Analgesic effect of the main components of Corydalis yanhusuo (yanhusuo in Chinese) is caused by inhibition of voltage gated sodium channels

Efficacy and safety of Chinese patent medicines combined with conventional therapies for endometriosis: A systematic review and bayesian network meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Conventional hormonal treatments for endometriosis (EMs) are often associated with significant side effects. In recent years, many clinical trials and studies have highlighted the remarkable efficacy of Chinese patent medicines (CPMs) in alleviating endometriosis-related pain, reducing CA125 markers, regulating hormone levels, and preventing symptom recurrence. Numerous randomized controlled trials (RCTs) have been conducted on CPMs such as Shaofu Zhuyu Decoction (SZD), Dan'e Fukang Plaster (DFP), Sanjie Zhentong Capsule (SZC), Guizhi Fuling Capsule (GFC), Xiaojin Capsule (XC), Gongliu Xiao Capsule (GLXC), Xuefu Zhuyu Capsule (XZC), Jingtong Yushu Granule (JYG), Zhitong Huazheng Capsule (ZHC), and Kuntai Capsule (KTC) for the treatment of endometriosis. However, these studies have yet to be evaluated through a network meta-analysis (NMA) compliant with PRISMA standards.

AIM OF THE STUDY

This study aimed to compare the efficacy and safety of ten CPMs for treating EMs through a NMA on RCTs.

MATERIALS AND METHODS

PubMed, Cochrane, Embase, Web of Science, China National Knowledge Infrastructure, VIP Information, WanFang, and China Biomedicine databases were searched up to October 2024 for studies on the efficacy and safety of CPMs in treating EMs. Two researchers independently screened the studies, extracted data, and assessed quality using the Cochrane Risk of Bias 2.0 tool and the Confidence in Network Meta-Analysis framework. The NMA was conducted using Bayesian methods with StataSE and Rstudio, generating network diagrams, league tables, and Surface Under the Cumulative Ranking (SUCRA) line charts. This study was registered with PROSPERO (CRD42023477523).

RESULTS

148 eligible trials involving 10 CPMs and 16198 participants were included in this NMA; all subsequent estimates refer to the comparison with conventional therapies. All 10 CPMs effectively improved the total effective rate and VAS pain scores. SZC induced the most significant improvement in total effective rate(compared to hormone therapy: risk ratio 5.51, 95% confidence interval 4.21 to 7.2, SUCRA 86.3%, moderate confidence of evidence; compared to GnRH-a: 4.74, (3.18-7), moderate confidence of evidence). DFP proved to be the most effective CPM for lowering the VAS pain scores. (compared to hormone therapy: mean difference -2.1, (-2.94 to -1.29), 78.8%, moderate confidence of evidence; and GnRH-a (-2.07, (-2.73 to -1.41), low confidence of evidence). Moreover, this study demonstrated the safety of CPMs, particularly in reducing hormonal and liver-related side effects. Specific CPMs like XZC, SZC, DFP, KTC, and GFC showed markedly lower relative risks of adverse events when compared to conventional therapies.

CONCLUSION

Chinese patent medicine may effectively treat EMs, excelling in total effective rate, pain relief, CA125 reduction, and safety. Nevertheless, these findings are preliminary and require validation through high-quality studies.

Phytochemical-based therapeutics from traditional eastern medicine: analgesic effects and ion channel modulation

Pain management remains a major challenge in the healthcare system. While synthetic analgesics are widely used for pain management, their effectiveness in managing chronic pain is often limited due to low efficacy or side effects. Thus, there is growing interest in exploring alternative pain relief methods, particularly using medicinal plants from traditional Eastern medicine and their phytochemicals. Previous studies have demonstrated the modulatory effects of various phytochemicals derived from herbal medicine on pain-related ion channels, such as voltage-gated sodium channels (Nav), calcium channels (Ca2+), and transient receptor potential (TRP) channels. Since these ion channels are integral to the transmission and modulation of pain signals, the ability of specific phytochemicals to activate or inhibit these channels presents a promising avenue for the development of novel analgesics. The goal of this review is to merge herbal insights with ion channel research to highlight the potential of natural compounds for safe and effective pain management. In this regard, we summarize the discovery and characterization of pain-relieving phytochemicals from herbal medicine, and we discuss their mechanisms of action and their potential to mimic or enhance the effects of conventional analgesics through ion channel modulation.

The analgesic effect and mechanism of the active components screening from Corydalis yanhusuo by P2X3 receptors

ETHNOPHARMACOLOGICAL RELEVANCE

Cavidine (CAV) is the main bioactive ingredient of Corydalis ternata f. yanhusuo (Y.H.Chou & Chun C.Hsu) Y.C.Zhu, which is a traditional Chinese herbal containing a variety of uses such as analgesic, anticancer, and anti-inflammatory properties.

AIM OF THE STUDY

The goal is to screen Corydalis yanhusuo for anti-central sensitization active components and investigate and clarify the pharmacological mechanism and therapeutic efficacy of the active ingredient CAV in the treatment of chronic pain.

MATERIAL AND METHODS

First, cell membrane immobilized chromatography was used to screen the bioactive ingredients in Corydalis yanhusuo. Spare nerve injury (SNI) model and complete Freund's adjuvant (CFA) mice model were constructed to identify the analgesic effect of CAV. RNA-seq and bioinformatics analyses were used to explore the potential targets of CAV in CFA mice and SNI mice. HE staining was used to observe the infiltration of inflammatory cells in the dorsal root ganglion (DRG) and spinal cord(SC) of CFA mice and SNI mice. WB and qPCR were used to detect the level of inflammatory factors TNF-α, IL-1β, and IL-6 in DRG and SC of mice. SNI and CFA mice were used to study the effect and mechanism of CAV on microglial activation.

RESULTS

9 potential active ingredients were screened out from Corydalis yanhusuo that can regulate P2X3 receptors. CAV showed good analgesic effects, increased the mechanical pain and thermal pain thresholds of CFA mice and SNI mice, inhibited the expression of DRG and SC inflammatory factors, downregulated IBA-1, and inhibited microglial activation. Further in vivo and in vitro experiments showed that CAV significantly inhibited the expression of P2X3 receptors and the activation of its downstream MAPK pathway in DRG neurons and SC.

CONCLUSION

This study is the first to indicate that CAV exerts an analgesic effect by inhibiting microglia activation via the P2X3 signaling pathway axis, providing the clinical utility of CAV in chronic pain therapy.

Large variability in the alkaloid content of Corydalis yanhusuo dietary supplements

Introduction

Extracts from the rhizome of the traditional Chinese medicinal plant Corydalis yanhusuo (CY) mediate a number of biologic effects that are associated with its content of isoquinoline alkaloids. CY alkaloids have shown analgesic, cardioprotective, and anti-addictive effects in animal models of disease. Since CY alkaloids are available to consumers as dietary supplements we analyzed the content of alkaloids in 14 products including open powders, capsules, and liquid formulations, capturing a majority of the products available online in the US.

Methods

Nineteen alkaloids were quantified using HPLC analyses with diode array detection after extraction using a weak cation exchange column.

Results

Total alkaloid content was highly variable among the products, ranging from below quantifiable in some to ≈11 mg/g in others. Five of the products had comparable content of alkaloids (9.5 ± 1.6 mg/g), equaling about the amount of alkaloids of an extract prepared from CY rhizome (12.7 mg/g). The other samples had much lower content (1.8 ± 0.9 mg/g), or alkaloids were below quantifiable. One of the products was highly enriched in tetrahydropalmatine (≈5 mg/g), suggesting adulteration from the natural product, and raising concerns about possible toxicologic liability.

Discussion

Considering alkaloid content as a key quality criterium for CY supplements, the large variability among the products seems unacceptable and makes it difficult for consumers to select products with an appropriate content of alkaloids.

Effects of typical plant growth regulator chlormequat chloride on alkaloidal compounds in Corydalis yanhusuo and molecular mechanisms

The effects of chlormequat chloride, a typical plant growth regulator, on the medicinal herb Corydalis yanhusuo were investigated. A standardized field experiment was conducted to investigate the molecular mechanisms and variations in active compounds resulting from chlormequat chloride treatment. Samples of C. yanhusuo were collected under controlled conditions and at varying doses of chlormequat chloride. The differential compounds identified in both control and treated groups of C. yanhusuo were primarily alkaloids, as determined by non-targeted metabolomics analysis. The metabolite content was determined through the precise quantification of 12 enriched alkaloidal compounds across various categories of C. yanhusuo using targeted metabolomics. A comprehensive metabolomics evaluation method was developed that focuses on pharmacodynamically active compounds. Transcriptomic analysis also facilitates the identification of differential genes and enzymes associated with alkaloid production between the two groups. Chlormequat chloride significantly increased the yield of C. yanhusuo, but the content of the quantitatively abundant alkaloids decreased. It was suggested that the level of cytochrome P450 enzymes, primarily involved in the biosynthesis of benzylisoquinoline alkaloids, was inhibited by chlormequat chloride. In conclusion, this study revealed a dose-dependent effect of chlormequat chloride on C. yanhusuo and its associated molecular mechanisms as determined by omics analysis.

Protopine Exerts Neuroprotective Effects on Neonatal Hypoxic-Ischemic Brain Damage in Rats via Activation of the AMPK/PGC1α Pathway

Introduction

Neonatal hypoxic-ischemic encephalopathy (HIE), caused by perinatal asphyxia, is characterized by high morbidity and mortality, but there are still no effective therapeutic drugs. Mitochondrial biogenesis and apoptosis play key roles in the pathogenesis of HIE. Protopine (Pro), an isoquinoline alkaloid, has anti-apoptotic and neuro-protective effects. However, the protective roles of Pro on neonatal hypoxic-ischemic brain injury remain unclear.

Methods

In this study, we established a CoCl2-induced PC12 cell model in vitro and a neonatal rat hypoxic-ischemic (HI) brain damage model in vivo to explore the neuro-protective effects of Pro and try to elucidate the potential mechanisms.

Results

Our results showed that Pro significantly reduced cerebral infarct volume, alleviated brain edema, inhibited glia activation, improved mitochondrial biogenesis, relieved neuron cell loss, decreased cell apoptosis and reactive oxygen species (ROS) after HI damage. In addition, Pro intervention upregulated the levels of p-AMPK/AMPK and PGC1α as well as the downstream mitochondrial biogenesis related factors, such as nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), but the AMPK inhibitor compound c (CC) could significantly reverse these effects of Pro.

Discussion

Pro may exert neuroprotective effects on neonatal hypoxic-ischemic brain damage via activation of the AMPK/PGC1α pathway, suggesting that Pro may be a promising therapeutic candidate for HIE, and our study firstly demonstrate the neuro-protective roles of Pro in HIE models.

A novel isoquinoline alkaloid HJ-69 isolated from Zanthoxylum bungeanum attenuates inflammatory pain by inhibiting voltage-gated sodium and potassium channels

ETHNOPHARMACOLOGY RELEVANCE

Zanthoxylum bungeanum Maxim. (Z. bungeanum), a member of the Rutaceae family, has a rich history of traditional use in Asia for treating arthritis and toothache conditions. As characteristic chemical components, numerous kinds of alkaloids have been extracted from plants and their diverse biological activities have been reported. However, research on the isoquinoline alkaloid, a specific type of alkaloids, in Z. bungeanum was scarce.

AIM OF THE STUDY

The study aimed to isolate a novel isoquinoline alkaloid from Z. bungeanum and explore its pharmacological activity in vitro and analgesic activity in vivo.

MATERIALS AND METHODS

Isoquinoline alkaloid isolation and identification from Z. bungeanum were conducted using chromatographic and spectroscopic methods. The whole-cell patch-clamp technique was applied to assess its impact on neuronal excitability, and endogenous voltage-gated potassium (Kv) and sodium (Nav) currents in acutely isolated mouse small-diameter dorsal root ganglion (DRG) neurons. Its inhibitory impacts on channels were further validated with HEK293 cells stably expressing Nav1.7 and Nav1.8, and Chinese hamster ovary (CHO) cells transiently expressing Kv2.1. The formalin inflammatory pain model was utilized to evaluate the potential analgesic activity in vivo.

RESULTS

A novel isoquinoline alkaloid named HJ-69 (N-13-(3-methoxyprop-1-yl)rutaecarpine) was isolated and identified from Z. bungeanum for the first time. HJ-69 significantly suppressed the firing frequency and amplitudes of action potentials in DRG neurons. Consistently, it state-dependently inhibited endogenous Nav currents of DRG neurons, with half maximal inhibitory concentration (IC50) values of 13.06 ± 2.06 μM and 30.19 ± 2.07 μM for the inactivated and resting states, respectively. HJ-69 significantly suppressed potassium currents in DRG neurons, which notably inhibited the delayed rectifier potassium (IK) currents (IC50 = 6.95 ± 1.29 μM) and slightly affected the transient outward potassium (IA) currents (IC50 = 523.50 ± 39.16 μM). Furtherly, HJ-69 exhibited similar potencies on heterologously expressed Nav1.7, Nav1.8, and Kv2.1 channels, which correspondingly represent the main components in neurons. Notably, intraperitoneal administration of 30 mg/kg and 100 mg/kg HJ-69 significantly alleviated pain behaviors in the mouse inflammatory pain model induced by formalin.

CONCLUSION

The study concluded that HJ-69 is a novel and active isoquinoline alkaloid, and the inhibition of Nav and Kv channels contributes to its analgesic activity. HJ-69 may be a promising prototype for future analgesic drug discovery based on the isoquinoline alkaloid.

Enhanced Efficacy of Ciprofloxacin and Tobramycin against Staphylococcus aureus When Combined with Corydalis Tuber and Berberine through Efflux Pump Inhibition

One way that bacteria develop antibiotic resistance is by reducing intracellular antibiotic concentrations through efflux pumps. Therefore, enhancing the efficacy of antibiotics using efflux pump inhibitors provides a way to overcome this type of resistance. Notably, an increasing number of pathogenic Staphylococcus aureus strains have efflux pump genes. In this study, the extract from Corydalis ternata Nakai tuber (Corydalis Tuber) at 512 mg/L was demonstrated to have an antibiotic synergistic effect with ciprofloxacin at 2 mg/L and tobramycin at 1024 mg/L against methicillin-resistant S. aureus (MRSA). Berberine, an isoquinoline alkaloid identified in Corydalis Tuber, was identified as contributing to this effect. Ethidium bromide efflux pump activity assays showed that Corydalis Tuber extract and berberine inhibited efflux, suggesting that they are efflux pump inhibitors. Molecular docking simulations suggested that berberine binds to S. aureus efflux pump proteins MepA, NorA, NorB, and SdrM. Additionally, berberine and Corydalis Tuber extract inhibit biofilm formation, which can confer antibiotic resistance. This study's findings suggest that Corydalis Tuber, a traditional herbal medicine, and berberine, a medicinal supplement, act as S. aureus efflux pump inhibitors, synergistically increasing the efficacy of ciprofloxacin and tobramycin and showing promise as a treatment for antibiotic-resistant S. aureus infections, including MRSA.

The road to evolution of ProTx2: how to be a subtype-specific inhibition of human Nav1.7

The human voltage-gated sodium channel Nav1.7 is a widely proven target for analgesic drug studies. ProTx2, a 30-residue polypeptide from Peruvian green tarantula venom, shows high specificity to activity against human Nav1.7, suggesting its potential to become a non-addictive analgesic. However, its high sensitivity to human Nav1.4 raises concerns about muscle side effects. Here, we engineered three mutants (R13A, R13D, and K27Y) of ProTx2 to evaluate their pharmacological activities toward Nav1.7 and Nav1.4. It is demonstrated that the mutant R13D maintained the analgesic effect in mice while dramatically reducing its muscle toxicity compared with ProTx2. The main reason is the formation of a strong electrostatic interaction between R13D and the negatively charged amino acid residues in DII/S3-S4 of Nav1.7, which is absent in Nav1.4. This study advances our understanding and insights on peptide toxins, paving the way for safer, effective non-addictive analgesic development.

Characterization of CYP82 genes involved in the biosynthesis of structurally diverse benzylisoquinoline alkaloids in Corydalis yanhusuo

Benzylisoquinoline alkaloids (BIAs) represent a significant class of secondary metabolites with crucial roles in plant physiology and substantial potential for clinical applications. CYP82 genes are involved in the formation and modification of various BIA skeletons, contributing to the structural diversity of compounds. In this study, Corydalis yanhusuo, a traditional Chinese medicine rich in BIAs, was investigated to identify the catalytic function of CYP82s during BIA formation. Specifically, 20 CyCYP82-encoding genes were cloned, and their functions were identified in vitro. Ten of these CyCYP82s were observed to catalyze hydroxylation, leading to the formation of protopine and benzophenanthridine scaffolds. Furthermore, the correlation between BIA accumulation and the expression of CyCYP82s in different tissues of C. yanhusuo was assessed their. The identification and characterization of CyCYP82s provide novel genetic elements that can advance the synthetic biology of BIA compounds such as protopine and benzophenanthridine, and offer insights into the biosynthesis of BIAs with diverse structures in C. yanhusuo.

Real-world observations and impacts of Chinese herbal medicine for migraine: results of a registry-based cohort study

Background: Migraine is a prevalent, recurrent condition with substantial disease burden. Chinese herbal medicine (CHM) has been used frequently for migraine in controlled clinical settings. This study is to summarise the characteristics of patients who seek clinical care in a tertiary Chinese medicine hospital in China; to gather their preferences and values of using CHM; to explore the effect of CHM for migraine and its comorbidities in a real-world setting, and to collect first-hand expertise of clinicians' practice pattern in prescribing CHM for migraine. Methods: This registry-based cohort study was prospectively conducted at Guangdong Provincial Hospital of Chinese Medicine from December 2020 to May 2022. Adult migraine patients seeking their initial anti-migraine clinical care at the hospital were consecutively recruited and followed up for 12 weeks. Practitioners specialised in headache management prescribed individualised treatments without research interference. Standardised case report forms were employed to gather information on patients' preferences and perspective of seeking clinical care, as well as to assess participants' migraine severity, comorbidities, and quality of life, at 4-weeks intervals. Various analytical methods were utilised based on the computed data. Results: In this study, we observed 248 participants. Of these, 73 received CHM treatment for 28 days or longer. Notably, these participants exhibited a greater disease severity, compared to those treated with CHM for less than 28 days. Of the 248 participants, 83.47% of them expected CHM would effectively reduce the severity of their migraine, around 50% expected effects for migraine-associated comorbidities, while 51.61% expressing concerns about potential side effects. CHM appeared to be effective in reducing monthly migraine days and pain intensity, improving patients' quality of life, and potentially reducing comorbid anxiety, with a minimum of 28 days CHM treatment. Herbs such as gan cao, gui zhi, chuan xiong, fu ling, bai zhu, yan hu suo, etc. were frequently prescribed for migraine, based on patients' specific symptoms. Conclusion: CHM appeared to be beneficial for migraine and comorbid anxiety in real-world clinical practice when used continuously for 28 days or more. Clinical Trial Registration: clinicaltrials.gov, identifier ChiCTR2000041003.

Corydaline binds to a druggable pocket of hEAG1 channel and inhibits hepatic carcinoma cell viability

Ether-à-go-go (EAG) potassium channels play a crucial role in the regulation of neuronal excitability and cancer progression, rendering them potential drug targets for cancer therapy. However, the scarcity of information regarding the selection sites on hEAG1 has posed a challenge in the discovery of new hEAG1 inhibitors. In this study, we introduced a novel natural product, corydaline, which selectively inhibits the hEAG1 channel without sensitivity to other KCNH channels. The IC50 of corydaline for the hEAG1 channel was 11.3 ± 0.6 μM, whereas the IC50 for hEAG2 and hERG1 were 73.6 ± 9.9 μM and 111.4 ± 8.5 μM, respectively. Molecular dynamics simulations together with site-directed mutagenesis, have unveiled that the site corydaline forms interactions with Lys217, Phe273, Pro276, Trp295 and Arg366, situated within the intracellular transmembrane segments S1-S4 of the voltage-sensor domain, be considered a novel drug pocket for hEAG1. Additionally, the intergaration of sequence alignment and 3D structural modeling revealed differences between the voltage sensor domain of hEAG1 channel and other EAG channels, suggesting the feasibility of a VSD modulation approach that could potentially lead to the selective inhibition of hEAG1 channels. Furthermore, antitumor experiments demonstrated that corydaline can inhibit the proliferation and migration of hepatic carcinoma cells by targeting hEAG1. The identification of this novel druggable pocket offers the possibility for drug screening against diseases linked to abnormal hEAG1 channels.

Integrating Full-Length and Second-Generation Transcriptomics to Reveal Differentially Expressed Genes Associated with the Development of Corydalis yanhusuo Tuber

Corydalis yanhusuo is a medicinal herb in China that has been widely used to treat various kinds of pain. The tuber is the main organ of C. yanhusuo used for medicinal purposes, but changes in related genes during the development of the tuber have rarely been reported. To identify the differentially expressed genes during tuber development, C. yanhusuo full-length transcriptomic sequencing was performed using single-molecule real-time technology, and tubers at three development stages were selected for comparative transcriptome analysis. A total of 90,496 full-length non-chimeric transcripts were obtained, and 19,341 transcripts were annotated in at least one public database. A total of 9221 differentially expressed genes were identified during the swelling process of C. yanhusuo tuber. A Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis revealed that differentially expressed genes associated with a "starch and sucrose metabolism pathway", "phenylpropanoid biosynthesis pathway", "isoquinoline alkaloid biosynthesis pathway", "zeatin biosynthesis pathway", and "brassinosteroid biosynthesis pathway" were predominantly enriched. In addition, the genes involved in cell wall metabolism were potentially associated with tuber swelling. These processes regulated and were involved in C. yanhusuo tuber development. The results provide a foundation for further research on tuber formation in medicinal plants.

The composition, pharmacological effects, related mechanisms and drug delivery of alkaloids from Corydalis yanhusuo

Corydalis yanhusuo W. T. Wang, also known as yanhusuo, yuanhu, yanhu and xuanhu, is one of the herb components of many Chinese Traditional Medicine prescriptions such as Jin Ling Zi San and Yuanhu-Zhitong priscription. C. yanhusuo was traditionally used to relieve pain and motivate blood and Qi circulation. Now there has been growing interest in pharmacological effects of alkaloids, the main bioactive components of C. yanhusuo. Eighty-four alkaloids isolated from C. yanhusuo are its important bioactive components and can be characterized into protoberberine alkaloids, aporphine alkaloids, opiate alkaloids and others and proper extraction or co-administration methods modulate their contents and efficacy. Alkaloids from C. yanhusuo have various pharmacological effects on the nervous system, cardiovascular system, cancer and others through multiple molecular mechanisms such as modulating neurotransmitters, ion channels, gut microbiota, HPA axis and signaling pathways and are potential treatments for many diseases. Plenty of novel drug delivery methods such as autologous red blood cells, self-microemulsifying drug delivery systems, nanoparticles and others have also been investigated to better exert the effects of alkaloids from C. yanhusuo. This review summarized the alkaloid components of C. yanhusuo, their pharmacological effects and mechanisms, and methods of drug delivery to lay a foundation for future investigations.

From Plant to Chemistry: Sources of Active Opioid Antinociceptive Principles for Medicinal Chemistry and Drug Design

Pain continues to be an enormous global health challenge, with millions of new untreated or inadequately treated patients reported annually. With respect to current clinical applications, opioids remain the mainstay for the treatment of pain, although they are often associated with serious side effects. To optimize their tolerability profiles, medicinal chemistry continues to study novel ligands and innovative approaches. Among them, natural products are known to be a rich source of lead compounds for drug discovery, and they hold potential for pain management. Traditional medicine has had a long history in clinical practice due to the fact that nature provides a rich source of active principles. For instance, opium had been used for pain management until the 19th century when its individual components, such as morphine, were purified and identified. In this review article, we conducted a literature survey aimed at identifying natural products interacting either directly with opioid receptors or indirectly through other mechanisms controlling opioid receptor signaling, whose structures could be interesting from a drug design perspective.

Natural products as the calcium channel blockers for the treatment of arrhythmia: Advance and prospect

Arrhythmia is one of the commonly heart diseases with observed abnormal heart-beat rhythm that caused by the obstacles of cardiac activity and conduction. The arrhythmic pathogenesis is complex and capricious and related with other cardiovascular diseases that may lead to heart failure and sudden death. In particular, calcium overload is recognized as the main reason causing arrhythmia through inducing apoptosis in cardiomyocytes. Moreover, calcium channel blockers have been widely used as the routine drugs for the treatment of arrhythmia, but the different arrhythmic complications and adverse effects limit their further applications and demand new drug discovery. Natural products have always been the rich minerals for the development of new drugs that could be employed as the versatile player for the discovery of safe and effective anti-arrhythmia drugs with new mechanisms. In this review, we summarized natural products with the activity against calcium signaling and the relevant mechanism of actions. We are expected to provide an inspiration for the pharmaceutical chemists to develop more potent calcium channel blockers for the treatment of arrhythmia.

Argentatin C Analogues with Potential Antinociceptive Activity and Other Triterpenoid Constituents from the Aerial Parts of Parthenium incanum

Four new triterpenes, 25-dehydroxy-25-methoxyargentatin C (1), 20S-hydroxyargentatin C (2), 20S-hydroxyisoargentatin C (3), and 24-epi-argentatin C (4), together with 10 known triterpenes (5-14) were isolated from the aerial parts of Parthenium incanum. The structures of 1-4 were elucidated by detailed analysis of their spectroscopic data, and the known compounds 5-14 were identified by comparison of their spectroscopic data with those reported. Since argentatin C (11) was found to exhibit antinociceptive activity by decreasing the excitability of rat and macaque dorsal root ganglia (DRG) neurons, 11 and its new analogues 1-4 were evaluated for their ability to decrease the excitability of rat DRG neurons. Of the argentatin C analogues tested, 25-dehydroxy-25-methoxyargentatin C (1) and 24-epi-argentatin C (4) decreased neuronal excitability in a manner comparable to 11. Preliminary structure-activity relationships for the action potential-reducing effects of argentatin C (11) and its analogues 1-4, and their predicted binding sites in pain-relevant voltage-gated sodium and calcium channels (VGSCs and VGCCs) in DRG neurons are presented.

Interaction between Changan Granule and its main components in the plasma and CYP450 enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

Changan Granule (CAG) is a Chinese patent drug developed based on an empirical prescription in accordance with the formulation theory of Traditional Chinese Medicine. The prescription is composed of eight herbal drugs which have been traditionally used by Chinese people for a long history. It has effects of invigorating spleen and supplementing qi, as well as regulating liver and ceasing diarrhea, and is indicated for the treatment of irritable bowel syndrome (IBS).

AIM OF THE STUDY

This study was aimed to investigate the interaction between CAG and its main components and cytochrome P450 (CYP450) enzymes so as to characterize the major metabolites and metabolic enzymes and evaluate the safety concerns to its clinical use.

MATERIALS AND METHODS

Both in vivo and in vitro experiments using such as diarrhea-predominant IBS (IBS-D) rat model, HepG2 cells, and human liver microsomes (HLM) were carried out to investigate the interaction between CAG and its main components and CYP450 enzymes. Real-time quantitative PCR (qPCR), ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and cocktail probes were employed to qualitatively or quantitatively measure the metabolites and metabolic enzymes.

RESULTS

CAG inhibited the enzyme activities of CYP1A2, CYP2E1, CYP2D6, CYP2C9, and CYP3A4 and the mRNA expressions of CYP2E1, CYP2C9, CYP3A4, and CYP2D6 in vitro. CAG down-regulated the increased expression of CYP1A2 and up-regulated the decreased expression of CYP3A1 in vivo. Twenty-two metabolites were characterized from the main components of CAG after incubation with HLM in vitro. CYP2D6, CYP2E1, CYP3A4 and CYP2C9 were identified as the characteristic metabolic enzymes.

CONCLUSIONS

This study provides a reference for clinical application of CAG in safety. CAG and CYP450 enzymes are interacted. CAG is mainly metabolized by CYP2E1 and CYP2D6. The expression of CYP2E1 and CYP2D6 are more susceptible to be influenced by CAG in comparison with that of CYP3A4, CYP2C9 and CYP1A2. It implies the potential risk of interaction when CAG is taken together with the drugs metabolized by CYP2E1 and CYP2D6.

Pharmacological mechanism of natural drugs and their active ingredients in the treatment of arrhythmia via calcium channel regulation

Arrhythmia is characterized by abnormal heartbeat rhythms and frequencies caused by heart pacing and conduction dysfunction. Arrhythmia is the leading cause of death in patients with cardiovascular disease, with high morbidity and mortality rates, posing a serious risk to human health. Natural drugs and their active ingredients, such as matrine(MAT), tetrandrine(TET), dehydroevodiamine, tanshinone IIA, and ginsenosides, have been widely used for the treatment of atrial fibrillation, ventricular ectopic beats, sick sinus syndrome, and other arrhythmia-like diseases owing to their unique advantages. This review summarizes the mechanism of action of natural drugs and their active ingredients in the treatment of arrhythmia via the regulation of Ca²⁺, such as alkaloids, quinones, saponins, terpenoids, flavonoids, polyphenols, and lignan compounds, to provide ideas for the innovative development of natural drugs with potential antiarrhythmic efficacy.

Dehydrocorydaline alleviates sleep deprivation-induced persistent postoperative pain in adolescent mice through inhibiting microglial P2Y12 receptor expression in the spinal cord

During adolescence, a second period of central nervous system (CNS) plasticity that follows the fetal period, which involves sleep deprivation (SD), becomes apparent. SD during adolescence may result in abnormal development of neural circuits, causing imbalance in neuronal excitation and inhibition, which not only results in pain, but increases the chances of developing emotion disorders in adulthood, such as anxiety and depression. The quantity of surgeries during adolescence is also consistently on the rise, yet the impact and underlying mechanism of preoperative SD on postoperative pain remain unexplored. This study demonstrates that preoperative SD induces upregulation of the P2Y12 receptor, which is exclusively expressed on spinal microglia, and phosphorylation of its downstream signaling pathway p38Mitogen-activated protein/Nuclear transcription factor-κB (p38MAPK/NF-κB)in spinal microglia, thereby promoting microglia activation and microglial transformation into the proinflammatory M1 phenotype, resulting in increased expression of proinflammatory cytokines that exacerbate persisting postoperative incisional pain in adolescent mice. Both intrathecal minocycline (a microglia activation inhibitor) and MRS2395 (a P2Y12 receptor blocker) effectively suppressed microglial activation and proinflammatory cytokine expression. Interestingly, supplementation with dehydrocorydaline (DHC), an extract of Rhizoma Corydalis, inhibited the P2Y12/p38MAPK/NF-κB signaling pathway, microglia activation, and expression of pro-inflammatory cytokines in the model mice. Taken together, the results indicate that the P2Y12 receptor and microglial activation are important factors in persistent postoperative pain caused by preoperative SD in adolescent mice and that DHC has analgesic effects by acting on these targets.

Plant-derived natural products targeting ion channels for pain

Chronic pain affects approximately one-fifth of people worldwide and reduces quality of life and in some cases, working ability. Ion channels expressed along nociceptive pathways affect neuronal excitability and as a result modulate pain experience. Several ion channels have been identified and investigated as potential targets for new medicines for the treatment of a variety of human diseases, including chronic pain. Voltage-gated channels Na⁺ and Ca²⁺ channels, K⁺ channels, transient receptor potential channels (TRP), purinergic (P2X) channels and acid-sensing ion channels (ASICs) are some examples of ion channels exhibiting altered function or expression in different chronic pain states. Pharmacological approaches are being developed to mitigate dysregulation of these channels as potential treatment options. Since natural compounds of plant origin exert promising biological and pharmacological properties and are believed to possess less adverse effects compared to synthetic drugs, they have been widely studied as treatments for chronic pain for their ability to alter the functional activity of ion channels. A literature review was conducted using Medline, Google Scholar and PubMed, resulted in listing 79 natural compounds/extracts that are reported to interact with ion channels as part of their analgesic mechanism of action. Most in vitro studies utilized electrophysiological techniques to study the effect of natural compounds on ion channels using primary cultures of dorsal root ganglia (DRG) neurons. In vivo studies concentrated on different pain models and were conducted mainly in mice and rats. Proceeding into clinical trials will require further study to develop new, potent and specific ion channel modulators of plant origin.

Plant and fungi derived analgesic natural products targeting voltage-gated sodium and calcium channels

Voltage-gated sodium and calcium channels (VGSCs and VGCCs) play an important role in the modulation of physiologically relevant processes in excitable cells that range from action potential generation to neurotransmission. Once their expression and/or function is altered in disease, specific pharmacological approaches become necessary to mitigate the negative consequences of such dysregulation. Several classes of small molecules have been developed with demonstrated effectiveness on VGSCs and VGCCs; however, off-target effects have also been described, limiting their use and spurring efforts to find more specific and safer molecules to target these channels. There are a great number of plants and herbal preparations that have been empirically used for the treatment of diseases in which VGSCs and VGCCs are involved. Some of these natural products have progressed to clinical trials, while others are under investigation for their action mechanisms on signaling pathways, including channels. In this review, we synthesize information from ~30 compounds derived from natural sources like plants and fungi and delineate their effects on VGSCs and VGCCs in human disease, particularly pain. [Figure: see text].

Acute, chronic, and genotoxic studies on the protopine total alkaloids of the Macleaya cordata (willd.) R. Br. in rodents

The protopine alkaloids are widely distributed within the opium poppy family and have a wide range of pharmacological effects. MPTA is a product of the protopine total alkaloids extracted from the Macleaya cordata (Willd.) R. Br. Previously, we reported good anti-inflammatory activity of MPTA as well as oral acute and sub-chronic toxicity studies in rats. In order to perform a systematic toxicological safety assessment of MPTA, oral acute toxicity, genotoxicity (bone marrow cell chromosome aberration test, sperm abnormality test, bone marrow cell micronucleus test, and rat teratogenicity test), and chronic toxicity in mice were performed in this study. In the oral acute toxicity test, the LD₅₀ in ICR mice was 481.99 mg/kg, with 95% confidence limits ranging from 404.27 to 574.70 mg/kg. All three mutagenicity tests tested negative in the range of 60.25–241.00 mg/kg. The results of the teratogenicity test in rats showed no reproductive or embryonic developmental toxicity at only 7.53 mg/kg, which can be considered as a no observed effect level (NOEL) for the teratogenicity test. Therefore, MPTA is safe for use at the doses tested, but attention should be paid to the potential risk to pregnant animals and the safety evaluation and toxicity mechanisms in target animals should be further investigated.

Inhibitory Activity of Quaternary Isoquinoline Alkaloids on Soluble Epoxide Hydrolase

The quaternary isoquinoline alkaloids of palmatine (1), berberine (2), and jatrorrhizine (3) were evaluated in terms of their ability to inhibit soluble epoxide hydrolase (sEH). They had similar inhibitory activities, with IC₅₀ values of 29.6 ± 0.5, 33.4 ± 0.8, and 27.3 ± 0.4 μM, respectively. Their respective Ki values of 26.9, 46.8, and 44.5 μM—determined by enzyme kinetics—indicated that they inhibited the catalytic reaction by binding noncompetitively with sEH. The application of computational chemistry to the in vitro results revealed the site of the receptor to which the ligand would likely bind. Accordingly, three alkaloids were identified as having a suitable basic skeleton for lead compound development of sEH inhibitors.

Prediction and verification of potential lead analgesic and antiarrhythmic components in Corydalis yanhusuo W. T. Wang based on voltage-gated sodium channel proteins

Corydalis yanhusuo W. T. Wang, a traditional Chinese herbal medicine, has been used as an analgesic for thousands of years and it also promotes blood circulation. In this study, 33 Corydalis yanhusuo alkaloid active components were acquired from Traditional Chinese Medicine Database and Analysis Platform (TCMSP). A total of 543 pain-related targets, 1774 arrhythmia targets, and 642 potential targets of these active components were obtained using Swiss Target Prediction, GeneCards, Open Target Platform, and Therapeutic Target Database. Fifty intersecting targets were visualized through a Venn diagram, KEGG and GO pathway enrichment analysis. The analysis proposed that sodium ion channels are likely potential targets of Corydalis yanhusuo active components as analgesia and anti-arrhythmia agents. Molecular docking showed that the 33 components could bind to Nav1.7 and Nav1.5 (two subtypes of ion channel proteins) with different binding energies. In a patch clamp study, dihydrosanguinarine and dihydrochelerythrine, two monomers with the strongest binding effects, could inhibit the peak currents and promote both activation and inactivation phases of Nav1.5. Meanwhile, dihydrosanguinarine and dihydrochelerythrine could also inhibit peak currents and promote the activation phase of Nav1.7. Therefore, the findings from this study provide valuable information for future uses of traditional Chinese medicines to treat pain and cardiovascular disease.

Exploring the Anti-inflammatory Effects of Protopine Total Alkaloids of Macleaya Cordata (Willd.) R. Br

Macleaya cordata (Willd). R. Br. is a Chinese medicinal plant commonly used externally to treat inflammatory-related diseases such as arthritis, sores, and carbuncles. This study aimed to evaluate the anti-inflammatory activity of protopine total alkaloids (MPTAs) in Macleaya cordata (Willd.) R. Br. in vivo tests in rats with acute inflammation showed that MPTA (2.54 and 5.08 mg/kg) showed significant anti-inflammatory activity 6 h after carrageenan injection. Similarly, MPTA (3.67 and 7.33 mg/kg) showed significant anti-inflammatory activity in the mouse ear swelling test. In addition, the potential mechanisms of the anti-inflammatory effects of MPTA were explored based on network pharmacology and molecular docking. The two main active components of MPTA, protopine and allocryptopine, were identified, and the potential targets and signaling pathways of MPTA's anti-inflammatory effects were initially revealed using tools and databases (such as SwissTargetPrediction, GeneCards, and STRING) combined with molecular docking results. This study provides the basis for the application of MPTA as an anti-inflammatory agent.

Treatment of Gastrointestinal Disorders-Plants and Potential Mechanisms of Action of Their Constituents

The worldwide prevalence of gastrointestinal diseases is about 40%, with standard pharmacotherapy being long-lasting and economically challenging. Of the dozens of diseases listed by the Rome IV Foundation criteria, for five of them (heartburn, dyspepsia, nausea and vomiting disorder, constipation, and diarrhoea), treatment with herbals is an official alternative, legislatively supported by the European Medicines Agency (EMA). However, for most plants, the Directive does not require a description of the mechanisms of action, which should be related to the therapeutic effect of the European plant in question. This review article, therefore, summarizes the basic pharmacological knowledge of synthetic drugs used in selected functional gastrointestinal disorders (FGIDs) and correlates them with the constituents of medicinal plants. Therefore, the information presented here is intended as a starting point to support the claim that both empirical folk medicine and current and decades-old treatments with official herbal remedies have a rational basis in modern pharmacology.

Identification and Quantification, Metabolism and Pharmacokinetics, Pharmacological Activities, and Botanical Preparations of Protopine: A Review

Through pharmacological activity research, an increasing number of natural products and their derivatives are being recognized for their therapeutic value. In recent years, studies have been conducted on Corydalis yanhusuo W.T. Wang, a valuable medicinal herb listed in the Chinese Pharmacopoeia. Protopine, one of its components, has also become a research hotspot. To illustrate the identification, metabolism, and broad pharmacological activity of protopine and the botanical preparations containing it for further scientific studies and clinical applications, an in-depth and detailed review of protopine is required. We collected data on the identification and quantification, metabolism and pharmacokinetics, pharmacological activities, and botanical preparations of protopine from 1986 to 2021 from the PubMed database using “protopine” as a keyword. It has been shown that protopine as an active ingredient of many botanical preparations can be rapidly screened and quantified by a large number of methods (such as the LC-ESI-MS/MS and the TLC/GC-MS), and the possible metabolic pathways of protopine in vivo have been proposed. In addition, protopine possesses a wide range of pharmacological activities such as anti-inflammatory, anti-platelet aggregation, anti-cancer, analgesic, vasodilatory, anticholinesterase, anti-addictive, anticonvulsant, antipathogenic, antioxidant, hepatoprotective, neuroprotective, and cytotoxic and anti-proliferative activities. In this paper, the identification and quantification, metabolism and pharmacokinetics, pharmacological activities, and botanical preparations of protopine are reviewed in detail to lay a foundation for further scientific research and clinical applications of protopine.