Nuciferine restored impaired glucose tolerance and insulin resistance in diabetic mice. Hepatic levels of total cholesterol, triglycerides and LDL were decreased, as were the number of lipid droplets, by nuciferine treatment. Furthermore, nuciferine up-regulated β-oxidation related genes in livers of diabetic mice. Luciferase reporter cell assay showed that nuciferine directly reversed palmitic acid-induced inhibition of PPARα transcriptional activity. Silencing PPARγ coactivator-1α (PGC1α) expression in HepG2 cells abolished the effects of nuciferine in accelerating β-oxidation.

CONCLUSIONS AND IMPLICATIONS

Nuciferine improved lipid profile and attenuated hepatic steatosis in HFD/STZ-induced diabetic mice by activating the PPARα/PGC1α pathway. Nuciferine may be a potentially important candidate in improving hepatic steatosis and the management of T2DM.

PLGA nanoparticles for the oral delivery of nuciferine: preparation, physicochemical characterization and in vitro/in vivo studies

This article reports a promising approach to enhance the oral delivery of nuciferine (NUC), improve its aqueous solubility and bioavailability, and allow its controlled release as well as inhibiting lipid accumulation. NUC-loaded poly lactic-co-glycolic acid nanoparticles (NUC-PLGA-NPs) were prepared according to a solid/oil/water (s/o/w) emulsion technique due to the water-insolubility of NUC. PLGA exhibited excellent loading capacity for NUC with adjustable dosing ratios. The drug loading and encapsulation efficiency of optimized formulation were 8.89 ± 0.71 and 88.54 ± 7.08%, respectively. NUC-PLGA-NPs exhibited a spherical morphology with average size of 150.83 ± 5.72 nm and negative charge of -22.73 ± 1.63 mV, which are suitable for oral administration. A sustained NUC released from NUC-PLGA-NPs with an initial exponential release owing to the surface associated drug followed by a slower release of NUC, which was entrapped in the core. In addition, ∼77 ± 6.67% was released in simulating intestinal juice, while only about 45.95 ± 5.2% in simulating gastric juice. NUC-PLGA-NPs are more efficient against oleic acid (OA)-induced hepatic steatosis in HepG2 cells when compared to naked NUC (n-NUC, *p < 0.05). The oral bioavailability of NUC-PLGA-NPs group was significantly higher (**p < 0.01) and a significantly decreased serum levels of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), as well as a higher concentration of high-density lipoprotein cholesterol (HDL-C) was observed, compared with that of n-NUC treated group. These findings suggest that NUC-PLGA-NPs hold great promise for sustained and controlled drug delivery with improved bioavailability to alleviating lipogenesis.

Total flavonoids from Astragalus alleviate endothelial dysfunction by activating the Akt/eNOS pathway

Objective

To investigate the vasodilative and endothelial-protective effects and the underlying mechanisms of total flavonoids from Astragalus (TFA).

Methods

The vasodilative activities of TFA were measured with a myograph ex vivo using rat superior mesenteric arterial rings. The primary human umbilical vein endothelial cell (HUVEC) viabilities were assayed using the cell counting kit-8 after hypoxia or normoxia treatment with or without TFA. Akt, P-Akt, eNOS, P-eNOS, Erk, P-Erk, Bcl-2 and Bax expression were analyzed using western blotting.

Results

TFA showed concentration-dependent vasodilative effects on rat superior mesenteric arterial rings, but had no effects on normal or potassium chloride precontracted arterial rings. TFA did not affect HUVEC viabilities in normoxia, but dramatically promoted cell proliferation in the concentration range of 1 to 30 µg/mL under hypoxia. Moreover, TFA significantly increased the ratios of P-Akt/Akt and P-eNOS/eNOS in vascular endothelial cells under hypoxic conditions, but did not change the P-Erk/Erk or Bcl-2/Bax ratios.

Conclusions

TFA might exhibit vasorelaxant and endothelial-protective effects via the Akt/eNOS signaling pathway.

Nelumbo nucifera leaves extracts inhibit mouse airway smooth muscle contraction

Background

Alkaloids extracted from lotus leaves (AELL) can relax vascular smooth muscle. However, whether AELL has a similar relaxant role on airway smooth muscle (ASM) remains unknown. This study aimed to explore the relaxant property of AELL on ASM and the underlying mechanism.

Methods

Alkaloids were extracted from dried lotus leaves using the high temperature rotary evaporation extraction method. The effects of AELL on mouse ASM tension were studied using force measuring and patch-clamp techniques.

Results

It was found that AELL inhibited the high K⁺ or acetylcholine chloride (ACh)-induced precontraction of mouse tracheal rings by 64.8 ± 2.9%, or 48.8 ± 4.7%, respectively. The inhibition was statistically significant and performed in a dose-dependent manner. Furthermore, AELL-induced smooth muscle relaxation was partially mediated by blocking voltage-dependent Ca²⁺ channels (VDCC) and non-selective cation channels (NSCC).

Conclusion

AELL, which plays a relaxant role in ASM, might be a new complementary treatment to treat abnormal contractions of the trachea and asthma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1674-7) contains supplementary material, which is available to authorized users.

The Blue Lotus Flower (Nymphea caerulea) Resin Used in a New Type of Electronic Cigarette, the Re-Buildable Dripping Atomizer

The blue lotus flower (Nymphea caerulea) is an Egyptian water lily containing apomorphine and nuciferine. Apomorphine has been described as a psychoactive alkaloid and is a non-selective dopamine agonist primarily used to treat Parkinson's disease as it stimulates dopamine receptors and improves motor function. Nuciferine is an alkaloid associated with dopamine receptor blockade. Today, blue lotus flower is used as a sleep aid and anxiety reliever. The rebuildable dripping atomizer (RDA) is an electronic cigarette that allows direct application of an e-liquid onto the coil in the atomizer for aerosolization, compared to a typical electronic cigarette where the e-liquid is wicked from a storage vessel to the coil. Our laboratory received a dark-brown resin material from a concerned parent. The resin had been confiscated from an adolescent who had a reported history of marijuana use. The resin was later identified as blue lotus flower (N. caerulea). This resin, together with four commercially available blue lotus products, was analyzed for content. Apomorphine was detected in two samples, and nuciferine was detected in all five samples. The confiscated resin was determined to contain no apomorphine and 4300 ng/g of nuciferine. The nuciferine resin was shown to aerosolize using aRDA electric cigarette.

Chinese innovation in cardiovascular drug discovery

This article is part of a themed section on Chinese Innovation in Cardiovascular Drug Discovery. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-23