Severe aconite poisoning successfully treated with veno-arterial extracorporeal membrane oxygenation: A case report

BACKGROUND

Most species of aconite contain highly toxic aconitines, the oral ingestion of which can be fatal, primarily because they cause ventricular arrhythmias. We describe a case of severe aconite poisoning that was successfully treated through veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and in which detailed toxicological analyses of the aconite roots and biological samples were performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

CASE SUMMARY

A 23-year-old male presented to the emergency room with circulatory collapse and ventricular arrhythmia after ingesting approximately half of a root labeled, "Aconitum japonicum Thunb". Two hours after arrival, VA-ECMO was initiated as circulatory collapse became refractory to antiarrhythmics and vasopressors. Nine hours after arrival, an electrocardiogram revealed a return to sinus rhythm. The patient was weaned off VA-ECMO and the ventilator on hospital days 3 and 5, respectively. On hospital day 15, he was transferred to a psychiatric hospital. The other half of the root and his biological samples were toxicologically analyzed using LC-MS/MS, revealing 244.3 mg/kg of aconitine and 24.7 mg/kg of mesaconitine in the root. Serum on admission contained 1.50 ng/mL of aconitine. Beyond hospital day 2, neither were detected. Urine on admission showed 149.09 ng/mL of aconitine and 3.59 ng/mL of mesaconitine, but these rapidly decreased after hospital day 3.

CONCLUSION

The key to saving the life of a patient with severe aconite poisoning is to introduce VA-ECMO as soon as possible.

Changes to PUFA-PPAR pathway during mesaconitine induced myocardial coagulative necrosis

Coagulation necrosis is characterized by the denaturation of structural proteins and lysosomal enzymes; its occurrence in myocardium can lead to heart failure. Current studies on myocardial injury primarily focus on inflammation, hypertrophy, and hemorrhage, while those on myocardial coagulation necrosis are still limited. Mesaconitine (MA), a C₁₉ diester diterpenoid alkaloid derived from Aconitum carmichaelii Debx, has strong cardiotoxicity. During this study, the myocardial cells of SD rats showed significant coagulative necrosis after 6 days of oral administration of MA at a dose of 1.2 mg/kg/day. Investigations of its biological mechanism showed abnormal levels of polyunsaturated fatty acids (PUFAs) and Peroxisome proliferator activated receptors Alpha (PPARα) pathway related protein. Moreover, MA affected the PPARα signaling pathway through interactions with proteins such as POR, TFAM and GPD1, indirectly indicating that these above proteins are important targets for blocking myocardial coagulative necrosis. This study thus discusses the effects of the use of cardiotoxic compound, MA, to initiate myocardial coagulative necrosis and its associated toxic mechanisms.

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.

Cytotoxic Effects of Mesaconitine, the Aconitum carmichaelii Debx Bioactive Compound, on HBEC-5i Human Brain Microvascular Endothelial Cells: Role of Ca2+ Signaling-Mediated Pathway

Mesaconitine, one of Aconitum carmichaelii Debx bioactive compounds, was shown to evoke Ca²⁺ homeostasis and its related physiological effects in endothelial cell types. However, the effect of mesaconitine on Ca²⁺ signaling and cell viability in human brain microvascular endothelial cells is unclear. This study focused on exploring whether mesaconitine changed cytosolic Ca²⁺ concentrations ([Ca²⁺]_i), affected cell viability, and established the relationship between Ca²⁺ signaling and viability in HBEC-5i human brain microvascular endothelial cells. In HBEC-5i cells, cell viability was measured by the cell proliferation reagent (WST-1). [Ca²⁺]_i was measured by the Ca²⁺-sensitive fluorescent dye fura-2. Mesaconitine (10-100 μM) concentration dependently induced [Ca²⁺]_i rises. Ca²⁺ removal reduced the signal by approximately 25%. Mesaconitine (40-100 μM) caused cytotoxicity in HBEC-5i cells. This cytotoxic response was significantly reversed by chelation of cytosolic Ca²⁺ with BAPTA/AM. In Ca²⁺-containing medium, mesaconitine-induced Ca²⁺ entry was inhibited by 25% by modulators of store-operated Ca²⁺ channels and protein kinase C (PKC). Furthermore, mesaconitine also induced Mn²⁺ influx suggesting of Ca²⁺ entry. In Ca²⁺-free medium, treatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin abolished mesaconitine-evoked [Ca²⁺]_i rises. Conversely, treatment with mesaconitine abolished thapsigargin-evoked [Ca²⁺]_i rises. Inhibition of phospholipase C (PLC) with U73122 abolished mesaconitine-induced [Ca²⁺]_i rises. In sum, mesaconitine caused cytotoxicity that was triggered by preceding [Ca²⁺]_i rises. Furthermore, mesaconitine induced [Ca²⁺]_i rises by evoking Ca²⁺ entry via PKC-sensitive store-operated Ca²⁺ channels and PLC-dependent Ca²⁺ release from the endoplasmic reticulum. It suggests that Ca²⁺ signaling have a potential cytotoxic effect on mesaconitine-treated human brain microvascular endothelial cells.

Pharmacokinetics of aconitine-type alkaloids after oral administration of Fuzi (Aconiti Lateralis Radix Praeparata) in rats with chronic heart failure by microdialysis and ultra-high performance liquid chromatography-tandem mass spectrometry

ETHNOPHARMACOLOGICAL RELEVANCE

Fuzi [the lateral root of Aconitum carmichaeli Debx (Ranunculaceae)] is a well-known traditional medicinal herb used to treat chronic heart failure (CHF). Aconitine-type alkaloids are major alkaloids that are responsible for the pharmacological activity and toxicity of this herb.To investigate therapeutic effects and pharmacokinetic profiles of aconitine-type alkaloids in CHF rats.

MATERIALS AND METHODS

The plasma pharmacokinetic profiles of aconitine, mesaconitine, and hypaconitine were investigated after once treatment of Fuzi extract (containing aconitine 0.086 mg/g, mesaconitine 0.84 mg/g, and hypaconitine 1.97 mg/g) using a rapid and sensitive combinative method of ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and microdialysis (MD). The cardiac function and antioxidant enzyme activities were also evaluated.

RESULTS

Recoveries of MD sampling ranged from 35.06% to 45.74% with RSD below 6.05%. Fuzi extract improved the myocardial function and antioxidant enzymatic activities of rats with CHF. Aconitine, mesaconitine, and hypaconitine exhibited slower absorption into the bloodstream, and yielded 11-fold less values of area under concentration-time curve (AUC) in the CHF rats than those in normal rats. The plasma AUC showed that the maximum blood concentration (Cmax) was 5.561 ng/mL for aconitine, 17.30 ng/mL for mesaconitine, and 17.78 ng/mL for hypaconitine in normal rats, while these were 0.6059 ng/mL, 2.430, and 0.7461 ng/mL in CHF rats, respectively.

CONCLUSION

Aconitine-type alkaloids associated with Fuzi׳s efficacy have lower intake and slower elimination in the CHF rats, indicating a non-interdependent relationship between its efficacy and toxicity. It may contribute to the depth understanding of the toxicological and pharmacological profiles of Fuzi and further benefit the herbal drug development with safety and efficacy for CHF treatment.

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.