Aconitine Research Articles

Bidirectional Ventricular Tachycardia Induced by Aconiti Lateralis Radix Praeparata: A Case Report

Herbal soups are important therapeutic agents used in Chinese medicine for various conditions. Therefore, aconitine-induced poisoning may be frequently encountered in practice among Chinese communities. However, there is limited information regarding life-threatening bidirectional ventricular tachyarrhythmia induced by aconitine intoxication and its management. We present the case of a 48-year-old woman with bidirectional ventricular tachyarrhythmia attributed to the use of processed Fuzi and describe the successful therapeutic approach adopted in this case. J Med Cases. 2016;7(3):102-104 doi: http://dx.doi.org/10.14740/jmc2416w

Encapsulation of Aconitine in Self-Assembled Licorice Protein Nanoparticles Reduces the Toxicity In Vivo.

Many herbal medicines and compositions are clinically effective but challenged by its safety risks, i.e., aconitine (AC) from aconite species. The combined use of Radix glycyrrhizae (licorice) with Radix aconite L. effectively eliminates toxicity of the later while increasing efficacy. In this study, a boiling-stable 31-kDa protein (namely GP) was purified from licorice and self-assembled into nanoparticles (206.2 ± 2.0 nm) at pH 5.0, 25 °C. The aconitine-encapsulated GP nanoparticles (238.2 ± 1.2 nm) were prepared following the same procedure and tested for its toxicity by intraperitoneal injection on ICR mouse (n = 8). Injection of GP-AC nanoparticles and the mixed licorice-aconite decoction, respectively, caused mild recoverable toxic effects and no death, while the aconitine, particle-free GP-AC mixture and aconite decoction induced sever toxic effects and 100 % death. Encapsulation of poisonous alkaloids into self-assembled herbal protein nanoparticles contributes to toxicity attenuation of combined use of herbs, implying a prototype nanostructure and a universal principle for the safer clinical applications of herbal medicines.

Biological activities and pharmacokinetics of aconitine, benzoylaconine, and aconine after oral administration in rats.

Aconitine (AC), benzoylaconine (BAC), and aconine (ACN) are three representative alkaloids in Aconitum tubers. Knowing that the drug disposal process in vivo is closely related to the toxicity and efficacy of a drug, it is important to classify the disposal properties of these alkaloids. In this study, the pharmacokinetics of the three alkaloids was investigated. The results showed that the three alkaloids could be quickly absorbed, especially BAC, whose Tmax was 0.31 ± 0.17 h. Their Cmax was 10.99, 3.99, and 4.29 ng·mL(-1) respectively, indicating that AC had better absorption than BAC and ACN. Subsequently, we further investigated their absorption mechanism using the Caco-2 cell monolayer model in vitro. The results showed that they were poorly absorbed, and the absorption of AC and BAC was inhibited by P-gp, while the absorption of ACN was in a form of passive diffusion. The t1/2 of AC, BAC and ACN was 1.41, 9.49, and 3.32 h, respectively, indicating that the metabolic or excretion rate of AC was quicker than that of BAC and ACN. Therefore, their metabolic stability was further investigated by using rat liver microsomes in vitro, which showed that AC was easier to be metabolized than BAC and ACN. The excretion experiments showed that AC and ACN were primarily excreted in urine, while BAC was excreted in faeces. In addition, the results of tissue distribution experiments showed that the three alkaloids distributed throughout all the organs, although the distribution rate of AC was slower than that of BAC and ACN. Copyright © 2015 John Wiley & Sons, Ltd.

Panax ginseng inhibits intestinal absorption of toxic Aconitum carmichaeli alkaloids in Vitro.

To evaluate the rationality and compatibility of Shenfu Formula (, SFF), a typical Chinese medicine (CM) comprised of Panax ginseng and Aconitum carmichaeli. Caco-2 cells were used to study the permeability of Aconitum carmichaeli marker compounds when the CM preparation was combined with Panax ginseng. P-glycoprotein (P-gp) activity and protein as well as multidrug resistance 1 (MDR1) mRNA were analyzed with rhodamine123 efflflux, western blot and real time quantitative polymerase chain reaction. Aconitine (AC), mesaconitine (MA), hypaconitine (HA) and fifive other active alkaloids in Aconitum carmichaeli were selected as marker compounds. Panax ginseng inhibited intestinal absorption of highly toxic AC, MA and HA from Aconitum carmichaeli in Caco-2 cells. P-gp and breast cancer resistance protein (BCRP) were observed to be involved in AC, MA and HA efflflux. Panax ginseng induced P-gp activity in Caco-2 cells via increased MDR1/P-gp expression. Thus, Panax ginseng facilitated P-gp-mediated efflflux of toxic Aconitum carmichaeli alkaloids and restricted their intestinal absorption without inflfluencing other active components. Future studies to elucidate mechanism of reduced toxicity of Aconitum carmichaeli when combined with Panax ginseng will guide future formula optimization.

Effects of aconitine, mesaconitine and hypaconitine on calcium release in isolated adult rat cardiac myocytes

Objective To investigate the effects of aconitine, mesaconitine and hypaconitine on calcium release in isolated adult rat cardiac myocytes. Methods The left ventricular cardiac myocytes isolated from adult Sprague-Dawley rats were perfused with acnitine, mesaconitine and hypaconitine at 0.3 μmol/L, 1 μmol/L, 3 μmol/L for 12 min. The spontaneous calcium release (SCR) rate, the end-diastolic [Ca2+] (F0) and the calcium transient amplitude (ΔF) were detected 4 min, 8 min and 12 min after the perfusion. 12 min after the perfusion with acnitine, mesaconitine and hypaconitine at 0.3 μmol/L, the changes of systolic dynamics and calcium transient were detected for the positive inotropic effect. Results Any of aconitine, mesaconitine and hypaconitine induced SCR, mesconitine- induced SCR rate was highest at low concentration (0.3 μmol/L), and aconitine-induced SCR rate highest at high concentration (3 μmol/L). Compared with the control, 12 min after the perfusion with acnitine, mesaconitine and hypaconitine at 3 μmol/L elevated F0 (1.459 ± 0.379, 1.585 ± 0.493, 1.213 ± 0.254 vs. 1.079 ± 0.108, all P<0.05) and ΔF(1.615 ± 0.455, 2.210 ± 0.756, 1.528 ± 0.422 vs. 1.036 ± 0.125, all P<0.05), mesaconitine with ΔF higher than aconitine and hypaconitine. At low concentration (0.3 μmol/L), compared with control, aconitine, mesaconitine and hypaconitine increased ΔF (0.409 ± 0.127, 0.423 ± 0.107, 0.414 ± 0.118 vs. 0.260 ± 0.065; P<0.05 or P<0.01) and contraction amplitudes (5.464% ± 2.239%, 7.449% ± 2.548%, 5.524% ± 1.645% vs. 3.428% ± 0.911%; P<0.05 or P<0.01), prolonged the time to peak of calcium transient (0.041 ± 0.016 s, 0.039 ± 0.009 s, 0.038 ± 0.011 s vs. 0.032 ± 0.007 s; P<0.05 or P<0.01); compared with aconitine, mesaconitine and hypaconitine decreased calcium transient time constant (0.301 ± 0.054 s, 0.324 ± 0.064 s vs. 0.361 ± 0.076 s; P<0.05 or P<0.01) and diastolic t50 (0.124 ± 0.035 s, 0.126 ± 0.040 s vs. 0.157 ± 0.056 s; P<0.05 or P<0.01). Conclusions Aconitine, mesaconitine and hypaconitine reveal the positive inotropic effects couple with the toxic effects. Increased [Ca2+] in cardiac myocytes is the key factor for the positive inotropic effects, but also the risk factor for SCR. Key words: Calcium; Myocytes, cardiac; Drugs, Chinese herbal; Aconitine; Rats; Mesaconitine; Hypaconitine

Multidrug resistance-associated protein 2 is involved in the efflux of Aconitum alkaloids determined by MRP2-MDCKII cells.

Aconitum alkaloids mainly contain highly toxic aconitine (AC), mesaconitine (MA), and hypaconitine (HA) and less toxic benzoylaconine (BAC), benzoylmesaconine (BMA), benzoylhypaconine (BHA), aconine, mesaconine, and hypaconine. The efflux transporters including P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance-associated protein 2 (MRP2) can efflux toxicants to prevent poisoning. Our previous publication has proved that P-gp and BCRP contributed to the efflux of AC, MA and HA, which is demonstrated in the human colonic adenocarcinoma cell lines (Caco-2 cells), Mardin-Darby canine kidney cell lines transfected with MDR1 or BCRP (MDR1-MDCKII and BCRP-MDCKII cells). However, the role of MRP2 remains uncertain. The MRP2-MDCKII cells were used to determine the efflux ratios (Er) and intracellular amounts of Aconitum alkaloids. In addition, the importance of MRP2 was further investigated with or without the MRP2 inhibitor, LTC4. The Er values of AC, MA, HA, BAC, BMA and BHA in MRP2-MDCKII cells (6.4 ± 0.3, 5.9 ± 0.5, 2.2 ± 0.2, 1.6 ± 0.3, 1.7 ± 0.2 and 1.9 ± 0.2 respectively) were significantly higher than those in MDCKII cells, which were close to 1. In the presence of LTC4, the Er values of AC, MA, HA, BAC, BMA and BHA were reduced to approximately 1 and their intracellular amounts were also significantly increased in MRP2-MDCKII cells. MRP2 was involved in the efflux of AC, MA, HA, BAC, BMA and BHA, which would be useful for the safe application of these components or their herbs.

In vivo and in vitro metabolites from the main diester and monoester diterpenoid alkaloids in a traditional chinese herb, the aconitum species.

Diester diterpenoid alkaloids (DDAs), such as aconitine (AC), mesaconitine (MA), and hypaconitine (HA), are both pharmacologically active compounds and toxic ingredients in a traditional Chinese herb, the Aconitum species. Many DDA metabolism studies have been performed to explore mechanisms for reducing toxicity in these compounds and in Aconitum species extracts for safe clinical administration. In this review, we summarize recent progress on the metabolism of toxic AC, MA, and HA and corresponding monoester diterpenoid alkaloids (MDAs) in the gastrointestinal tract and liver in different animal species and humans in vivo and/or in vitro, where these alkaloids are primarily metabolized by cytochrome P450 enzymes, carboxylesterases, and intestinal bacteria, which produces phase I metabolites, ester hydrolysed products, and lipoalkaloids. Furthermore, we classify metabolites detected in the blood and urine, where the aforementioned metabolites are absorbed and excreted. Less toxic MDAs and nontoxic alcohol amines are the primary DDA metabolites detected in the blood. Most other DDAs metabolites produced in the intestine and liver detected in the urine have not been reported in the blood. We propose an explanation for this nonconformity. Finally, taking AC, for instance, we generalize a process of toxicity reduction in the body after oral AC administration for the first time.

Solid lipid nanoparticles formulated for transdermal aconitine administration and evaluated in vitro and in vivo

Solid lipid nanoparticles formulated for transdermal aconitine administration and evaluated in vitro and in vivo

Qualitative and quantitative analysis of drug interactions: Fritillary mediating the transport of alkaloids in caco-2 cells by p-glycoprotein

Ultra performance liquid chromatographic-electrospray ionization-mass spectrometry(UPLC-ESI-MS) was used to investigate the potential interaction between selected ingredients of Aconitum and fritillary. The efflux ratios of 14-benzoylmesaconine(BM), 14-benzoylaconine(BC), 14-benzoylhypaconine(BH), mesaconitine(MA), aconitine( AC) and hypaconitine(HA) was 11.16, 12.53, 11.69, 12.8, 11.03 and 6.15, respectively, and the secretion of them was inhibited by Verapamil, which means they are the substrates of permeability-glycoprotein(P-gp). The transport of Aconitum alkaloids extract through a Caco-2 cell monolayer was determined in the absence and presence of fritillary extract. And the fritillary extract increased the absorption of Aconitum alkaloids. Peimine(PE) and peiminine( PEN) in fritillary increased the absorption of pure Aconitum alkaloids. The transport of digoxin was respectively enhanced by PE and PEN, which means they are the inhibitors of P-gp. PEN showed more effective inhibition than PE at the same concentration. The in vitro data suggest that the compounds such as fritillary present in alkaloids were able to inhibit the P-gp activity and lead modifying the transport of alkaloids.

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 2.85×10−5cm/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 1490.7ng/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.

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

Ethnopharmacological relevanceRadix 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 studyIn 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 methodsA 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). ResultsComparing 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. ConclusionThe 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.

Transcellular transport of aconitine across human intestinal Caco-2 cells

Aconitine (AC) is a highly toxic compound present in plants of the genus Aconitum. The transcellular transport mechanism of AC was investigated using Caco-2 cells. The flux of AC was time- and concentration-dependent in both apical-to-basolateral and the reverse direction. The efflux of AC was more than two-fold that in the opposite direction. The influx of AC was temperature-, pH- and Na(+)-dependent. Glucose markedly decreased the absorption of AC. However, the efflux of AC was temperature- and pH-dependent, but Na(+)-independent. Cyclosporin A and verapamil, both inhibitors of P-glycoprotein (P-gp), significantly decreased the efflux of AC. In addition, MK-571, an inhibitor of multidrug resistance-associated protein 2 (MRP2), exhibited the same trend but to a lesser extent. These results indicate that both the influx and efflux of AC across Caco-2 monolayers were through an active process. A pH-dependent carrier-mediated transport system was the major absorption mechanism and a sodium-dependent glucose transporter may be involved. The active efflux of AC across Caco-2 cells was mediated mainly by ABC-transporter P-gp. It is involved in reducing the toxicity of AC to organisms and is the major reasons for the poor absorption of AC in vivo.

Simultaneous determination of four trace aconitum alkaloids in urine using ultra performance liquid chromatography-mass spectrometry

A rapid, specific and sensitive ultra performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of four trace alkaloids, including aconitine (AC), hypaconitine (HA), mesaconitine (MA) and yunaconitine (YA) in human urine samples. UPLC-MS-MS system coupled with an electrospray ionization (ESI) source was performed in multiple reaction monitoring (MRM) mode. The sample preparation was performed with hollow fiber microextraction (HF-LPME) prior to the analysis. The enrichment factors of the four alkaloids were 102 - 301. The separation was applied on a Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 micro m) with a gradient elution of acetonitrile and 10 mmol/L NH4HCO3, as mobile phase. The retention times , were less than 3 min. This method significantly improved the detection sensitivity, and the limits of quantitation were from 0. 01 to 0.1 ng/L. The calibration curves were linear over the ranges of 0.01 - 10 ng/L for AC, MA and YA, 0.1 - 100 ng/L for HA in human urine samples, and the correlation coefficients were 0. 998 1, 0.998 4, 0.999 5 and 0.998 6, respectively. The method was proved to be rapid and sensitive for aconitum alkaloid analysis in urine samples.

Metabolite profile analysis of aconitine in rabbit stomach after oral administration by liquid chromatography/electrospray ionization/multiple-stage tandem mass spectrometry

1. Aconitine (AC), an active and highly toxic constituent extracted from aconitum plants, is well known for its excellent effects against rheumatism and rheumatoid arthritis. The metabolism of AC in liver and intestine has been previously reported. However, little is known about the metabolism of AC in stomach. In this study, the metabolite profiling of AC in stomachs of rabbit and rat was performed by liquid chromatography/electrospray ionization/multiple-stage tandem mass spectrometry (LC/ESI/MSn), for the first time.2. The samples were purified by liquid–liquid extraction, separated using an Agilent extended C18 column following a linear gradient elution and then detected by ESI/MSn in positive ion mode. Metabolites were identified by comparing their protonated molecules, fragmentation patterns and chromatographic behaviors with those of standard compounds and data from authorized literature works.3. In conclusion, 14 metabolites were identified in animal stomach after oral administration of AC. The presentation of a large amount of metabolites of AC in stomach suggested that, for aconitum alkaloids, the stomach might play an important role in their metabolism.

The role of efflux transporters on the transport of highly toxic aconitine, mesaconitine, hypaconitine, and their hydrolysates, as determined in cultured Caco-2 and transfected MDCKII cells

Aconitum alkaloids including aconitine (AC), mesaconitine (MA), hypaconitine (HA), are highly toxic. Their hydrolysates, such as benzoylaconine (BAC), benzoylmesaconine (BMA), benzoylhypaconine (BHA), aconine, and mesaconine, are considerably less toxic. Efflux transporters, including P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein isoform 2 (MRP2), act as a first line of defence and play key roles in toxicity prevention. The aim of the present study was to determine the role of efflux transporters in the transport of Aconitum alkaloids using cultured Caco-2, MDR1-MDCKII and BCRP-MDCKII cells. Bidirectional transport assays of the Aconitum alkaloids were performed with or without P-gp (cyclosporine A and verapamil), BCRP (Ko143) and MRP2 (MK571) inhibitors. The efflux ratios (Er) of AC, MA, and HA in Caco-2 cells were 34.6±4.2, 29.7±2.1, and 15.6±2.1, respectively; those of BAC, BMA, and BHA were approximately 4, and those of aconine and mesaconine were equal to 1. The Er values of AC, MA, and HA in MDR1-MDCKII and BCRP-MDCKII cells were significantly higher than those in parental MDCKII cells. Taken together the results of Er values and intracellular amounts in the presence of inhibitors, P-gp and BCRP were involved in the transport of AC, MA and HA; and MRP2 might transport AC, MA, HA, BAC, BMA and BHA.

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.

Identification and determination of Aconitum alkaloids in Aconitum herbs and Xiaohuoluo pill using UPLC-ESI-MS.

A rapid, specific, and sensitive ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) method to examine the chemical differences between Aconitum herbs and processed products has been developed and validated. Combined with chemometrics analysis of principal component analysis (PCA) and orthogonal projection to latent structural discriminate analysis, diester-diterpenoid and monoester-type alkaloids, especially the five alkaloids which contributed to the chemical distinction between Aconitum herbs and processed products, namely mesaconitine (MA), aconitine (AC), hypaconitine (HA), benzoylmesaconitine (BMA), and benzoylhypaconitine (BHA), were picked out. Further, the five alkaloids and benzoylaconitine (BAC) have been simultaneously determined in the Xiaohuoluo pill. Chromatographic separations were achieved on a C18 column and peaks were detected by mass spectrometry in positive ion mode and selected ion recording (SIR) mode. In quantitative analysis, the six alkaloids showed good regression, (r) > 0.9984, within the test ranges. The lower limit quantifications (LLOQs) for MA, AC, HA, BMA, BAC, and BHA were 1.41, 1.20, 1.92, 4.28, 1.99 and 2.02 ng·mL−1, respectively. Recoveries ranged from 99.7% to 101.7%. The validated method was applied successfully in the analysis of the six alkaloids from different samples, in which significant variations were revealed. Results indicated that the developed assay can be used as an appropriate quality control assay for Xiaohuoluo pill and other herbal preparations containing Aconitum roots.

Intestinal Transport of Pure Diester-type Alkaloids from an Aconite Extract across the Caco-2 Cell Monolayer Model

Aconitine (AC), mesaconitine (MA), and hypaconitine (HA) are the active alkaloids identified in aconite tuber, an important traditional Chinese medicine. The study is aimed to investigate their intestinal transport profiles and potential interaction during the intestinal absorption using the Caco-2 cell monolayer model. All three alkaloids had good permeability with P(app) values greater than 1 × 10 (-6) cm · s (-1). However, AC, MA, and HA in a mixture and as an extract, in both cases with the same content of alkaloids, showed higher transport efficiency in the apical to basolateral, and lower transport efficiency in the basolateral to apical directions. Digoxin, as a P-glycoprotein (P-gp) substrate, was substantially effluxed in the basolateral to apical direction but inhibited by the three alkaloids. Furthermore, the backwards transport of MA and HA was inhibited by the P-gp inhibitor verapamil. These observations indicated that the three alkaloids may not only be P-gp inhibitors but also its substrates; they interact with each other and can potentially enhance their own bioavailability when taken concomitantly.

Development and validation of a highly sensitive UPLC-MS/MS method for simultaneous determination of aconitine, mesaconitine, hypaconitine, and five of their metabolites in rat blood and its application to a pharmacokinetics study of aconitine, mesaconitine, and hypaconitine

A rapid, specific and sensitive method was developed for the simultaneous determination of eight Aconitum alkaloids: aconitine (AC), mesaconitine (MA), hypaconitine (HA), benzoylaconine (BAC), benzoylmesaconine (BMA), benzoylhypaconine (BHA), aconine and mesaconine in rat blood by ultra-performance liquid chromatography coupled tandem mass spectrometry (UPLC-MS/MS).The UPLC-MS/MS system coupled with an electrospray ionization (ESI) source was operated in a positive mode via multiple-reaction monitoring (MRM). Samples were treated with methanol to remove protein prior to analysis by UPLC-MS/MS. The analytes were separated with a Waters C18 column (1.7 µm, 50 × 2.1 mm) and a gradient elution using acetonitrile and 0.1% formic acid-water as the mobile phases.The linear response range was from 0.125 to 1000 nmol/L for these eight alkaloids and the correlation coefficients (r2 values) were all higher than 0.997. The method was validated with respect to precision, accuracy, recovery, matrix effect, carryover effect and sample stability, and found to be within the acceptable limits.The developed and validated method was successfully applied to simultaneously determine the eight Aconitum alkaloids in rats blood after intravenous administration of a mixture of AC, MA and HA.

Quantitative determination of total aconitines in commercial Aconitum L. Chinese medicine

Aconitines is predominant bioactive constituents in Aconitum L. Chinese medicines, which often cause serious toxicities problem in clinical application. This experiment evaluates the qualities of commercial Aconitum L. Chinese medicines by investigating the content of total aconitines. It was determined by the visible spectrophotometric method. The commercial 20 Radix Aconiti Lateralis Preparata, 26 Radix Aconiti Preparata and 20 Radix Aconiti Kusnezoffii Preparata, the total content of aconitines ranges from 0.017 to 2.81%, 0.278 to 1.303%, and from 0.0066 to 1.526%, respectively. The results showed that the total content of aconitines in Aconitum L. Chinese medicines were obviously different, this may pose serious problem in clinical applications. Key words: Aconitum L. Chinese medicines, total alkaloids, visible spectrophotometry method, aconitine.