Aconitine induces cardiomyocyte damage by mitigating BNIP3-dependent mitophagy and the TNFα-NLRP3 signalling axis

Cardiovascular disease: Mitochondrial dynamics and mitophagy crosstalk mechanisms with novel programmed cell death and macrophage polarisation

Several cardiovascular illnesses are associated with aberrant activation of cellular pyroptosis, ferroptosis, necroptosis, cuproptosis, disulfidptosis, and macrophage polarisation as hallmarks contributing to vascular damage and abnormal cardiac function. Meanwhile, these three novel forms of cellular dysfunction are closely related to mitochondrial homeostasis. Mitochondria are the main organelles that supply energy and maintain cellular homeostasis. Mitochondrial stability is maintained through a series of regulatory pathways, such as mitochondrial fission, mitochondrial fusion and mitophagy. Studies have shown that mitochondrial dysfunction (e.g., impaired mitochondrial dynamics and mitophagy) promotes ROS production, leading to oxidative stress, which induces cellular pyroptosis, ferroptosis, necroptosis, cuproptosis, disulfidptosis and macrophage M1 phenotypic polarisation. Therefore, an in-depth knowledge of the dynamic regulation of mitochondria during cellular pyroptosis, ferroptosis, necroptosis, cuproptosis, disulfidptosis and macrophage polarisation is necessary to understand cardiovascular disease development. This paper systematically summarises the impact of changes in mitochondrial dynamics and mitophagy on regulating novel cellular dysfunctions and macrophage polarisation to promote an in-depth understanding of the pathogenesis of cardiovascular diseases and provide corresponding theoretical references for treating cardiovascular diseases.

Physiologically based pharmacokinetic modeling for confirming the role of CYP3A1/2 and P-glycoprotein in detoxification mechanism between glycyrrhizic acid and aconitine in rats

Fuzi, an effective common herb, is often combined with Gancao to treat disease in clinical practice with enhancing its efficacy and alleviating its toxicity. The major toxic and bioactive compounds in Fuzi and Gancao are aconitine (AC) and glycyrrhizic acid (GL), respectively. This study aims to elucidate detoxification mechanism between AC and GL from pharmacokinetic perspective using physiologically based pharmacokinetic (PBPK) model. In vitro experiments exhibited that AC was mainly metabolized by CYP3A1/2 in rat liver microsomes and transported by P-glycoprotein (P-gp) in Caco-2 cells. Kinetics assays showed that the Km and Vmax of AC towards CYP3A1/2 were 2.38 μM and 57.3 pmol/min/mg, respectively, whereas that of AC towards P-gp was 11.26 μM and 147.1 pmol/min/mg, respectively. GL markedly induced the mRNA expressions of CYP3A1/2 and MDR1a/b in rat primary hepatocytes. In vivo studies suggested that the intragastric and intravenous administration of GL significantly reduced systemic exposure of AC by 27% and 33%, respectively. Drug-drug interaction (DDI) model of PBPK predicted that co-administration of GL would decrease the exposure of AC by 39% and 45% in intragastric and intravenous dosing group, respectively. The consistency between predicted data and observed data confirmed that the upregulation of CYP3A1/2 and P-gp was the crucial detoxification mechanism between AC and GL. Thus, this study provides a demonstration for elucidating the compatibility mechanisms of herbal formula using PBPK modeling and gives support for the clinical co-medication of Fuzi and Gancao.

Protective effect of ginsenoside Rb1 against aconitine cardiotoxicity studied by myocardial injury, action potential, and calcium signaling

Aconitine is the main active component of Aconitum plants. Although aconitine has effects that include strengthening the heart, analgesia, anti-tumor, and immune-regulating effects, aconitine has both efficacy and toxicity, especially cardiotoxicity. Severe effects can include arrhythmia and cardiac arrest, which limits the clinical application of aconitine-containing traditional Chinese medicine. Ginsenoside Rb1(Rb1) is mainly found in plants, such as ginseng and Panax notoginseng, and has cardiovascular-protective and anti-arrhythmia effects. This study aimed to investigate the detoxifying effects of Rb1 on aconitine cardiotoxicity and the electrophysiological effect of Rb1 on aconitine-induced arrhythmia in rats. Pathological analysis, myocardial enzymatic indexes, and Western blotting were used to investigate the ameliorating effect of Rb1 on aconitine cardiotoxicity. Optical mapping was used to evaluate the effect of Rb1 on action potential and calcium signaling after aconitine-induced arrhythmia. Rb1 inhibited pathological damage caused by aconitine, decreased myocardial enzyme levels, and restored the balance of apoptotic protein expression by reducing the expression of Bax and cleaved caspase 3 and increasing the expression of Bcl-2, thereby reducing myocardial damage caused by aconitine. Rb1 also reduced the increase in heart rate caused by aconitine, accelerated action potential conduction and calcium signaling, and reduced the dispersion of action potential and calcium signal conduction. Rb1 reduced the cardiotoxicity of aconitine by attenuating aconitine-induced myocardial injury and inhibiting the aconitine-induced retardation of ventricular action potential and calcium signaling in rats.

A toxicological review of alkaloids

Alkaloids are naturally occurring compounds with complex structures found in natural plants. To further improve the understanding of plant alkaloids, this review focuses on the classification, toxicity and mechanisms of action, providing insight into the occurrence of alkaloid-poisoning events and guiding the safe use of alkaloids in food, supplements and clinical applications. Based on their chemical structure, alkaloids can be divided into organic amines, diterpenoids, pyridines, isoquinolines, indoles, pyrrolidines, steroids, imidazoles and purines. The mechanisms of toxicity of alkaloids, including neurotoxicity, hepatoxicity, nephrotoxicity, cardiotoxicity and cytotoxicity, have also been reviewed. Some cases of alkaloid poisoning have been introduced when used as food or clinically, including accidental food poisoning, excessive consumption, and poisoning caused by the improper use of alkaloids in a clinical setting, and the importance of safety evaluation was illustrated. This review summarizes the toxicity and mechanism of action of alkaloids and provides evidence for the need for the safe use of alkaloids in food, supplements and clinical applications.

Comprehensive insight into the pharmacology, pharmacokinetics, toxicity, detoxification and extraction of hypaconitine from Aconitum plants

ETHNOPHARMACOLOGICAL RELEVANCE

Hypaconitine (HA), a diterpenoid alkaloid, mainly derived from Aconitum plants such as Acoitum carmichaeli Debx. And Aconitum nagarum Stapf., has recently piqued significant interest among the scientific community given its multifaceted attributes including anti-inflammatory, anticancer, analgesic, and cardio-protective properties.

AIM OF THE STUDY

This review presents a comprehensive exploration of the research advancements regarding the traditional uses, pharmacology, pharmacokinetics, toxicity, and toxicity reduction of HA. It aims to provide a thorough understanding of HA's multifaceted properties and its potential applications in various fields.

MATERIALS AND METHODS

A systematic literature search was conducted using several prominent databases including PubMed, Web of Science, NCBI, and CNKI. The search was performed using specific keywords such as "hypaconitine," "heart failure," "anti-inflammatory," "aconite decoction," "pharmacological," "pharmacokinetics," "toxicity," "detoxification or toxicity reduction," and "extraction and isolation." The inclusion of these keywords ensured a comprehensive exploration of relevant studies and enabled the retrieval of valuable information pertaining to the various aspects of HA.

RESULTS

Existing research has firmly established that HA possesses a range of pharmacological effects, encompassing anti-cardiac failure, anti-inflammatory, analgesic, and anti-tumor properties. The therapeutic potential of HA is promising, with potential applications in heart failure, ulcerative colitis, cancer, and other diseases. Pharmacokinetic studies suggest that HA exhibits high absorption rates, broad distribution, and rapid metabolism. However, toxic effects of HA on the nerves, heart, and embryos have also been observed. To mitigate these risks, HA needs attenuation before use, with the most common detoxification methods being processing and combined use with other drugs. Extraction methods for HA most commonly include cold maceration, soxhlet reflux extraction, and ultrasonic-assisted extraction. Despite the potential therapeutic benefits of HA, further research is warranted to elucidate its anti-heart failure effects, particularly in vivo, exploring aspects such as in vivo metabolism, distribution, and metabolites. Additionally, the therapeutic effects of HA monomers on inflammation-induced diseases and tumors should be validated in a more diverse range of experimental models, while the mechanisms underlying the therapeutic effects of HA should be investigated in greater detail.

CONCLUSION

This review serves to emphasize the therapeutic potential of HA and highlights the crucial need to address its toxicity concerns before considering clinical application. Further research is required to comprehensively investigate the pharmacological properties of HA, with particular emphasis on its anti-cardiac failure and anti-inflammatory activities. Such research endeavors have the potential to unveil novel treatment avenues for a broad spectrum of diseases.

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.

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

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

Deciphering the toxicity-effect relationship and action patterns of traditional Chinese medicines from a smart data perspective: a comprehensive review

In Chinese medicine, the primary considerations revolve around toxicity and effect. The clinical goal is to achieve maximize effect while minimizing toxicity. Nevertheless, both clinical and experimental research has revealed a distinct relationship between these two patterns of action in toxic Traditional Chinese Medicines (TCM). These TCM often exhibit characteristic "double-sided" or "multi-faceted" features under varying pathological conditions, transitioning between effective and toxic roles. This complexity adds a layer of challenge to unraveling the ultimate objectives of Traditional Chinese medicine. To address this complexity, various hypotheses have been proposed to explain the toxicity and effect of Traditional Chinese Medicines. These hypotheses encompass the magic shrapnel theory for effect, the adverse outcome pathway framework, and the indirect toxic theory for toxicity. This review primarily focuses on high-, medium-, and low-toxicity Traditional Chinese Medicines as listed in Chinese Pharmacopoeia. It aims to elucidate the essential intrinsic mechanisms and elements contributing to their toxicity and effectiveness. The critical factors influencing the mechanisms of toxicity and effect are the optimal dosage and duration of TCM administration. However, unraveling the toxic-effect relationships in TCM presents a formidable challenge due to its multi-target and multi-pathway mechanisms of action. We propose the integration of multi-omics technology to comprehensively analyze the fundamental metabolites, mechanisms of action, and toxic effects of TCM. This comprehensive approach can provide valuable insights into the intricate relationship between the effect and toxicity of these TCM.

Current status of research on endophytes of traditional Tibetan medicinal plant and their metabolites

The Qinghai-Tibet Plateau, known as the "Third Pole of the World," has a rich variety of medicinal plants that play an important role in the field of medicine due to its unique geographical environment. However, due to the limited resources of Tibetan medicinal plants and the fragility of the ecological environment of the Qinghai-Tibet Plateau, more and more Tibetan medicinal plants are on the verge of extinction. As a reservoir of biologically active metabolites, endophytes of medicinal plants produce a large number of compounds with potential applications in modern medicine (including antibacterial, immunosuppressive, antiviral, and anticancer) and are expected to be substitutes for Tibetan medicinal plants. This paper reviews 12 Tibetan medicinal plants from the Qinghai-Tibet Plateau, highlighting the diversity of their endophytes, the diversity of their metabolites and their applications. The results show that the endophytes of Tibetan medicinal plants are remarkably diverse, and the efficacy of their metabolites involves various aspects, such as antioxidant, anti-disease and anti-parasitic. In addition, conservation measures for the resources of Tibetan medicinal plants are summarised to provide a reference for an in-depth understanding of the endophytes of Tibetan medicinal plants and to stimulate the scientific community to bioprospect for the endophytes of Tibetan medicinal plants, as well as to provide ideas for their rational exploitation.

Role of the HIF-1α/BNIP3 Signaling Pathway in Recurrent Hepatocellular Carcinoma and the Mechanism of Traditional Chinese Medicine

Recurrence of hepatocellular carcinoma (HCC) negatively affects the quality of life of patients and leads to death. Studies have shown that recurrent hepatocellular carcinoma (RHCC) is closely related to tissue hypoxia and autophagy. It has been shown that hypoxia-inducible factor-1α (HIF-1α) and its downstream factor BCL-2 19 kDa-interacting protein 3 (BNIP3) promote cellular autophagy under hypoxic conditions, resulting in metastasis and RHCC. In this article, the molecular structures of HIF-1α and BNIP3 are described, and the significance of the HIF-1α/BNIP3 signaling pathway in RHCC is explained. Moreover, the role and mechanism of traditional Chinese medicine (TCM) in treating RHCC by modulating the HIF-1α/BNIP3 signaling pathway is discussed. Studies have shown that the HIF-1α/BNIP3 signaling pathway is a potential target of TCM in the treatment of RHCC. The mechanism of the HIF-1α/BNIP3 signaling pathway in RHCC and the progress achieved in TCM research on targeting and regulating this pathway are also reviewed in this article. The objective was to provide a theoretical basis for the prevention and treatment of RHCC, as well as further drug development.

Detoxification mechanisms of ginseng to aconite: A review

ETHNOPHARMACOLOGICAL RELEVANCE

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

AIM OF THE REVIEW

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

ETHNOPHARMACOLOGICAL RELEVANCE

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

AIM OF THE STUDY

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

A review: Pharmacokinetics and pharmacology of aminoalcohol-diterpenoid alkaloids from Aconitum species

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum medicinal materials, such as Aconitum carmichaelii Debeaux (Chinese: Wutou/) and Aconitum kusnezoffii Reichb. (Chinese: Caowu/), are a kind of important Traditional Chinese Medicine (TCM) with great medicinal value. Statistics show that there are over 600 efficient TCM formulations comprising Aconitum medicinal materials. But high toxicity limits their clinical application. Clinically, the Aconitum medicinal materials must undergo a complex processing process that includes soaking, steaming, and boiling with pharmaceutical excipients, which makes highly toxic ester diterpenoid alkaloids are hydrolyzed to form less toxic aminoalcohol-diterpenoid alkaloids (ADAs).

AIM OF THE STUDY

This review aims to summarize the pharmacokinetic and pharmacological activities of low-toxicity ADAs, providing a reference for future ADAs research and drug development.

MATERIALS AND METHODS

Accessible literature on ADAs published between 1984 and 2022 were screened and obtained from available electronic databases such as PubMed, Web of Science, Springer, Science Direct and Google Scholar, followed by systematic analysis.

RESULTS

ADAs are secondary products of plant metabolism, widely distributed in the Aconitum species and Delphinium species. The toxicity of ADAs as pharmacodynamic components of Aconitum medicinal materials is much lower than that of other diterpenoid alkaloids due to the absence of ester bonds. On the one hand, the pharmacokinetics of ADAs have received little attention compared to other toxic alkaloids. The research primarily focuses on aconine and mesaconine. According to existing studies, ADAs absorption in the gastrointestinal tract is primarily passive with a short T_max. Simultaneously, efflux transporters have less impact on ADAs absorption than non-ADAs. After entering the body, ADAs are widely distributed in the heart, liver, lungs, and kidney, but less in the brain. Notably, aconine is not well metabolized by liver microsomes. Aconine and mesaconine are excreted in urine and feces, respectively. ADAs, on the other hand, have been shown to have a variety of pharmacological activities, including cardiac, analgesic, anti-inflammatory, anti-tumor, antioxidant, and regenerative effects via regulating multiple signaling pathways, including Nrf2/ARE, PERK/eIF2α/ATF4/Chop, ERK/CREB, NF-κB, Bcl-2/Bax, and GSK3β/β-catenin signaling pathways.

CONCLUSIONS

ADAs have been shown to have beneficial effects on heart disease, neurological disease, and other systemic diseases. Moreover, ADAs have low toxicity and a wide range of safe doses. All of these suggest that ADAs have great potential for drug development.

Neurotoxicity mechanism of aconitine in HT22 cells studied by microfluidic chip-mass spectrometry

Aconitine, a common and main toxic component of Aconitum, is toxic to the central nervous system. However, the mechanism of aconitine neurotoxicity is not yet clear. In this work, we had the hypothesis that excitatory amino acids can trigger excitotoxicity as a pointcut to explore the mechanism of neurotoxicity induced by aconitine. HT22 cells were simulated by aconitine and the changes of target cell metabolites were real-time online investigated based on a microfluidic chip-mass spectrometry system. Meanwhile, to confirm the metabolic mechanism of aconitine toxicity on HT22 cells, the levels of lactate dehydrogenase, intracellular Ca²⁺, reactive oxygen species, glutathione and superoxide dismutase, and ratio of Bax/Bcl-2 protein were detected by molecular biotechnology. Integration of the detected results revealed that neurotoxicity induced by aconitine was associated with the process of excitotoxicity caused by glutamic acid and aspartic acid, which was followed by the accumulation of lactic acid and reduction of glucose. The surge of extracellular glutamic acid could further lead to a series of cascade reactions including intracellular Ca²⁺ overload and oxidative stress, and eventually result in cell apoptosis. In general, we illustrated a new mechanism of aconitine neurotoxicity and presented a novel analysis strategy that real-time online monitoring of cell metabolites can provide a new approach to mechanism analysis.

Processed lateral root of Aconitum carmichaelii Debx.: A review of cardiotonic effects and cardiotoxicity on molecular mechanisms

Fuzi, the lateral root of A. carmichaelii Debx., is a typical traditional herbal medicine with both poisonousness and effectiveness, and often used in the treatment of heart failure and other heart diseases. In this review, we searched domestic and foreign literature to sort out the molecular mechanisms of cardiotonic and cardiotoxicity of Fuzi, also including its components. The major bioactive components of Fuzi for cardiotonic are total alkaloids, polysaccharide and the water-soluble alkaloids, with specific mechanisms manifested in the inhibition of myocardial fibrosis, apoptosis and autophagy, and improvement of mitochondrial energy metabolism, which involves RAAS system, PI3K/AKT, JAK/STAT, AMPK/mTOR signaling pathway, etc. Diester-diterpenoid alkaloids in Fuzi can produce cardiotoxic effects by over-activating Na⁺ and Ca²⁺ ion channels, over-activating NLRP3/ASC/caspase-3 inflammatory pathway and mitochondria mediated apoptosis pathway. And three clinically used preparations containing Fuzi are also used as representatives to summarize their cardiac-strengthening molecular mechanisms. To sum up, Fuzi has shown valuable cardiotonic effects due to extensive basic and clinical studies, but its cardiotonic mechanisms have not been systematically sorted out. Therefore, it is a need for deeper investigation in the mechanisms of water-soluble alkaloids with low content but obvious therapeutic effect, as well as polysaccharide.

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.

Aconitum pendulum and Aconitum flavum: A narrative review on traditional uses, phytochemistry, bioactivities and processing methods

ETHNOPHARMACOLOGICAL RELEVANCE

Composed of dried Aconitum pendulum and Aconitum flavum roots, Tiebangchui, is an important Tibetan medicine and has been traditionally and widely used as a remedy for cold and pain for thousands of years because of its extraordinary pharmacological activities. The toxicity and efficacy of Tiebangchui as a typical toxic traditional Tibetan medicine, are interdependent, and thus to make sure its safe use in clinics is also noteworthy.

AIM OF THE STUDY

This review aims to document and summarize critical and comprehensive information about traditional uses, phytochemistry, pharmacology, toxicology and processing methods of Tiebangchui. Perspectives for possible future investigations have been discussed.

MATERIALS AND METHODS

Relevant information about Tiebangchui (A. pendulum and A. flavum) was collected from internationally recognized electronic scientific databases, such as Web of Science, PubMed, Science Direct, Springer Link, ACS, and CNKI. Then, classic Tibetan medical books, such as Four Medical Tantra, and Jing Zhu Materia Medica, and official drug standards were reviewed.

RESULTS

A total of 95 chemical constituents have been isolated and identified from Tiebangchui, and most of them were diterpenoid alkaloids. These phytochemicals showed a wide range of pharmacological properties, such as anti-inflammation, anti-rheumatoid arthritis, analgesic, local anesthetic, anti-cancer and anti-bacterial activities. Hence, Tiebangchui is broadly used in hundreds of preparations to treat fever, arthritis, rheumatic arthralgia, traumatic injury, furuncle and swelling. Cardiotoxicity, neurotoxicity and gastrointestinal toxicity are the main toxic effects caused by the Aconitum alkaloids of Tiebangchui. Various processing methods, including steaming, decocting and sand-frying, and traditional Tibetan medicine processing methods, such as processing with Hezi decoction, Qingke wine and Zanba, are effective in attenuating toxicity while retaining efficacy.

CONCLUSIONS

The present review provides primary information of Tiebangchui, particularly for its traditional uses, botanical characteristics, phytochemicals, outstanding bioactivities and processing methods. However, studies that explored the in vivo pharmacokinetics and mechanism of Tiebangchui, as well as its quality markers, qualitative and quantitative analysis are still insufficient. Processing methods that attenuate toxicities, evaluations of efficacy, in vivo processes and biological effects, the mechanisms of processed products should be further explored.

An Updated Meta-Analysis Based on the Preclinical Evidence of Mechanism of Aconitine-Induced Cardiotoxicity

Background: Most Aconitum species in traditional Chinese medicine have the effect of dispelling wind, dehumidifying, warming the meridian, and relieving pain. Aconitine is the characteristic chemical component with the function of anti-inflammation, analgesic, and heart-strengthening effects. However, improper use will produce cardiotoxicity and neurotoxicity. Currently, the mechanisms of cardiotoxicity caused by aconitine are wheels within wheels without being fully disclosed. The systematic review and meta-analysis were therefore conducted to summarize the available evidence of myocardial toxicity caused by aconitine.

Methods: We searched PubMed, Embase, Web of Science, National Knowledge Infrastructure, WANFANG, and VIP information database for relevant preclinical studies. All the data were analyzed by RevMan version 5.3.

Results: Thirty-two studies met the final inclusion criteria, including both in vivo and in vitro study types. After aconitine treatment, the heart rate of animals was obviously abnormal, and the morphology and function of myocardial cells were significantly changed. Aconitine can induce changes in the electrophysiological activity of cardiac myocytes by regulating Na⁺, Ca²⁺, and K⁺ currents. Meanwhile, the mechanisms of cardiotoxicity of aconitine may be related to triggering mitochondrial dysfunction by inducing mitochondrial apoptosis and autophagy. It should not be ignored that the overactivation of NLRP3 inflammasome also exacerbates aconitine’s cardiotoxicity.

Conclusion: The altered ion channels and mitochondrial function, as well as the signaling pathways interacting with NLRP3, may deserve further study for aconitine-induced cardiotoxicity.

Assessing Drug-Induced Mitochondrial Toxicity in Cardiomyocytes: Implications for Preclinical Cardiac Safety Evaluation

Drug-induced cardiotoxicity not only leads to the attrition of drugs during development, but also contributes to the high morbidity and mortality rates of cardiovascular diseases. Comprehensive testing for proarrhythmic risks of drugs has been applied in preclinical cardiac safety assessment for over 15 years. However, other mechanisms of cardiac toxicity have not received such attention. Of them, mitochondrial impairment is a common form of cardiotoxicity and is known to account for over half of cardiovascular adverse-event-related black box warnings imposed by the U.S. Food and Drug Administration. Although it has been studied in great depth, mitochondrial toxicity assessment has not yet been incorporated into routine safety tests for cardiotoxicity at the preclinical stage. This review discusses the main characteristics of mitochondria in cardiomyocytes, drug-induced mitochondrial toxicities, and high-throughput screening strategies for cardiomyocytes, as well as their proposed integration into preclinical safety pharmacology. We emphasize the advantages of using adult human primary cardiomyocytes for the evaluation of mitochondrial morphology and function, and the need for a novel cardiac safety testing platform integrating mitochondrial toxicity and proarrhythmic risk assessments in cardiac safety evaluation.

Hematological and Histopathological Effects of Subacute Aconitine Poisoning in Mouse

Aconitine is the principal toxic ingredient of Aconitum, which can cause systemic poisoning involving multiple organs and systems after animal ingestion. The purpose of this study was to investigate the effects of aconitine on hematological indices and histological changes in mice. One hundred twenty mice were divided into a control group (normal saline), low-dose group (0.14 μmol/L), middle-dose group (0.28 μmol/L) and high-dose group (0.56 μmol/L), which were continuously lavaged for 30 days. The blood of 10 mice were collected randomly and analyzed by group at the 10th, 20th, and 30th days, and some tissues were collected and stained with hematoxylin-eosin to observe histological changes at the 30th day. Compared with the control group, the organ coefficient (%) of liver, spleen, lungs, and brain of the high-dose group were significantly increased (p < 0.05 or p < 0.01). WBC and Gran initially decreased and then increased in each poisoning group, with significant differences in the high-dose group (p < 0.05 or p < 0.01). RBC, HGB, HCT, and PLT decreased continuously in all groups except the low-dose group at the 20th and 30th days (p < 0.05 or p < 0.01). Moreover, BUN, ALT and AST increased in each poisoning group, in comparison with the control group, with significant differences except for the low-dose group (p < 0.05 or p < 0.01). CRE initially increased and then decreased, the TP and ALB decreased, with significant differences observed in the high-dose and middle-dose groups (p < 0.05). All the mice in the poison-treated groups showed varying degrees of histopathological changes such as degeneration and necrosis of tissues, especially heart and cerebellum. Our data suggest that different doses of aconitine have remarkable effects on hematological and histopathological changes in mice, in a significant time and dose-effect relationship.

Dopamine Homeostasis Imbalance and Dopamine Receptors-Mediated AC/cAMP/PKA Pathway Activation are Involved in Aconitine-Induced Neurological Impairment in Zebrafish and SH-SY5Y Cells

Aconitine is one of the main bioactive and toxic ingredients of Aconitum species. Increasingly, aconitine has been reported to induce neurotoxicity. However, whether aconitine has effects on the dopaminergic nervous system remains unclear. In this study, zebrafish embryos at 6-days postfertilization were exposed to aconitine at doses of 0.5, 1, and 2 μM for 24 h, and SH-SY5Y cells were treated with 50, 100, and 200 μM of aconitine for 24 h. Results demonstrated that aconitine treatment induced deformities and enhanced the swimming behavior of zebrafish larvaes. Aconitine exposure suppressed cell proliferation and increased the number of reactive oxygen species and apoptosis in zebrafish larvaes and SH-SY5Y cells. Aconitine altered the levels of dopamine and its metabolites by regulating the expression of genes and proteins related to dopamine synthesis, storage, degradation, and reuptake in vivo and in vitro. Moreover, aconitine activated the AC/cAMP/PKA pathway by activating the dopamine D1 receptor (D1R) and inhibiting the dopamine D2 receptor (D2R) to disturb intracellular calcium homeostasis, eventually leading to the damage of nerve cells. Furthermore, the D1R antagonist SCH23390 and D2R agonist sumanirole pretreatment effectively attenuated the excitatory state of larvaes. Sumanirole and PKA antagonist H-89 pretreatment effectively decreased intracellular Ca²⁺ accumulation induced by aconitine in vivo. SCH23390 and sumanirole also reduced aconitine-induced cytotoxicity by inhibiting the AC/cAMP/PKA pathway in vitro. These results suggested that dopamine homeostasis imbalance and dopamine receptors (DRs)-mediated AC/cAMP/PKA pathway activation might be vital mechanisms underlying aconitine-induced neurological injury.

Double-Negative T Cells Regulate Hepatic Stellate Cell Activation to Promote Liver Fibrosis Progression via NLRP3

Aim

We mainly explored the role and mechanism of double-negative T cells (DNTs) in liver fibrosis.

Methods

DNTs were co-cultured with mouse hepatic stellate cells (HSCs). Later, cell viability was detected by Cell Counting Kit-8 (CCK-8) assay; α-SMA expression was measured through fluorescence staining; TNF-α, IL-6, and MMP-9 levels were measured by ELISA; and the expression of Bcl-2, TGF-β1, NLRP3, ASC, and TNFR1 proteins in HSCs was detected by Western blotting (WB) assay. At the same time, HSC-NLRP3-/- and HSC-TNFR1-/- are used to explore the mechanism. In mouse experiments, mice were intraperitoneally injected with DNTs; afterward, the hepatic tissue fibrosis degree was detected by Masson staining, α-SMA expression was measured through immunohistochemistry (IHC) assay, and histopathological changes were detected by sirius-red staining and H&E staining.

Results

The results suggested that DNTs promoted HSC activation and NLRP3 activation. The effect of DNTs on activating HSC-NLRP3-/- was suppressed, and the difference was significant as compared with HSCs. HSC-TNFR1-/- activation was also inhibited. To explore the mechanism of DNT-secreted TNF-α in TNFR1-NLRP3 activation, we transfected DNTs with TNF-α siRNA; as a result, DNTs with TNF-α silencing did not significantly affect HSC activation. DNTs promoted hepatic tissue fibrosis progression and HSC activation; after treatment with NLRP3 inhibitor, the effect of DNTs on promoting fibrosis was suppressed.

Conclusion

We discovered that DNTs played an important role in liver fibrosis and that DNTs promoted HSC activation via the TNF-α-TNFR1-NLRP3 signal axis, thus further promoting liver fibrosis progression.

Guizhi-Shaoyao-Zhimu decoction attenuates monosodium urate crystal-induced inflammation through inactivation of NF-κB and NLRP3 inflammasome

ETHNOPHARMACOLOGICAL RELEVANCE

Guizhi-Shaoyao-Zhimu decoction (GSZD), a classical traditional Chinese medicine (TCM) prescription, is used empirically to treat various types of arthritis in TCM clinical practice. However, the underlying mechanisms of GSZD on gouty inflammation are not totally elucidated.

AIM OF STUDY

The purpose of this study is to investigate the effects of GSZD on peritoneal recruitment of neutrophils, production of proinflammatory mediators, activations of nuclear factor (NF)-κB and nucleotide oligomerization domain-like receptor protein-3 (NLRP3) inflammasome in mice with monosodium urate crystal (MSU)-induced peritonitis (MIP).

MATERIALS AND METHODS

Mice were intragastrically administered with GSZD for 7 days. After the last administration, mice were intraperitoneally injected with MSU. Peritoneal exudates of mice were harvested, and total peritoneal cells were calculated. Levels of interleukin (IL)-1β, IL-6 and monocyte chemotactic protein (MCP)-1 in peritoneal exudates were tested by enzyme-linked immunosorbent assay. Expressions of IL-1β, NLRP3, cysteinyl aspartate specific proteinase (caspase)-1, apoptosis-associated speck-like protein containing the caspase activation and recruitment domain (ASC), phosphorylated (p)-p65, inhibitor of NF-κB (IκB)α, p-IκB kinase (IKK)β, nuclear p65, p-mitogen-activated protein kinases (MAPKs) in peritoneal cells were analyzed by Western blot. Binding activity of NF-κB to DNA was measured by a Trans AM™ kit for p65. Interaction between ASC and pro-caspase-1 was assessed by co-immunoprecipitation assay.

RESULTS

Total peritoneal cells, levels of IL-1β, IL-6 and MCP-1 were significantly reduced by GSZD treatment in peritoneal exudates of MIP mice. As for the activation of NF-κB, GSZD treatment significantly reduced the levels of p-p65, p-IKKβ, nuclear p65 and p-MAPKs, enhanced the level of IκBα and abated the binding ability of NF-κB to DNA in peritoneal cells of MIP mice. As for the activation of NLRP3 inflammasome, GSZD treatment significantly reduced the levels of IL-1β, NLRP3 and caspase-1, and alleviated the interaction between ASC and pro-caspase-1 in peritoneal cells of MIP mice. Nevertheless, GSZD didn't remarkably change the level of ASC.

CONCLUSIONS

These results suggest that GSZD attenuates the MSU-induced inflammation through inhibiting the activations of NF-κB and NLRP3 inflammasome.

Aconitine induces autophagy via activating oxidative DNA damage-mediated AMPK/ULK1 signaling pathway in H9c2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum species, with a medicinal history of 2000 years, was traditionally used in the treatment of rheumatism, arthritis, bruises, and pains. However, many studies have reported that Aconitum species can cause arrhythmia in experimental animals, resulting in myocardial fibrosis and cardiomyocyte damage. Cardiotoxicity is the main toxic effect of aconitine, but the detailed mechanism remains unclear.

AIM OF THE STUDY

This study aimed to explore the effects and underlying mechanism of autophagy in H9c2 cardiomyocytes induced by aconitine.

MATERIALS AND METHODS

H9c2 cells were incubated with different concentrations of aconitine for 24 h, and the intervention sections were pretreated with various inhibitors for 1 h. The effects of aconitine on the oxidative DNA damage, autophagy and viability of H9c2 cells were evaluated by flow cytometry, confocal microscopy, enzyme-linked immunosorbent assay and Western blot.

RESULTS

In H9c2 cells, the cell viability declined, LDH release rate, the number of autophagosomes, protein expression levels of LC3 and Beclin-1 increased significantly after 24 h of aconitine incubation. The pretreatment of autophagy inhibitor 3-MA decreased markedly autophagosomes and protein expression levels of LC3 and Beclin-1, which suggested that aconitine could induce cell autophagy. The significant increase of ROS and 8-OHdG showed that aconitine could cause oxidative DNA damage through ROS accumulation. Meanwhile, treatment of aconitine dramatically increased AMPK^Thr172 and ULK1^Ser317 phosphorylation, and Compound C inhibited AMPK^Thr172 and ULK1^Ser317 phosphorylation, which proved that aconitine induced autophagy via AMPK activation mediated ULK1 phosphorylation. Antioxidant NAC significantly reduced LDH, ROS and 8-OHdG, inhibited the phosphorylation of AMPK^Thr172 and ULK1^Ser317, and down-regulated autophagosomes and proteins expression levels of LC3 and Beclin-1. Consequently, the inhibition of oxidative DNA damage and AMPK/ULK1 signaling pathway alleviated the aconitine-induced autophagic death of H9c2 cells.

CONCLUSIONS

These results showed that aconitine induces autophagy of H9c2 cardiomyocytes by activating AMPK/ULK1 signaling pathway mediated by oxidative DNA damage. The autophagy induced by aconitine in cardiomyocytes is dependent on the activation of the AMPK pathway, which may provide novel insights into the prevention of aconitine-related toxicity.

Aconitine induces cell apoptosis via mitochondria and death receptor signaling pathways in hippocampus cell line

Aconitine is a plant toxin derived from aconitum genus and well known for its neurological and vascular toxicity. However, the mechanism of toxicity on the growth and apoptosis of the neurological cells has not been well investigated. In this study, we used HT22 cell lines derived from hippocampus to explore the mechanism. We began with examination of the viability and DA (dopamine) contents of cells treated with different dose of aconitine. In this study, we investigated the role of apoptosis in AC-induced HT22 cells. Our results showed that aconitine inhibited HT22 cells growth and increased DA contents in a dose dependent manner. Aconitine treatment induced apoptosis in HT22 cells and we found aconitine induced apoptosis by upregulating the expression of Bax, Cyto c, Apaf-1, Caspase9, Fas, Fas-L, Fadd, Caspase8, Caspase3 with concomitant decreasing of Bcl-2 and Bid expression. Collectively, results suggest that aconitine induce apoptosis through mitochondrial-mediated and death receptor signaling pathways in HT22 cells.

Design, Synthesis, and Biological Evaluation of Pyrano[2,3-c]-pyrazole-Based RalA Inhibitors Against Hepatocellular Carcinoma

The activation of Ras small GTPases, including RalA and RalB, plays an important role in carcinogenesis, tumor progress, and metastasis. In the current study, we report the discovery of a series of 6-sulfonylamide-pyrano [2,3-c]-pyrazole derivatives as novel RalA inhibitors. ELISA-based biochemical assay results indicated that compounds 4k–4r suppressed RalA/B binding capacities to their substrates. Cellular proliferation assays indicated that these RalA inhibitors potently inhibited the proliferation of HCC cell lines, including HepG2, SMMC-7721, Hep3B, and Huh-7 cells. Among the evaluated compounds, 4p displayed good inhibitory capacities on RalA (IC₅₀ = 0.22 μM) and HepG2 cells (IC₅₀ = 2.28 μM). Overall, our results suggested that a novel small-molecule RalA inhibitor with a 6-sulfonylamide-pyrano [2, 3-c]-pyrazole scaffold suppressed autophagy and cell proliferation in hepatocellular carcinoma, and that it has potential for HCC-targeted therapy.

A New Strategy for the Rapid Identification and Validation of the Direct Targets of Aconitine-Induced Cardiotoxicity

Background

The interaction of small molecules with direct targets constitutes the molecular initiation events of drug efficacy and toxicity. Aconitine, an active compound of the Aconitum species, has various pharmacological effects but is strongly toxic to the heart. The direct targets of aconitine-induced cardiotoxicity remain unclear.

Methods

We predicted the toxic targets of aconitine based on network pharmacology and followed a novel proteomic approach based on the "drug affinity responsive target stability" technology combined with LC-MS/MS to identify the direct targets of aconitine. The identified targets were analysed from the perspective of multilevel and multidimensional bioinformatics through a network integration method. The binding sites were investigated via molecular docking to explore the toxicity mechanism and predict the direct targets of aconitine. Finally, atomic force microscopy (AFM) imaging was performed to verify the affinity of aconitine to the direct targets.

Results

PTGS2, predicted by network pharmacology as a toxic target, encodes cyclooxygenase 2 (COX-2), which is closely related to myocardial injury. Furthermore, cytosolic phospholipase A2 (cPLA2) is the upstream signal protein of PTGS2, and it is a key enzyme in the metabolism of arachidonic acid during an inflammatory response. We determined cPLA2 as a direct target, and AFM imaging verified that aconitine could bind to cPLA2 well; thus, aconitine may cause the expression of PTGS2/COX-2 and release inflammatory factors, thereby promoting myocardial injury and dysfunction.

Conclusion

We developed a complete set of methods to predict and verify the direct targets of aconitine, and cPLA2 was identified as one. Overall, the novel strategy provides new insights into the discovery of direct targets and the molecular mechanism of toxic components that are found in traditional Chinese medicine.

Decreased dynamin-related protein 1-related mitophagy induces myocardial apoptosis in the aging heart

An increase in cardiomyocyte apoptosis is the main contributor to the observed high morbidity of cardiac disease during aging. Mitochondria play important roles in cardiac apoptosis, and dynamin-related protein 1 (Drp1) is the critical factor that participates in mitochondrial fission and induces mitophagy to maintain mitochondria quality. However, whether Drp1 is involved in the increase of apoptosis in aging heart remains unclear. The purpose of this study was to determine whether Drp1 participates in inducing the apoptosis through regulating mitophagy in aging myocardium. To explore the effect of mitophagy and apoptosis in aging heart, we detected the expression of COX IV and the co-localization of COX IV and LC3 II, which reflect mitophagy, and measured adenosine triphosphate and reactive oxygen species contents, which reflect mitochondrial injury. Cell apoptosis was detected by measuring the activity of caspase-3 and the expression of cleaved caspase-3 and further confirmed by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay. The results showed an increase in apoptosis and a decrease in mitophagy in aging cardiomyocytes, and apoptosis was ameliorated after the induction of mitophagy by carbonyl cyanide m-chlorophenyl hydrazone (a mitophagy activator) in D-galactose (D-gal)-induced senescence H9c2 cells. To clarify the role of Drp1 in apoptosis, we knocked down Drp1 by transfecting si-Drp1, or overexpressed Drp1 in senescent cells, and then detected mitophagy, mitochondrial injury, and apoptosis. The data showed that downregulated Drp1 induces mitochondrial damage and apoptosis. In addition, to explore the regulatory relationship between Drp1 and phosphatase and tensin homologue (PTEN)-induced putative kinase 1 (PINK1)/Parkin-mediated mitophagy, we detected the expressions of PINK1 and Parkin after the overexpression of Drp1 in the D-gal group cells and found that Drp1-mediated mitophagy inhibited the PINK1/Parkin pathway in senescent cells. Our results demonstrated that insufficient Drp1 induces cardiomyocyte apoptosis by inhibiting mitophagy, and Drp1 affects the PINK1/Parkin pathway of mitophagy in the aging heart.

Aconitine Induces TRPV2-Mediated Ca2+ Influx through the p38 MAPK Signal and Promotes Cardiomyocyte Apoptosis

Aconitine is the main effective component of traditional Chinese medicine Aconitum, which has been proved to have severe cardiovascular toxicity. The toxic effect of aconitine on cardiomyocytes is related to intracellular calcium overload, but the mechanism remains unclear. The aim of this study was to explore the mechanism of aconitine inducing intracellular Ca²⁺ overload and promoting H9c2 cardiomyocyte apoptosis through transient receptor potential cation channel subfamily V member 2 (TRPV2). After treated with different concentrations of aconitine, the level of cell apoptosis, intracellular Ca²⁺, and expression of p-p38 MAPK and TRPV2 of H9c2 cardiomyocytes were detected. The results showed that aconitine induced Ca²⁺ influx and H9c2 cardiomyocyte apoptosis in a dose-dependent manner and promoted p38 MAPK activation as well as TRPV2 expression and plasma membrane (PM) metastasis. siTRPV2, tranilast, and SB202190 reversed intracellular Ca²⁺ overload and H9c2 cardiomyocyte apoptosis induced by aconitine. These results suggested that aconitine promoted TRPV2 expression and PM metastasis through p38 MAPK signaling, thus inducing intracellular Ca²⁺ overload and cardiomyocyte apoptosis. Furthermore, TRPV2 is a potential molecular target for the treatment of aconitine poisoning.

Ultrasound-assisted C3F8-filled PLGA nanobubbles for enhanced FGF21 delivery and improved prophylactic treatment of diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious cardiac complication of diabetes that currently lacks specific treatment. Fibroblast growth factor 21 (FGF21) has been proved to have cardioprotective effect in DCM. However, the insufficient cardiac delivery effect of FGF21 limits its application in DCM. Therefore, to improve the therapeutic efficacy of FGF21 in DCM, an effective drug delivery system is urgently required. In this study, perfluoropropane (C₃F₈) and polyethylenimine (PEI)-doped poly (lactic-co-glycolic acid) (PLGA) nanobubbles (CPPNBs) were synthesized via double-emulsion evaporation and FGF21 was efficiently absorbed (CPPNBs@FGF21) via the electrostatic incorporation effect. CPPNBs@FGF21 could effectively deliver FGF21 to the myocardial tissue through the cavitation effect under low-frequency ultrasound (LFUS). The as-prepared CPPNBs@FGF21 could efficiently load FGF21 after doping with the cationic polymer PEI, and displayed uniform dispersion and favorable biosafety. After filling with C₃F₈, CPPNBs@FGF21 could be used for distribution monitoring through ultrasound imaging. Moreover, CPPNBs@FGF21 significantly downregulated the expression of ANP, CTGF, and caspase-3 mRNA via the action of LFUS owing to increased FGF21 release, therefore exhibiting enhanced inhibition of myocardial hypertrophy, apoptosis, and interstitial fibrosis in DCM mice. In conclusion, we established an effective protein delivery nanocarrier for the diagnosis and prophylactic treatment of DCM. STATEMENT OF SIGNIFICANCE: Diabetic cardiomyopathy (DCM) is a serious cardiac complication of diabetes that currently lacks effective clinical treatments. Fibroblast growth factor 21 (FGF21) can protect cardiomyocytes from diabetic damage, but insufficient cardiac drug delivery limits the application of FGF21 in DCM. In this study, perfluoropropane (C3F8) and polyethylenimine (PEI)-doped poly (lactic-co-glycolic acid) (PLGA) nanobubbles loaded with FGF21 (CPPNBs@FGF21) were developed for the prophylactic treatment of DCM. CPPNBs@FGF21 could effectively deliver the FGF21 to the myocardial tissue through the cavitation effect of low-frequency ultrasound (LFUS). Our results indicated that CPPNBs@FGF21 combined with LFUS could significantly down-regulate the expressions of ANP, CTGF, and caspase-3 mRNA, and as a result, it prevented the myocardial hypertrophy, apoptosis, and interstitial fibrosis of DCM mice. Overall, we established an effective protein delivery nanocarrier for the diagnosis and prophylactic treatment of DCM.

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.

Repeated Aconitine Treatment Induced the Remodeling of Mitochondrial Function via AMPK-OPA1-ATP5A1 Pathway

Aconitine is attracting increasing attention for its unique positive inotropic effect on the cardiovascular system, but underlying molecular mechanisms are still not fully understood. The cardiotonic effect always requires abundant energy supplement, which is mainly related to mitochondrial function. And OPA1 has been documented to play a critical role in mitochondrial morphology and energy metabolism in cardiomyocytes. Hence, this study was designed to investigate the potential role of OPA1-mediated regulation of energy metabolism in the positive inotropic effect caused by repeated aconitine treatment and the possible mechanism involved. Our results showed that repeated treatment with low-doses (0-10 μM) of aconitine for 7 days did not induce detectable cytotoxicity and enhanced myocardial contraction in Neonatal Rat Ventricular Myocytes (NRVMs). Also, we first identified that no more than 5 μM of aconitine triggered an obvious perturbation of mitochondrial homeostasis in cardiomyocytes by accelerating mitochondrial fusion, biogenesis, and Parkin-mediated mitophagy, followed by the increase in mitochondrial function and the cellular ATP content, both of which were identified to be related to the upregulation of ATP synthase α-subunit (ATP5A1). Besides, with compound C (CC), an inhibitor of AMPK, could reverse aconitine-increased the content of phosphor-AMPK, OPA1, and ATP5A1, and the following mitochondrial function. In conclusion, this study first demonstrated that repeated aconitine treatment could cause the remodeling of mitochondrial function via the AMPK-OPA1-ATP5A1 pathway and provide a possible explanation for the energy metabolism associated with cardiotonic effect induced by medicinal plants containing aconitine.

Aconitine induces mitochondrial energy metabolism dysfunction through inhibition of AMPK signaling and interference with mitochondrial dynamics in SH-SY5Y cells

Aconitine, a highly toxic alkaloid derived from Aconitum L., affects the central nervous system and peripheral nervous system. However, the underlying mechanism of aconitine-induced neurotoxicity remains unclear. This study investigates the effects and mechanism of aconitine on mitochondrial energy metabolism in SH-SY5Y cells. Results demonstrated that aconitine exposure suppressed cell proliferation and led to an increase in reactive oxygen species (ROS) and excessive lactate dehydrogenase (LDH) release. Aconitine (400 μmol/L) induced abnormal mitochondrial energy metabolism that quantified by the significant decrease in ATP production, basal respiration, proton leak, maximal respiration, and succinate dehydrogenase (SDH) activity. Phosphorylation of AMPK was significantly reduced in aconitine-treated SH-SY5Y cells. The AMPK activator AIACR pretreatment effectively promoted ATP production to ameliorate mitochondrial energy metabolism disorder caused by aconitine. Mitochondrial biosynthesis was inhibited after treatment with 400 μmol/L aconitine, which was characterized by mitochondria number, TFAM expression, and mtDNA copy number. Moreover, aconitine prompted the down-regulation of mitochondrial fusion proteins OPA1, Mfn1 and Mfn2, and the up-regulation of mitochondrial fission proteins p-Drp1 and p-Mff. These results suggest that aconitine induces mitochondrial energy metabolism dysfunction in SH-SY5Y cells, which may involve the inhibition of AMPK signaling and abnormal mitochondrial dynamics.

Involvement of Nrf2-HO-1/JNK-Erk Signaling Pathways in Aconitine-Induced Developmental Toxicity, Oxidative Stress, and ROS-Mitochondrial Apoptosis in Zebrafish Embryos

Aconitine (AC), one of the bioactive diterpenoid alkaloids extracted from Aconitum plants, is widely used in traditional herbal medicine to treat various diseases. Emerging evidence indicates that AC has attracted great interest for its wide cardiotoxicity and neurotoxicity. However, the toxic effects of AC on embryonic development and its underlying mechanisms remain unclear. Here, a developmental toxicity assay of AC was performed on zebrafish embryos from 4 to 96 h post fertilization (hpf), and its underlying mechanisms were discussed. AC exposure impaired the cardiac, liver, and neurodevelopment. Especially, a high dose of AC (7.27 and 8.23 μM) exposure resulted in malformations at 72 and 96 hpf, including reduced body length, curved body shape, pericardial edema, yolk retention, swim bladder and brain developmental deficiency, and degeneration of dopaminergic neurons. High-concentration AC exposure caused a deficient cardiovascular system with cardiac dysfunctions, increased heart rates at 72 and 96 hpf, and reduced locomotor behavior at 120 hpf. AC treatment significantly increased the ROS level and triggered cell apoptosis in the heart and brain regions of embryos at 96 hpf in 7.27 and 8.23 μM AC treatment zebrafish. Oxidative stress was confirmed by reduced levels of T-SOD activity associated with accumulation of lipid peroxidation in larvae. The expression levels of oxidative stress-related genes (Nrf2, HO-1, Cat, and Sod-1) Erk1/2 and Bcl-2 were significantly downregulated at 96 hpf. The expression pattern of JNK and mitochondrial apoptosis-related genes (Bad, Bax, Cyto C, Casp-9, and Casp-3) was significantly upregulated. Taken together, all these parameters collectively provide the first evidence of AC-induced developmental toxicity in zebrafish embryo/larvae through ROS-medicated mitochondrial apoptosis involving Nrf2/HO-1 and JNK/Erk pathways.

NLRP3 Inflammasome: A Promising Therapeutic Target for Drug-Induced Toxicity

Drug-induced toxicity, which impairs human organ function, is a serious problem during drug development that hinders the clinical use of many marketed drugs, and the underlying mechanisms are complicated. As a sensor of infections and external stimuli, nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome plays a key role in the pathological process of various diseases. In this review, we specifically focused on the role of NLRP3 inflammasome in drug-induced diverse organ toxicities, especially the hepatotoxicity, nephrotoxicity, and cardiotoxicity. NLRP3 inflammasome is involved in the initiation and deterioration of drug-induced toxicity through multiple signaling pathways. Therapeutic strategies via inhibiting NLRP3 inflammasome for drug-induced toxicity have made significant progress, especially in the protective effects of the phytochemicals. Growing evidence collected in this review indicates that NLRP3 is a promising therapeutic target for drug-induced toxicity.

Risk Compounds, Preclinical Toxicity Evaluation, and Potential Mechanisms of Chinese Materia Medica-Induced Cardiotoxicity

Chinese materia medica (CMM) has been applied for the prevention and treatment of diseases for thousands of years. However, arrhythmia, myocardial ischemia, heart failure, and other cardiac adverse reactions during CMM application were gradually reported. CMM-induced cardiotoxicity has aroused widespread attention. Our review aimed to summarize the risk compounds, preclinical toxicity evaluation, and potential mechanisms of CMM-induced cardiotoxicity. All relevant articles published on the PubMed, Embase, and China National Knowledge Infrastructure (CNKI) databases for the latest twenty years were searched and manually extracted. The risk substances of CMM-induced cardiotoxicity are relatively complex. A single CMM usually contains various risk compounds, and the same risk substance may exist in various CMM. The active and risk substances in CMM may be transformed into each other under different conditions, such as drug dosage, medication methods, and body status. Generally, the risk compounds of CMM-induced cardiotoxicity can be classified into alkaloids, terpenoids, steroids, heavy metals, organic acids, toxic proteins, and peptides. Traditional evaluation methods of chemical drug-induced cardiotoxicity primarily include cardiac function monitoring, endomyocardial biopsy, myocardial zymogram, and biomarker determination. In the preclinical stage, CMM-induced cardiotoxicity should be systematically evaluated at the overall, tissue, cellular, and molecular levels, including cardiac function, histopathology, cytology, myocardial zymogram, and biomarkers. Thanks to the development of systematic biology, the higher specificity and sensitivity of biomarkers, such as genes, proteins, and metabolic small molecules, are gradually applied for evaluating CMM-induced cardiotoxicity. Previous studies on the mechanisms of CMM-induced cardiotoxicity focused on a single drug, monomer or components of CMM. The interaction among ion homeostasis (sodium, potassium, and calcium ions), oxidative damage, mitochondrial injury, apoptosis and autophagy, and metabolic disturbance is involved in CMM-induced cardiotoxicity. Clarification on the risk compounds, preclinical toxicity evaluation, and potential mechanisms of CMM-induced cardiotoxicity must be beneficial to guide new CMM development and post-marketed CMM reevaluation.

Mitochondrial quality surveillance as a therapeutic target in myocardial infarction

Myocardial infarction (MI) is a leading cause of morbidity and mortality worldwide. As mitochondrial dysfunction critically contributes to the pathogenesis of MI, intensive research is focused on the development of therapeutic strategies targeting mitochondrial homeostasis. Mitochondria possess a quality control system which maintains and restores their structure and function by regulating mitochondrial fission, fusion, biogenesis, degradation and death. In response to slight damage such as transient hypoxia or mild oxidative stress, mitochondrial metabolism shifts from oxidative phosphorylation to glycolysis, in order to reduce oxygen consumption and maintain ATP output. Mitochondrial dynamics are also activated to modify mitochondrial shape and structure, in order to meet cardiomyocyte energy requirements through augmenting or reducing mitochondrial mass. When damaged mitochondria cannot be repaired, poorly structured mitochondria will be degraded through mitophagy, a process which is often accompanied by mitochondrial biogenesis. Once the insult is severe enough to induce lethal damage in the mitochondria and the cell, mitochondrial death pathway activation is an inevitable consequence, and the cardiomyocyte apoptosis or necrosis program will be initiated to remove damaged cells. Mitochondrial quality surveillance is a hierarchical system preserving mitochondrial function and defending cardiomyocytes against stress. A failure of this system has been regarded as one of the potential pathologies underlying MI. In this review, we discuss the recent findings focusing on the role of mitochondrial quality surveillance in MI, and highlight the available therapeutic approaches targeting mitochondrial quality surveillance during MI.

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.

Discovery of novel TNNI3K inhibitor suppresses pyroptosis and apoptosis in murine myocardial infarction injury

Myocardial infarction (MI) injury is a highly lethal syndrome that has, until recently, suffered from a lack of clinically efficient targeted therapeutics. The cardiac troponin I interacting kinase (TNNI3K) exacerbates ischemia-reperfusion (IR) injury via oxidative stress, thereby promoting cardiomyocyte death. In this current study, we designed and synthesized 35 novel TNNI3K inhibitors with a pyrido[4,5]thieno[2,3-d] pyrimidine scaffold. In vitro results indicated that some of the inhibitors exhibited sub-micromolar TNNI3K inhibitory capacity and good kinase selectivity, as well as cytoprotective activity, in an oxygen-glucose deprivation (OGD) injury cardiomyocyte model. Furthermore, investigation of the mechanism of the representative derivative compound 6o suggested it suppresses pyroptosis and apoptosis in cardiomyocytes by interfering with p38MAPK activation, which was further confirmed in a murine myocardial infarction injury model. In vivo results indicate that compound 6o can markedly reduce myocardial infarction size and alleviate cardiac tissue damage in rats. In brief, our results provide the basis for further development of novel TNNI3K inhibitors for targeted MI therapy.

Research Progress on Anti-Inflammatory Effects and Mechanisms of Alkaloids from Chinese Medical Herbs

As the spectrum of diseases keeps changing and life pace keeps going faster, the probability and frequency of diseases caused by human inflammatory reactions also keep increasing. How to develop effective anti-inflammatory drugs has become the hotspot of researches. It has been found that alkaloids from Chinese medical herbs have anti-inflammatory, analgesic, antitumor, anticonvulsant, diuretic, and antiarrhythmic effects, among which the anti-inflammatory effect is very prominent and commonly used in the treatment of rheumatoid arthritis, ankylosing spondylitis, and other rheumatic immune diseases, but its mechanism of action has not been well explained. Based on this, this paper will classify alkaloids according to structural types and review the plant sources, applicable diseases, and anti-inflammatory mechanisms of 16 kinds of alkaloids commonly used in clinical treatment, such as berberine, tetrandrine, and stephanine, with the aim of providing a reference for drug researches and clinical applications.

Aconitine induces cardiomyocyte damage by mitigating BNIP3-dependent mitophagy and the TNFα-NLRP3 signalling axis

Objectives

Aconitine, the natural product extracted from Aconitum species, is widely used for the treatment of various diseases, including rheumatism, arthritis, bruises, fractures and pains. However, many studies have reported cardiotoxicity and neurotoxicity caused by aconitine, but the detailed mechanism underlying aconitine's effect on these processes remains unclear.

Materials and methods

The effects of aconitine on the inflammation, apoptosis and viability of H9c2 rat cardiomyocytes were evaluated by flow cytometry, Western blot, RNA sequencing and bioinformatics analysis.

Results

Aconitine suppressed cardiomyocyte proliferation and induced inflammation and apoptosis in a dose‐ and time‐dependent manner. These inflammatory damages could be reversed by a TNFα inhibitor and BNIP3‐mediated mitophagy. Consistent with the in vitro results, overexpression of BNIP3 in heart tissue partially suppressed the cardiotoxicity of aconitine by inhibiting apoptosis and the NLRP3 inflammasome.

Conclusions

Our findings lay a foundation for the application of a TNFα inhibitor and BNIP3 to aconitine‐induced cardiac toxicity prevention and therapy, thereby demonstrating potential for further investigation.