The effects of Aconitum alkaloids on the central nervous system

Screening tools to evaluate the neurotoxic potential of botanicals: building a strategy to assess safety

AREAS COVERED

This paper outlines the selection of NAMs, including in vitro assays using primary rat cortical neurons, zebrafish embryos, and Caenorhabditis elegans. These assays aim to assess neurotoxic endpoints such as neuronal activity and behavioral responses. Microelectrode array recordings of rat cortical neurons provide insights into the impact of botanical extracts on neuronal function, while the zebrafish embryos and C. elegans assays evaluate neurobehavioral responses. The paper also provides an account of the selection of botanical case studies based on expert judgment and existing neuroactivity/toxicity information. The proposed battery of assays will be tested with these case studies to evaluate their utility for neurotoxicity screening.

EXPERT OPINION

The complexity of botanicals necessitates the use of multiple NAMs for effective neurotoxicity screening. This paper discusses the evaluation of methodologies to develop a robust framework for evaluating botanical safety, including complex neuronal models and key neurodevelopmental process assays. It aims to establish a comprehensive screening framework.

A concise and stereoselective synthesis of the BCDF tetracyclic ring system of C19-diterpenoid alkaloids

A new synthetic route for the BCDF tetracyclic ring system of C19-diterpenoid alkaloids (C19-DTAs) has been developed. The key step is a Pd-catalyzed transannular alkenylation that installs a functionalized bridged F ring. The overall strategy is concise and stereoselective, and it provides a valuable new tool for the synthesis of C19-DTAs. The synthesis begins with a bridged [3.2.1] ring system, which is converted to a key intermediate through a series of highly regio- and stereoselective processes. The introduction of an allylic side chain with high precision is accomplished, culminating in a Pd-catalyzed transannular alkenylation that installs a functionalized bridged F ring to yield the BCDF tetracyclic analog of C19-DTAs.

Harnessing the power of natural alkaloids: the emergent role in epilepsy therapy

The quest for effective epilepsy treatments has spotlighted natural alkaloids due to their broad neuropharmacological effects. This review provides a comprehensive analysis of the antiseizure properties of various natural compounds, with an emphasis on their mechanisms of action and potential therapeutic benefits. Our findings reveal that bioactive substances such as indole, quinoline, terpenoid, and pyridine alkaloids confer medicinal benefits by modulating synaptic interactions, restoring neuronal balance, and mitigating neuroinflammation-key factors in managing epileptic seizures. Notably, these compounds enhance GABAergic neurotransmission, diminish excitatory glutamatergic activities, particularly at NMDA receptors, and suppress proinflammatory pathways. A significant focus is placed on the strategic use of nanoparticle delivery systems to improve the solubility, stability, and bioavailability of these alkaloids, which helps overcome the challenges associated with crossing the blood-brain barrier (BBB). The review concludes with a prospective outlook on integrating these bioactive substances into epilepsy treatment regimes, advocating for extensive research to confirm their efficacy and safety. Advancing the bioavailability of alkaloids and rigorously assessing their toxicological profiles are essential to fully leverage the therapeutic potential of these compounds in clinical settings.

Stereocontrolled synthesis of the aconitine D ring from D-glucose

The synthesis of a fully oxygenated aconitine D ring precursor from (D)-(+)-glucose is described. The route features a highly diastereoselective alkynyl Grignard ketone addition and a base-mediated enelactone to 1,3-diketone rearrangement.

Anti-rheumatic potential vis-à-vis aconitine and hypaconitine content analysis in different Aconitum spp. from Sikkim Himalayas (India)

Aconitum spp. are important medicinal plants mentioned in Ayurveda as Ativisa or Vatsanabha. The present study aims to evaluate anti-rheumatic potential in seven Aconitum species and correlation with aconitine and hypaconitine content. Anti-rheumatic potential was analyzed through in vitro xanthine oxidase inhibition, anti-inflammatory and ROS scavenging assays; and quantification of aconitine and hypaconitine with RP-HPLC method validated as per ICH guidelines. The findings reveal that A. palmatum possessed the most promising response (IC50 =12.68±0.15 μg/ml) followed by A. ferox (IC50 =12.912±1.87 μg/ml) for xanthin oxidase inhibition. We observed a wide variation in aconitine and hypaconitine content ranging from 0.018 %-1.37 % and 0.0051 %-0.077 % respectively on dry weight basis. Aconitine and hypaconitine showed moderate positive correlation (r=0.68 and 0.59 respectively) with anti-rheumatic potential. The study identifies potential alternative species of Aconitum that can help in sustainable availability of quality raw material.

Therapeutic Potentials of Aconite-like Alkaloids: Bioinformatics and Experimental Approaches

Compounds from plants that are used in traditional medicine may have medicinal properties. It is well known that plants belonging to the genus Aconitum are highly poisonous. Utilizing substances derived from Aconitum sp. has been linked to negative effects. In addition to their toxicity, the natural substances derived from Aconitum species may have a range of biological effects on humans, such as analgesic, anti-inflammatory, and anti-cancer characteristics. Multiple in silico, in vitro, and in vivo studies have demonstrated the effectiveness of their therapeutic effects. In this review, the clinical effects of natural compounds extracted from Aconitum sp., focusing on aconitelike alkaloids, are investigated particularly by bioinformatics tools, such as the quantitative structure- activity relationship method, molecular docking, and predicted pharmacokinetic and pharmacodynamic profiles. The experimental and bioinformatics aspects of aconitine's pharmacogenomic profile are discussed. Our review could help shed light on the molecular mechanisms of Aconitum sp. compounds. The effects of several aconite-like alkaloids, such as aconitine, methyllycacintine, or hypaconitine, on specific molecular targets, including voltage-gated sodium channels, CAMK2A and CAMK2G during anesthesia, or BCL2, BCL-XP, and PARP-1 receptors during cancer therapy, are evaluated. According to the reviewed literature, aconite and aconite derivatives have a high affinity for the PARP-1 receptor. The toxicity estimations for aconitine indicate hepatotoxicity and hERG II inhibitor activity; however, this compound is not predicted to be AMES toxic or an hERG I inhibitor. The efficacy of aconitine and its derivatives in treating many illnesses has been proven experimentally. Toxicity occurs as a result of the high ingested dose; however, the usage of this drug in future research is based on the small quantity of an active compound that fulfills a therapeutic role.

Research progress of plant-derived natural alkaloids in central nervous system diseases

Central nervous system (CNS) disease is one of the most important causes of human death. Because of their complex pathogenesis, more and more attention has been paid to them. At present, drug treatment of the CNS is the main means; however, most drugs only relieve symptoms, and some have certain toxicity and side effects. Natural compounds derived from plants can provide safer and more effective alternatives. Alkaloids are common nitrogenous basic organic compounds found in nature, which exist widely in many kinds of plants and have unique application value in modern medicine. For example, Galantamine and Huperzine A from medicinal plants are widely used drugs on the market to treat Alzheimer's disease. Therefore, the main purpose of this review is to provide the available information on natural alkaloids with the activity of treating central nervous system diseases in order to explore the trends and perspectives for the further study of central nervous system drugs. In this paper, 120 alkaloids with the potential effect of treating central nervous system diseases are summarized from the aspects of sources, structure types, mechanism of action and structure-activity relationship.

Effects of aconitine on the respiratory activity of brainstem-spinal cord preparations isolated from newborn rats

Aconitine is a sodium channel opener, but its effects on the respiratory center are not well understood. We investigated the dose-dependent effects of aconitine on central respiratory activity in brainstem-spinal cord preparations isolated from newborn rats. Bath application of 0.5-5 μM aconitine caused an increase in respiratory rhythm and decrease in the inspiratory burst amplitude of the fourth cervical ventral root (C4). Separate application of aconitine revealed that medullary neurons were responsible for the respiratory rhythm increase, and neurons in both the medulla and spinal cord were involved in the decrease of C4 amplitude by aconitine. A local anesthetic, lidocaine (100 μM), or a voltage-dependent sodium channel blocker, tetrodotoxin (0.1 μM), partially antagonized the C4 amplitude decrease by aconitine. Tetrodotoxin treatment tentatively decreased the respiratory rhythm, but lidocaine tended to further increase the rhythm. Treatment with 100 μM riluzole or 100 μM flufenamic acid, which are known to inhibit respiratory pacemaker activity, did not reduce the respiratory rhythm enhanced by aconitine + lidocaine. The application of 1 μM aconitine depolarized the preinspiratory, expiratory, and inspiratory motor neurons. The facilitated burst rhythm of inspiratory neurons after aconitine disappeared in a low Ca2+/high Mg2+ synaptic blockade solution. We showed the dose-dependent effects of aconitine on respiratory activity. The antagonists reversed the depressive effects of aconitine in different manners, possibly due to their actions on different sites of sodium channels. The burst-generating pacemaker properties of neurons may not be involved in the generation of the facilitated rhythm after aconitine treatment.

Identification and quality evaluation of different processed products of Aconitum carmichaelii by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry and ultra-high-performance liquid chromatography-tandem mass spectrometry

Aconitum carmichaelii is widely used to treat chronic and intractable diseases due to its remarkable curative effect, but it is also a highly toxic herb with severe cardiac and neurotoxicity. It has been combined with honey for thousands of years to reduce toxicity and enhance efficacy, but there has been no study on the chemical constituent changes in the honey-processing so far. In this study, the chemical constituents of A. carmichaelii before and after honey-processing were characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. The results showed that a total of 118 compounds were identified, of which six compounds disappeared and five compounds were newly produced after honey-processing, and the cleavage pathway of main components was elucidated. At the same time, 25 compounds were found to have significant effects on different products, among which four compounds with the biggest difference were selected for quantitative analysis by ultra-high-performance liquid chromatography-tandem mass spectrometry. This study not only explained the chemical differences between the different products, but also helped to control the quality of the honey-processed products more effectively, and laid a foundation for further elucidating the mechanism of chemical constituent change during the honey-processing of A. carmichaelii.

Mechanism of aconitine mediated neuronal apoptosis induced by mitochondrial calcium overload caused by MCU

Aconitine is a crucial toxic component in Chinese herbal medicines such as Aconitum, Aconitum coreanum, and Aconitum soongaricum. The poisoning symptoms of the central nervous system and cardiovascular system caused by it are relatively common in China, and there are many studies on cardiovascular system diseases caused by aconitine. However, the specific mechanism of neurotoxicity induced by aconitine is still unclear. This study explored the effect and mechanism of mitochondrial calcium uniporter on mitochondrial energy metabolism disorder in aconitine poisoning hippocampal neurons. The results showed that after treatment with 400μmol/L aconitine, mitochondrial energy metabolism was abnormal in rat hippocampal neuron cells, the expression of MCU in mitochondria was up-regulated, calcium overload in mitochondria, ATP production decreased, and mitochondrial membrane potential Changes, increased expression of the apoptosis gene Cleaved-Caspase-3. After treatment with the MCU agonist spermine, mitochondrial energy metabolism was significantly abnormal, and cell apoptosis was increased considerably. However, pretreatment with calcium ion channel inhibitor Ruthenium Red (RR) effectively promoted the generation of ATP, thereby improving mitochondrial energy metabolism disorders and reducing cell apoptosis. These results suggest that aconitine induces mitochondrial energy metabolism dysfunction in hippocampal neurons, which may be related to the increased expression of MCU.

The known, unknown, and the intriguing about members of a critically endangered traditional medicinal plant genus Aconitum

Humanity will always be indebted to plants. In the ongoing scientific era, the 'Herbal Revolution' has helped discover several valuable medicinal plants and associated novel secondary metabolites from the diverse unexplored ecosystems, treating several diseases via phytotherapy. The Aconitum genus comprises several economically-important poisonous mountainous medicinal plant species whose unique biodiversity is on the verge of extinction due to illegal human intervention triggered habitat loss, over-harvesting, and unrestricted trading. Owing to its vast diversity of diterpene alkaloids, most species are extensively used to treat several ailments in rural parts of the world. Irrespective of this, many unexplored and intriguing prospects exist to understand and utilize this critical plant for human benefit. This systematic review tries to fill this gap by compiling information from the sporadically available literature known for ~300 Aconitum spp. regarding its nomenclature and classification, endangerment, plant morphology, ploidy, secondary metabolites, drug pharmacokinetics, conservation, and omics-based computational studies. We also depicted the disparity in the studied model organisms for this diverse genus. The absence of genomic/metagenomic data is becoming a limiting factor in understanding its plant physiology, metabolic pathways, and plant-microbes interactions, and therefore must be promoted. Additionally, government support and public participation are crucial in establishing conservation protocols to save this plant from endangerment.

A review on efforts for improvement in medicinally important chemical constituents inAconitum through biotechnological interventions

The genus Aconitum belongs to the family Ranunculaceae, is endowed with more than 350 species on the earth. Medicinally important aconitine type of diterpenoid alkaloids are the characteristic compounds in most of the Aconitum species. The present review endeavored the major research carried out in the field of genetic resource characterization, pharmacological properties, phytochemistry, major factors influencing quantity, biosynthetic pathways and processing methods for recovery of active ingredients, variety improvement, propagation methods, and important metabolite production through cell/organ culture of various Aconitum species. More than 450 derivatives of aconitine-type C19 and C20-diterpenoid alkaloids along with a few other non-alkaloidal compounds, such as phenylpropanoids, flavonoids, terpenoids, and fatty acids, have been identified in the genus. A few Aconitum species and their common diterpenoid alkaloid compounds are also well characterized for analgesic, inflammatory and cytotoxic properties. However, the different isolated compound needs to be validated for supporting other traditional therapeutical uses of the plant species. Aconitine alkaloids shared common biosynthesis pathway, but their diversification mechanism remains unexplored in the genus. Furthermore, the process needs to be developed on secondary metabolite recovery, mass-scale propagation methods, and agro-technologies for maintaining the quality of products. Many species are losing their existence in nature due to over-exploitation or anthropogenic factors; thus, temporal monitoring of the population status in its habitat, and suitable management programs for ascertaining conservation needs to be developed.

Synthesis, Pharmacological Evaluation, and Molecular Modeling of Lappaconitine-1,5-Benzodiazepine Hybrids

Diterpenoid alkaloids, originating from the amination of natural tetracyclic diterpenes, have long interested scientists due to their medicinal uses and infamous toxicity which has limited the clinical application of the native compound. Alkaloid lappaconitine extracted from various Aconitum and Delphinium species has displayed extensive bioactivities and active ongoing research to reduce its adverse effects. A convenient route to construct hybrid molecules containing diterpenoid alkaloid lappaconitine and 3H-1,5-benzodiazepine fragments was proposed. The key stage involved the formation of 5'-alkynone-lappaconitines in situ by acyl Sonogashira coupling of 5'-ethynyllappaconitine, followed by cyclocondensation with o-phenylenediamine. New hybrid compounds showed low toxicity and outstanding analgesic activity in experimental pain models, which depended on the nature of the substituent in the benzodiazepine nucleus. An analogous dependence was also shown for the antiarrhythmic activity in the epinephrine arrhythmia test in vivo. Studies on the isolated atrium have shown that the mechanism of action of the new compounds is included the blockade of beta-adrenergic receptors and potassium channels. Molecular docking analysis was conducted to determine the binding potential of target molecules with the voltage-gated sodium channel NaV1.5. All obtained results provide a basis for future rational modifications of lappaconitine, reducing side effects, while retaining its therapeutic effects.

Neuropharmacological Potential of Diterpenoid Alkaloids

This study provides a narrative review of diterpenoid alkaloids (DAs), a family of extremely important natural products found predominantly in some species of Aconitum and Delphinium (Ranunculaceae). DAs have long been a focus of research attention due to their numerous intricate structures and diverse biological activities, especially in the central nervous system (CNS). These alkaloids originate through the amination reaction of tetra or pentacyclic diterpenoids, which are classified into three categories and 46 types based on the number of carbon atoms in the backbone structure and structural differences. The main chemical characteristics of DAs are their heterocyclic systems containing β-aminoethanol, methylamine, or ethylamine functionality. Although the role of tertiary nitrogen in ring A and the polycyclic complex structure are of great importance in drug-receptor affinity, in silico studies have emphasized the role of certain sidechains in C13, C14, and C8. DAs showed antiepileptic effects in preclinical studies mostly through Na⁺ channels. Aconitine (1) and 3-acetyl aconitine (2) can desensitize Na⁺ channels after persistent activation. Lappaconitine (3), N-deacetyllapaconitine (4), 6-benzoylheteratisine (5), and 1-benzoylnapelline (6) deactivate these channels. Methyllycaconitine (16), mainly found in Delphinium species, possesses an extreme affinity for the binding sites of α7 nicotinic acetylcholine receptors (nAChR) and contributes to a wide range of neurologic functions and the release of neurotransmitters. Several DAs such as bulleyaconitine A (17), (3), and mesaconitine (8) from Aconitum species have a drastic analgesic effect. Among them, compound 17 has been used in China for decades. Their effect is explained by increasing the release of dynorphin A, activating the inhibitory noradrenergic neurons in the β-adrenergic system, and preventing the transmission of pain messages by inactivating the Na⁺ channels that have been stressed. Acetylcholinesterase inhibitory, neuroprotective, antidepressant, and anxiolytic activities are other CNS effects that have been investigated for certain DAs. However, despite various CNS effects, recent advances in developing new drugs from DAs were insignificant due to their neurotoxicity.

Chinese herbal medicine for the treatment of cardiovascular diseases ─ targeting cardiac ion channels

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality, imposing an increasing global health burden. Cardiac ion channels (voltage-gated Na_V, Ca_V, K_Vs, and others) synergistically shape the cardiac action potential (AP) and control the heartbeat. Dysfunction of these channels, due to genetic mutations, transcriptional or post-translational modifications, may disturb the AP and lead to arrhythmia, a major risk for CVD patients. Although there are five classes of anti-arrhythmic drugs available, they can have varying levels of efficacies and side effects on patients, possibly due to the complex pathogenesis of arrhythmias. As an alternative treatment option, Chinese herbal remedies have shown promise in regulating cardiac ion channels and providing anti-arrhythmic effects. In this review, we first discuss the role of cardiac ion channels in maintaining normal heart function and the pathogenesis of CVD, then summarize the classification of Chinese herbal compounds, and elaborate detailed mechanisms of their efficacy in regulating cardiac ion channels and in alleviating arrhythmia and CVD. We also address current limitations and opportunities for developing new anti-CVD drugs based on Chinese herbal medicines.

Detoxification mechanisms of ginseng to aconite: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Aconite (Fuzi, FZ), the processed root tuber of Aconitum carmichaelii Debx., is utilized as a classic medicine to treat diseases of the cardiovascular system and immune system. Resulting from the narrow margin of safety between a therapeutic dose and a toxic dose, FZ often causes cardiotoxicity including hypotension, palpitation, and bradycardia. Contributing to the detoxification effects of the other famous herbal medicine ginseng (Renshen, RS), which is the dried root and rhizome of Panax ginseng C. A. Meyer, people broadly combine FZ and RS as compatibility more than 1800 years to attenuate the toxicity of FZ. However, the systematic detoxification mechanisms of RS to FZ have not been fully revealed.

AIM OF THE REVIEW

Aiming to provide a comprehensive interpretation of the attenuation processes of FZ via RS, this review summarizes the up-to-date information about regulatory mechanisms of RS to FZ to shed the light on the essence of detoxification.

MATERIALS AND METHODS

Literature was searched in electronic databases, including PubMed, Web of Science ScienceDirect, Google Scholar, CNKI and WanFang Data. Relevant studies on detoxification mechanisms were included while irrelevant and duplicate studies were excluded. According to the study design, subject, intervention regime, outcome, first author and year of publication of included data, detoxification mechanisms of RS to FZ were summarized and visualized.

RESULTS

A total of 144 studies were identified through databases from their inception up to Oct. 2022. Included information indicated that diester-diterpenoid alkaloids (DDAs) were the main toxic substances of FZ. The main mechanisms that RS attenuates the toxicity of FZ were transforming toxic compounds of FZ, affecting the absorption and metabolism of FZ as well as the FZ-induced cell toxicity alleviation.

CONCLUSION

FZ, as a famous traditional Chinese medicine, has good prospects for utilization. The narrow margin of safety between a therapeutic dose and a toxic dose of FZ limits its clinical effect and safety while RS is always combined with FZ to alleviate its toxicity. However, mechanisms responsible for the detoxification process have not been well identified. Therefore, detoxification mechanisms of RS to FZ are reviewed to ensure the safety and effectiveness of FZ.

Neoline, fuziline, songorine and 10-OH mesaconitine are potential quality markers of Fuzi: In vitro and in vivo explorations as well as pharmacokinetics, efficacy and toxicity evaluations

ETHNOPHARMACOLOGICAL RELEVANCE

Fuzi, the lateral roots of Aconitum carmichaelii Debx, plays an irreplaceable role in treating Yang deficiency and cold coagulation syndromes. However, Fuzi has a narrow margin of safety since its pharmacological constituents, Aconitum alkaloids, have potential cardiotoxicity and neurotoxicity. The current quality markers (Q-markers) for the control of Fuzi's efficacy and toxicity are 3 monoester-diterpenoid alkaloids, namely, benzoylaconine (BAC), benzoylhypaconine and benzoylmesaconine (BMA) and 3 diester-diterpenoid alkaloids, namely, aconitine (AC), hypaconitine and mesaconitine (MA). However, mounting evidence indicates that the current 6 Q-markers may not be efficacy- or toxicity-specific enough for Fuzi.

AIM OF THE STUDY

The aim of this study was to explore and evaluate efficacy- or toxicity-specific potential quality markers (PQ-markers) of Fuzi.

MATERIALS AND METHODS

PQ-markers were explored by analyzing 30 medicinal samples and alkaloids exposed in mouse. Pharmacokinetics of PQ-markers on C57BL/6J mice were determined. Anti-inflammatory effects of PQ-markers were evaluated by λ-carrageenan-induced paw edema model and lipopolysaccharide-induced RAW264.7 cell inflammatory model, while analgesic effects were assessed by acetic acid-induced pain model and Hargreaves test. Cardiotoxicity and neurotoxicity of PQ-markers were assessed by histological and biochemical analyses, while acute toxicity was evaluated by modified Kirschner method.

RESULTS

After in vitro and in vivo explorations, 7 PQ-markers, namely, neoline (NE), fuziline (FE), songorine (SE), 10-OH mesaconitine (10-OH MA), talatizamine, isotalatizidine and 16β-OH cardiopetalline, were found. In the herbal medicines, NE, FE, SE and 10-OH MA were found in greater abundance than many other alkaloids. Specifically, the amounts of NE, FE and SE in the Fuzi samples were all far higher than that of BAC, and the contents of 10-OH MA in 56.67% of the samples were higher than that of AC. In mouse plasma and tissues, NE, FE, SE, talatizamine, isotalatizidine and 16β-OH cardiopetalline had higher contents than the other alkaloids, including the 6 current Q-markers. The pharmacokinetics, efficacy and toxicity of NE, FE, SE and 10-OH MA were further evaluated. The average oral bioavailabilities of NE (63.82%), FE (18.14%) and SE (49.51%) were higher than that of BMA (3.05%). Additionally, NE, FE and SE produced dose-dependent anti-inflammatory and analgesic effects, and their actions were greater than those of BMA. Concurrently, the toxicities of NE, FE and SE were lower than those of BMA, since no cardiotoxicity or neurotoxicity was found in mice after NE, FE and SE treatment, while BMA treatment notably increased the creatine kinase activity and matrix metalloproteinase 9 level in mice. The average oral bioavailability of 10-OH MA (7.02%) was higher than that of MA (1.88%). The median lethal dose (LD₅₀) of 10-OH MA in mice (0.11 mg/kg) after intravenous injection was close to that of MA (0.13 mg/kg). Moreover, 10-OH MA produced significant cardiotoxicity and neurotoxicity, and notable anti-inflammatory and analgesic effects that were comparable to those of MA.

CONCLUSIONS

Seven PQ-markers of Fuzi were found after in vitro and in vivo explorations. Among them, NE, FE and SE were found to be more efficacy-specific than BMA, and 10-OH MA was as toxicity-specific as MA.

Total Synthesis of Puberuline C

Puberuline C (1) is an architecturally complex C₁₉-diterpenoid alkaloid with a unique ring fusion pattern. The 6/7/5/6/6/6-membered rings (ABCDEF-rings) contain one tertiary amine and six oxygen functionalities, and possess 12 contiguously aligned stereocenters, three of which are quaternary. These structural features of 1 make its chemical construction exceptionally challenging. Here, we disclose the first total synthesis of 1. The synthesis was accomplished from 2-cyclohexenone (9) by integrating radical cascade and Mukaiyama aldol reactions as the key transformations. A double Mannich reaction fused the A- and E-rings, and Sonogashira coupling attached the C-ring, efficiently leading to ACE-rings with the requisite 19 carbons of 1. The chemically stable tertiary chloride of the ACE-ring structure was then transformed to the corresponding bridgehead radical, which participated in the simultaneous cyclization of the B- and F-rings via a highly organized radical cascade process. This unusual step installed five contiguous stereocenters, including two quaternary carbons, without damaging the preexisting multiple polar functionalities. Subsequently, the intramolecular Mukaiyama aldol reaction between silyl enol ether and acetal was realized by applying a combination of SnCl₄ and ZnCl₂, forging the last remaining D-ring of the hexacycle. Finally, 3 was elaborated into 1 through regio- and stereoselective functionalizations of the BCD-rings. Our novel radical-based strategy achieved the total synthesis of 1 in 32 total steps from simple 9, demonstrating the power of the radical cascade reaction to streamline the assembly of highly complex molecules.

Poisonous Piperidine Plants and the Biodiversity of Norditerpenoid Alkaloids for Leads in Drug Discovery: Experimental Aspects

There are famous examples of simple (e.g., hemlock, Conium maculatum L.) and complex (e.g., opium poppy, Papaver somniferum L., Papaveraceae) piperidine-alkaloid-containing plants. Many of these are highly poisonous, whilst pepper is well-known gastronomically, and several substituted piperidine alkaloids are therapeutically beneficial as a function of dose and mode of action. This review covers the taxonomy of the genera Aconitum, Delphinium, and the controversial Consolida. As part of studying the biodiversity of norditerpenoid alkaloids (NDAS), the majority of which possess an N-ethyl group, we also quantified the fragment occurrence count in the SciFinder database for NDA skeletons. The wide range of NDA biodiversity is also captured in a review of over 100 recently reported isolated alkaloids. Ring A substitution at position 1 is important to determine the NDA skeleton conformation. In this overview of naturally occurring highly oxygenated NDAs from traditional Aconitum and Delphinium plants, consideration is given to functional effect and to real functional evidence. Their high potential biological activity makes them useful candidate molecules for further investigation as lead compounds in the development of selective drugs.

A Metabolomic Study of the Analgesic Effect of Lappaconitine Hydrobromide (LAH) on Inflammatory Pain

Lappaconitine (LA) is a C-18 diterpene alkaloid isolated from Aconitum sinomontanum Nakai that has been shown to relieve mild to moderate discomfort. Various researchers have tried to explain the underlying mechanism of LA's effects on chronic pain. This article uses metabolomics technology to investigate the metabolite alterations in the dorsal root ganglion (DRG) when lappaconitine hydrobromide (LAH) was injected in an inflammatory pain model, to explain the molecular mechanism of its analgesia from a metabolomics perspective. The pain model used in this study was a complete Freund's adjuvant (CFA)-induced inflammatory pain model in rats. There were two treatment groups receiving different dosages of LAH (4 mg/kg LAH and 8 mg/kg LAH). The analgesic mechanism of LAH was investigated with an analgesic behavioral test, tissue sections, and metabolomics. The results of the analgesic behavioral experiment showed that both 4 mg/kg LAH and 8 mg/kg LAH could significantly improve the paw withdrawal latency (PWL) of rats. The tissue section results showed that LAH could reduce the inflammatory response and enlargement of the paw and ankle of rats and that there was no significant difference in the tissue sections of the DRG. The metabolomics results showed that retinol metabolism and glycerophospholipid metabolism in the CFA-induced inflammatory pain model were significantly affected and may exacerbate the inflammatory reactions and initiate persistent pain; in addition, the linoleic acid metabolism, arachidonic acid metabolism, and alanine, aspartate, and glutamate metabolism were also slightly affected. Among them, the alpha-linolenic acid metabolism was up-regulated after LAH treatment, while the retinol metabolism was down-regulated. These results suggest that LAH could effectively reduce inflammatory pain and might achieve this by regulating the lipid metabolism in the rat DRG.

Design, synthesis, and biological evaluation of low-toxic lappaconitine derivatives as potential analgesics

The C₁₈-diterpenoid alkaloid lappaconitine (LA) is a non-addictive analgesic used in China. The toxicity (LD₅₀ = 11.7 mg/kg) limits its application. Two series of LA derivatives, including amides and sulfonamides (1-93), were designed and synthesized by modification on their C4 acetamidobenzoate side chains in this work. In vivo analgesic activity and toxicity of all derivatives were evaluated, and the structure-activity relationship was summarized. Six lead compounds (35, 36, 39, 49, 70, and 89) exhibited approximate analgesic activity to LA but with significantly reduced toxicity. The therapeutic index of these compounds is 14-30 times that of LA. In vivo metabolism study of the lead compounds 39, 49, 70, and 89 were conducted by UPLC-MS^E, indicating the reason for the low toxicity of the potential derivatives might be they are difficult to metabolize to toxic metabolite N-deacetyllappaconitine compared to LA. The effects of lead compounds on sodium channels and hERG channels were also studied by ion channel reader (ICR) which further revealed their analgesic and toxicity-attenuating mechanisms. Sodium channel assay revealed that the analgesic mechanism of these lead compounds was inhibiting the Na_v 1.7 channels. Taken together, compound 39 was provided as a new analgesic lead compound with significantly low toxicity and comparable activity to LA.

Emerging Promise of Phytochemicals in Ameliorating Neurological Disorders

BACKGROUND

The field of medicine and synthetic drug development have advanced rapidly over the past few decades. However, research on alternative medicine such as phytochemicals cannot be ignored. The main reason for prominent curiosity about phytochemicals stems from the belief that usage of natural compounds is safer and has lesser detrimental side effects.

OBJECTIVE

The aim of the present review was to discuss in detail with several phytochemicals that have been studied or are being studied in the context of various neurological disorders including depression, Alzheimer's disease, Huntington's disease and even neuroinflammatory disorders such as encephalitis.

METHODS

The potential role of phytochemicals in the treatment or management of symptoms associated with neurological disorders have been included in this article. All data included in this paper has been pooled from various databases including Google Scholar, PubMed, Science Direct, Springer and Wiley Online Library.

RESULTS

Phytochemicals have been widely studied for their therapeutic properties associated with neurological disorders. Using various experimental techniques for both in vivo and in vitro experiments, studies have shown that phytochemicals do have antioxidant, anti-inflammatory and neuroprotective activities which play major roles in the treatment of neurological diseases.

CONCLUSION

Even though there has been compelling evidence of the therapeutic role of phytochemicals, further research is still required to evaluate the safety and efficacy of these medicines. Using previously published papers as foundation for additional research such as preclinical studies and clinical trials, phytochemicals can become a safer alternative to synthetic drugs for treating a spectrum of neurological diseases.

Poisonous Plants of the Indian Himalaya: An Overview

Indian Himalayan region (IHR) supports a wide diversity of plants and most of them are known for their medicinal value. Humankind has been using medicinal plants since the inception of civilization. Various types of bioactive compounds are found in plants, which are directly and indirectly beneficial for plants as well as humans. These bioactive compounds are highly useful and being used as a strong source of medicines, pharmaceuticals, agrochemicals, food additives, fragrances, and flavoring agents. Apart from this, several plant species contain some toxic compounds that affect the health of many forms of life as well as cause their death. These plants are known as poisonous plants, because of their toxicity to both humans and animals. Therefore, it is necessary to know in what quantity they should be taken so that it does not have a negative impact on health. Recent studies on poisonous plants have raised awareness among people who are at risk of plant toxicity in different parts of the world. The main aim of this review article is to explore the current knowledge about the poisonous plants of the Indian Himalayas along with the importance of these poisonous plants to treat different ailments. The findings of the present review will be helpful to different pharmaceutical industries, the scientific community and researchers around the world.

Analgesic Alkaloids Derived From Traditional Chinese Medicine in Pain Management

Chronic pain is one of the most prevalent health problems. The establishment of chronic pain is complex. Current medication for chronic pain mainly dependent on anticonvulsants, tricyclic antidepressants and opioidergic drugs. However, they have limited therapeutic efficacy, and some even with severe side effects. We turned our interest into alkaloids separated from traditional Chinese medicine (TCM), that usually act on multiple drug targets. In this article, we introduced the best-studied analgesic alkaloids derived from TCM, including tetrahydropalmatine, aloperine, oxysophocarpine, matrine, sinomenine, ligustrazine, evodiamine, brucine, tetrandrine, Stopholidine, and lappaconitine, focusing on their mechanisms and potential clinical applications. To better describe the mechanism of these alkaloids, we adopted the concept of drug-cloud (dCloud) theory. dCloud illustrated the full therapeutic spectrum of multitarget analgesics with two dimensions, which are “direct efficacy”, including inhibition of ion channels, activating γ-Aminobutyric Acid/opioid receptors, to suppress pain signal directly; and “background efficacy”, including reducing neuronal inflammation/oxidative stress, inhibition of glial cell activation, restoring the balance between excitatory and inhibitory neurotransmission, to cure the root causes of chronic pain. Empirical evidence showed drug combination is beneficial to 30–50% chronic pain patients. To promote the discovery of effective analgesic combinations, we introduced an ancient Chinese therapeutic regimen that combines herbal drugs with “Jun”, “Chen”, “Zuo”, and “Shi” properties. In dCloud, “Jun” drug acts directly on the major symptom of the disease; “Chen” drug generates major background effects; “Zuo” drug has salutary and supportive functions; and “Shi” drug facilitates drug delivery to the targeted tissue. Subsequently, using this concept, we interpreted the therapeutic effect of established analgesic compositions containing TCM derived analgesic alkaloids, which may contribute to the establishment of an alternative drug discovery model.

Anti-rheumatic, and analgesic effects by the parent tuberous roots of Aconitum jaluense in adjuvant induced arthritis rats

AIM OF THE STUDY

The aim of this study was to test the anti-rheumatic effects of A. jaluense tubers in acute and chronic arthritis rats, and to assign its ingredients through UHPLC-TOF/MS.

MATERIALS AND METHODS

Subcutaneous injection of carrageenan for acute arthritis and complete Freund's adjuvant (CFA) for chronic arthritis was carried out in the hind paw of SD rats. The paw volume was measured by a plethysmometer thermal hyperalgesia was tested using a thermal plantar tester, and mechanical hyperalgesia was evaluated by ankle flexion evoked vocalizations. The expression of c-Fos in the brain hippocampus was measured with the avidin-biotin-peroxidase technique. The ingredients were assigned by UHPLC-TOF/MS, chromatography was performed by UHPLC system with DAD detector and BEH C₁₈ column, and spectroscopy was conducted by ESI-MS system.

RESULTS AND DISCUSSION

The 80% ethanoic extract of A. jaluense tubers showed an acute anti-inflammatory effect by suppressing the edema volume in the hind paw of carrageenan-stimulated rats. In addition, A. jaluense tubers exerted an anti-rheumatic activity by reducing the secondary swelling volume from an immunological reaction in the left hind paw of CFA-induced chronic arthritis rats. Additionally, oral treatment with the 80% ethanoic extract -showed potent analgesic effects in the arthritis rats by recovering the paw withdrawal latency stimulated by the thermal hyperalgesia and by reducing the vocalization scores evoked by ankle flexion on both hind paws. Moreover, its treatment also indicated an anti-psychiatric effect by controlling the c-Fos protein expression of the brain hippocampus in CFA-stimulated arthritis rats. These results suggested that these therapeutic effects were exhibited by less toxic mono-esterified diterpenoid alkaloids (MDAs), and nontoxic non-esterified diterpenoid alkaloids (NDAs).

CONCLUSION

A. jaluense tubers may act as viable therapeutic or preventive candidates for acute and chronic arthritis, particularly, for immune-inflammatory rheumatoid arthritis to suppress the pain and psychiatric condition.

Gallic Acid Inhibits Mesaconitine-Activated TRPV1-Channel-Induced Cardiotoxicity

Aconiti Kusnezoffii Radix (Caowu) is often combined or processed with Chebulae Fructus (Hezi) to achieve attenuation purposes in Mongolian medicine. Mesaconitine (MA), a main bioactive ingredient of Caowu, is also famous for its high cardiotoxicity while exerting good anti-inflammatory and analgesic properties. Gallic acid (GA), one of the leading chemical components in Hezi, possesses cardiac protection. This study aimed to clarify the detoxification effects of GA from Hezi on MA-induced cardiotoxicity and whether the detoxification mechanism is related to the TRPV1 channel. Cell viability was determined by methyl thiazol tetrazolium (MTT), and lactate dehydrogenase (LDH) leakage rate was determined by ELISA. Hoechst 33258, JC-1, DCFH-DA, and Fluo-3 AM staining were conducted to detect apoptosis, mitochondrial membrane potential, reactive oxygen species (ROS), and Ca2+ respectively; TRPV1 channel current was recorded by whole-cell patch-clamp technology to observe the effect of GA and MA alone or in combination on TRPV1 channel. The results showed that GA exhibited pronounced detoxification effects on MA-induced cardiotoxicity. GA significantly inhibited the MA-induced decrease in cell viability; suppressed the MA-induced LDH leakage rate, apoptosis, and the release of ROS and Ca2+; and alleviated the reduction of mitochondrial membrane potential. We found that MA-induced cardiotoxicity was significantly attenuated in H9c2 cells pretreated with the TRPV1 antagonist BCTC. In the whole-cell patch-clamp experiment, the TRPV1 channel current increase was caused by the GA and MA treatment, whereas it was reduced by the cotreatment of GA and MA. Our data demonstrate that GA in Hezi can reduce MA-induced cardiotoxicity by inhibiting intracellular Ca2+ influx, restoring mitochondrial membrane potential, and reducing apoptosis. The detoxification mechanism may be related to the desensitization of the TRPV1 channel by the combined application of MA and GA.

Attenuation and Structural Transformation of Crassicauline A During Sand Frying Process and Antiarrhythmic Effects of its Transformed Products

To ensure safety and efficacy, most Aconitum herbs should be processed before clinical application. The processing methods include boiling, steaming, and sand frying. Among these methods, the transformation pathways of diterpenoid alkaloids in the process of sand frying are more complicated. Therefore, crassicauline A, a natural product with two ester bonds, was chosen as the experimental object. Consequently, a known alkaloid, together with three new alkaloids, was derived from crassicauline A. Meanwhile, the cardiotoxicity of converted products was reduced compared with their parent compound. Interestingly, some diterpenoid alkaloids have similar structures but opposite effects, such as arrhythmia and antiarrhythmic. Considering the converted products are structural analogues of crassicauline A, herein, the antiarrhythmic activity of the transformed products was further investigated. In a rat aconitine-induced arrhythmia assay, the three transformed products, which could dose-dependently delay the ventricular premature beat (VPB) incubation period, reduce the incidence of ventricular tachycardia (VT), combined with the increasing arrhythmia inhibition rate, exhibited prominent antiarrhythmic activities. Our experiments speculated that there might be at least two transformation pathways of crassicauline A during sand frying. The structure-activity data established in this paper constructs the critical pharmacophore of diterpenoid alkaloids as antiarrhythmic agents, which could be helpful in searching for the potential drugs that are equal or more active and with lower toxicity, than currently clinical used antiarrhythmic drugs.

Norditerpenoid alkaloids from Aconitum and Delphinium: structural relevance in medicine, toxicology, and metabolism

Covering: 77 A.D. up to 2020Norditerpenoid alkaloids (NDA), typically N-ethylpiperidine containing C19 or C18 natural product diterpenes, are hexacycles with several contiguous often oxygenated stereocentres. As a function of their structural complexity, they display important pharmacological activities. The processed plants are used as important folk drugs and four NDAs have now been clinically approved. Many metabolism studies on Aconitum alkaloids have been reported as the understanding of their biotransformation in living systems and in cell-free systems is important for the development of these alkaloids as drugs. This Highlight sets out the missing links in NDA biosynthesis, their biological applications, SAR, toxicity, metabolism, and analytical studies.

Quantitative Electrophysiological Evaluation of the Analgesic Efficacy of Two Lappaconitine Derivatives: A Window into Antinociceptive Drug Mechanisms

Quantitative evaluation of analgesic efficacy improves understanding of the antinociceptive mechanisms of new analgesics and provides important guidance for their development. Lappaconitine (LA), a potent analgesic drug extracted from the root of natural Aconitum species, has been clinically used for years because of its effective analgesic and non-addictive properties. However, being limited to ethological experiments, previous studies have mainly investigated the analgesic effect of LA at the behavioral level, and the associated antinociceptive mechanisms are still unclear. In this study, electrocorticogram (ECoG) technology was used to investigate the analgesic effects of two homologous derivatives of LA, Lappaconitine hydrobromide (LAH) and Lappaconitine trifluoroacetate (LAF), on Sprague-Dawley rats subjected to nociceptive laser stimuli, and to further explore their antinociceptive mechanisms. We found that both LAH and LAF were effective in reducing pain, as manifested in the remarkable reduction of nocifensive behaviors and laser-evoked potentials (LEPs) amplitudes (N2 and P2 waves, and gamma-band oscillations), and significantly prolonged latencies of the LEP-N2/P2. These changes in LEPs reflect the similar antinociceptive mechanism of LAF and LAH, i.e., inhibition of the fast signaling pathways. In addition, there were no changes in the auditory-evoked potential (AEP-N1 component) before and after LAF or LAH treatment, suggesting that neither drug had a central anesthetic effect. Importantly, compared with LAH, LAF was superior in its effects on the magnitudes of gamma-band oscillations and the resting-state spectra, which may be associated with their differences in the octanol/water partition coefficient, degree of dissociation, toxicity, and glycine receptor regulation. Altogether, jointly applying nociceptive laser stimuli and ECoG recordings in rats, we provide solid neural evidence for the analgesic efficacy and antinociceptive mechanisms of derivatives of LA.

Wenxin Keli for the Treatment of Arrhythmia-Systems Pharmacology and In Vivo Pharmacological Assessment

This study employed a systems pharmacology approach to identify the active compounds and action mechanisms of Wenxin Keli for arrhythmia treatment. Sixty-eight components identified in vivo and in vitro by UPLC/Q-TOF-MS were considered the potential active components of Wenxin Keli. Network pharmacology further revealed 33 key targets and 75 KEGG pathways as possible pathways and targets involved in WK-mediated treatment, with the CaMKII/CNCA1C/Ca²⁺ pathway being the most significantly affected. This finding was validated using an AC-induced rat arrhythmias model. Pretreatment with Wenxin Keli reduced the malignant arrhythmias and shortened RR, PR, and the QT interval. Wenxin Keli exerted some antiarrhythmic effects by inhibiting p-CaMKII and intracellular Ca²⁺ transients and overexpressing CNCA1C. Thus, suppressing SR Ca²⁺ release and maintaining intracellular Ca²⁺ balance may be the primary mechanism of Wenxin Keli against arrhythmia. In view of the significance of CaMKII and NCX identified in this experiment, we suggest that CaMKII and NCX are essential targets for treating arrhythmias.

Structural diversity, bioactivities, and biosynthesis of natural diterpenoid alkaloids

Covering: 2009 to 2018. Diterpenoid alkaloids, originating from the amination of natural tetracyclic diterpenes, are a diverse class of compounds having complex structural features with many stereocenters. The important pharmacological activities and structural complexity of the diterpenoid alkaloids have long interested scientists due to their medicinal uses, infamous toxicity, and unique biosynthesis. Since 2009, 373 diterpenoid alkaloids, assigned to 46 skeletons, have been isolated and identified from plants mostly in the Ranunculaceae family. The names, classes, molecular weight, molecular formula, NMR data, and plant sources of these diterpene alkaloids are collated here. This review will be a detailed update of the naturally occurring diterpene alkaloids reported from the plant kingdom from 2009-2018, providing an in-depth discussion of their diversity, biological activities, pharmacokinetics, toxicity, application, evolution, and biosynthesis.

The toxicology and detoxification of Aconitum: traditional and modern views

Aconitum carmichaeli Debx.-derived herbal medicine has been used for anti-inflammation and anti-arrhythmia purpose for more than two thousand years. It is processed into Chuanwu (Radix Aconiti praeparata) and Fuzi (Radix Aconiti lateralis praeparata) in Traditional Chinese Medicine, which are two useful drugs but with toxic properties. There have been patients poisoned by accidental ingestion of Aconitum plants or misuse of the herbal drug, and this is of great concern to study in-depth. In this review, we provided the traditional and contemporary practice of using Aconitum herbs as medicine, from functions, processing methods to toxicity in ethnomedicine aspects to discuss the underlying connections of traditional and modern understanding on the toxicity of Aconitum plants. We summarized the functions and toxicology of the herbal drugs are analyzed from chemical and clinical aspects, with the help of traditional and modern knowledge of medicine. The medicinal doses and lethal doses determined by researches are summarized, and the usage and processing methods are updated and reviewed in the modern view. In addition, clinical management of poisoned cases using western medicine is discussed. This review provides insights and awareness of safety when using Aconitum-derived herbal medicine, and the application of modern scientific knowledge to optimize the detoxification processes. We suggest the possibility to renew the current standard processing method from the official Pharmacopoeia all over the world.

Classification, Toxicity and Bioactivity of Natural Diterpenoid Alkaloids

Diterpenoid alkaloids are natural compounds having complex structural features with many stereo-centres originating from the amination of natural tetracyclic diterpenes and produced primarily from plants in the Aconitum, Delphinium, Consolida genera. Corals, Xenia, Okinawan/Clavularia, Alcyonacea (soft corals) and marine sponges are rich sources of diterpenoids, despite the difficulty to access them and the lack of availability. Researchers have long been concerned with the potential beneficial or harmful effects of diterpenoid alkaloids due to their structural complexity, which accounts for their use as pharmaceuticals as well as their lousy reputation as toxic substances. Compounds belonging to this unique and fascinating family of natural products exhibit a broad spectrum of biological activities. Some of these compounds are on the list of clinical drugs, while others act as incredibly potent neurotoxins. Despite numerous attempts to prepare synthetic products, this review only introduces the natural diterpenoid alkaloids, describing 'compounds' structures and classifications and their toxicity and bioactivity. The purpose of the review is to highlight some existing relationships between the presence of substituents in the structure of such molecules and their recognised bioactivity.

How Aconiti Radix Cocta can Treat Gouty Arthritis Based on Systematic Pharmacology and UPLC-QTOF-MS/MS

Background: Gouty arthritis (GA) is a common metabolic disease caused by a long-term disorder of purine metabolism and increased serum levels of uric acid. The processed product of dried root of Aconitum carmichaeli Debeaux (Aconiti Radix cocta, ARC) is used often in traditional Chinese medicine (TCM) to treat GA, but its specific active components and mechanism of action are not clear.

Methods: First, we used ultra-performance liquid chromatography-quadrupole/time-of-flight tandem mass spectrometry to identify the chemical spectrum of ARC. Based on this result, we explored the active components of ARC in GA treatment and their potential targets and pathways. Simultaneously, we used computer simulations, in vitro cell experiments and animal experiments to verify the prediction results of systems pharmacology. In vitro, we used aurantiamide acetate (AA) to treat monosodium urate (MSU)-stimulated THP-1 cells and demonstrated the reliability of the prediction by western blotting and real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR). ELISAs kit were used to measure changes in levels of proinflammatory factors in rats with GA induced by MSU to demonstrate the efficacy of ARC in GA treatment.

Results: Forty-three chemical constituents in ARC were identified. ARC could regulate 65 targets through 29 active components, and then treat GA, which involved 1427 Gene Ontology (GO) terms and 146 signaling pathways. Signaling pathways such as proteoglycans in cancer, C-type lectin receptor signaling pathway, and TNF signaling pathway may have an important role in GA treatment with ARC. In silico results showed that the active components songoramine and ignavine had high binding to mitogen-activated protein kinase p38 alpha (MAPK14) and matrix metallopeptidase (MMP)9, indicating that ARC treatment of GA was through multiple components and multiple targets. In vitro experiments showed that AA in ARC could effectively reduce expression of MAPK14, MMP9, and cyclooxygenase2 (PTGS2) in THP-1 cells stimulated by MSU, whereas it could significantly inhibit the mRNA expression of Caspase-1, spleen tyrosine kinase (SYK), and PTGS2. Animal experiments showed that a ARC aqueous extract could significantly reduce expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and intereleukin (IL)-18 in the serum of GA rats stimulated by MSU. Hence, ARC may inhibit inflammation by regulating the proteoglycans in cancer-associated signaling pathways.

Conclusion: ARC treatment of GA may have the following mechanisms, ARC can reduce MSU crystal-induced joint swelling, reduce synovial tissue damage, and reduce the expression of inflammatory factors in serum. AA in ARC may inhibit inflammation by regulating the protein expression of MAPK14, MMP9, and PTGS2 and the mRNA expression of caspase-1, SYK, and PTGS2.

An Effective Phytoconstituent Aconitine: A Realistic Approach for the Treatment of Trigeminal Neuralgia

Trigeminal neuralgia pain remains a challenge to treat. Natural compounds may be promising options for relieving pain. This study was aimed at investigating the effects of aconitine in a rat model of trigeminal neuralgia pain. Infraorbital nerve chronic constriction injury was performed in adult Wistar Albino rats. After the neuropathic pain developed, the rats were assigned to one of the treatment groups: carbamazepine 40 or 80 mg/kg; aconitine 0.25, 0.50, or 0.75 mg/kg; or saline injection (control group). Behavioral testing with von Frey filaments and the rotarod test were carried out before the surgical procedure and on the 24th to 29th postoperative days. Following the completion of tests, ipsilateral and contralateral spinal cords were harvested for Western blot analyses to assess NR-1 protein expression. ANOVA followed by Mann-Whitney U test was performed for the statistical analyses. P values of <0.05 were considered significant. Aconitine significantly reduced mechanical sensitivity in a dose-dependent manner. A significant reduction in motor coordination was noted for the higher doses of aconitine which was similar with the 40 and 80 mg/kg doses of carbamazepine. NR-1 expression was reduced in the ipsilateral spinal cord, whereas no significant difference was noted between the groups in the expression of NR-1 in the contralateral spinal cord. Aconitine had a significant pain relieving effect, which was similar to carbamazepine, in a dose-dependent manner. Aconitine may be an alternative pharmacological agent for the control of trigeminal neuralgia pain.

Biologically Significant and Recently Isolated Alkaloids from Endophytic Fungi

A selection of the established and recently characterized alkaloids from the exploration of plant- and some marine-associated endophytic fungi is reviewed, with reference to alkaloids of biological significance.

Effects of processed Aconiti tuber on the extinction and reinstatement of morphine-induced conditioned place preference in rats

AIM OF THE STUDY

To investigate the effect of processed Aconiti tuber (PAT) administered during or after the time of conditioned place preference (CPP) training on the extinction and reinstatement of morphine-priming CPP in rats. The dynorphin level in rats' nucleus accumbens (NAc) is detected as a target of the Dynorphin/Kappa Opioid Receptor (KOR) system for the possible mechanism.

MATERIALS AND METHODS

Eight groups of rats were subcutaneously (s.c.) injected with morphine (10mg/kg) (on days 2,4,6,8) or saline (1ml/kg) (on days 3,5,7,9) alternately for 8 days. Five groups, including groups (Mor + Water, Mor + PAT (1.0/3.0g/kg) (S) and Sal + PAT(1.0/3.0g/kg)), were orally given distilled water or PAT 1.0 or 3.0 g/kg daily on days 1-8 during CPP training while other three groups, including groups (Sal + Water and Mor + PAT (1.0/3.0g/kg)(P), were given distilled water or PAT daily from day 10 until CPP was extinct. Morphine 1mg/kg (s.c.) was used to reinstate the extinct CPP and the CPP scores were recorded. The dynorphin concentration in nucleus accumbens (NAc) was assayed by radioimmunoassay after the last CPP measurement.

RESULTS

1) The CPP extinction shortened in Mor + PAT (1.0/3.0 g/kg) (S) groups but extended in Mor + PAT (1.0/3.0 g/kg)(P) groups. 2) Morphine-priming CPP did not change either in Mor + PAT (1.0/3.0 g/kg) (S) or Mor + PAT (1.0/3.0 g/kg)(P) groups. 3) The dynorphin concentration in NAc increased either in Mor + PAT (1.0/3.0 g/kg)(S) or Mor + PAT (1.0/3.0 g/kg)(P) groups.

CONCLUSIONS

1) PAT shortened the extinction from morphine induced CPP when administrated before CPP acquisition, whereas it extended the extinction when administrated after CPP formation. 2) PAT administrated during or after CPP training did not affect morphine-priming reinstatement of morphine induced CPP. 3) Dynorphin/KOR system might be a target to regulate morphine-induced CPP extinction but not reinstatement.

Mechanical allodynia triggered by cold exposure in mice with the Scn11a p.R222S mutation: a novel model of drug therapy for neuropathic pain related to NaV1.9

Mutations within the SCN11A gene which encodes the voltage-gated sodium channel NaV1.9 mainly expressed in small fiber sensory neurons have been associated with neuropathic disorders; however, suitable medications have not been fully investigated. To develop drug therapies against NaV1.9-related neuropathic pain, we aimed to establish a novel model using mice carrying the Scn11a p.R222S mutation initially identified in patients with familial episodic limb pain that is characterized by paroxysmal pain induced by fatigue or bad weather conditions. We investigated the influence of cold exposure (4 °C, overnight) on the behavioral and biochemical phenotypes of Scn11a p.R222S mutant (R222S) and wild type C57BL/6N (WT) mice. We also tested the effects of acetaminophen (125, 250 mg/kg, perorally, p.o.) and traditional Japanese medicine, goshajinkigan (0.5 or 1.0 g/kg, p.o.), which are analgesic drugs prescribed to patients with neuropathic pain, in this model of cold-induced mechanical allodynia in R222S mice.Cold-exposed R222S mice exhibited enhanced mechanical allodynia and thermal hypersensitivity compared with WT mice. The decrease of the mechanical withdrawal threshold in R222S mice was reversible 24 h after housing at room temperature. There was no significant change in the levels of interleukin-1β, interleukin-6, tumor necrosis factor-α, or interferon-γ in the plasma or spinal cords of WT and R222S mice after cold exposure. Both acetaminophen (250 mg/kg) and goshajinkigan (1.0 g/kg) significantly attenuated mechanical allodynia in R222S mice. The model of cold-induced mechanical allodynia in mice with the Scn11a p.R222S mutation is novel and useful for evaluating analgesic drugs for intractable neuropathies related to NaV1.9.

Cardiac efficacy and toxicity of aconitine: A new frontier for the ancient poison

Aconitine (AC) is well-known as the main toxic ingredient and active compound of Aconitum species, of which several aconites are essential herbal medicines of Traditional Chinese Medicine (TCM) and widely applied to treat diverse diseases for their excellent anti-inflammatory, analgesic, and cardiotonic effects. However, the cardiotoxicity and neurotoxicity of AC attracted a lot of attention and made it a favorite botanic poison in history. Nowadays, the narrow therapeutic window of AC limits the clinical application of AC-containing herbal medicines; overdosing on AC always induces ventricular tachyarrhythmia and heart arrest, both of which are potentially lethal. But the underlying cardiotoxic mechanisms remained chaos. Recently, beyond its cardiotoxic effects, emerging evidence shows that low doses of AC or its metabolites could generate cardioprotective effects and are necessary to aconite's clinical efficacy. Consistent with TCM's theory that even toxic substances are powerful medicines, AC thus could not be simply identified as a toxicant or a drug. To prevent cardiotoxicity while digging the unique value of AC in cardiac pharmacology, there exists a huge urge to better know the characteristic of AC being a cardiotoxic agent or a potential heart drug. Here, this article reviews the advances of AC metabolism and focuses on the latest mechanistic findings of cardiac efficacy and toxicity of this aconite alkaloid or its metabolites. We also discuss how to prevent AC-related cardiotoxicity, as well as the issues before the development of AC-based medicines that should be solved, to provide new insight into the paradoxical nature of this ancient poison.

Use of medicinal plants for headache, and their potential implication in medication-overuse headache: Evidence from a population-based study in Nepal

Background

In Nepal, traditional treatment using medicinal plants is popular. Whereas medication-overuse headache is, by definition, caused by excessive use of acute headache medication, we hypothesized that medicinal plants, being pharmacologically active, were as likely a cause.

Methods

We used data from a cross-sectional, nationwide population-based study, which enquired into headache and use of medicinal plants and allopathic medications. We searched the literature for pharmacodynamic actions of the medicinal plants.

Results

Of 2100 participants, 1794 (85.4%) reported headache in the preceding year; 161 (7.7%) reported headache on ≥15 days/month, of whom 28 (17.4%) had used medicinal plants and 117 (72.7%) allopathic medication(s). Of 46 with probable medication-overuse headache, 87.0% (40/46) were using allopathic medication(s) and 13.0% (6/46) medicinal plants, a ratio of 6.7:1, higher than the overall ratio among those with headache of 4.9:1 (912/185). Of 60 plant species identified, 49 were pharmacodynamically active on the central nervous system, with various effects of likely relevance in medication-overuse headache causation.

Conclusions

MPs are potentially a cause of medication-overuse headache, and not to be seen as innocent in this regard. Numbers presumptively affected in Nepal are low but not negligible. This pioneering project provides a starting point for further research to provide needed guidance on use of medicinal plants for headache.

Role of the Phytochemical Compounds like Modulators in Gut Microbiota and Oxidative Stress

BACKGROUND

Currently, daily consumption of green herb functional food or medicinal herbs has increased as adopted by many people worldwide as a way of life or even as an alternative to the use of synthetic medicines. Phytochemicals, which are a series of compounds of relatively complex structures and restricted distribution in plants, usually perform the defensive functions for plants against insects, bacteria, fungi or other pathogenic factors. A series of studies have found their effectiveness in the treatment or prevention of systemic diseases such as autoimmune diseases, cancer, neurodegenerative diseases, Crohn's disease and so on.

OBJECTIVE

This review systematizes the literature on the mechanisms of the phytochemicals that react against unique free radicals and prevent the oxidative stress and also summarizes their role in gut microbiota inhibiting bacterial translocation and damage to the intestinal barrier and improving the intestinal membrane condition.

CONCLUSION

The gut microbiota modulation and antioxidant activities of the phytochemicals shall be emphasized on the research of the active principles of the phytochemicals.

Hybrides of Alkaloid Lappaconitine with Pyrimidine Motif on the Anthranilic Acid Moiety: Design, Synthesis, and Investigation of Antinociceptive Potency

Convenient and efficient routes to construct hybrid molecules containing diterpene alkaloid lappaconitine and pyrimidine fragments are reported. One route takes place via first converting of lappaconitine to 1-ethynyl-lappaconitine, followed by the Sonogashira cross-coupling-cyclocondensation sequences. The other involves the palladium-catalyzed carbonylative Sonogashira reaction of 5'-iodolappaconitine with aryl acetylene and Mo (CO)6 as the CO source in acetonitrile and subsequent cyclocondensation reaction of the generated alkynone with amidines. The reaction proceeded cleanly in the presence of the PdCl2-(1-Ad)2PBn∙HBr catalytic system. The protocol provides mild reaction conditions, high yields, and high atom and step-economy. Pharmacological screening of lappaconitine-pyrimidine hybrids for antinociceptive activity in vivo revealed that these compounds possessed high activity in experimental pain models, which was dependent on the nature of the substituent in the 2 and 6 positions of the pyrimidine nucleus. Docking studies were undertaken to gain insight into the possible binding mode of these compounds with the voltage-gated sodium channel 1.7. The moderate toxicity of the leading compound 12 (50% lethal dose (LD50) value was more than 600 mg/kg in vivo) and cytotoxicity to cancer cell lines in vitro encouraged the further design of therapeutically relevant analogues based on this novel type of lappaconitine-pyrimidine hybrids.

Clinical relationship between blood concentration and clinical symptoms in aconitine intoxication

BACKGROUND

Aconitine is well-known for its potential analgesic, anti-inflammatory, and circulation promoting effects and has been widely used as a folk medicine in South Korea. Owing to its extremely toxic nature and relatively low safety margin, intoxication is sometimes fatal. The toxic compound mainly affects the central nervous system, heart, and muscle, resulting in cardiovascular complications.

PURPOSE

To determine the exact relationship between blood concentration of aconitine and clinical manifestation.

BASIC PROCEDURES

The National Forensic Service (NFS) was commissioned to assist in a quantitative analysis of highly toxic aconitine and corresponding blood concentrations by analyzing the body fluids of three patients who were suspected of aconitine poisoning.

MAIN FINDINGS

Aconitine blood values tested by the NFS showed that patients with a blood concentration below a certain level developed symptoms slowly and showed a high severity of clinical manifestation. There was no correlation between blood concentration and symptoms or ECG results.

CONCLUSIONS

In case of suspected aconitine poisoning, an emergency care department should be visited, even with symptomatic improvement, and the patient should be monitored for at least 24 h, depending on the level of recovery and changes in ECG results.

Neuropharmacological Effects of Mesaconitine: Evidence from Molecular and Cellular Basis of Neural Circuit

Mesaconitine (MA), a diester-diterpenoid alkaloid in aconite roots, is considered to be one of the most important bioactive ingredients. In this review, we summarized its neuropharmacological effects, including analgesic effects and antiepileptiform effects. Mesaconitine can act on the central noradrenergic system and the serotonin system; behaving like the norepinephrine reuptake inhibitors and tricyclic antidepressants that increase norepinephrine levels in stress-induced depression. Therefore, the possible perspectives for future studies on the depression of MA were also discussed as well. The pharmacological effect of MA on depression is worthy of further study.