A case of fatal poisoning with the aconite plant: quantitative analysis in biological fluid

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.

Genetic identification and subsequent LC-QTOF MS analysis of plant remains (Oenanthe spp.) could prove the cause of an undetermined sudden death

In recent years, recorded cases related to forensic botany and, in particular, of plant poisoning have become rare. We report on the medicolegal characteristics of an undetermined sudden death (USD) of a woman in which scene there were remnants of a vegetal peeling. After the autopsy, macroscopic findings reported multiorgan failure and requested the investigation of the cause of death. Postmortem blood was firstly investigated on cyanide toxicity presumptively coming from a yucca-like root; however, found cyanide levels were under normality. Because of the lack of morphological features of the encountered plant remains, a genetic nrDNA ITS2 sequence investigation was followed. The resulting DNA sequence could identify the evidence as the water dropwort (Oenanthe spp.) which contains oenanthotoxin, a potent toxin that may be fatal, similar to the more commonly found in hemlock Conium or cowbane Cicuta species. A liquid chromatography-tandem high resolution mass spectrometry (LC-QTOF MS) was later applied to analyse the vegetal extract and stomach content and successfully confirmed the toxin existence. Medicolegal and analytical findings at the forensic laboratory were described, where both biological and chemical techniques could successfully conjugate, as an interdisciplinary research, and explain premortem symptoms and postmortem findings. Present data can be helpful in future investigation on poisoning cases by conjugated polyacetylenes . The present work tries to emphasize the often undervalued plant evidence in legal medicine diagnosis in the context of an unexplained death.

Rapid identification of Aconitum plants based on loop-mediated isothermal amplification assay

Objective

Aconitum plants (Ranunculaceae) exhibit toxicity, and accidental ingestion of the plants has been reported in Japan. Identifying the cause of poisoning is important for emergency medical treatment, and a rapid and simple detection technique is required for the identification of poisoning cause. In the present study, we developed a rapid and simple method for detecting Aconitum plant DNA using a loop-mediated isothermal amplification (LAMP) assay.

Results

Specific LAMP primers for Aconitum plants were designed based on the trnL–trnF intergenic spacer region. Using the LAMP primers, the LAMP assay included an initiation reaction of 10 min followed by amplification for 20 min at the isothermal reaction temperature of 65 °C. The LAMP reaction was demonstrated to be specific and highly sensitive to Aconitum plants, given that the assay can be used for 1 pg of purified DNA. Using raw extracted DNA as template, the entire detection procedure from DNA extraction to final detection required only 30 min. Moreover, the protocol identified samples containing approximately 5 mg of Aconitum plants cooked and digested with artificial gastric juice. The currently proposed protocol exhibits good potential as a screening method of Aconitum plant poisoning for emergency medical care.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4463-1) contains supplementary material, which is available to authorized users.

Pharmacokinetic comparisons of benzoylmesaconine in rats using ultra-performance liquid chromatography-tandem mass spectrometry after administration of pure benzoylmesaconine and Wutou decoction

Wutou decoction is widely used in China because of its therapeutic effect on rheumatoid arthritis. Benzoylmesaconine (BMA), the most abundant component of Wutou decoction, was used as the marker compound for the pharmacokinetic study of Wutou decoction. The aim of the present study was to compare the pharmacokinetics of BMA in rats after oral administration of pure BMA and Wutou decoction. Pure BMA (5 mg/kg) and Wutou decoction (0.54 g/kg, equivalent to 5 mg/kg BMA) were orally administered to rats with blood samples collected over 10 h. Quantification of BMA in rat plasma was achieved using sensitive and validated ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Specifically, the half-life (T_1/2) and mean residence time values of pure BMA were 228.3 ± 117.0 min and 155.0 ± 33.2 min, respectively, whereas those of BMA in Wutou decoction were decreased to 61.8 ± 35.1 min and 55.8 ± 16.4 min, respectively. The area under the curve (AUC) of BMA after administration of Wutou decoction was significantly decreased (five-fold) compared with that of pure BMA. The results indicate that the elimination of BMA in rats after the administration of Wutou decoction was significantly faster compared with that of pure BMA.

Absorption and metabolism of three monoester-diterpenoid alkaloids in Aconitum carmichaeli after oral administration to rats by HPLC-MS

ETHNOPHARMACOLOGICAL RELEVANCE

Aconitum carmichaelii (AC) is a well-known herbal medicine for its excellent pharmacological effects and toxicity. The monoester-diterpenoid alkaloids (MDAs), including benzoylmesaconine (BMC), benzoylaconine (BAC) and benzoylhyaconine (BHC), are the main active components in AC. It was found that the diester alkaloids could be transformed into monoester-diterpenoid alkaloids after being decocted. In Chinese pharmacopoeia, the MDAs are also used as phytochemical markers for the quality control of AC. Benzoylmesaconine, benzoylaconine and benzoylhyaconine are representatives of monoester-diterpenoid alkaloids. It was reported that the absolute bioavailability of MDAs was very low but there was toxicity often occurred in AC. Because most of DDAs are transformed into MDAs after decoction, we speculate that some other components may promote the bioavailability of MDAs but result in toxicity by enhancing their absorption. To demonstrate the dynamic changes of MDAs in vivo and reveal the causes of low bioavailability and toxicity, this study will explore the mechanisms of absorption and metabolism of 3 MDAs.

MATERIALS AND METHODS

A sensitive, accurate and specific LC-MS method was developed to determine the three MDAs in rat plasma. The pharmacokinetic parameters were estimated after orally administered 3 MDAs to the Male Sprague-Dawley rats, and the metabolism stability was calculated after incubating with rat liver microsomes, finally, the absorption characteristics of the 3 MDAs were investigated using Caco-2 transwell model.

RESULTS

It was found that the pharmacokinetic parameters of 3 MDAs were similar, Cmax and Tmax were very small, and t1/2 was large, which indicated 3 MDAs can be absorbed rapidly and is difficult to be metabolized or excreted. However, the low Cmax indicated that the bioavailability of 3 MDAs will be very low and their absorption may be inhibited by some transport proteins. By incubating three MDAs in rat liver microsomes, it was proved that they almost can't be metabolized in vivo. The Caco-2 transwell experiments reveal that the P-gp inhibits the absorption of MDAs.

CONCLUSIONS

LC-MS combined with a direct precipitation method for the simultaneous quantification of 3 MDAs in rat plasma has been developed and validated and successfully used in pharmacokinetic study of 3 MDAs. It was proved that the three components almost can't be metabolized in vivo, and P-gp inhibits the absorption of MDAs.

Comparative study on effects of single and multiple oral administration of mungbean (Phaseolus radiatus L.) seed extract on the pharmacokinetics of aconitine by UHPLC-MS

The study was aimed to investigate the effects of single and multiple oral administration of mungbean (Phaseolus radiatus L.) seed extract (ME) on the pharmacokinetics of aconitine in rats. The Sprague-Dawley rats were randomly divided into three groups (six rats each group). In group 1, rats were orally administered 500 µg/kg aconitine after receiving a single oral dose of 1 g/kg ME. In group 2, rats were orally administered with 500 µg/kg aconitine at day 7 of treatment with 1 g/kg/day ME. In group 3, rats were orally administered with 500 µg/kg aconitine. Blood samples were collected at different time points (0.083, 0.25, 0.5, 1.0, 1.5, 2.0, 4.0, 6.0, 8.0 and 10.0 h). The concentration of aconitine in rats plasma was determined by a fully validated ultra-high-performance liquid chromatography coupled with mass spectrometry method. The results showed that single and multiple oral co-administration of ME significantly altered the pharmacokinetic parameters of aconitine.

The effects of Rhizoma Zingiberis on pharmacokinetics of six Aconitum alkaloids in herb couple of Radix Aconiti Lateralis-Rhizoma Zingiberis

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Aconiti Lateralis (Fuzi in Chinese, derived from the lateral roots of Aconitum Carmichaeli Debx.) is widely used for the treatment of heart failure, internal cold, arthralgia, diarrhea and edema for thousands of years. It was usually prescribed in combination with Rhizoma Zingiberis (Ganjiang in Chinese, derived from the dry rhizome of Zingiber officinale Rosc.) to decrease toxicity and increase efficacy.

AIM OF THE STUDY

In order to investigate the influence of Rhizoma Zingiberis on pharmacokinetics of six Aconitum alkaloids, i.e. aconitine (AC), hypaconitine (HA), mesaconitine (MA), benzoylaconine (BAC), benzoylhypaconine (BHA) and benzoylmesaconine (BMA), in Fuzi-Ganjiang herb couple, the comparative pharmacokinetics of six Aconitum alkaloids after oral administration of Fuzi and Fuzi-Ganjiang aqueous extract was carried out.

MATERIALS AND METHODS

A sensitive, specific and rapid LC-MS/MS method was developed to determine the six analytes in plasma. Then the rats were randomly divided into two groups and orally administered with Fuzi and Fuzi-Ganjiang aqueous extract. At designated time points after oral administration, the concentrations of the six Aconitum alkaloids in rat plasma were determined, and main pharmacokinetic parameters were investigated using 3P97 (Practical Pharmacokinetics Program Version 1.0).

RESULTS

Comparing with Fuzi group, both T1/2 and AUC0-t of AC and HA decreased (P<0.05), while T1/2, AUC0-t and Cmax of BAC, BHA increased (P<0.05) in Fuzi-Ganjiang group, which indicated that Ganjiang could promote the elimination of AC and HA and enhance the absorption of BAC, BHA and BMA.

CONCLUSION

The differences of pharmacokinetics of Aconitum alkaloids in rat plasma could support those of pharmacologics and toxicity in previous reports between Fuzi and Fuzi-Ganjiang herb couple. The results might be helpful in explaining the mechanism of combination of Fuzi-Ganjiang to decrease toxicity and increase efficacy.

Monoester-Diterpene Aconitum Alkaloid Metabolism in Human Liver Microsomes: Predominant Role of CYP3A4 and CYP3A5

Aconitum, widely used to treat rheumatoid arthritis for thousands of years, is a toxic herb that can frequently cause fatal cardiac poisoning. Aconitum toxicity could be decreased by properly hydrolyzing diester-diterpene alkaloids into monoester-diterpene alkaloids. Monoester-diterpene alkaloids, including benzoylaconine (BAC), benzoylmesaconine (BMA), and benzoylhypaconine (BHA), are the primary active and toxic constituents of processed Aconitum. Cytochrome P450 (CYP) enzymes protect the human body by functioning as the defense line that limits the invasion of toxicants. Our purposes were to identify the CYP metabolites of BAC, BMA, and BHA in human liver microsomes and to distinguish which isozymes are responsible for their metabolism through the use of chemical inhibitors, monoclonal antibodies, and cDNA-expressed CYP enzyme. High-resolution mass spectrometry was used to characterize the metabolites. A total of 7, 8, and 9 metabolites were detected for BAC, BMA, and BHA, respectively. The main metabolic pathways were demethylation, dehydrogenation, demethylation-dehydrogenation, hydroxylation and didemethylation, which produced less toxic metabolites by decomposing the group responsible for the toxicity of the parent compound. Taken together, the results of the chemical inhibitors, monoclonal antibodies, and cDNA-expressed CYP enzymes experiments demonstrated that CYP3A4 and CYP3A5 have essential functions in the metabolism of BAC, BMA, and BHA.

Quantification of aconitine in post-mortem specimens by validated liquid chromatography-tandem mass spectrometry method: three case reports on fatal 'monkshood' poisoning

The diester-diterpene alkaloid aconitine was quantified by liquid chromatography-tandem mass spectrometry in post-mortem specimens of three cases where suicidal ingestion of Aconitum napellus L. ('monkshood') was supposed. In an attempt at rationalization, sample preparation and chromatographic conditions of plasma/serum drug analysis routine were utilized. Linearity was established from 0.5 to 20 µg L⁻¹ using newborn calf serum (NCS) as a surrogate calibration matrix for all sample types and mesaconitine as an internal standard. Validation (selectivity, sensitivity, precision, accuracy, recovery of the extraction procedure, matrix effect, processed sample stability) confirmed the applicability of the analytical method to various post-mortem matrices. Internal standard selection was based on multi-matrix process efficiency data. In human post-mortem peripheral blood a lower limit of quantification of 0.51 µg L⁻¹ and a limit of detection of 0.13 µg L⁻¹ were accomplished (0.1 ml sample aliquots). Aconitine was degraded to a large extent in different sample types when being stored at +20 °C for 30 days, while at -20 °C and for some matrices also at +4 °C no appreciable degradation occurred. Aconitine concentrations in real samples were 10.3-17.9 µg L⁻¹ (peripheral blood, n = 3), 14.9-87.9 µg L⁻¹ (heart blood, n = 3), 317-481 µg L⁻¹ (urine, n = 2), 609-4040 µg L⁻¹ (stomach content, n = 3), 139-240 µg L⁻¹ (bile, n = 2), 8.4 µg L⁻¹ (vitreous humor, n = 1), 54.7 µg L⁻¹ (pericardial fluid, n = 1), 492 µg kg⁻¹ (liver, n = 1), 15.2-19.7 mg L⁻¹ (unknown liquids secured onsite, n = 3). Together with concomitant circumstances the analytical data provided compelling evidence for acute Aconitum poisoning as being the cause of death.

Poisoning: fact or fiction?

Analytical toxicology is a complex discipline. Simply detecting a poison in a biological sample does not necessarily mean that the individual from whom the sample was obtained had been poisoned. An analysis can prove exposure and perhaps give an indication of the magnitude of exposure, but the results have to be placed in proper context. Even if sampling was ante-mortem an analysis does not necessarily prove the effects that the drug or poison had on the victim immediately before or at the time of sampling. Tolerance is one big issue, the mechanism of exposure (how the drug got into the body) is another, and of course with post-mortem work there are always additional considerations such as site of sample collection and the possibility of post-mortem change in analyte concentration. There are also questions of quality and reliability, and whether a particular analysis and the interpretation placed upon the result are appropriate in a particular case.

Fatal aconitine intoxication or thyroid storm? A case report

The case of a female in the latter half of her teens found dead in her father's apartment is reported. A glass containing liquid and plant remnants was found at the death scene. There were no indications of any intervention or the application of force by a third party. Autopsy showed unremarkable findings. Toxicological investigations revealed lethal doses of aconitine, a highly poisonous alkaloid and the major active compound of Aconitum napellus, in all specimens. Plant remnants were identified as A. napellus leaves by a botanist and toxicological examination of the liquid in the glass on site showed extremely high concentrations of aconitine. Additionally, laboratory results revealed that the young female was suffering from thyrotoxicosis factitia, an uncommon form of hyperthyroidism caused by misuse or overdosing of thyroid hormones in order to loose weight. A rare but serious and often fatal complication of hyperthyroidism is thyroid storm. Eventually the condition of thyroid storm due to thyrotoxicosis factitia could have contributed to the woman's death from aconitine poisoning.

Establishment of a bioassay for the toxicity evaluation and quality control of Aconitum herbs

Currently, no bioassay is available for evaluating the toxicity of Aconitum herbs, which are well known for their lethal cardiotoxicity and neurotoxicity. In this study, we established a bioassay to evaluate the toxicity of Aconitum herbs. Test sample and standard solutions were administered to rats by intravenous infusion to determine their minimum lethal doses (MLD). Toxic potency was calculated by comparing the MLD. The experimental conditions of the method were optimized and standardized to ensure the precision and reliability of the bioassay. The application of the standardized bioassay was then tested by analyzing 18 samples of Aconitum herbs. Additionally, three major toxic alkaloids (aconitine, mesaconitine, and hypaconitine) in Aconitum herbs were analyzed using a liquid chromatographic method, which is the current method of choice for evaluating the toxicity of Aconitum herbs. We found that for all Aconitum herbs, the total toxicity of the extract was greater than the toxicity of the three alkaloids. Therefore, these three alkaloids failed to account for the total toxicity of Aconitum herbs. Compared with individual chemical analysis methods, the chief advantage of the bioassay is that it characterizes the total toxicity of Aconitum herbs. An incorrect toxicity evaluation caused by quantitative analysis of the three alkaloids might be effectively avoided by performing this bioassay. This study revealed that the bioassay is a powerful method for the safety assessment of Aconitum herbs.

Seven cases of fatal aconite poisoning: forensic experience in China

This paper presents seven fatal cases of aconite poisoning encountered in the Tongji Center for Medicolegal Expertise in Hubei (TCMEH), China, from 1999 to 2008 retrospectively. In six of the cases, deaths occurred after drinking homemade medicated liquor containing aconite, and in one case death was due to ingestion of traditional Chinese medication containing aconite. Forensic autopsy and pathological examinations ruled out the presence of physical trauma or life-threatening diseases. Diagnosis of aconite poisoning was made after postmortem toxicological analysis. Animal experiment was performed in one case demonstrating that the medicated liquor could cause death rapidly. We present the autopsy and histopathological findings, toxicological analysis, and results of animal experiment done on samples from those seven cases. As an important herbal Chinese medicine, Aconitum species deserve special attention, especially because it contains poisonous alkaloids.

Microsomal cytochrome P450-mediated metabolism of hypaconitine, an active and highly toxic constituent derived from Aconitum species

Hypaconitine (HA), an active and highly toxic constituent derived from Aconitum species, is widely used to treat rheumatism. Little is known about the hepatic cytochrome P450-catalyzed metabolism of HA. The present study investigated the metabolism of HA in vitro using male human liver microsomes (MHLMS). Chemical inhibitors of specific CYP enzymes, CYP-specific inhibitory monoclonal antibodies (mAbs), and cDNA-expressed CYP enzymes were used to confirm the enzyme subtypes involved in the metabolism. Liquid chromatography-high resolution mass spectrometry (LC-MS) was used to detect and identify metabolites. A total of 11 metabolites were identified in MHLMS incubations. The major metabolic pathways included demethylation (M1-M3), demethylation-dehydrogenation (M4-M6), hydroxylation (M7, M8), and didemethylation (M9-M11). M8 was identified as mesaconitine (MA), another active and highly toxic constituent of Aconitum. The results of chemical inhibition, monoclonal antibody inhibition, and cDNA-expressed CYP enzyme studies showed that the primary contributors toward HA metabolism were CYP3A4 and 3A5, with secondary contributions by CYP2C19, 2D6, and CYP2E1. CYP1A2 and 2C8 provided minor contributions.

Diterpenoid alkaloids

The lasting attention that researchers have devoted to diterpenoid alkaloids is due to their various bioactivities and toxicities, structural complexity, and intriguing chemistry. From 1998 to the end of 2008, more than 300 new diterpenoid alkaloids were isolated from Nature. This review focuses on their structural relationships, and investigations into their chemical reactions, synthesis, and biological activities. A table that lists the names, plant sources, and structural types is given along with 363 references.

Severe Acute Poisoning with HomemadeAconitum napellusCapsules: Toxicokinetic and Clinical Data

Aconitum napellus is an extremely dangerous plant that contains various toxic diterpenoid alkaloids, mainly aconitine primarily concentrated in the roots. We report a case of acute intoxication of a 21-year-old man admitted to our Emergency Department after the ingestion, in order to sleep, of three homemade Aconitum napellus capsules. Capsules were measured to contain 237 mg of root and 19 microg of aconitine. The patient experienced the first symptoms on wakening 5 hours later with generalized paresthesia, nausea, diarrhea, vertigo, thoracic pain dyspnea, and dyschromatopsia. At admission, 7 hours after intake electrocardiographic analysis showed a sinusal bradycardia with polymorphic and bigeminal ventricular extrasystolia. Cardiovascular and neurological symptoms disappeared, respectively within 11 and 13 hours of ingestion. The patient was discharged from the ICU on day 2. Plasmatic concentrations at H7, H9, H14 H19, and after ingestion were, respectively, of 1.75, 0.75, 0.35, and 0.02 ng/mL. The calculated half-life of aconitine was 3 hours. To our knowledge, this is the first reported case with an aconitine toxicokinetic-effect relationship. The authors stress that clinicians must be aware of possible occurrence of acute poisoning with Aconitum napellus in European countries and in the United States as herbal medicine is becoming increasingly popular.

Effects of aconitine on [Ca2+] oscillation in cultured myocytes of neonatal rats

In order to investigate the effects of aconitine on [Ca2+] oscillation patterns in cultured myocytes of neonatal rats, fluorescent Ca2+ indicator Fluo-4 NW and laser scanning confocal microscope (LSCM) were used to detect the real-time changes of [Ca2+] oscillation patterns in the cultured myocytes before and after aconitine (1.0 micromol/L) incubation or antiarrhythmic peptide (AAP) and aconitine co-incubation. The results showed under control conditions, [Ca2+] oscillations were irregular but relatively stable, occasionally accompanied by small calcium sparks. After incubation of the cultures with aconitine, high frequency [Ca2+] oscillations emerged in both nuclear and cytoplasmic regions, whereas typical calcium sparks disappeared and the average [Ca2+] in the cytoplasm of the cardiomyocyte did not change significantly. In AAP-treated cultures, intracellular [Ca2+] oscillation also changed, with periodic frequency, increased amplitudes and prolonged duration of calcium sparks. These patterns were not altered significantly by subsequent aconitine incubation. The basal value of [Ca2+] in nuclear region was higher than that in the cytoplasmic region. In the presence or absence of drugs, the [Ca2+] oscillated synchronously in both the nuclear and cytoplasmic regions of the same cardiomyocyte. It was concluded that although oscillating strenuously at high frequency, the average [Ca2+] in the cytoplasm of cardiomyocyte did not change significantly after aconitine incubation, compared to the controls. The observations indicate that aconitine induces the changes in [Ca2+] oscillation frequency other than the Ca2+ overload.

A case of fatal aconitine poisoning by Monkshood ingestion

Accidental aconitine poisoning is extremely rare in North America. This report describes the confirmation of a case of accidental aconitine poisoning using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The case involved a 25-year-old man who died suddenly following a recreational outing with friends where he consumed a number of wild berries and plants including one that was later identified as Monkshood (Aconitum napellus). Postmortem blood and urine samples were available for analysis. All routine urine and blood toxicology screens were negative. The LC-MS/MS method allowed sensitive quantification of aconitine, the main toxin in A. napellus, and showed 3.6 and 149 microg/L in blood and urine, respectively. These concentrations were similar to that reported in other aconitine-related deaths. This case illustrates the dangers of consuming unidentified plants, and documents concentrations of aconitine in blood and urine in a fatal case of A. napallus-related poisoning.

Simultaneous determination of three aconitum alkaloids in urine by LC-MS-MS

A sensitive method has been developed for the identification and quantification of the toxic alkaloids yunaconitine, crassicauline A, and foresaconitine in urine specimens. After solid-phase extraction using Oasis MCX cartridges, the extracts were analyzed by LC-MS-MS. The limit of detection is 0.03 ng/mL urine for yunaconitine and 0.05 ng/mL urine for crassicauline A and foresaconitine; the limit of quantitation is 0.15 ng/mL urine for yunaconitine and 0.20 ng/mL urine for crassicauline A and foresaconitine. The method was employed in the analysis of the urine of a 55-year-old male who died after ingestion of herbal medicine powder made from the roots of aconite. Yunaconitine, crassicauline A and foresaconitine were identified in the urine. Crassicauline A and foresaconitine were thus identified in a biological specimen for the first time.

Aconitine alters connexin43 phosphorylation status and [Ca2+] oscillation patterns in cultured ventricular myocytes of neonatal rats

Aconitine, a highly poisonous type of alkaloid, has a widespread effect in stimulating the membranes of cardiomyocyte. However, other effects of aconitine on cardiomyocyte are unknown. In this study, we investigated whether aconitine also affects the phosphorylation status of connexin43 (Cx43) and intracellular [Ca(2+)] oscillation patterns in cultured ventricular myocytes of neonatal rats. As determined by Western blot analysis, a decreased percentage (47.68+/-2.29%) of phosphorylated Cx43 (P-Cx43) and a concomitant increased percentage (52.32+/-2.29%) of nonphosphorylated Cx43 (NP-Cx43) were found in aconitine-treated cultures, compared to the controls (82.77+/-2.04% for P-Cx43 and 17.23+/-2.04% for NP-Cx43). Quantitative immunofluorescent microscopy revealed similar changes in phosphorylation status occurring in Cx43 containing gap junctions in the cultures under the same treatment conditions. Real-time laser scanning microscopy indicated that intracellular [Ca(2+)] oscillations were relatively stable in control cultures, with occasional calcium sparks; after being treated with aconitine, high frequency [Ca(2+)] oscillations emerged, whereas typical calcium sparks disappeared. Furthermore, Western blot analysis revealed that, after aconitine treatment, the amount of phosphorylated PKCalpha decreased significantly. These observations suggest that aconitine not only induces dephosphorylation of Cx43 and PKCalpha, but also alters intracellular [Ca(2+)] oscillation patterns in cultured cardiomyocytes.

Aconitine involvement in an unusual homicide case

We describe a homicide complicated by an aconitine poisoning, which was initially thought to be a strangulation case. Routine toxicological analyses demonstrated only a small amount of alcohol in the blood and the urine. The case could not be clarified until 5 years after the event. A new element in the investigation made the wife the prime suspect, and finally, after thorough interrogation, she confessed her crime. She had mixed a decoction of three plants of Aconitum with red wine. Additional toxicological analyses, using the liquid chromatography-tandem mass spectrometry (LC-MS-MS) technique demonstrated 810 ng/ml of aconitine in urine, 6.5 ng/g in liver and 1.3 ng/g in the kidneys. Even though aconitine poisoning is still rare in Europe, it should be taken into account in suicides and homicides, particularly in unclarified cases.