Ester Hydrolysis Differentially Reduces Aconitine-Induced Anti-hypersensitivity and Acute Neurotoxicity: Involvement of Spinal Microglial Dynorphin Expression and Implications for Aconitum Processing

Advancements in Non-Addictive Analgesic Diterpenoid Alkaloid Lappaconitine: A Review

The perennial herb Aconitum sinomontanum Nakai (Ranunculaceae) has been utilized as a traditional oriental medicine in China for numerous years. The principal pharmacological constituent of A. sinomontanum, lappaconitine (LA), exhibits analgesic, anti-inflammatory, anti-tumor, anti-arrhythmic, and anti-epileptic activities. Due to its potent efficacy and non-addictive nature, LA is widely utilized in the management of cancer pain and postoperative analgesia. This review encompasses the research advancements pertaining to LA including extraction methods, separation techniques, pharmacological properties, chemical modifications, and clinical applications. Additionally, it offers insights into the potential applications and current challenges associated with LA to facilitate future research endeavors.

A review of Aconiti Lateralis Radix Praeparata (Fuzi) for kidney disease: phytochemistry, toxicology, herbal processing, and pharmacology

Background

Aconiti Lateralis Radix Praeparata, commonly known as Fuzi in. traditional Chinese medicine (TCM), is widely utilized in clinical practice despite its inherent toxicity. Since ancient times, TCM practitioners have explored various processing techniques to broaden its clinical applications and enhance its safety profile. This review aims to summarize the effects of processing on the chemical composition, toxicity, and pharmacological properties of Fuzi, as well as investigate potential underlying mechanisms.

Methods

Data on phytochemistry, toxicology, pharmacology, and processing methods of Fuzi were gathered from the literature of electronic databases, including Web of Science, PubMed, and CNKI.

Results

Fuzi contains over 100 kinds of chemical compounds, including alkaloids, flavonoids, and polysaccharides, among which alkaloids are the main active compounds. Diester-diterpenoid alkaloids are the main contributors to Fuzi's toxicity and have side effects on some organs, such as the heart, liver, kidneys, nervous system, and reproductive system. The chemical composition of aconite, particularly its alkaloid content, was changed by hydrolysis or substitution reaction during processing to enhance its efficacy and reduce its toxicity. Salted aconite could enhance the therapeutic efficacy of Fuzi in treating kidney diseases and influence its pharmacokinetics.

Conclusion

Processing plays an important role in increasing the efficiency and decreasing toxicity of aconite. Further studies are needed to elucidate the changes of aconite before and after processing and the underlying mechanisms of these changes, thereby providing evidence for the clinical safety of drug use.

Dexamethasone attenuates neuropathic pain through spinal microglial expression of dynorphin A via the cAMP/PKA/p38 MAPK/CREB signaling pathway

This study aimed to elucidate the opioid mechanisms underlying dexamethasone-induced pain antihypersensitive effects in neuropathic rats. Dexamethasone (subcutaneous and intrathecal) and membrane-impermeable Dex-BSA (intrathecal) administration dose-dependently inhibited mechanical allodynia and thermal hyperalgesia in neuropathic rats. Dexamethasone and Dex-BSA treatments increased expression of dynorphin A in the spinal cords and primary cultured microglia. Dexamethasone specifically enhanced dynorphin A expression in microglia but not astrocytes or neurons. Intrathecal injection of the microglial metabolic inhibitor minocycline blocked dexamethasone-stimulated spinal dynorphin A expression; intrathecal minocycline, the glucocorticoid receptor antagonist Dex-21-mesylate, dynorphin A antiserum, and κ-opioid receptor antagonist GNTI completely blocked dexamethasone-induced mechanical antiallodynia and thermal antihyperalgesia. Additionally, dexamethasone elevated spinal intracellular cAMP levels, leading to enhanced phosphorylation of PKA, p38 MAPK and CREB. The specific adenylate cyclase inhibitor DDA, PKA inhibitor H89, p38 MAPK inhibitor SB203580 and CREB inhibitor KG-501 completely blocked dexamethasone-induced anti-neuropathic pain and increased microglial dynorphin A exprression. In conclusion, this study reveal that dexamethasone mitigateds neuropathic pain through upregulation of dynorphin A in spinal microglia, likely involving the membrane glucocorticoid receptor/cAMP/PKA/p38 MAPK/CREB signaling pathway.

Aconitine and its derivatives: bioactivities, structure-activity relationships and preliminary molecular mechanisms

Aconitine (AC), which is the primary bioactive diterpene alkaloid derived from Aconitum L plants, have attracted considerable interest due to its unique structural feature. Additionally, AC demonstrates a range of biological activities, such as its ability to enhance cardiac function, inhibit tumor growth, reduce inflammation, and provide analgesic effects. However, the structure-activity relationships of AC are remain unclear. A clear understanding of these relationships is indeed critical in developing effective biomedical applications with AC. In line with these challenges, this paper summarized the structural characteristics of AC and relevant functional and bioactive properties and the structure-activity relationships presented in biomedical applications. The primary temporal scope of this review was established as the period spanning from 2010 to 2023. Subsequently, the objective of this review was to provide a comprehensive understanding of the specific action mechanism of AC, while also exploring potential novel applications of AC derivatives in the biomedical field, drawing upon their structural characteristics. In conclusion, this review has provided a comprehensive analysis of the challenges and prospects associated with AC in the elucidation of structure-bioactivity relationships. Furthermore, the importance of exploring modern biotechnology approaches to enhance the potential biomedical applications of AC has been emphasized.

Nephrotoxicity assessment of podophyllotoxin-induced rats by regulating PI3K/Akt/mTOR-Nrf2/HO1 pathway in view of toxicological evidence chain (TEC) concept

Adverse reactions to traditional Chinese medicine have hindered the healthy development and internationalization process of the traditional Chinese medicine industry. The critical issue that needs to be solved urgently is to evaluate the safety of traditional Chinese medicine systematically and effectively. Podophyllotoxin (PPT) is a highly active compound extracted from plants of the genus Podophyllum such as Dysosma versipellis (DV). However, its high toxicity and toxicity to multiple target organs affect the clinical application, such as the liver and kidney. Based on the concurrent effects of PPT's medicinal activity and toxicity, it would be a good example to conduct a systematic review of its safety. Therefore, this study revolves around the Toxicological Evidence Chain (TEC) concept. Based on PPT as the main toxic constituent in DV, observe the objective toxicity impairment phenotype of animals. Evaluate the serum biochemical indicators and pathological tissue sections for substantial toxic damage results. Using metabolomics, lipidomics, and network toxicology to evaluate the nephrotoxicity of PPT from multiple perspectives systematically. The results showed that PPT-induced nephrotoxicity manifested as renal tubular damage, mainly affecting metabolic pathways such as glycerophospholipid metabolism and sphingolipid metabolism. PPT inhibits the autophagy process of kidney cells through the PI3K/Akt/mTOR and Nrf2/HO1 pathways and induces the activation of oxidative stress in the body, thereby causing nephrotoxic injury. This study fully verified the feasibility of the TEC concept for the safety and toxicity evaluation of traditional Chinese medicine. Provide a research template for systematically evaluating the safety of traditional Chinese medicine.

Global Trends and Hotspots on Microglia Associated with Pain from 2002 to 2022: A Bibliometric Analysis

Background

Researchers have made significant progress in microglia associated with pain in recent years. However, more relevant bibliometric analyses are still needed on trends and directions in this field. The aim of this study is to provide a comprehensive perspective and to predict future directions of pain-related microglia research via bibliometric tools.

Methods

English articles and reviews related with pain and microglia were extracted from the Web of Science core collection (WosCC) database between 2002 to 2022. Bibliometric tools such as VOSviewer, CiteSpace, and Bibliometrix R package were used to analyze publication characteristics, countries, authors, institutions, journals, research hotspots, and trend topics.

Results

A total of 2761 articles were included in this analysis. Research on microglia associated with pain has increased significantly over the last two decades. China (n = 1020, 36.94%) and the United States (n = 751, 27.20%) contributed the most in terms of publications and citations, respectively. Kyushu University published the most articles in this field compared to other institutions, and Professor Inoue Kazuhide (n = 54) at this university made outstanding contributions in this field. Molecular Pain (n = 113) was the journal with the most publication, while Journal of Neuroscience had the highest number of citations. According to the authors keywords analysis, the research in this area can be summarized into 7 clusters such as "microglia activation pathways", "pain treatment research", "mental symptoms of chronic pain", and so on.

Conclusion

This study provides a comprehensive analysis of pain-related microglia research in the past two decades. We identified the countries, institutions, scholars, and journals with the highest number of publications and the most influence in the field, and the research trends identified in this paper may provide new insights for future research.

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.

Inhibition of SLC7A11-GPX4 signal pathway is involved in aconitine-induced ferroptosis in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum species, with a long history of traditional application, were applied to treat rheumatism, arthritis, stroke, and pain in Chinese medical practice. However, misuse of Aconitum species may induce central nervous toxic effects, such as numbness, vomiting, and even coma. Aconitine has been proved to be the main toxic component of Aconitum plants. Neurotoxicity is the main toxic effect of aconitine, while the underlying mechanism of aconitine remains unclear.

AIM OF THE STUDY

The purpose of the study is to explore the effects and molecular mechanism of ferroptosis caused by aconitine in vivo and in vitro.

MATERIALS AND METHODS

Six-dpf zebrafish larvae and SH-SY5Y cells were treated with different concentrations of aconitine for 24 h. Inhibitors treatment, e.g. pretreatment with Necrostain-1 (Nec-1) and Z-VZD-FMK for 12 h, or with Ferrostain-1 (Fer-1) for 4 h, were involved in the identification of aconitine-induced ferroptosis. Transient transfection experiment was conducted to explore the effects of SLC7A11 in the process of aconitine-induced ferroptosis. The effects of aconitine on morphological changes, lipid peroxidation, ferrous ion, and ferroptosis were detected by transmission electron microscope, flow cytometry, confocal microscopy, enzyme-linked immunosorbent assay and western blotting.

RESULTS

In SH-SY5Y cells, morphological changes including shrunken mitochondria, increased mitochondrial membranes density and ruptured mitochondrial membranes were captured in aconitine-treated group. The cell viability and GSH content dose-dependently declined, levels of lipid reactive oxygen species (ROS), malondialdehyde (MDA), and ferrous ion significantly increased after aconitine exposure for 24 h. Ferroptosis inhibitor Fer-1 pretreatment effectively increased cell viability, GSH content, and decreased levels of MDA and lipid peroxidation, suggesting that aconitine induced ferroptosis. In addition, the protein expression of SLC7A11 and GPX4 were improved after Fer-1 preincubation, which indicated that aconitine triggered ferroptosis via the inhibition of SLC7A11 and the inactivation of GPX4. Ferroptotic characteristics, including GSH depletion and lipid peroxidation accumulation, were alleviated via overexpression of SLC7A11 to increase protein expression of GPX4. In zebrafish experiment, GSH depletion, lipid peroxidation accumulation, iron overload, and the decreased protein expression of SLC7A11 and GPX4 were also induced in zebrafish larvae after aconitine exposure. Taken together, aconitine triggered ferroptotic cell death via inhibiting SLC7A11/GPX4 signal pathway in vivo and in vitro.

CONCLUSION

All results indicated that aconitine triggered ferroptosis of SH-SY5Y cells and zebrafish larvae nerve cells, which involved the inhibition of SLC7A11/GPX4 signal pathway mediated by lipid peroxidation damage and iron overload.

Ethnopharmacological use, pharmacology, toxicology, phytochemistry, and progress in Chinese crude drug processing of the lateral root of Aconitum carmichaelii Debeaux. (Fuzi): A review

ETHNOPHARMACOLOGICAL RELEVANCE

The lateral root of Aconitum carmichaelii Debeaux. (also known as Fuzi in Chinese) is a toxic Chinese medicine but widely used in clinical practice with remarkable effects. It is specifically used to treat cardiovascular diseases, rheumatoid arthritis, and other diseases, in Korea, Japan, and India.

AIM OF THIS REVIEW

This study aimed to summarize and discuss the effects of drug processing on toxicity, chemical composition, and pharmacology of the lateral root of Aconitum carmichaelii Debeaux. This review could provide feasible insights for further studies.

MATERIALS AND METHODS

Relevant information on phytochemistry, pharmacology, and toxicology of Fuzi was collected through published materials and electronic databases, including the Chinese Pharmacopoeia, Flora of China, Web of Science, PubMed, Baidu Scholar, Google Scholar, and CNKI.

RESULTS

More than 100 chemical compounds, including alkaloids, flavonoids, and polysaccharides were revealed. Modern pharmacological studies show that these chemical components have good effects on anti-inflammatory, anti-tumor, anti-aging, treatment of cardiovascular diseases, and improving immunity. Di-ester alkaloids are the main source of Fuzi toxicity. Increasing studies have shown that Fuzi can induce multiple organ damage, especially cardiotoxicity and neurotoxicity. At present, most of the Fuzi used in clinical practice are processed. The processing affects the chemical structure, pharmacology, and toxicology of Fuzi. Moreover, different processing methods have different effects on Fuzi.

CONCLUSIONS

This review analyzed the effects of Fuzi processing methods on its toxicity and efficiency. The lateral roots of aconite are the known medicinal part of Fuzi; however, the aerial parts of aconite are understudied and require further research to expand its medicinal potential. Processing and compatibility are the primary means to reduce Fuzi toxicity. Nevertheless, establishing a reasonable unified safe dose range requires further discussion.

Advances on pharmacology and toxicology of aconitine

Aconitum alkaloids are considered to be the characteristic bioactive ingredients of Aconitum species, which are widely applied to the treatment of diverse diseases, and aconitine (AC) is found in most Aconitum plants. Research evidence shows that low-dose AC has a good therapeutic potential in heart failure, myocardial infarction, neuroinflammatory diseases, rheumatic diseases, and tumors, which has become one of the hotspots in global research in recent years. However, the cardiotoxicity and neurotoxicity of AC have also attracted extensive attention. Excessive use of AC always induces ventricular tachyarrhythmia and heart arrest, even can be potentially lethal. Therefore, AC cannot simply be regarded as a good medicine or a toxicant, but its underlying curative and toxic properties remained chaos. In order to dig the unique pharmacological value of AC while preventing its toxicity, the pharmacological activities and toxic effects of AC were summarized in this paper, providing new insight into the safe and effective use of AC in clinical practice.

An insight into current advances on pharmacology, pharmacokinetics, toxicity and detoxification of aconitine

Aconitine is a diterpenoid alkaloid, which mainly exists in the plants of Aconitum. In the last decade, a plethora of studies on the pharmacological activities of aconitine has been conducted and demonstrated that aconitine possessed an extensive range of pharmacological activities such as anti-tumor, anti-inflammatory, analgesic, local anesthesia, and immunomodulatory effects. Pharmacokinetic studies indicated that aconitine may have the characteristics of poor bioavailability, wide distribution, and slow elimination. However, studies have also found that aconitine has toxic effects on the heart, nerves, embryos, etc. Therefore, we believe that aconitine may not be suitable for heart patients and pregnant women to treat related diseases. It is important to note that all of these pharmacological effects require further high-quality studies to determine the clinical efficacy of aconitine. This review aims to summarize the advances in pharmacological, pharmacokinetics, toxicity, and detoxification of aconitine in the last decade with an emphasis on its anti-tumor and anti-inflammatory activities, to provide researchers with the latest information and point out the limitations of relevant research at the current stage and the aspects that should be strengthened in future research.

Diagnostic ions guided 2D-locating strategy for characterization of chemical analogues in complex herbal medicines using liquid chromatography-ion mobility-mass spectrometry

Rapid characterization of chemical analogues in potentially toxic complex matrix was essential for prevention of accidental poisoning. On the basis of the fragment ions possessed not only the same retention times (RT) but the same drift times (DT) on liquid chromatography-ion mobility-mass spectrometry (LC-IM-MS), an alternating frames (AF)-data independent acquisition (DIA) was utilized for simultaneous detection and rapid match of precursor/product ions with a fast switch of low/high collision energy (CE). A diagnostic ions guided 2D-locating strategy was developed for identification of chemical analogues in potentially toxic herbal medicines using LC-IM-MS. Firstly, the 2D-locations (RT, DT) of diagnostic ions were screened from high-fragment IM-MS frames according to their m/z. Then, the correlated precursor ions were extracted from the complex background interference in low-fragment IM-MS frames based on diagnostic ions' 2D-locations. Finally, the remained ions were characterized using double-bond equivalent analysis combined with MS/MS fragment interpretation. Totally, 236 diterpene alkaloids including eight compounds with potential new esterification types were characterized in processed lateral roots of Aconitum carmichaelii Debx. Moreover, the LC-IM-MS distribution regularities of diterpene alkaloids with various chemical structure types were further investigated and discussed. This study presented an innovative idea for revealing the chemical basis related to the toxicities of potentially poisonous herbal medicines to ensure the medication safety.

A systematic review of pharmacological activities, toxicological mechanisms and pharmacokinetic studies on Aconitum alkaloids

The tubers and roots of Aconitum (Ranunculaceae) are widely used as heart medicine or analgesic agents for the treatment of coronary heart disease, chronic heart failure, rheumatoid arthritis and neuropathic pain since ancient times. As a type of natural products mainly extracted from Aconitum plants, Aconitum alkaloids have complex chemical structures and exert remarkable biological activity, which are mainly responsible for significant effects of Aconitum plants. The present review is to summarize the progress of the pharmacological, toxicological, and pharmacokinetic studies of Aconitum alkaloids, so as to provide evidence for better clinical application. Research data concerning pharmacological, toxicological and pharmacokinetic studies of Aconitum alkaloids were collected from different scientific databases (PubMed, CNKI, Google Scholar, Baidu Scholar, and Web of Science) using the phrase Aconitum alkaloids, as well as generic synonyms. Aconitum alkaloids are both bioactive compounds and toxic ingredients in Aconitum plants. They produce a wide range of pharmacological activities, including protecting the cardiovascular system, nervous system, and immune system and anti-cancer effects. Notably, Aconitum alkaloids also exert strong cardiac toxicity, neurotoxicity and liver toxicity, which are supported by clinical studies. Finally, pharmacokinetic studies indicated that cytochrome P450 proteins (CYPs) and efflux transporters (ETs) are closely related to the low bioavailability of Aconitum alkaloids and play an important role in their metabolism and detoxification in vivo.

Protopanaxadiol alleviates neuropathic pain by spinal microglial dynorphin A expression following glucocorticoid receptor activation

BACKGROUND AND PURPOSE

New remedies are required for the treatment of neuropathic pain due to insufficient efficacy of available therapies. This study provides a novel approach to develop painkillers for chronic pain treatment.

EXPERIMENTAL APPROACH

The rat formalin pain test and spinal nerve ligation model of neuropathic pain were used to evaluate antinociception of protopanaxadiol. Primary cell cultures, immunofluorescence staining, and gene and protein expression were also performed for mechanism studies.

KEY RESULTS

Gavage protopanaxadiol remarkably produces pain antihypersensitive effects in neuropathic pain, bone cancer pain and inflammatory pain, with efficacy comparable with gabapentin. Long-term PPD administration does not induce antihypersensitive tolerance, but prevents and reverses the development and expression of morphine analgesic tolerance. Oral protopanaxadiol specifically stimulates spinal expression of dynorphin A in microglia but not in astrocytes or neurons. Protopanaxadiol gavage-related pain antihypersensitivity is abolished by the intrathecal pretreatment with the microglial metabolic inhibitor minocycline, dynorphin antiserum or specific κ-opioid receptor antagonist GNTI. Intrathecal pretreatment with glucocorticoid receptor)antagonists RU486 and dexamethasone-21-mesylate, but not GPR-30 antagonist G15 or mineralocorticoid receptor antagonist eplerenone, completely attenuates protopanaxadiol-induced spinal dynorphin A expression and pain antihypersensitivity in neuropathic pain. Treatment with protopanaxadiol, the glucocorticoid receptor agonist dexamethasone and membrane-impermeable glucocorticoid receptor agonist dexamethasone-BSA in cultured microglia induces remarkable dynorphin A expression, which is totally blocked by pretreatment with dexamthasone-21-mesylate.

CONCLUSION AND IMPLICATIONS

All the results, for the first time, indicate that protopanaxadiol produces pain antihypersensitivity in neuropathic pain probably through spinal microglial dynorphin A expression after glucocorticoid receptor activation and hypothesize that microglial membrane glucocorticoid receptor/dynorphin A pathway is a potential target to discover and develop novel painkillers in chronic pain.

Bulleyaconitine A Inhibits Morphine-Induced Withdrawal Symptoms, Conditioned Place Preference, and Locomotor Sensitization Via Microglial Dynorphin A Expression

Bulleyaconitine A (BAA), a C19-diterpenoid alkaloid, has been prescribed as a nonnarcotic analgesic to treat chronic pain over four decades in China. The present study investigated its inhibition in morphine-induced withdrawal symptoms, conditioned place preference (CPP) and locomotor sensitization, and then explored the underlying mechanisms of actions. Multiple daily injections of morphine but not BAA up to 300 μg/kg/day into mice evoked naloxone-induced withdrawal symptoms (i.e., shakes, jumps, genital licks, fecal excretion and body weight loss), CPP expression, and locomotor sensitization. Single subcutaneous BAA injection (30–300 μg/kg) dose-dependently and completely attenuated morphine-induced withdrawal symptoms, with ED₅₀ values of 74.4 and 105.8 μg/kg in shakes and body weight loss, respectively. Subcutaneous BAA (300 μg/kg) also totally alleviated morphine-induced CPP acquisition and expression and locomotor sensitization. Furthermore, subcutaneous BAA injection also specifically stimulated dynorphin A expression in microglia but not astrocytes or neurons in nucleus accumbens (NAc) and hippocampal, measured for gene and protein expression and double immunofluorescence staining. In addition, subcutaneous BAA-inhibited morphine-induced withdrawal symptoms and CPP expression were totally blocked by the microglial metabolic inhibitor minocycline, dynorphin A antiserum, or specific KOR antagonist GNTI, given intracerebroventricularly. These results, for the first time, illustrate that BAA attenuates morphine-induced withdrawal symptoms, CPP expression, and locomotor sensitization by stimulation of microglial dynorphin A expression in the brain, suggesting that BAA may be a potential candidate for treatment of opioids-induced physical dependence and addiction.

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.

Potential Molecular Mechanisms and Drugs for Aconitine-Induced Cardiotoxicity in Zebrafish through RNA Sequencing and Bioinformatics Analysis

Background

Accumulating evidence suggests that cardiotoxicity is one of the main manifestations of aconitine (AC) poisoning. However, the molecular mechanism of AC-induced cardiotoxicity remains unclear, there is little direct evidence for therapeutic targets and drugs of AC-induced cardiotoxicity.

Material/Methods

Zebrafish were exposed to AC to evaluate cardiotoxicity by calculating the heart rates and observing the changes of cardiac and vascular structure. RNA-seq (RNA sequencing) and bioinformatics analysis were used to obtain differentially expressed genes (DEGs). The anti-AC cardiotoxicity compound was identified via connectivity map (CMAP) analysis and molecular docking.

Results

AC-induced cardiotoxicity in zebrafish predominantly included arrhythmias, extended sinus venous and bulbus arteriosus (SV-BA) distance, and larger pericardial edema aera. A total of 1380 DEGs were identified by RNA-seq and bioinformatics analysis. cyclin-dependent kinase-1 (CDK1) was screened as the hub gene and the most potential therapeutic target due to its significant downregulation in cardiotoxicity based on protein-protein interaction (PPI) and drug-gene interaction (DGIdb) network analysis. Cell cycle signal pathway was the most significant pathways identified in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Furthermore, the expression of CDK1 was validated in the Gene Expression Omnibus (GEO) database GSE71906, GSE65705, and GSE95140. Finally, heptaminol was identified as a novel anti-AC cardiotoxicity compound via CMAP analysis and molecular docking.

Conclusions

Totally, hub genes and key pathways identified in this study can aid in the understanding of the molecular changes in AC-induced cardiotoxicity. Meanwhile, we provide a systematic method to explore drug toxicity prevention and treatment.

Bulleyaconitine A Inhibits Visceral Nociception and Spinal Synaptic Plasticity through Stimulation of Microglial Release of Dynorphin A

Background

Visceral pain is one of the most common types of pain and particularly in the abdomen is associated with gastrointestinal diseases. Bulleyaconitine A (BAA), isolated from Aconitum bulleyanum, is prescribed in China to treat chronic pain. The present study is aimed at evaluating the mechanisms underlying BAA visceral antinociception.

Methods

The rat model of chronic visceral hypersensitivity was set up by colonic perfusion of 2,4,6-trinitrobenzene sulfonic acid (TNBS) on postnatal day 10 with coapplication of heterotypic intermittent chronic stress (HeICS).

Results

The rat model of chronic visceral hypersensitivity exhibited remarkable abdominal withdrawal responses and mechanical hyperalgesia in hind paws, which were dose-dependently attenuated by single subcutaneous of administration of BAA (30 and 90 μg/kg). Pretreatment with the microglial inhibitor minocycline, dynorphin A antiserum, and κ-opioid receptor antagonist totally blocked BAA-induced visceral antinociception and mechanical antihyperalgesia. Spontaneous excitatory postsynaptic currents (sEPSCs) in spinal dorsal horn lamina II neurons were recorded by using whole-cell patch clamp. Its frequency (but not amplitude) from TNBS-treated rats was remarkably higher than that from naïve rats. BAA (1 μM) significantly reduced the frequency of sEPSCs from TNBS-treated rats but not naïve rats. BAA-inhibited spinal synaptic plasticity was blocked by minocycline, the dynorphin A antiserum, and κ-opioid receptor antagonist. Dynorphin A also inhibited spinal synaptic plasticity in a κ-opioid receptor-dependent manner.

Conclusions

These results suggest that BAA produces visceral antinociception by stimulating spinal microglial release of dynorphin A, which activates presynaptic κ-opioid receptors in afferent neurons and inhibits spinal synaptic plasticity, highlighting a novel interaction mode between microglia and neurons.

The spinal microglial IL-10/β-endorphin pathway accounts for cinobufagin-induced mechanical antiallodynia in bone cancer pain following activation of α7-nicotinic acetylcholine receptors

Background

Cinobufagin is the major bufadienolide of Bufonis venenum (Chansu), which has been traditionally used for the treatment of chronic pain especially cancer pain. The current study aimed to evaluate its antinociceptive effects in bone cancer pain and explore the underlying mechanisms.

Methods

Rat bone cancer model was used in this study. The withdrawal threshold evoked by stimulation of the hindpaw was determined using a 2290 CE electrical von Frey hair. The β-endorphin and IL-10 levels were measured in the spinal cord and cultured primary microglia, astrocytes, and neurons.

Results

Cinobufagin, given intrathecally, dose-dependently attenuated mechanical allodynia in bone cancer pain rats, with the projected E_max of 90% MPE and ED₅₀ of 6.4 μg. Intrathecal cinobufagin also stimulated the gene and protein expression of IL-10 and β-endorphin (but not dynorphin A) in the spinal cords of bone cancer pain rats. In addition, treatment with cinobufagin in cultured primary spinal microglia but not astrocytes or neurons stimulated the mRNA and protein expression of IL-10 and β-endorphin, which was prevented by the pretreatment with the IL-10 antibody but not β-endorphin antiserum. Furthermore, spinal cinobufagin-induced mechanical antiallodynia was inhibited by the pretreatment with intrathecal injection of the microglial inhibitor minocycline, IL-10 antibody, β-endorphin antiserum and specific μ-opioid receptor antagonist CTAP. Lastly, cinobufagin- and the specific α-7 nicotinic acetylcholine receptor (α7-nAChR) agonist PHA-543613-induced microglial gene expression of IL-10/β-endorphin and mechanical antiallodynia in bone cancer pain were blocked by the pretreatment with the specific α7-nAChR antagonist methyllycaconitine.

Conclusions

Our results illustrate that cinobufagin produces mechanical antiallodynia in bone cancer pain through spinal microglial expression of IL-10 and subsequent β-endorphin following activation of α7-nAChRs. Our results also highlight the broad significance of the recently uncovered spinal microglial IL-10/β-endorphin pathway in antinociception.

Discrimination of the Geographical Origin of the Lateral Roots of Aconitum carmichaelii Using the Fingerprint, Multicomponent Quantification, and Chemometric Methods

Fuzi is a well-known traditional Chinese medicine developed from the lateral roots of Aconitum carmichaelii Debx. It is rich in alkaloids that display a wide variety of bioactivities, and it has a strong cardiotoxicity and neurotoxicity. In order to discriminate the geographical origin and evaluate the quality of this medicine, a method based on high-performance liquid chromatography (HPLC) was developed for multicomponent quantification and chemical fingerprint analysis. The measured results of 32 batches of Fuzi from three different regions were evaluated by chemometric analysis, including similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA), and linear discriminant analysis (LDA). The content of six representative alkaloids of Fuzi (benzoylmesaconine, benzoylhypaconine, benzoylaconine, mesaconitine, hypaconitine, and aconitine) were varied by geographical origin, and the content ratios of the benzoylmesaconine/mesaconitine and diester-type/monoester-type diterpenoid alkaloids may be potential traits for classifying the geographical origin of the medicine. In the HPLC fingerprint similarity analysis, the Fuzi from Jiangyou, Sichuan, was distinguished from the Fuzi from Butuo, Sichuan, and the Fuzi from Yunnan. Based on the HCA and PCA analyses of the content of the six representative alkaloids, all of the batches were classified into two categories, which were closely related to the plants' geographical origins. The Fuzi samples from Jiangyou were placed into one category, while the Fuzi samples from Butuo and Yunnan were put into another category. The LDA analysis provided an efficient and satisfactory prediction model for differentiating the Fuzi samples from the above-mentioned three geographical origins. Thus, the content of the six representative alkaloids and the fingerprint similarity values were useful markers for differentiating the geographical origin of the Fuzi samples.

Lappaconitine, a C18-diterpenoid alkaloid, exhibits antihypersensitivity in chronic pain through stimulation of spinal dynorphin A expression

Lappaconitine is a representative C18-diterpenoid alkaloid extracted from Aconitum sinomontanum Nakai and has been prescribed as a pain relief medicine in China for more than 30 years. This study evaluated its antihypersensitivity activity in the rat models of neuropathic and cancer pains and explored its underlying mechanisms. Subcutaneous injection of cumulative doses of lappaconitine produced dose-dependent mechanical antiallodynia and thermal antihyperalgesia in spinal nerve ligation-induced neuropathic rats. The cumulative dose-response analysis exhibited their E_max values of 53.3 and 58.3% MPE, and ED₅₀ values of 1.1 and 1.6 mg/kg. Single intrathecal lappaconitine dose in neuropathy also dose- and time-dependently blocked mechanical allodynia, with an E_max of 66.1% MPE and an ED₅₀ of 0.8 μg. Its multiple twice-daily intrathecal administration over 7 days did not induce mechanical antiallodynic tolerance. Subcutaneous cumulative doses of lappaconitine also produced dose-dependent blockade of mechanical allodynia in the rat bone cancer pain model induced by tibia implantation of cancer cells, with the E_max of 57.9% MPE and ED₅₀ of 2.0 mg/kg. Furthermore, lappaconitine treatment stimulated spinal dynorphin A expression in neuropathic rats, and in primary cultures of microglia but not neurons or astrocytes. Intrathecal pretreatment with the specific microglia depletor liposome-encapsulated clodronate, dynorphin A antibody, and κ-opioid receptor antagonist GNTI totally suppressed intrathecal and subcutaneous lappaconitine-induced mechanical antiallodynia. This study suggests that lappaconitine exhibits antinociception through directly stimulating spinal microglial dynorphin A expression. Graphical Abstract ᅟ.

Research on Q-markers of Qiliqiangxin capsule for chronic heart failure treatment based on pharmacokinetics and pharmacodynamics association

BACKGROUND

Qiliqiangxin capsule (QLQX), composed of 11 herbs, is an effective traditional Chinese medicine (TCM) that has been widely used for treatment of chronic heart failure (CHF) in China. In the Chinese pharmacopoeia (Ch.P.) only astragaloside was described as the marker component to control the quality of QLQX, which could not reflect the overall effectiveness.

PURPOSE

The aim of this work was to investigate the quality markers (Q-markers) of QLQX based on the association of the pharmacodynamics (PD) of inhibitory effect on activated renin-angiotensin-aldosterone system (RAAS) and the pharmacokinetics (PK) of bioactive compounds according to the Q-marker theory.

METHODS

The contents of astragaloside, calycosin-7-glucoside, sinapine, ginsenoside Rb1, ginsenoside Rb2, ginsenoside Rg1, salvianolic acid A, salvianolic acid B, danshensu, rosmarinic acid, formononetin, aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine and benzoylhypacoitine were determined by an HPLC-MS/MS method both in QLQX preparation and in the plasma of CHF rats administered intragastrically with QLQX. The effect of lowering angiotensin II (Ang II) production by QLQX was assayed by ELISA. The association between PK and PD was explored and the bioactive compounds with higher content in vitro and better exposure in vivo, which were closely related to the inhibitory effect on the activated RAAS, were identified as Q-markers of QLQX for CHF treatment.

RESULTS

The contents of 17 constituents were in the order of salvianolic acid B > danshensu > ginsenoside Rb1 > sinapine > benzoylmesaconine > astragaloside > benzoylhypacoitine > ginsenoside Rb2 > salvianolic acid A > ginsenoside Rg1 > calycosin-7-glucoside > rosmarinic acid > formononetin > benzoylaconine > hypaconitine > aconitine > mesaconitine in QLQX preparation. PK and PD association study of 14 bioactive compounds of QLQX showed the maximum effect (E_max) of astragaloside, calycosin-7-glucoside, sinapine and ginsenoside Rg1 and their peak concentration (C_max) appeared at the same time; while the time of E_max of ginsenoside Rb1, ginsenoside Rb2, salvianolic acid A, salvianolic acid B, danshensu, rosmarinic acid, formononetin, benzoylaconine, benzoylmesaconine and benzoylhypacoitine was delayed from the time of their C_max.

CONCLUSIONS

Astragaloside, calycosin-7-glucoside, sinapine and ginsenoside Rg1 are suitable as the Q-markers of QLQX for CHF treatment, which have higher content in vitro, finer exposure in vivo and a direct correlation with the inhibitory effect on activated RAAS.

Research progress of aconitine toxicity and forensic analysis of aconitine poisoning

Chinese herbal medicines have been extensively used in China and other countries for centuries. Aconitine, a diterpenoid alkaloid extracted from Aconitum plants, has anti-inflammatory and analgesic activities, but can also induce severe arrhythmia and neurotoxicity. Aconitine poisoning accidents caused by misuse, suicide, or homicide have been reported in recent years. In China, fatal aconitine poisoning can occasionally happen on account of accidental ingestion of some wild plants or consumption of herbal decoction made from the roots of Aconitum plants. However, it is rather difficult for forensic experts to find the specific results in present forensic autopsy of aconitine-induced death. To further clarify its potential risk following the widespread application of aconitine, toxicological characteristics and pharmacokinetics of aconitine are reviewed. Moreover, gastrointestinal, neurological, and cardiovascular symptoms were observed frequently in aconitine poisoning cases. In addition, the review also aims at providing some convincing evidences for forensic experts to identify unexplained death with postmortem examination.

Liposome-encapsulated clodronate specifically depletes spinal microglia and reduces initial neuropathic pain

Liposome-encapsulated clodronate (LEC) is a specific depletor of macrophages. Our study characterized the LEC depletory effects, given intrathecally, on spinal microglia and assessed its effects on initiation and maintenance of neuropathic pain. Measured by using the MTT assay, LEC treatment specifically inhibited cell viability of cultured primary microglia, but not astrocytes or neurons, from neonatal rats, with an IC₅₀ of 43 μg/mL. In spinal nerve ligation-induced neuropathic rats, pretreatment (1 day but not 5 days earlier) with intrathecal LEC specifically depleted microglia (but not astrocytes or neurons) in both contralateral and ipsilateral dorsal horns by the same degree (63% vs. 71%). Intrathecal injection of LEC reversibly blocked the antinociceptive effects of the GLP-1 receptor agonist exenatide and dynorphin A stimulator bulleyaconitine, which have been claimed to be mediated by spinal microglia, whereas it failed to alter morphine- or the glycine receptor agonist gelsemine-induced mechanical antiallodynia which was mediated via the neuronal mechanisms. Furthermore, intrathecal LEC injection significantly attenuated initial (one day after nerve injury) but not existing (2 weeks after nerve injury) mechanical allodynia. Our study demonstrated that LEC, given intrathecally, is a specific spinal microglial inhibitor and significantly reduces initiation but not maintenance of neuropathic pain, highlighting an opposite role of spinal microglia in different stages of neuropathic pain.

Endogenous Opiates and Behavior: 2016

This paper is the thirty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2016 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Aconitine induces apoptosis in H9c2 cardiac cells via mitochondria‑mediated pathway

Aconitine, a diterpenoid alkaloids derived from Aconitum plants, is widely employed to treat various diseases. The aim of the present study was to investigate the apoptotic effect of aconitine in H9c2 cardiac cells. H9c2 cell apoptosis induced by aconitine was detected by a Cell Counting kit-8 assay, DAPI staining, Annexin V-FITC/propidium iodide double staining and western blotting. The effects of aconitine on reactive oxygen species levels and mitochondrial membrane potential were confirmed by fluorescence microscopy and flow cytometry. In addition, ATP contents were determined using a ATP-dependent bioluminescence assay kit. The levels of peroxisome proliferator activated receptor γ co-activator 1α (PGC-1α) expression and apoptosis-associated proteins including Caspase-3, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and Cytochrome c were also assessed. Taken together, the results indicated that aconitine may inhibit cell viability, decrease PGC-1α expression, induce mitochondrial dysfunctions, upregulate Cytochrome c, Bax and Caspase-3, and downregulate Bcl-2, suggesting that aconitine may induce apoptosis through mitochondria-mediated signaling pathways in H9c2 cells.

Molecular signaling underlying bulleyaconitine A (BAA)-induced microglial expression of prodynorphin

Bulleyaconitine (BAA) has been shown to possess antinociceptive activities by stimulation of dynorphin A release from spinal microglia. This study investigated its underlying signal transduction mechanisms. The data showed that (1) BAA treatment induced phosphorylation of CREB (rather than NF-κB) and prodynorphin expression in cultured primary microglia, and antiallodynia in neuropathy, which were totally inhibited by the CREB inhibitor KG-501; (2) BAA upregulated phosphorylation of p38 (but not ERK or JNK), and the p38 inhibitor SB203580 (but not ERK or JNK inhibitor) and p38β gene silencer siRNA/p38β (but not siRNA/p38α) completely blocked BAA-induced p38 phosphorylation and/or prodynorphin expression, and antiallodynia; (3) BAA stimulated cAMP production and PKA phosphorylation, and the adenylate cyclase inhibitor DDA and PKA inhibitor H-89 entirely antagonized BAA-induced prodynorphin expression and antiallodynia; (4) The Gs-protein inhibitor NF449 completely inhibited BAA-increased cAMP level, prodynorphin expression and antiallodynia, whereas the antagonists of noradrenergic, corticotrophin-releasing factor, A1 adenosine, formyl peptide, D1/D2 dopamine, and glucagon like-peptide-1 receptors failed to block BAA-induced antiallodynia. The data indicate that BAA-induced microglial expression of prodynorphin is mediated by activation of the cAMP-PKA-p38β-CREB signaling pathway, suggesting that its possible target is a Gs-protein-coupled receptor - "aconitine receptor", although the chemical identity is not illustrated.

Concurrent bullatine A enhances morphine antinociception and inhibits morphine antinociceptive tolerance by indirect activation of spinal κ-opioid receptors

ETHNOPHARMACOLOGICAL RELEVANCE

Bullatine A, a C₂₀-diterpenoid alkaloid and one of the major effective ingredients in Aconiti brachypodi Radix (Xue-shang-yi-zhi-hao), can block pain hypersensitivity in a variety of rodent models through expression of spinal microglial dynorphin A.

AIM OF THE STUDY

To assess the interaction between bullatine A and morphine on antinociception in acute nociception and pain hypersensitivity states, with the exogenous synthetic dynorphin A as a comparison MATERIALS AND METHODS: Spinal nerve ligation-induced neuropathic rats and naïve mice were used for assessing the acute and chronic interactions of bullatine A/dynorphin A with morphine.

RESULTS

Single subcutaneous injection of bullatine A or dynorphin A(1-17) did not either alter formalin- and thermally (hot-plate and water immersion tests)-induced acute nociception or potentiate morphine antinociception in naïve mice. In contrast, bullatine A dose-dependently inhibited formalin-induced tonic pain with the efficacy of 54% inhibition and the half-effective dose of 0.9mg/kg. Concurrent bullatine A additively enhanced morphine antinociception. In neuropathic rats, the antinociceptive effects of multiple bidaily intrathecal injections of bullatine A and dynorphin A remained consistent over 13 days, whereas morphine produced progressive and complete tolerance to antinociception, which was completely inhibited by concurrent bullatine A and dynorphin A. A single intrathecal injection of bullatine A and dynorphin A immediately reversed established morphine tolerance in neuropathic rats, although the blockade was a less degree in the thermally induced mouse acute nociceptive tests. The inhibitory effects of bullatine A and dynorphin A on morphine tolerance were immediately and completely attenuated by intrathecal dynorphin A antibody and/or selective κ-opioid receptor antagonist GNTI.

CONCLUSION

These results suggest that bullatine A produces antinociception without induction of tolerance and inhibits morphine antinociceptive tolerance, and provide pharmacological basis for concurrent bullatine A and morphine treatment for chronic pain and morphine analgesic tolerance.