Aconite poisoning

Aconitine: A review of its pharmacokinetics, pharmacology, toxicology and detoxification

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitine, a C₁₉-norditerpenoid alkaloid, derives from many medicinal plants such as Aconitum carmichaelii Debx. (Chinese:), Aconitum kusnezoffii Reichb (Chinese:), which were used to rheumatic fever, painful joints and some endocrinal disorders.

AIMS OF THE REVIEW

The present paper reviews research progress relating to the pharmacokinetics, physiological and pathological processes of aconitine, while some promising research direction and the detoxification of aconitine are also discussed.

MATERIALS AND METHODS

The accessible literature on aconitine, from 1990 to 2020, obtained from published materials of electronic databases, such as SCI finder, PubMed, Web of Science, Science Direct, Springer and Google Scholar was systematically analyzed.

RESULTS

In this review, we address the pharmacokinetics of aconitine, as well as its pharmacological effects including anti-cancer, anti-inflammatory, anti-virus, immunoregulation, analgesic, insecticide and inhibition of androgen synthesis. Further, we summarize the toxicity of aconitine such as cardiotoxicity and neurotoxicity, on which we strikingly focus on the ways to reduce the toxicity of aconitine based.

CONCLUSIONS

Aconitine plays an vital role in a wide range of physiological and pathological processes and we can reduce the toxicity of aconitine by compatibility and hydrolysis. Although some issues still exist, such as the correlative relationship between the dose and toxicity of aconitine not being clear, our review may provide new ideas for the application of aconitine in the treatment of related diseases.

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.

Glycyrrhiza uralensis promote the metabolism of toxic components of Aconitum carmichaeli by CYP3A and alleviate the development of chronic heart failure

Aconitum, as "the first drug of choice for invigorating Yang and saving lives", has been widely used for the treatment of heart failure. However, toxic components of Aconitum can easily lead to serious arrhythmia, even death (Y. CT., 2009; Zhang XM., 2018). In this study, a High Performance Liquid Chromatography (HPLC) method for the determination of aconitine (AC), mesaconitine (MA) and hypaconitine (HA) was established; The effect of Glycyrrhiza on CYP3A1 / 2 mRNA expression was detected by RT-PCR; SD rats were given Aconitum and compatibility of Glycyrrhizae and Aconitum by gavage respectively, the blood concentration of toxic components were determined by LC-MS / MS; The CHF rat model was established by intraperitoneal injection of adriamycin (2.5 mg / kg), and were randomly divided into model, Aconitum, the compatibility of Glycyrrhizae and Aconitum and Captopril group, 5 mice/group. After 4 weeks of gavage, the corresponding indexes were detected by ELISA and HPLC. The results showed that Ketoconazole significantly inhibited the metabolites of AC, MA and HA; Glycyrrhiza induced CYP3A gene expression; The level of ALD in the compatibility of Glycyrrhizae and Aconitum group was significantly lower than that in Aconitum group. After intervention with the compatibility of Glycyrrhizae and Aconitum, ATP increased, ADP decreased significantly. In conclusion, we found Glycyrrhiza promoted the metabolism of toxic components of Aconitum by up regulating the expression of CYP3A, and reduced the content of BNP, Ang II and ALD, improved the energy metabolism disorder of myocardium, alleviated the development of CHF.

Ginsenoside Rg1 Reduces Cardiotoxicity While Increases Cardiotonic Effect of Aconitine in vitro

OBJECTIVE

To explore the synergic mechanism of ginsenoside Rg₁ (Rg₁) and aconitine (AC) by acting on normal neonatal rat cardiomyocytes (NRCMs) and pentobarbital sodium (PS)-induced damaged NRCMs.

METHODS

The toxic, non-toxic, and effective doses of AC and the most suitable compatibility concentration of Rg₁ for both normal and damaged NRCMs exposed for 1 h were filtered out by 3- (4,5)-dimethylthiahiazo (-z-y1)-3,5-diphenytetrazoliumromide, respectively. Then, normal NRCMs or impaired NRCMs were treated with chosen concentrations of AC alone or in combination with Rg₁ for 1 h, and the cellular activity, cellular ultrastructure, apoptosis, leakage of acid phosphatase (ACP) and lactate dehydrogenase (LDH), intracellular sodium ions [Na⁺], potassium ions [K⁺] and calcium ions [Ca²⁺] levels, and Nav1.5, Kv4.2, and RyR₂ genes expressions in each group were examined.

RESULTS

For normal NRCMs, 3000 µ mol/L AC significantly inhibited cell viability (P<0.01), promoted cell apoptosis, and damaged cell structures (P<0.05), while other doses of AC lower than 3000 µ mol/L and the combinations of AC and Rg₁ had little toxicity on NRCMs. Compared with AC acting on NRCMs alone, the co-treatment of 3000 and 10 µ mol/L AC with 1 µ mol/L Rg₁ significantly decreased the level of intracellular Ca²⁺ (P<0.01 or P<0.05), and the co-treatment of 3000 µ mol/L AC with 1 µ mol/L Rg₁ significantly decreased the level of intracellular Ca²⁺ via regulating Nav1.5, RyR₂ expression (P<0.01). For damaged NRCMs, 1500 µ mol/L AC aggravated cell damage (P<0.01), and 0.1 and 0.001 µ mol/L AC showed moderate protective effect. Compared with AC used alone, the co-treatment of Rg₁ with AC reduced the cell damage, 0.1 µ mol/L AC with 1 µ mol/L Rg₁ significantly inhibited the level of intracellular Na⁺ (P<0.05), 1500 µ mol/L AC with 1 µ mol/L Rg₁ significantly inhibited the level of intracellular K⁺ (P<0.01) via regulating Nav1.5, Kv4.2, RyR₂ expressions in impaired NRCMs.

CONCLUSION

Rg₁ inhibited the cardiotoxicity and enhanced the cardiotonic effect of AC via regulating the ion channels pathway of [Na⁺], [K⁺], and [Ca²⁺].

A case report of bidirectional ventricular tachycardia secondary to aconitum toxicity

We present a case of malignant ventricular arrhythmia secondary to unintentional aconite poisoning. Healthcare workers need to be vigilant regarding cases of aconitum toxicities, especially in atypical presentations. There is also a need to educate the public regarding the consumption and preparation of potent TCM herbs that may result in lethal toxicity.

Several Alkaloids in Chinese Herbal Medicine Exert Protection in Acute Kidney Injury: Focus on Mechanism and Target Analysis

Objectives

Acute kidney injury (AKI) is a loose set of kidney diseases accompanied by a variety of syndromes, which is a serious threat to human life and health. Some alkaloids are derived from various Chinese herbs have been widely concerned in the improvement of AKI. This review provides the research progress of alkaloids in AKI experimental models and discusses the related molecular mechanisms. Key Findings. Alkaloids can protect AKI through various mechanisms including antioxidant stress, improvement of mitochondrial damage, reduction of cell death, induction of autophagy, and inhibition of inflammation. These mechanisms are mainly related to the activation of Nrf2/HO-1 signaling pathway, inhibition of ferroptosis and apoptosis, regulation of PINK1/Parkin pathway, inhibition of TLR4/NF-κB pathway and NLRP3 inflammatory bodies, upregulation of Klotho protein level and so on. In addition, there are a few alkaloids that have certain toxicity on the kidney.

Conclusion

Alkaloids have been shown to significantly improve AKI, but only in pharmacological studies. This paper summarizes the main experimental models currently used in AKI research and describes some representative alkaloids based on recent research. Their potential roles in the prevention and treatment of AKI through different mechanisms are highlighted.

Management of a patient with polymorphic ventricular tachycardia from aconitum poisoning

An 81-year-old man presented to the Emergency Department with shortness of breath, generalised weakness, numbness, giddiness, nausea and vomiting after consuming an inadequately prepared Traditional Chinese Medicine preparation that contained herbal aconitum (Chuanwu and Caowu). His electrocardiogram (ECG) and rhythm strips showed multiple runs of non-sustained ventricular tachycardia monomorphic ventricular tachycardia and slowed polymorphic ventricular tachycardia. He was treated with intravenous (IV) amiodarone, magnesium and lignocaine, and was started on IV noradrenaline after developing haemodynamic compromise. There was no digoxin detected in the blood and urine. At 12 h, aconitine was not detected in the blood (cut off at <1 ng/mL) but aconitine and hypaconitine was detected in the urine qualitatively. He underwent a coronary angiogram at 12 h post-admission which showed minor coronary artery disease. A formal echocardiogram showed left ventricular ejection fraction 50–55% with no regional wall motion abnormalities of the left ventricle. He made an uneventful recovery and reverted to normal sinus rhythm at 29 h of admission. He was discharged well on Day 4 of admission with a diagnosis of polymorphic ventricular tachycardia secondary to Aconitum poisoning.

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

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

Role of Higenamine in Heart Diseases: A Mini-Review

Higenamine, a natural product with multiple targets in heart diseases, is originally derived from Aconitum, which has been traditionally used in China for the treatment of heart disease, including heart failure, arrhythmia, bradycardia, cardiac ischemia/reperfusion injury, cardiac fibrosis, etc. This study is aimed to clarify the role of higenamine in heart diseases. Higenamine has effects on improving energy metabolism of cardiomyocytes, anti-cardiac fibroblast activation, anti-oxidative stress and anti-apoptosis. Accumulating evidence from various studies has shown that higenamine exerts a wide range of cardiovascular pharmacological effects in vivo and in vitro, including alleviating heart failure, reducing cardiac ischemia/reperfusion injury, attenuating pathological cardiac fibrosis and dysfunction. In addition, several clinical studies have reported that higenamine could continuously increase the heart rate levels of healthy volunteers as well as patients with heart disease, but there are variable effects on systolic blood pressure and diastolic blood pressure. Moreover, the heart protection and therapeutic effects of higenamine on heart disease are related to regulating LKB1/AMPKα/Sirt1, mediating the β2-AR/PI3K/AKT cascade, induction of heme oxygenase-1, suppressing TGF-β1/Smad signaling, and targeting ASK1/MAPK (ERK, P38)/NF-kB signaling pathway. However, the interventional effects of higenamine on heart disease and its underlying mechanisms based on experimental studies have not yet been systematically reviewed. This paper reviewed the potential pharmacological mechanisms of higenamine on the prevention, treatment, and diagnosis of heart disease and clarified its clinical applications. The literature shows that higenamine may have a potent effect on complex heart diseases, and proves the profound medicinal value of higenamine in heart disease.

Indigo-A New Tribological Substance Class for Non-Toxic and Ecological Gliding Surfaces on Ice, Snow, and Water

The biogenic substance E-indigo can form supramolecular, hydrophobic structures using self-organization. These structures show a low coefficient of friction as a gliding layer against polar surfaces. The formation of primary particles with platelet morphology based on hydrogen-bonded E-indigo molecules is ideal to produce the gliding layer. Structures with excellent gliding properties can be achieved by means of directed friction and high pressure, as well as through tempering. The resulting hard, thin gliding layer of E-indigo does not easily absorb dirt and, thus, prevents a rapid increase in friction. Field tests on snow, with cross-country skis, have shown promising results in comparison to fluorinated and non-fluorinated waxes. Based on quantitative structure–activity relationship (QSAR) data for E-indigo, and its isomers and tautomers, it has been demonstrated that both the application and abrasion of the thin indigo layers are harmless to health, and are ecologically benign and, therefore, sustainable.

Systematic investigation on the distribution of four hidden toxic Aconitum alkaloids in commonly used Aconitum herbs and their acute toxicity

Yunaconitine (YAC), crassicauline A (CCA), 8-deacetylyunaconitine (DYA), and 8-deacetylcrassicauline A (DCA), as hidden toxic Aconitum alkaloids, are detected in some products of processed Aconitum carmichaelii lateral root and poisoning cases. The distribution and toxicity of these four components in Aconitum herbs should be further systematically studied for medication safety. This study developed a new UHPLC-QQQ-MS/MS method to determine ten Aconitum alkaloids, including aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine, benzoylhypaconine, YAC, CCA, DYA, and DCA, for Aconitum herbs simultaneously. YAC and CCA were founded in some samples of unprocessed A. carmichaelii lateral root (7.04%), A. carmichaelii root (9.43%), A. brachypodum root (6.00%), and A. ouvrardianum root (100%). Four hidden toxic Aconitum alkaloids were detected in processed A. carmichaelii lateral root (2.56%) and A. vilmorinianum root (100%). Four hidden toxic Aconitum alkaloids played significant roles in the classification of Aconitum herbs by OPLS-DA analysis. The acute toxicity test was performed by up-and-down procedure (UDP). The oral administration of the half lethal dose (LD₅₀) of YAC, CCA, DYA, and DCA to female ICR mice was 2.37 mg/kg, 5.60 mg/kg, 60.0 mg/kg, and 753 mg/kg, respectively. The LD₅₀ by intravenous injection was 0.200 mg/kg, 0.980 mg/kg, 7.60 mg/kg, and 34.0 mg/kg, respectively. The LD₅₀ of unprocessed A. carmichaelii lateral root, A. vilmorinianum root, and A. brachypodum root to mice orally was 1.89 g/kg, 0.950 g/kg, and 0.380 g/kg, respectively. Symptoms of Aconitum alkaloid poisoning in mice were decreased activity, fur erect, palpebral edema, vomiting, polypnea, and convulsions. The main change of organs was flatulence. No poisoning or death occurred in mice at the maximum dosage (27.0 g/kg) of A. ouvrardianum root orally. To better control the quality and safety of Aconitum herbs, this study provides favorable support for improving the existing standards to strengthen the supervision of the four hidden toxic Aconitum alkaloids.

Natural products: potential treatments for cisplatin-induced nephrotoxicity

Cisplatin is a clinically advanced and highly effective anticancer drug used in the treatment of a wide variety of malignancies, such as head and neck, lung, testis, ovary, breast cancer, etc. However, it has only a limited use in clinical practice due to its severe adverse effects, particularly nephrotoxicity; 20%–35% of patients develop acute kidney injury (AKI) after cisplatin administration. The nephrotoxic effect of cisplatin is cumulative and dose dependent and often necessitates dose reduction or withdrawal. Recurrent episodes of AKI result in impaired renal tubular function and acute renal failure, chronic kidney disease, uremia, and hypertensive nephropathy. The pathophysiology of cisplatin-induced AKI involves proximal tubular injury, apoptosis, oxidative stress, inflammation, and vascular injury in the kidneys. At present, there are no effective drugs or methods for cisplatin-induced kidney injury. Recent in vitro and in vivo studies show that numerous natural products (flavonoids, saponins, alkaloids, polysaccharide, phenylpropanoids, etc.) have specific antioxidant, anti-inflammatory, and anti-apoptotic properties that regulate the pathways associated with cisplatin-induced kidney damage. In this review we describe the molecular mechanisms of cisplatin-induced nephrotoxicity and summarize recent findings in the field of natural products that undermine these mechanisms to protect against cisplatin-induced kidney damage and provide potential strategies for AKI treatment.

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.

Case Report: Venoarterial Extracorporeal Membrane Oxygenation Support for Caowu-Induced Cardiac Arrest

Introduction: Caowu, the main root of the Aconitum plant, is widely used in China. Aconitine is the main toxic component of Aconitum, which can cause a variety of malignant arrhythmias and lead to death. Four patients who developed malignant arrhythmia after drinking medicinal wine containing Caowu were reported in this study. Cardiac arrest occurred soon after symptom onset. All patients received venoarterial extracorporeal membrane oxygenation (VA-ECMO) support after conservative medical treatment had failed. Patients who were directly transferred to our hospital received VA-ECMO support earlier than patients who were first treated at a local hospital. One patient received hemoperfusion in the emergency room before VA-ECMO support; the other three patients began hemoperfusion after VA-ECMO treatment. Surviving patients who received VA-ECMO earlier after symptom onset showed no obvious neurological complications. The patient who received a longer cardiopulmonary resuscitation time but received hemoperfusion before VA-ECMO had mild neurological complications. The mortality rate was 25% (1 of 4 patients). Two patients had thrombotic complications in venous vessels.

Conclusions: Cardiogenic shock due to refractory ventricular tachycardia caused by aconitine is lethal. Conservative supportive treatment did not provide a short-term antiarrhythmic effect and the cardiogenic shock was not well controlled. VA-ECMO treatment combined with hemoperfusion is promising temporary support to successfully treat aconitine-induced cardiogenic shock caused by refractory ventricular tachycardia.

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

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

Attenuated Structural Transformation of Aconitine during Sand Frying Process and Antiarrhythmic Effect of Its Converted Products

The transformation pathways of diterpenoid alkaloids have been clarified in the boiling and steaming process. Aconitine, a famous diterpenoid alkaloid, is successively transformed into benzoylaconine and aconine during the processes of boiling and steaming, but the transformation pathway remains to be determined in the sand frying process. The present study aims at investigating the transformation pathways of aconitine in the process of sand frying, as well as assessing the cardiotoxicity and antiarrhythmic activity of aconitine and its converted products. The parameters of temperature and time for the structural transformation of aconitine were confirmed by HPLC. The converted products were further separated and identified by column chromatography, NMR, and HR-ESI-MS. Furthermore, by observing the lead II electrocardiogram (ECG) changes in rats under an equivalent dose, the cardiotoxicity of aconitine and its converted products were compared. Ultimately, the antiarrhythmic effect of the converted products was investigated by employing the model of aconitine-induced arrhythmia. Consequently, the structure of aconitine was converted when processed at 120°C–200°C for 1–40 min. Two diterpenoid alkaloids, a pair of epimers, namely, pyroaconitine and 16-epi-pyroaconitine, were further isolated from processed aconitine. 0.03 mg/kg aconitine induced arrhythmias in normal rats, while the converted products did not exhibit arrhythmias under an equal dose. In the antiarrhythmic assay, 16-epi-pyroaconitine could dose-dependently delay the onset time of VPB, reduce the incidence of VT, and increase the arrhythmia inhibition rate, demonstrating comparatively strong antiarrhythmic activity. Conclusively, compared with the prototype compound aconitine, the converted products exhibited lower cardiotoxicity. Further investigations on the cardiotoxicity indicated that pyroaconitine with β configuration had a stronger cardiotoxicity than 16-epi-pyroaconitine with α configuration. Furthermore, 16-epi-pyroaconitine could antagonize the arrhythmogenic effect caused by the prototype compound aconitine; the antiarrhythmic effect of 16-epi-pyroaconitine was stronger than lidocaine and propafenone, which had the potential to be developed as antiarrhythmic drugs.

A system for reporting and evaluating adverse drug reactions of herbal medicine in Taiwan from 1998 to 2016

The Taiwan Adverse Drug Reaction Reporting System for Herbal Medicine (TADRRS-HM) has systematically documented suspected adverse events from adverse drug reaction (ADR) reports from 1998 (prior to its formal establishment in 2001) and evaluates safety profiles of herbal medicines. This article describes findings from 2079 ADR reports filed between 1998 and 2016: 941 reports involved single herbs and 87 involved folk herbals; 842 were generated from clinical trials, while 209 ADR reports involving foods, health foods, dietary supplement foods and herbal cuisine were grouped as Other. Severity assessments using the Modified Hartwig and Siegel scale classified 72.4% of ADRs as mild, 17.4% as moderate and 6.5% as severe. System Organ Class classification of the ADRs identified gastrointestinal system disorders as the most common (33.4%), followed by skin and subcutaneous tissue disorders (21.2%). The TADRRS-HM records indicate that herbal medicines may cause a wide range of ADRs. Aconiti Radix, Xiao-Qing-Long-Tang, and Datura suaveolens were the most commonly reported single herb, herbal formula, and folk herbal, respectively. The data indicate that herbal medicines may cause a wide range of ADRs. This system will confer long-term benefits for the development of Taiwan’s herbal medicines adverse reaction database and facilitate epidemiological analysis.

Traditional herbal medicine and nanomedicine: Converging disciplines to improve therapeutic efficacy and human health

Traditional herbal medicine (THM), an ancient science, is a gift from nature. For thousands of years, it has helped humans fight diseases and protect life, health, and reproduction. Nanomedicine, a newer discipline has evolved from exploitation of the unique nanoscale morphology and is widely used in diagnosis, imaging, drug delivery, and other biomedical fields. Although THM and nanomedicine differ greatly in time span and discipline dimensions, they are closely related and are even evolving toward integration and convergence. This review begins with the history and latest research progress of THM and nanomedicine, expounding their respective developmental trajectory. It then discusses the overlapping connectivity and relevance of the two fields, including nanoaggregates generated in herbal medicine decoctions, the application of nanotechnology in the delivery and treatment of natural active ingredients, and the influence of physiological regulatory capability of THM on the in vivo fate of nanoparticles. Finally, future development trends, challenges, and research directions are discussed.

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.

Structural diversity, bioactivities, and biosynthesis of natural diterpenoid alkaloids

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

[Aconitine poisoning due to confusion of aconite leaves with lovage]

Due to a mix-up an older couple (69 years and 71 years) ate a meal with herbs from their garden that contained leaves of monkshood (Aconitum napellus). The monkshood plants grew close to the herbs in their garden. Both patients developed the typical symptoms of aconitine poisoning with paresthesia, hypotension and bradycardia. Over the course of time both developed cardiac arrhythmia with ventricular extrasystoles and required monitoring on the intensive care unit (ICU). The husband was more severely affected and needed catecholamines for successful treatment of hypotension (70/40 mmHg) and bradycardia (45 bpm). The toxicological analysis of the patients' serum taken 3.5 h after ingestion led to the detection of 1.8 ng/ml and 2.0 ng/ml aconitine, respectively. The patients were discharged in good general condition after 1 and 2 days, respectively. Monkshood (Aconitum napellus) is one of the most toxic native plants that can also be found in gardens due to its popularity as an ornamental plant. All parts of the plant contain toxic diterpenoid alkaloids, such as aconitine. Aconitine causes persistent activation of the fast voltage-gated sodium channels resulting in severe cardiac and neurological toxicity. Treatment of aconitine-induced ventricular arrhythmias is challenging as they are often refractory to electrical cardioversion and antiarrhythmic drugs.

Reflections on the aconitine poisoning

Aconitine is a natural toxic substance belonging to the family of aconitum alkaloids, which is used in small doses by Traditional Chinese practitioners. We present a case of accidental death due to acute aconitine poisoning. A 65-year-old Chinese man presented to a medical clinic with fever and shoulder pain. Soon after administration of intravenous ceftriaxone, a bottle of Chinese medicinal wine was administered. The man rapidly experienced headache, hearing loss and tinnitus, nausea, diarrhea, numbness of the lips, tongue, face, and the upper and lower extremities, cold sweat, fall of blood pressure, and discomfort of the entire body, and he died on the same day. Postmortem examination showed cyanosis of the nail beds, severe congestion in lungs and other organs, bilateral pleural effusions, and infiltration of basophils in the intestinal submucosa. No significant increase of IgE was found in the blood. Toxicological analysis detected aconitine in the medicinal wine, blood, and stomach contents by liquid chromatography-tandem mass spectrometry (LC-MS⁄MS). Aconitine was quantified in cardiac blood as 16.4 ng/ml, and in stomach contents (63.8 ng/ml) and wine sample (10.1 ug/ml). The cause of death was aconitine poisoning. This case report highlights the danger of aconitine. LC-MS⁄MS has the advantages of high analytic speed, sensitivity, and accuracy. It would be desirable for the government to control the use of aconitine-containing herbal extracts.

Classification, Toxicity and Bioactivity of Natural Diterpenoid Alkaloids

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

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.

A perfect refractory electrical storm by acute toxicity of accidental aconitine intake

A 51-years-old male presented with drooling, hematemesis and diarrhea in emergency department after accidental ingestion of homemade aconitine tincture. Examination revealed shock and initial ECG showed atrial fibrillation. The patient suddenly developed a pulseless wide QRS complex tachycardia requiring resuscitation maneuvers. The rhythm varied from monomorphic ventricular tachycardia to torsade de point to ventricular fibrillation. Repeated direct-current cardioversions were unsuccessful. After intravenous electrolyte correction and anti-arrhythmic drugs administration, a last direct-current shock was finally successful. Bradycardia and ventricular excitability persisted over 12 hours with gradual normalization. Patient was discharged in normal sinus rhythm without any medication and on follow-up he was totally asymptomatic. With the increasing popularity of traditional medicine, clinicians should be alerted to the risk of herbal substances with low margins of safety like Aconitum in order to allow correct diagnosis and treatment. The general public should be educated that herbal medicine is not always safe.

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 Neurotoxicity According to Administration Methods

We evaluated the toxic effects of aconitine on the human nervous system and its associated factors, and the general clinical characteristics of patients who visited the emergency room due to aconitine intoxication between 2008 and 2017. We also analyzed the differences related to aconitine processing and administration methods (oral pill, boiled in water, and alcohol-soaked), and the clinical characteristics of consciousness deterioration and neurological symptoms. Of the 41 patients who visited the hospital due to aconitine intoxication, 23 (56.1%) were female, and most were older. Aconitine was mainly used for pain control (28 patients, 68.3%) and taken as oral pills (19 patients, 46%). The patients showed a single symptom or a combination of symptoms; neurological symptoms were the most common (21 patients). All patients who took aconitine after processing with alcohol showed neurological symptoms and a higher prevalence of consciousness deterioration. Neurological symptoms occurred most frequently in patients with aconitine intoxication. Although aconitine intoxication presents with various symptoms, its prognosis may vary with the processing method and prevalence of consciousness deterioration during the early stages. Therefore, the administration method and accompanying symptoms should be comprehensively investigated in patients who have taken aconitine to facilitate prompt and effective treatment and better prognoses.

Mechanism of action of a diterpene alkaloid hypaconitine on cytotoxicity and inhibitory effect of BAPTA-AM in HCN-2 neuronal cells

Hypaconitine, a neuromuscular blocker, is a diterpene alkaloid found in the root of Aconitum carmichaelii. Although hypaconitine was shown to affect various physiological responses in neurological models, the effect of hypaconitine on cell viability and the mechanism of its action of Ca2+ handling is elusive in cortical neurons. This study examined whether hypaconitine altered viability and Ca2+ signalling in HCN-2 neuronal cell lines. Cell viability was measured by the cell proliferation reagent (WST-1). Cytosolic Ca2+ concentrations [Ca2+ ]i was measured by the Ca2+ -sensitive fluorescent dye fura-2. In HCN-2 cells, hypaconitine (10-50 μmol/L) induced cytotoxicity and [Ca2+ ]i rises in a concentration-dependent manner. Removal of extracellular Ca2+ partially reduced the hypaconitine's effect on [Ca2+ ]i rises. Furthermore, chelation of cytosolic Ca2+ with BAPTA-AM reduced hypaconitine's cytotoxicity. In Ca2+ -containing medium, hypaconitine-induced Ca2+ entry was inhibited by modulators (2-APB and SKF96365) of store-operated Ca2+ channels and a protein kinase C (PKC) inhibitor (GF109203X). Hypaconitine induced Mn2+ influx indirectly suggesting that hypaconitine evoked Ca2+ entry. In Ca2+ -free medium, treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished hypaconitine-induced [Ca2+ ]i rises. Conversely, treatment with hypaconitine inhibited thapsigargin-induced [Ca2+ ]i rises. However, inhibition of phospholipase C (PLC) with U73122 did not inhibit hypaconitine-induced [Ca2+ ]i rises. Together, hypaconitine caused cytotoxicity that was linked to preceding [Ca2+ ]i rises by Ca2+ influx via store-operated Ca2+ entry involved PKC regulation and evoking PLC-independent Ca2+ release from the endoplasmic reticulum. Because BAPTA-AM loading only partially reversed hypaconitine-induced cell death, it suggests that hypaconitine induced a second Ca2+ -independent cytotoxicity in HCN-2 cells.

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.

Toxicity of herbal medications suggested as treatment for COVID-19: A narrative review

OBJECTIVES

In the absence of a definitive cure, herbal medications are gaining increasing popularity in the general public for treatment of coronavirus disease 2019 (COVID-19). Although many herbal preparations are safe and can be used without complication, serious toxicities do occur. This article focuses on the major characteristics and toxicities of herbal preparations that have been proposed as treatments for COVID-19.

METHODS

A review was performed focusing on herbal preparations that have gained popularity as potential treatments for COVID-19. Some of these preparations have been directly recommended by government agencies, whereas others have gained popularity through various other news sources.

RESULTS

The herbal preparations covered in this paper include the cardiac glycoside oleandrin, plants of the Datura genus, and herbs commonly used in traditional Chinese Medicine including plants of the Aconitum genus, bitter apricot seeds, ephedra, and licorice root.

CONCLUSION

Although herbal preparations have been reported to aid in the treatment of COVID-19 with success, few clinical trials have been performed to evaluate their efficacy and instead rely mainly on in vitro studies and anecdotal reports. Furthermore, many of the herbal preparations suggested carry significant toxicities, and frontline healthcare workers should be aware of the common symptoms and toxidromes that result from these poisonings.

Inhibition of the INa/K and the activation of peak INa contribute to the arrhythmogenic effects of aconitine and mesaconitine in guinea pigs

Aconitine (ACO), a main active ingredient of Aconitum, is well-known for its cardiotoxicity. However, the mechanisms of toxic action of ACO remain unclear. In the current study, we investigated the cardiac effects of ACO and mesaconitine (MACO), a structurally related analog of ACO identified in Aconitum with undocumented cardiotoxicity in guinea pigs. We showed that intravenous administration of ACO or MACO (25 μg/kg) to guinea pigs caused various types of arrhythmias in electrocardiogram (ECG) recording, including ventricular premature beats (VPB), atrioventricular blockade (AVB), ventricular tachycardia (VT), and ventricular fibrillation (VF). MACO displayed more potent arrhythmogenic effect than ACO. We conducted whole-cell patch-clamp recording in isolated guinea pig ventricular myocytes, and observed that treatment with ACO (0.3, 3 μM) or MACO (0.1, 0.3 μM) depolarized the resting membrane potential (RMP) and reduced the action potential amplitude (APA) and durations (APDs) in a concentration-dependent manner. The ACO- and MACO-induced AP remodeling was largely abolished by an I_Na blocker tetrodotoxin (2 μM) and partly abolished by a specific Na⁺/K⁺ pump (NKP) blocker ouabain (0.1 μM). Furthermore, we observed that treatment with ACO or MACO attenuated NKP current (I_Na/K) and increased peak I_Na by accelerating the sodium channel activation with the EC₅₀ of 8.36 ± 1.89 and 1.33 ± 0.16 μM, respectively. Incubation of ventricular myocytes with ACO or MACO concentration-dependently increased intracellular Na⁺ and Ca²⁺ concentrations. In conclusion, the current study demonstrates strong arrhythmogenic effects of ACO and MACO resulted from increasing the peak I_Na via accelerating sodium channel activation and inhibiting the I_Na/K. These results may help to improve our understanding of cardiotoxic mechanisms of ACO and MACO, and identify potential novel therapeutic targets for Aconitum poisoning.

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.

Establishment of a High-Resolution Liquid Chromatography-Mass Spectrometry Spectral Library for Screening Toxic Natural Products

Many natural products have biological effects on humans and animals. Poisoning caused by natural products is common in clinical toxicology cases. Liquid chromatography-high-resolution-mass spectrometry (LC-HRMS) has recently emerged as a powerful analytical tool for large-scale target screening, and the application of LC-HRMS can be expanded to evaluate potential natural product poisoning in clinical cases. We report the construction of an LC-HRMS spectral library of 95 natural products commonly implicated in poisoning, and an LC-HRMS assay was validated for definitive detection of natural products in urine and serum samples. For each compound, the limit of detection (LOD) was determined in the analytical range of 1.0 - 1000 ng/mL for urine samples and 0.50 - 500 ng/mL for serum samples. The mean (SD) of matrix effects for urine samples and that for serum samples were both -21% (22%), and the mean (SD) of recovery for serum samples was 89% (26%). The LC-HRMS assay was successfully applied to identify natural products in clinical cases. The spectral library parameters of each compound are provided in the supplementary material to aid other laboratories in identification of unknown natural toxins and development of similar methods on different mass spectrometry platforms.

The Toxicity and Attenuation Methods of Toxic Chinese Materia Medica for its Reasonable Application: A Review

Over a millennia, traditional Chinese medicine (TCM) has been used to treat various diseases in China. In recent years, more and more Chinese materia medica (CMM) have been studied in scientific research projects, applied in clinical practice, and their extracts have even appeared in some health products. However, the toxicity of some CMM is often overlooked, including hepatotoxicity, nephrotoxicity, neurotoxicity, cardiotoxicity, etc. In this review, the toxic components and their toxicological mechanisms of some toxic CMM were listed according to the chemical structure classification of toxic components. Afterwards, the traditional methods (processing and compatibility) and modern methods (structural modification, biotransformation, etc.) of attenuation of CMM were discussed. Since ancient times, it has been said that "fight fire with fire, fight poison with poison," and toxic CMM are of great significance in the treatment of difficult and severe diseases. The rational application of toxic CMM and their components in clinical practice was also exemplified in this review. While the pharmacological effects of TCMs have been emphasized, the scientific attenuation and rational application of toxic components should be concerned. We hope this review can provide a reference for future related research.

Processing methods and mechanisms for alkaloid-rich Chinese herbal medicines: A review

The processing of Chinese herbal medicine is a form of pharmaceutical technology developed over thousands of years, in order to increase efficiency and decrease toxicity of herbs in traditional Chinese medicine (TCM). Herbal processing is essential for safe and effective application of TCM in clinical practice, as it alters the active chemical components and therefore the functions of herbal medicines. Alkaloid-rich herbal medicines in TCM are commonly processed by cleansing, cutting, processing by dry stir-frying, stir-frying with liquid adjuvants, and processing by water decoction. In addition, commonly used adjuvants for processing alkaloid-rich herbal medicines are river sand, wine, vinegar, brine, honey and herbal juice. For alkaloid-rich herbal medicines, the main chemical reactions that occur during processing include hydrolysis, oxidation, replacement, decomposition and condensation. This paper aimed to summarize the processing methods and mechanisms for alkaloid-rich Chinese herbal medicines, and provide much-needed theoretical support and scientific evidence for understanding those mechanisms and effects. Information on processing methods for alkaloid-rich herbal medicines was collected from classic books of herbal medicine, PhD and MSc dissertations, online scientific databases including PubMed, SciFinder, Scopus, Web of Science, Baidu Scholar and Google Scholar. This paper should help to advance our knowledge of the processing mechanisms and aid in the development of processing methods for alkaloid-rich Chinese herbal medicines.

Mdr1a, Bcrp and Mrp2 regulate the efficacy and toxicity of mesaconitine and hypaconitine by altering their tissue accumulation and in vivo residence

Mesaconitine (MA) and hypaconitine (HA) are the main bioactive/toxic alkaloids of Aconitum carmichaelii Debx, and MDR1, BCRP and MRP2 are involved in their efflux in vitro. This study aimed to explore the effects of Mdr1a, Bcrp and Mrp2 on the efficacy/toxicity of MA and HA by using efflux transporter gene knockout mouse models. The analgesic and anti-inflammatory effects, neurotoxicity/cardiotoxicity, and pharmacokinetic profiles of MA and HA were studied. Compared to wild-type mice, the analgesic effects of MA or HA were significantly enhanced in Mdr1a^--/-, Bcrp1^-/- and Mrp2^-/- mice, and the anti-inflammatory effects notably increased in Bcrp1^-/- and Mrp2^-/- mice. Compared to wild-type mice, Mdr1a^-/-, Bcrp1^-/- and Mrp2^-/- mice suffered from severe karyopyknosis and edema in the brain after MA or HA treatment. Meanwhile, significant arrhythmia appeared, and the heart rate and RR-interval were greatly altered in Mdr1a^-/-, Bcrp1^-/- and Mrp2^-/- mice. Additionally, obvious disorder of cardiomyocytes were observed, and the CK and cTnT (indicators of heart injury) levels were greatly enhanced in efflux transporter gene knockout mice. The brain levels of MA and HA were markedly increased in Mdr1a^-/-, Bcrp1^-/- and Mrp2^-/- mice, and the heart levels of MA and HA enhanced greatly in Mdr1a^-/- mice. The MRT_0-t values of MA and HA were remarkably enhanced in most efflux transporter gene knockout mice. In conclusion, Mdr1a, Bcrp and Mrp2 were all involved in regulating the efficacy/toxicity of MA and HA by altering their tissue accumulation and in vivo residence. Among the three efflux transporters, Mdr1a had a superior regulatory effect.