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

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

Structural characterization, in vivo toxicity and biological activity of two new pyro-type diterpenoid alkaloids derived from 3-acetylaconitine.

OBJECTIVE: The transformations that occur in diterpenoid alkaloids during the process of sand frying for Chinese herbal medicine preparation have yet to be clarified. This study investigated the structural changes that take place in 3-acetylaconitine during a simulation of heat-processing and evaluated the toxicity and biological activity of the pyrolysis products. METHODS: The diterpenoid alkaloid 3-acetylaconitine was heated at 180 °C for 15 min to simulate the process of sand frying. The pyrolysis products were separated using column chromatography, and their structures were investigated using high-resolution electrospray ionization mass spectroscopy and nuclear magnetic resonance spectroscopy. Further, in vivo cardiotoxicity and acute toxicity of 3-acetylaconitine and its pyrolysis products were compared, and the aconitine-induced arrhythmia model was employed to evaluate the antiarrhythmic effect of the pyrolysis products. RESULTS: Two new diterpenoid alkaloids, pyroacetylaconitine and 16-epi-pyroacetylaconitine, a pair of epimers at C-16, were isolated. After comparing the structures of these compounds, possible transformation pathways were proposed. Compared with the prototype compound, 3-acetylaconitine, the cardiotoxicity and acute toxicity of the heat-transformed products were significantly decreased. In the biological activity assay, the two pyrolysis products exhibited an effective increase in ventricular premature beat latency, a reduction in the occurrence of ventricular tachycardia, as well as an increase in the rate of arrhythmia inhibition, implying strong antiarrhythmic activity. CONCLUSION: Compared with 3-acetylaconitine, its pyrolysis products displayed lower toxicity and good antiarrhythmic effects; thus, they have potential for being developed into antiarrhythmic medicines. Please cite this article as: Wang YJ, Wang Y, Tao P. Structural characterization, in vivo toxicity and biological activity of two new pyro-type diterpenoid alkaloids derived from 3-acetylaconitine. J Integr Med. 2023; 21(3): 302-314.

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

ETHNOPHARMACOLOGICAL RELEVANCE: Aconitum species, with a long history of traditional application, were applied to treat rheumatism, arthritis, stroke, and pain in Chinese medical practice. However, misuse of Aconitum species may induce central nervous toxic effects, such as numbness, vomiting, and even coma. Aconitine has been proved to be the main toxic component of Aconitum plants. Neurotoxicity is the main toxic effect of aconitine, while the underlying mechanism of aconitine remains unclear. AIM OF THE STUDY: The purpose of the study is to explore the effects and molecular mechanism of ferroptosis caused by aconitine in vivo and in vitro. MATERIALS AND METHODS: Six-dpf zebrafish larvae and SH-SY5Y cells were treated with different concentrations of aconitine for 24 h. Inhibitors treatment, e.g. pretreatment with Necrostain-1 (Nec-1) and Z-VZD-FMK for 12 h, or with Ferrostain-1 (Fer-1) for 4 h, were involved in the identification of aconitine-induced ferroptosis. Transient transfection experiment was conducted to explore the effects of SLC7A11 in the process of aconitine-induced ferroptosis. The effects of aconitine on morphological changes, lipid peroxidation, ferrous ion, and ferroptosis were detected by transmission electron microscope, flow cytometry, confocal microscopy, enzyme-linked immunosorbent assay and western blotting. RESULTS: In SH-SY5Y cells, morphological changes including shrunken mitochondria, increased mitochondrial membranes density and ruptured mitochondrial membranes were captured in aconitine-treated group. The cell viability and GSH content dose-dependently declined, levels of lipid reactive oxygen species (ROS), malondialdehyde (MDA), and ferrous ion significantly increased after aconitine exposure for 24 h. Ferroptosis inhibitor Fer-1 pretreatment effectively increased cell viability, GSH content, and decreased levels of MDA and lipid peroxidation, suggesting that aconitine induced ferroptosis. In addition, the protein expression of SLC7A11 and GPX4 were improved after Fer-1 preincubation, which indicated that aconitine triggered ferroptosis via the inhibition of SLC7A11 and the inactivation of GPX4. Ferroptotic characteristics, including GSH depletion and lipid peroxidation accumulation, were alleviated via overexpression of SLC7A11 to increase protein expression of GPX4. In zebrafish experiment, GSH depletion, lipid peroxidation accumulation, iron overload, and the decreased protein expression of SLC7A11 and GPX4 were also induced in zebrafish larvae after aconitine exposure. Taken together, aconitine triggered ferroptotic cell death via inhibiting SLC7A11/GPX4 signal pathway in vivo and in vitro. CONCLUSION: All results indicated that aconitine triggered ferroptosis of SH-SY5Y cells and zebrafish larvae nerve cells, which involved the inhibition of SLC7A11/GPX4 signal pathway mediated by lipid peroxidation damage and iron overload.

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.

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.

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.

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.

Aconitine disrupts serotonin neurotransmission via 5-hydroxytryptamine receptor in zebrafish embryo.

Medicinal plants of the genus Aconitum are one of the most commonly used herbs in traditional medicine in East Asia to treat conditions related to the heart, pain, or inflammation. However, these herbs are also dangerous as accidental poisoning due to misuse is a recurring issue. These plants contain a number of diester-diterpenoid alkaloid compounds and aconitine is the most abundant and active one. This study investigated neurotoxicity of aconitine to zebrafish embryos in early development in relation to serotonin regulation. Experimental results showed that aconitine exposure (1, 10, and 100 µM) increased frequency of coiling behavior in zebrafish embryos in a dose-dependent manner and this effect can be triggered by either exposure to 5-hydroxytryptamine 1A (5-HT1A) receptor agonist (±)-8-hydroxy-2-(dipropylamino)tetralin (8-OH-DPAT) or overexpression of serotonin receptor 5-htr1ab. At the same time, coiling behavior caused by aconitine exposure could be rescued by co-exposure to 5-HT1A receptor antagonist WAY-100635 Maleate (WAY100635) and knockdown of 5-htr1ab using morpholino. Exposure to aconitine also significantly increased serotonin receptor 5-htr1ab and 5-htr1bd gene expression at 24 h post fertilization (hpf), but decreased their expression and protein expression of the serotonin receptor at 96 hpf with the high dose. These results suggest that neurotoxicity caused by aconitine is mediated through the 5-HT receptor.

Aconitine induces cardiotoxicity through regulation of calcium signaling pathway in zebrafish embryos and in H9c2 cells.

Fuzi, the processed lateral roots of Aconitum carmichaelii Debx., is a traditional herbal medicine that is well known for its excellent pharmacological effects and acute toxicity. Aconitine is one of the diester-diterpene alkaloids and well-known for its arrhythmogenic effects. However, the effects of aconitine in zebrafish have rarely been studied. Therefore, we investigated the effects of aconitine on zebrafish embryos and H9c2 cells. Zebrafish embryos at 48 hours postfertilization were exposed to aconitine, and then, cardiac function and apoptosis were measured. Through transcriptomic analysis, the cardiotoxicity of aconitine in zebrafish embryos was involved in regulating Ca2+ signal pathways. A reverse transcription-polymerase chain reaction was performed to verify the expression of Ca2+ pathway-related genes after 12, 24, 36 and 48 hours of treatment. Meanwhile, intracellular Ca2+ concentrations and cell apoptosis were observed in H9c2 cells treated with half-maximal inhibitory concentration values of aconitine for 30 minutes. The protein levels of troponin T (TnT), caspase 3, Bcl-2 and Bax were detected by western blot analysis. In vivo, 2.0 and 8.0 µm aconitine decreased the heart rate and inhibited the contraction of ventricles and atria in a dose- and time-dependent manner. Furthermore, aconitine increased expression of cacna1c, RYR2, atp2a2b, Myh6, troponin C, p38, caspase 3, Bcl-2 and Bax for 12 hours. In vitro, 1.5 and 4.5 mm aconitine caused intracellular Ca2+ ion oscillation, increased rates of apoptosis, inhibited TnT and Bcl-2 protein expression, and promoted caspase 3 and Bax protein expression. These data confirmed that aconitine at various concentrations induced cardiac dysfunction and apoptosis were related to the Ca2+ signaling pathway.

Optimization of the traditional processing method for precision detoxification of CaoWu through biomimetic linking kinetics and human toxicokinetics of aconitine as toxic target marker.

ETHNOPHARMACOLOGICAL RELEVANCE: CaoWu (Aconiti Kusnezoffii Radix), well known for its high toxicity leading to fatal ventricular arrhythmias, is detoxified by HeZi (Terminalia Chebula Retz) decoction to prepare ZhiCaoWu (Aconiti Kusnezoffii Radix Preparata) as one part of ingredients of NaRu-3 pill which is used for the treatment of rheumatoid arthritis (RA). Aconitine (AC) is a highly toxic alkaloid of CaoWu and it is used as toxic target marker for the quality control (QC) of ZhiCaoWu. In the traditional processing method, the vanish of astringent or spicy feeling in tongue is the important detoxification indicator of ZhiCaoWu. However, how CaoWu is detoxified to ZhiCaoWu and whether the appropriate content of AC in ZhiCaoWu can be efficiently perceived after the empirical detoxification still lack factual basis. AIM OF THE STUDY: The present study aimed to optimize the traditional processing method for precision detoxification of CaoWu through biomimetic linking kinetics and human toxicokinetics (TK) of AC, with a view of providing insights into the changes of toxic target marker. MATERIALS AND METHODS: CaoWu medicinal slices (Mes) and coarse powder (Cop) were processed by blank HeZi decoction through the soaking method for 7 days. High-performance liquid chromatography (HPLC) was used for the analysis of the samples. The acidity of blank HeZi decoction and HeZi processing decoction was directly determined by pH meter. The non-compartment analysis (NCA) was used to have an intuitive appreciation for AC and pH changes in HeZi processing decoction while the compartment model method was used to build the biomimetic linking kinetics model with the covariate. The inter-species scaling of animal TK parameters was conducted to predict human AC TK profiles. The possible uptake ways of AC (rapid-release or extended-release) for humans were attempted to assess the poisoning risk of AC in NaRu-3 pill. Based on the target content of AC in ZhiCaoWu, the biomimetic linking kinetics model was explored to optimize the traditional processing detoxification method of CaoWu. The assays of determining inflammatory cytokines in lipopolysaccharides (LPS)-induced RAW264.7 cells were performed to investigate the inflammatory modulation effects of AC in vitro. RESULTS: ZhiCaoWu was prepared by eliminating redundant AC in CaoWu through the repeatable replacement of HeZi processing decoction in which its acidity (pH) was affected. AC-pH changes in HeZi processing decoction were adequately depicted by a biomimetic linking kinetics model whose predictive power was determined by comparing the predictions of AC in ZhiCaoWu with the reported data. Rapid-release AC at the converted dose of 111.1 and 417.6 µg (0.011 and 0.042% of AC in NaRu-3 pill) reached maximum blood concentrations of 26.1 and 98.1 ng/mL at 0.3 h, in comparison with minimum human lethal concentration (100 ng/mL). Achieving the target content of AC (0.04%) in ZhiCaoWu or AC (0.011%) in NaRu-3 pill to precisely control the poisoning risk, the potential optimized protocols were that the processing time at 0.2-0.8% of AC in CaoWu was 2.0-4.4 days for Cop and 2.7-6.2 days for Mes. Correspondingly, pH values in HeZi processing decoction were 3.95 and 3.77 for Cop and Mes, respectively. Meanwhile, Lipopolysaccharides (LPS)-induced RAW264.7 cells were exposed to 0, 20, and 200 µM of AC for 12 h and AC at 20 µM enhanced the levels of IL-6, IL-10 and TNF-α. CONCLUSIONS: Thus, for the first time, a biomimetic linking kinetics model was built to optimize the traditional detoxification method. Moreover, pH changes could be developed as surrogate endpoint for guiding the processing detoxification of CaoWu. Notably, setting the content limit of AC (0.011%) was very rational to control the poisoning risk of NaRu-3 pill. In addition, it was possible that there existed the more complex mechanisms of AC for inflammatory modulation in vitro.

[Safety evaluation and risk control measures for Aconiti Kusnezoffii Radix].

Through the comprehensive and systematic research of domestic and overseas literature and information, we studied ancient original records on Aconiti Kusnezoffii Radix and its toxicity, analyzed related adverse cases and the animal toxicity experiments in recent years, then systematically analyzed the safety of Aconitum and its preparations, and finally we summarized the clinical characteristics and potential risk factors related to the safety of Aconitum. A report on adverse events of Aconitum in 76 patients with myocardial damage and renal damage accounting for 53.9% and 42.1% respectively, indicated that the safety problems of Aconitum may be related to heart toxicity and liver-kidney toxicity. Aconitum had complex compositions, and based on the animal experiments, Aconitum decoction had the highest toxicity at 2 h, and it reduced significantly at 4 h, which showed that the toxic components mainly depend on the hydrolysis or the decomposition degree of diester diterpenoid alkaloids. According to the toxicity study, Aconitum toxicity might occur in cardiovascular system, nervous system, kidney, embryo, reproductive system, and it was contraindicated in pregnant women. So far, specific antidote for aconitine poisoning is still a blank. The key for treatment is to correct arrhythmia timely and effectively, maintain stable vital signs, and meanwhile, give gastric lavage, intravenous fluid infusion and other therapies. So we suggest that the basic study for Aconitum toxicology should be strengthened, and the pharmacology and mechanism of toxicity, as well as the mechanism of processing for raising efficiency and reducing toxicity, should be further clarified to determine the quantity-effect relationship and eliminate safety hazards in using Aconitum.

Influence of total flavonoids derived from Choerospondias axillaris folium on aconitine-induced antiarrhythmic action and hemodynamics in Wistar rats.

It is well known that various traditional Chinese medicines produce antiarrhythmic actions. The aims of this study were to examine whether total flavones derived from Choerospondias axillaris folium (TFCF) also produced antiarrhythmic effects using a rat model of aconitine-induced arrhythmia and to compare these observations with the effects of total flavones of Choerospondias axillaris fructus (TFC). Wistar rats were orally administered TFC (0.2 g/kg) or TFCF (0.1, 0.2, or 0.4 g/kg) daily for 7 d. Subsequently, aconitine iv at 25 µg/kg was used to induce arrhythmia in these animals. Control (C) physiological saline and positive verapamil rats were also administered orally. The starting times of ventricular ectopic beats (VE), ventricular tachycardia (VT), ventricular fibrillation (VF), and heart arrest (HA) were recorded. In comparison to C, TFCF and TFC significantly prolonged the starting time of VE, VT, VF, and HA induced by aconitine. With respect to hemodynamics, TFC and high-dose TFCF were effective in reducing HR without associated changes in BP in all groups. TFC and TFCF decreased left ventricular systolic pressure (LVSP) and maximal velocity rate of ventricular pressure (+dp/dt max and -dp/dt min) with no marked effect on left ventricular end diastolic pressure (LVEDP) and -dp/dtmin. Data demonstrated that TFCF and TFC were equally effective in diminishing the aconitine-mediated arrhythmias. In addition, TFCF and TFC produced a similar reduction in HR with no accompanying change in BP. These findings indicate that the TFCF- and TFC-induced alterations may be attributed to inhibition of ventricular contraction without altering ventricular diastolic function.

Clinical Aspects of Aconitum Preparations.

Aconite species have played an important role in human history. Aconitum species have been used worldwide as poisons as well as remedies. Their potential in targeting several ailments such as pain, rheumatism, and lethargy has been recognized by Western, Chinese, and Indian health care practitioners. Aconite use in herbal preparations has declined, especially in Europe and the United States, in the first half of the twentieth century due to several reported toxicity cases. The situation has changed with the application of new technologies for the accurate analysis of its toxic components and the development of efficient detoxification protocols. Some Asian countries started small clinical trials to evaluate the potency and safety of different marketed aconite preparations. The current review summarizes therapeutic uses of aconite preparations in China, Taiwan, India, and Japan. It also highlights clinical trial results with special emphasis on their limitations. Modern drugs and pharmacopoeial preparations derived from aconite are also discussed.

Metabonomics study of the effects of pretreatment with glycyrrhetinic acid on mesaconitine-induced toxicity in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Aconitum carmichaelii Debx. (Fuzi), a commonly use traditional Chinese medicine (TCM), has often been used in combination with Rhizoma Glycyrrhizae (Gancao) to reduce its toxicity due to diester diterpenoid alkaloids aconitine, mesaconitine, and hypaconitine. However, the mechanism of detoxication is still unclear. Glycyrrhetinic acid (GA) is the metabolite of glycyrrhizinic acid (GL), the major component of Gancao. In present study, the effect of GA on the changes of metabolic profiles induced by mesaconitine was investigated using NMR-based metabolomic approaches. MATERIALS AND METHODS: Fifteen male Wistar rats were divided into a control group, a group administered mesaconitine alone, and a group administered mesaconitine with one pretreatment with GA. Their urine samples were used for NMR spectroscopic metabolic profiling. Statistical analyses such as orthogonal projections to latent structures-discriminant analysis (OPLS-DA), t-test, hierarchical cluster, and pathway analysis were used to detect the effects of pretreatment with GA on mesaconitine-induced toxicity. RESULTS: The OPLS-DA score plots showed the metabolic profiles of GA-pretreated rats apparently approach to those of normal rats compared to mesaconitine-induced rats. From the t-test and boxplot results, the concentrations of leucine/isoleucine, lactate, acetate, succinate, trimethylamine (TMA), dimethylglycine (DMG), 2-oxo-glutarate, creatinine/creatine, glycine, hippurate, tyrosine and benzoate were significantly changed in metabolic profiles of mesaconitine-induced rats. The disturbed metabolic pathways include amino acid biosynthesis and metabolism. CONCLUSIONS: GA-pretreatment can mitigate the metabolic changes caused by mesaconitine-treatment on rats, indicating that prophylaxis with GA could reduce the toxicity of mesaconitine at the metabolic level.

P-glycoprotein is responsible for the poor intestinal absorption and low toxicity of oral aconitine: in vitro, in situ, in vivo and in silico studies.

Aconitine (AC) is a highly toxic alkaloid from bioactive plants of the genus Aconitum, some of which have been widely used as medicinal herbs for thousands of years. In this study, we systematically evaluated the potential role of P-glycoprotein (P-gp) in the mechanisms underlying the low and variable bioavailability of oral AC. First, the bidirectional transport of AC across Caco-2 and MDCKII-MDR1 cells was investigated. The efflux of AC across monolayers of these two cell lines was greater than its influx. Additionally, the P-gp inhibitors, verapamil and cyclosporin A, significantly decreased the efflux of AC. An in situ intestinal perfusion study in rats showed that verapamil co-perfusion caused a significant increase in the intestinal permeability of AC, from 0.22×10(-5) to 2.85×10(-5) cm/s. Then, the pharmacokinetic profile of orally administered AC with or without pre-treatment with verapamil was determined in rats. With pre-treatment of verapamil, the maximum plasma concentration (Cmax) of AC increased sharply, from 39.43 to 1490.7 ng/ml. Accordingly, a 6.7-fold increase in the area under the plasma concentration-time curve (AUC0-12h) of AC was observed when co-administered with verapamil. In silico docking analyses suggested that AC and verapamil possess similar P-gp recognition mechanisms. This work demonstrated that P-gp is involved in limiting the intestinal absorption of AC and attenuating its toxicity to humans. Our data indicate that potential P-gp-mediated drug-drug interactions should be considered carefully in the clinical application of aconite and formulations containing AC.

[Rationality of the processing methods of aconiti lateralis radix (Fuzi) based on chemical analysis].

In this study, we explored the rationality of processing methods and mechanism of Aconiti Lateralis Radix (Fuzi) through comparing the chemical contents of diester alkaloids (DAs) and monoester alkaloids (MAs) in the raw material of Fuzi and its processed products. The results showed that the toxicity potency of MAs is at least lower than 1/64 to 1/180 of the toxicity potency of DAs. The contents of DAs in processed Fuzi decreased to 1/76.5 to 1/38.3 of the value of raw Fuzi. The contents of MAs in processed Fuzi significantly increased by 4.6 to 5.2 fold or basically the same as that of the raw Fuzi. The values of MAs/DAs of processed Fuzi were enhanced by 30 to 390 fold of the raw Fuzi. It was found that the contents of DAs were insignificantly different between "Wu dan fu pian" (steaming or stir-frying without Danba) and "Dan fu pian" (steaming or stir-frying with Danba). The result suggested that the abilities of "eliminating toxicity" of different processing methods were equivalent at all. In contrast, the contents of MAs contained in "Wu dan fu pian" were of 5.3 to 8.7 fold higher than the values in "Dan fu pian". This result suggested the processing method by steaming or stir-frying without Danba might have better effect for "conserving property" than the method processed with Danba stipulated by China Pharmacopoeia. We believe that the new processing method without Danba can be recommended in further application due to it offers a simple procedure and it will not introduce inorganic impurities in the products.

The exposure of highly toxic aconitine does not significantly impact the activity and expression of cytochrome P450 3A in rats determined by a novel ultra performance liquid chromatography-tandem mass spectrometric method of a specific probe buspirone.

Aconitum species are widely used to treat rheumatism, cardiovascular diseases, and tumors in China and other Asian countries. The herbs are always used with drugs such as paclitaxel. Aconitine (AC) is one of the main bioactive/high-toxic alkaloids of Aconitum roots. AC is metabolized by cytochrome P450 (CYP) 3A. However, whether AC inhibits/induces CYP3A, which causes drug-drug interaction (DDI) is unclear. Our study aims to explore the potent effects of AC, as a marker component of Aconitum, on CYP3A using the probe buspirone in rats. The effects of oral AC on pharmacokinetics of buspirone were evaluated. CYP3A activity and protein levels in rat liver microsomes pretreated with oral AC were also measured using in vitro buspirone metabolism and Western blot. Buspirone and its major metabolites 1-(2-pyrimidinyl)piperazine and 6'-hydroxybuspirone were determined using a newly validated UPLC-MS/MS method. Single dose and 7-day AC administration at 0.125mg/kg had no effect on CYP3A activity since no change in the formation of 1-(2-pyrimidinyl)piperazine and 6'-hydroxybuspirone. CYP3A activity and protein levels in liver microsomes were also not affected by 7-day AC pretreatment at 0.125mg/kg. Therefore, AC neither inhibits nor induces CYP3A in rats, indicating AC does not cause CYP3A-related DDI in the liver.

Cardioprotective effect of grape-seed proanthocyanidins on doxorubicin-induced cardiac toxicity in rats.

CONTEXT: Doxorubicin (Dox) is an anthracycline antibiotic used as anticancer agent. However, its use is limited due to its cardiotoxicity which is mainly attributed to accumulation of reactive oxygen species. OBJECTIVE: This study was conducted to assess whether the antioxidant, proanthocyanidins (Pro) can ameliorate Dox-induced cardiotoxicity in rats. MATERIALS AND METHODS: Male Sprague-Dawely rats were divided into four groups. Group I was control. Group II received Pro (70 mg/kg, orally) once daily for 10 days. Group III received doxorubicin 15 mg/kg i.p. as a single dose on the 7th day and Group IV animals were treated with Pro once daily for 10 days and Dox on the 7th day. The parameters of study were serum biomarkers, cardiac tissue antioxidant status, ECG, and effect on aconitine-induced cardiotoxicity. RESULTS: Cardiac toxicity of doxorubicin was manifested as a significant increase in heart rate, elevation of the ST segment, prolongation of the QT interval and an increase in T wave amplitude. In addition, Dox enhanced aconitine-induced cardiotoxicity by a significant decrease in the aconitine dose producing ventricular tachycardia (VT). Administration of Pro significantly suppressed Dox-induced ECG changes and normalized the aconitine dose producing VT. The toxicity of Dox was also confirmed biochemically by significant elevation of serum CK-MB and LDH activities as well as myocardial MDA and GSH contents and decrease in serum catalase and myocardial SOD activities. Administration of Pro significantly suppressed these biochemical changes. DISCUSSION AND CONCLUSION: These results suggest that proanthocyanidins might be a potential cardioprotective agent against Dox-induced cardiotoxicity due to its antioxidant properties.

Metabolomics study on Fuzi and its processed products using ultra-performance liquid-chromatography/electrospray-ionization synapt high-definition mass spectrometry coupled with pattern recognition analysis.

The lateral root of Aconitum carmichaelii Debx is named "Fuzi" which is widely distributed across Asia and North America and has been used to relieve joint pain and treat rheumatic diseases for over two thousand years. However, it has very narrow therapeutic ranges and despite the toxicological risk, its usage remains very high. A traditional Chinese processing approach (Paozhi, detoxifying measure) is necessary to remove the poisonous Aconitum alkaloids mainly deriving from the diester diterpene alkaloids (DDAs) including aconitine, mesaconitine and hypaconitine. They can be decomposed into less or non-toxic derivatives through Paozhi that plays an essential role in detoxification. Processed Fuzi is mainly focused on the three main forms of Yanfuzi (YFZ), Heishunpian (HSP) and Baifupian (BFP) which are highly desirable in order to guarantee the clinical safety and their low toxicity in decoctions. The difference in metabolomic characters between Fuzi and its processed preparations is still completely unclear. Therefore, this paper was designed to investigate a comprehensive metabolome of Fuzi and its processed products by ultra-performance liquid-chromatography/electrospray-ionization synapt high-definition mass spectrometry (UPLC-Q-TOF-HDMS) combined with pattern recognition methods. The difference in metabolic profiles between Fuzi and its processed preparations was well observed by the principal component analysis (PCA) of the MS spectra. Significant changes of 19 metabolite biomarkers were detected in the Fuzi samples and three preparations. The underlying regulations of Paozhi-perturbed metabolic pathways were also discussed according to the identified metabolites. The present study proves that UPLC-Q-TOF-HDMS based metabolomic analysis greatly contributes to the investigation of Fuzi metabolism through Paozhi techniques, and provides useful information to further comprehensively understand the pharmacological activity and potential toxicity of processed Fuzi in a clinical environment.