Aconitum Plants Research Articles

Four new C19-diterpenoid alkaloids from Delphinium elatum

Diterpenoid alkaloids with remarkable chemical properties and biological activities are frequently found in plants of the genera Aconitum, Delphinium, and Garrya. Accordingly, several C19-diterpenoid alkaloid components from Delphinium elatum cv. Pacific Giant, as well as their derivatives, exhibited cytotoxic activity against lung, prostate, nasopharyngeal, and vincristine-resistant nasopharyngeal cancer cell lines. Four new C19-diterpenoid alkaloids, elapacigine (1), N-deethyl-N-formylpaciline (2), N-deethyl-N-formylpacinine (3), and N-formyl-4,19-secoyunnadelphinine (4), together with 11 known C19-diterpenoid alkaloids were isolated in a phytochemical investigation on the seeds of D. elatum cv. Pacific Giant. Their structures were elucidated by extensive spectroscopic methods including NMR (1D and 2D), IR, and MS (HRMS). Three of the new C19-diterpenoid alkaloids (2–4) and five of the known diterpenoid alkaloids were evaluated for cytotoxic activity against five human tumor cell lines.

Aconitine induces apoptosis in H9c2 cardiac cells via mitochondria‑mediated pathway.

Aconitine, a diterpenoid alkaloids derived from Aconitum plants, is widely employed to treat various diseases. The aim of the present study was to investigate the apoptotic effect of aconitine in H9c2 cardiac cells. H9c2 cell apoptosis induced by aconitine was detected by a Cell Counting kit-8 assay, DAPI staining, Annexin V-FITC/propidium iodide double staining and western blotting. The effects of aconitine on reactive oxygen species levels and mitochondrial membrane potential were confirmed by fluorescence microscopy and flow cytometry. In addition, ATP contents were determined using a ATP-dependent bioluminescence assay kit. The levels of peroxisome proliferator activated receptor γ co-activator 1α (PGC-1α) expression and apoptosis-associated proteins including Caspase-3, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax) and Cytochrome c were also assessed. Taken together, the results indicated that aconitine may inhibit cell viability, decrease PGC-1α expression, induce mitochondrial dysfunctions, upregulate Cytochrome c, Bax and Caspase-3, and downregulate Bcl-2, suggesting that aconitine may induce apoptosis through mitochondria-mediated signaling pathways in H9c2 cells.

Four new diterpenoid alkaloids from Aconitum japonicum subsp. subcuneatum

Diterpenoid alkaloids with remarkable chemical properties and biological activities are frequently found in plants of the genera Aconitum, Delphinium, and Garrya. Accordingly, several diterpenoid alkaloid constituents of Aconitum and Delphinium plants as well as their derivatives exhibited cytotoxic activity against lung, prostate, nasopharyngeal, and vincristine-resistant nasopharyngeal cancer cell lines. Four new C19-diterpenoid alkaloids, 14-anisoyllasianine (1), 14-anisoyl-N-deethylaconine (2), N-deethylaljesaconitine A (3), and N-deethylnevadensine (4), together with 17 known C19- and C20-diterpenoid alkaloids, were isolated in a phytochemical investigation of rhizoma of Aconitum japonicum THUNB. subsp. subcuneatum (NAKAI) KADOTA. Their structures were elucidated by extensive spectroscopic methods including NMR (1D and 2D), IR, and MS (HRMS). Eight known diterpenoid alkaloids, lipoaconitine, lipomesaconitine, aconine, nevadenine, talatisamine, nevadensine, ryosenamine, and dehydrolucidusculine, were isolated the first time from A. japonicum subsp. subcuneatum. Three of the new C19-diterpenoid alkaloids (1, 3, 4) and six of the known diterpenoid alkaloids were evaluated for cytotoxic activity against five human tumor cell lines.

Anticancer Activities of C18-, C19-, C20-, and Bis-Diterpenoid Alkaloids Derived from Genus Aconitum.

Cancer is one of the most common lethal diseases, and natural products have been extensively studied as anticancer agents considering their availability, low toxicity, and economic affordability. Plants belonging to the genus Aconitum have been widely used medically in many Asian countries since ancient times. These plants have been proven effective for treating several types of cancer, such as lung, stomach, and liver cancers. The main effective components of Aconitum plants are diterpenoid alkaloids—which are divided into C18-, C19-, C20-, and bis-diterpenoid alkaloids—are reportedly some of the most promising, naturally abundant compounds for treating cancer. This review focuses on the progress of diterpenoid alkaloids with different structures derived from Aconitum plants and some of their derivatives with potential anticancer activities. We hope that this work can serve as a reference for further developing Aconitum diterpenoid alkaloids as anticancer agents.

Intensified wind pollination mediated by pollen dimorphism after range expansion in an ambophilous biennial Aconitum gymnandrum

Pollination systems and associated floral traits generally differ between core and marginal populations of a species. However, such differences are rarely examined in plants with a mixed wind‐ and bumblebee‐pollination system, and the role of wind pollination during range expansion in ambophilous plants remains unclear. We compared floral traits and the contributions of bumblebee and wind pollination in refugium and marginal populations of the ambophilous plant Aconitum gymnandrum. We found that most floral traits differed between the two populations, and those traits associated with the shift to wind pollination were pronounced in the marginal population. Bumblebee visitation rates varied significantly, but were generally low in the marginal population. Wind pollination occurred in both populations, and the efficiency was lower than that of bumblebee pollination. Two types of pollen grains, namely round and fusiform pollen, were transported to a stigma by bumblebees and wind, but fusiform pollen contributed to wind pollination to a larger degree, especially in the marginal population. Our results suggest that wind pollination was enhanced by pollen dimorphism in the marginal population of A. gymnandrum, and wind pollination may provide reproductive assurance when bumblebee activity is unpredictable during range expansion, indicating that ambophily is stable in this species and shift in pollination system could be common when plants colonize new habitats.

Ester Hydrolysis Differentially Reduces Aconitine-Induced Anti-hypersensitivity and Acute Neurotoxicity: Involvement of Spinal Microglial Dynorphin Expression and Implications for Aconitum Processing.

Aconitines, including bulleyaconitine A, probably the most bioactive and abundant alkaloids in Aconitum plant, are a group of diester C19-diterpenoid alkaloids with one acetylester group attached to C8 of the diterpenoid skeleton and one benzoylester group to C14. Hydrolysis of both groups is involved in the processing of Aconitum, a traditional Chinese medicinal approach. We recently demonstrated that bulleyaconitine A produced anti-hypersensitivity, which was mediated by stimulation of spinal microglial dynorphin A expression. This study aimed to elucidate whether the acetylester and benzoylester groups are involved in aconitine-induced dynorphin A expression, anti-hypersensitivity, neurotoxicity in neuropathic rats. Intrathecal administration of aconitine and benzoylaconine (but not aconine) attenuated mechanical allodynia and heat hyperalgesia, with normalized ED50 values of 35 pmol and 3.6 nmol, respectively. Aconitine and benzoylaconine anti-allodynia was completely blocked by the microglial inhibitor, dynorphin A antiserum, and κ-opioid receptor antagonist. Aconitine and benzoylaconine, but not aconine, stimulated dynorphin A expression in cultured primary spinal microglia, with EC50 values of 32 nM and 3 μM, respectively. Intrathecal aconitine, benzoylaconine and aconine induced flaccid paralysis and death, with normalized TD50 values of 0.5 nmol, 0.2 μmol, and 1.6 μmol, respectively. The TD50/ED50 ratios of aconitine and benzolyaconine were 14:1 and 56:1. Our results suggest that both the C8-acetyl and C14-benzoyl groups are essential for aconitine to stimulate spinal microglial dynorphin A expression and subsequent anti-hypersensitivity, which can be separated from neurotoxicity, because both benzoylaconine and aconine differentially produced anti-hypersensitivity and neurotoxicity due to their different stimulatory ability on dynorphin A expression. Our results support the scientific rationale for Aconitum processing, but caution should be taken to avoid overprocessing and excess hydrolysis of benzolyaconine to aconine.

The water extract of Veratrilla baillonii could attenuate the subacute toxicity induced by Aconitum brachypodum

BackgroundAconitum brachypodum Diels (Family Ranunculaceae) is a Chinese ethnodrug and is well known for both its therapeutic application and high toxicity. However, no detoxication strategy is available for the complete elimination of the toxicity of Aconitum plants.Veratrilla baillonii Franch is believed to possess antitoxic effects on the toxicity induced by Aconitum plants and has been clinically used for hundreds of time by Naxi and Lisu nationalities in Yunnan Province of China.To further address the mechanism of the detoxication of Veratrilla baillonii, the effect of water decoction of Veratrilla baillonii (WVBF) on subacute toxicology of SD rats induced by Aconitum brachypodum (CFA), a genus Aconitum, was determined and studied in the present work. MethodsThe clinical behavior and number of survivors for different dosage of WVBF (25, 50, 100mg/kg) on CFA (4mg/kg) induced rats were observed until day 28. Histological changes and haematological parameters were evaluated. Moreover, Na+-K+-ATPase pathway in heart as well as key enzymes in liver were determined to further discuss the mechanism. ResultsThe results showed that the exposure of CFA led to some subacute toxicity to rats, especially male ones, accompanied with abnormality of serum biochemical index in rats’ serum. The toxicological target organs of CFA may be the heart, liver, kidney and brain. It is demonstrated that WVBF could attenuate the toxicity induced by Aconitum brachypodum via promoting the metabolic enzymes CYP3A1 and CYP3A2 in liver, downregulating the expression of Sodium/Calcium exchanger 1 (NCX1) and SCN5A sodium channal mRNA, and inducing Na+/K+-ATPase activity in heart. This study provides insights into detoxifying measures of Aconitum plants. ConclusionsAconitum brachypodum may lead to subacute toxicity of rats after long term of administration, and the toxicity could be attenuated by Veratrilla baillonii via promoting the metabolic enzymes in liver, downregulating the expression of NCX1 and SCN5A mRNA, and inducing Na+/K+-ATPase activity in heart.

Diterpenoid Alkaloids as Antidotes to Aconitine-Type Neurotoxin Poisoning. Structure–Activity Relationship

The in vivo antidote activity of 72 diterpenoid alkaloids isolated from plants of the genera Aconitum, Delphinium, and Consolida and their derivatives was tested against poisoning of mice by a lethal dose of aconitine. The structure–activity relationship was analyzed. The use of diterpenoid alkaloids as versatile antidotes against poisoning of animals and humans by aconitine-, veratridine-, and batrachotoxin-type neurotoxins was justified.

Four new diterpenoid alkaloids from Delphinium elatum

Diterpenoid alkaloids exhibit remarkable chemical properties and biological activities. Such compounds are frequently found in plants of the genera Aconitum, Delphinium, and Garrya. Several diterpenoid alkaloid components from Delphinium elatum cv. Pacific Giant and their derivatives exhibited cytotoxic activity against lung, prostate, nasopharyngeal, and vincristine-resistant nasopharyngeal cancer cell lines. Phytochemical investigations on the seeds of D. elatum cv. Pacific Giant led to the isolation of four new C19-diterpenoid alkaloids, melpheline (1), 19-oxoisodelpheline (2), N-deethyl-19-oxoisodelpheline (3), and N-deethyl-19-oxodelpheline (4). The isolated alkaloids were elucidated by extensive spectroscopic methods including NMR (1D and 2D), IR, and MS (HRMS).

Production of genetically uniform plants from shoot tips of Aconitum heterophyllum Wall. – a critically endangered medicinal herb

ABSTRACTWe report the successful micropropagation of a critically endangered medicinal plant Aconitum heterophyllum Wall., using low concentrations of plant growth regulators (PGRs) and molecular validation of the clonal stocks. The maximum rate of in vitro shoot multiplication was obtained on 1.0 × Murashige and Skoog (MS) medium containing 0.25 mg L−1 Kinetin (Kn) plus 0.25 mg L−1 Indole acetic acid (IAA). Up to 100% rooting was obtained 15 for shoots cultured on 1.0 × MS medium supplemented with 1.0 mg L−1 IAA. Adding 0.25 mg L−1 2,4-dichlorophenoxyacetic acid (2, 4-D) to 1.0 × MS medium resulted in 100% callus formation, while adding 0.25 mg L−1 IAA plus 0.25 mg L−1 Kn to 1.0 × MS medium containing 0.25 mg L−1 2,4-D resulted in 100% generation of embryogenic callus. Inter-simple sequence repeat (ISSR) marker analysis was carried out to check for possible somaclonal variation in the plantlets obtained after three consecutive sub-cultures. Of the 15 ISSR primers used, 10 were found to be monomorphic, with 95–98% similarity, and were used for cluster analysis by the unweighted pair group using arithmetic averages (UPGMA) method. The results revealed that in vitro-regenerated plantlets did not exhibit any genetic polymorphism.

Predicting potential antitumor targets of Aconitum alkaloids by molecular docking and protein–ligand interaction fingerprint

Aconitine compounds are found in Aconitum Ouwu head, Chuan Wu, Aconitum, and other Ranunculaceae aconitum plants, which are not only active ingredient but also toxic component. In present study, 20 antitumor target proteins of different types were selected from Protein Data Bank ( http://www.rcsb.org ), for the purpose of finding potential antitumor targets of aconitum alkaloids, top ranked proteins were screened by molecular docking method, using the docking module in Sybyl-X 1.1 and Molecular Operating Environment (MOE) 2008, and screening result was verified by protein–ligand interaction fingerprint (PLIF) in MOE. Mesaconitine showed a C-shaped conformation when docking into heat-shock protein 90 (HSP90), which was similar with ANSA ring of geldanamycin. And the PLIF indicated that they shared many common amino acid residues interacted with HSP90; equally, Yunaconitine was found having similar conformation with the inhibitor of poly ADP-ribose polymerase-1 (PARP-1).

Antitoxic effect of Veratrilla baillonii on the acute toxicity in mice induced by Aconitum brachypodum, one of the genus Aconitum

Ethnopharmacological relevanceAconitum brachypodum Diels (Family Ranunculaceae) is well known for both its good therapy and high toxicity in Yunnan and Sichuan provinces in China. Noticeably, Veratrilla baillonii Franch (Family Gentianaceae), an ethnodrug used by Naxi and Lisu nationalities in Yunnan Province, has been widely considered to possess antitoxic effects on Aconitum plants in herbal therapy and folklore medicines. Materials and methodsThe present study was conducted to determine the detoxic activities of the water decoction of Veratrilla baillonii Franch (WVBF) on the the chloroform fraction of Aconitum brachypodum Diels (CFA) induced acute toxicity in mice. The physiological (symptoms, body weight, etc.) as well as pathological and clinical biochemistry parameters were assessed and used as the markers for the toxicity. 1H nuclear magnetic resonance (NMR) based metabolic approach was adopted to further discuss the mechanism. ResultsThe acute poisoning effects of CFA on mice were observed at doses of 20–62.5mgkg−1, resulting in an oral median lethal dose (LD50) of 41.3mgkg−1. Histologically, distinct degenerative changes of the heart, liver and kidney were observed. The biochemistry parameters in the serum as well as metabolites in heart and brain were also altered. However, WVBF (25–200mg/kg) attenuated all the acute toxicity and pathological changes, properly regulated the biochemistry parameters, and reversed the concentration alterations for some metabolites in the heart and brain of mice induced by 40mg/kg of CFA to a certain extent. ConclusionsWVBF significantly reduced the onset of the CFA toxicity. This study may contribute to further understanding of the toxicological and pharmacological profiles of Aconitum brachypodum and the detoxic property of Veratrilla baillonii.

Evaluation of Aconitum diterpenoid alkaloids as antiproliferative agents.

Little information has been reported on the antitumor effects of the diterpenoid alkaloid constituents of Aconitum plants, used in the herbal drug 'bushi'. This study was aimed at determining the antitumor activities of Aconitum C19-and C20-diterpenoid alkaloids and synthetic derivatives against lung (A549), prostate (DU145), nasopharyngeal (KB), and vincristine-resistant nasopharyngeal (KB-VIN) cancer cell lines. Newly synthesized C20-diterpenoid alkaloid derivatives showed substantial suppressive effects against all human tumor cell lines tested. In contrast, natural and derivatized C19-diterpenoid alkaloids showed only a slight or no effect. Most of the active compounds were hetisine-type C20-diterpenoid alkaloids, specifically kobusine and pseudokobusine analogs with two different substitution patterns, C-11 and C-11,15. Notably, several C20-diterpenoid alkaloids were more potent against multidrug-resistant KB subline KB-VIN cells. Pseudokobusine 11-3'-trifluoromethylbenzoate (94) is a possible promising new lead meriting additional evaluation against multidrug-resistant tumors.

In Situ Analysis for Herbal Pieces of Aconitum Plants by Using Direct Analysis in Real Time Mass Spectrometry

AbstractIn this study, an extend application was developed to in situ analyze the herbal pieces of Aconitum plants by Direct Analysis in Real Time Mass Spectrometry (DART‐MS). Nearly all aconitine‐type alkaloids can be desorbed and ionized in this method, including diester diterpenoid aconitines (DDAs), monoester diterpenoid aconitines (MDAs) and some other diterpenoid aconitines. The spectra of in situ analysis for the herbal pieces of aconitum plants are similar with that of their extracts. Radix Aconiti and Radix Aconiti Kusnezoffii can be distinguished from each other by the intensity differences of character fragment ions from MDAs, such as m/z 586, 572, and 556. The qualified and unqualified herbal pieces can be also identified by the relative abundances of DDAs. The RSD of the relative abundances of some character ions at m/z 556, 586, and 590 were 13.53%, 4.03%, and 12.03%, respectively. So this in situ analytical method can identify both the types of Aconitum preparata and their quality. It provides the following advantages in the analysis of Chinese herbs: fast detection without much pretreatment, high‐throughput analysis, and reduction of pollution without any organic solvent.

Diversity in aconitine alkaloid profile of Aconitum plants in Hokkaido contrasts with their genetic similarity.

Aconite tuber is a representative crude drug for warming the body internally in Japanese Kampo medicine and Chinese traditional medicine. The crude drug is used in major prescriptions for the aged. Varieties of Aconitum plants are distributed throughout the Japanese Islands, especially Hokkaido. With the aim of identifying the medicinal potential of Aconitum plants from Hokkaido, 107 specimens were collected from 36 sites in the summer of 2011 and 2012. Their nuclear DNA region, internal transcribed spacer (ITS), and aconitine alkaloid contents were analyzed. Phylogenic analysis of ITS by maximum parsimony analysis showed that the majority of the specimens were grouped into one cluster (cluster I), separated from the other cluster (cluster II) consisting of alpine specimens. The aconitine alkaloid content of the tuberous roots of 76 specimens showed 2 aspects-specimens from the same collection site showed similar aconitine alkaloid profiles, and cluster I specimens from different habitats showed various alkaloid profiles. Environmental pressure of each habitat is presumed to have caused the morphology and aconitine alkaloid profile of these genetically similar specimens to diversify.

Aconitine-induced Ca2 + overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na+ channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca2+ in aconitine poisoning. In this study, we explored the importance of pathological Ca2+ signaling in aconitine poisoning in vitro and in vivo. We found that Ca2+ overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca2+ handling proteins demonstrated that aconitine promoted Ca2+ overload through the expression regulation of Ca2+ handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca2+ overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase.

Analysis of the metabolites of mesaconitine in rat blood using ultrafast liquid chromatography and electrospray ionization mass spectrometry.

Background:Mesaconitine is the main active component of genus aconitum plants that are widely used in clinics in China. However, little has been known about the metabolic pathway of mesaconitine.Objective:To explore the metabolites and propose the pathway of mesaconitine.Materials and Methods:In the present study, mesaconitine (4 mg kg−1) was orally administered to male rats. Then, blood samples collected were pretreated using solid-phase extraction technique with C18 cartridges, and analyzed using LC/MS/MS method with electrospray ionization. Both positive ion mode and collision induced dissociation (CID) were used to elucidate the structures of the major metabolites of mesaconitine.Results:Ten compounds were identified, among which seven were new metabolites, and the metabolic pathway was proposed. The protonated molecular ions of seven new metabolites were at m/z 648, 618, 616, 602, 572, 468, and 542, multistage fragment ions with neutral loss of 28 u (CO), 60 u (CH3COOH), 18 u (H2O), and 32 u (CH3OH). These new metabolites detected firstly in vivo, were named 10-hydroxyl-mesaconitine, hypaconitine, dehydrated mesaconitine 16-O-demethylmesaconitine, 16-O-demethylhypaconitine, and 16-O-demethyl-dehydrated hypaconitine, respectively. Furthermore, the breaking sequence of methoxyl was obtained using quantum chemistry.Conclusion:The study proved that the method of solid-phase extraction technique coupled with MS and quantum chemistry can be applied to the analysis of metabolites in plasma quickly and conveniently.

Antisecretory and antimotility activity of Aconitum heterophyllum and its significance in treatment of diarrhea

Aim:The roots of the plant Aconitum heterophyllum (EAH) are traditionally used for curing hysteria, throat infection, dyspepsia, abdominal pain, diabetes, and diarrhea. Therefore, the present study was undertaken to determine the mechanism involved in the anti-diarrheal activity of roots of A. heterophyllum.Materials and Methods:Ant-diarrheal activity of ethanol extract at 50, 100, and 200 mg/kg p.o. was evaluated using fecal excretion and castor oil-induced diarrhea models, while optimized dose, that is, 100 mg/kg p.o. was further subjected to small intestinal transit, intestinal fluids accumulation, PGE2-induced enteropooling and gastric emptying test. To elucidate the probable mechanism, various biochemical parameters and Na+, K+ concentration in intestinal fluids were also determined. Further, antibacterial activity of extract along with its standardization using aconitine as a marker with the help of HPLC was carried out.Results:The results depicted a significant (P < 0.05) reduction in normal fecal output at 100 and 200 mg/kg p.o. of extract after 5th and 7th h of treatment. Castor oil-induced diarrhea model demonstrated a ceiling effect at 100 mg/kg p.o. with a protection of 60.185% from diarrhea. EAH at 100 mg/kg p.o. also showed significant activity in small intestinal transit, fluid accumulation, and PGE2-induced enteropooling models, which also restored the altered biochemical parameters and prevented Na+ and K+ loss. The extract with 0.0833% w/w of aconitine depicted a potential antibacterial activity of extract against microbes implicated in diarrhea.Conclusion:The study concluded antisecretory and antimotility effect of A. heterophyllum, which mediates through nitric oxide path way.

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.

Spasmolytic activity of diterpenoid alkaloids and their derivatives. Structure–activity relationship

The spasmolytic activity of diterpenoid alkaloids of various structural types that were isolated from plants of the genera Aconitum, Delphinium, and Consolida and their synthetic derivatives was studied in vitro using the barium-chloride contraction model of isolated sections of rat and rabbit small intestine. The structure–activity relationship of the spasmolytic activity was analyzed.