Identification of in vitro and in vivo metabolites of 12β-hydroxylveratroylzygadenine associated with neurotoxicity by using HPLC–MS/MS

Veratrum nigrum L.: A comprehensive review of ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics and metabolism, toxicity, and incompatibility

ETHNOPHARMACOLOGICAL RELEVANCE

Veratrum nigrum L. (V. nigrum) is a well-known herb with a lengthy history of use in Asian and European countries. V. nigrum has been traditionally used to treat epilepsy, hypertension, malignant sores, and stroke, and it possesses emetic and insecticide properties.

AIM OF THE REVIEW

This review summarized the ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics and metabolism, and toxicity of V. nigrum as well as its incompatibility with other herbs. Current challenges in the use of V. nigrum and possible future research directions were also discussed.

MATERIALS AND METHODS

Information on V. nigrum was collected from electronic databases such as PubMed, Google Scholar, Web of Science, CNKI, and WanFang DATA; Masterpieces of Traditional Chinese Medicine; local Chinese Materia Medica Standards; and relevant documents.

RESULTS

In ethnomedical practice, V. nigrum has been used as an emetic and insecticide. Approximately 137 compounds have been isolated from V. nigrum, including alkaloids, stilbenes, flavonoids, organic acids, and esters. Its crude extracts and compounds have shown various effects, including anticancer, hypotensive, insecticidal, and antimicrobial activities as well as the ability to improve hemorheological abnormalities. Pharmacokinetic studies have indicated that veratramine (VAM) and jervine have high bioavailability and possibly enterohepatic circulation. In addition, the sex-related pharmacokinetic differences in V. nigrum alkaloids warrant further attention. Toxicological studies have indicated that cevanine-type alkaloids and VAM may be the main toxic components of V. nigrum, and purine metabolism disorders may be related to V. nigrum toxicity. Furthermore, the neurotoxicity and embryotoxicity of V. nigrum have also been observed. The quality control of V. nigrum and the mechanism underlying its incompatibility with other herbs also deserve further research and refinement.

CONCLUSION

This review summarized the existing information on V. nigrum, laying the foundation for further studies on this herb and its safe use. Among the various compounds present in V. nigrum, steroid alkaloids are the most numerous and have high content; furthermore, they are closely related to the pharmacological effects of V. nigrum, but their toxicity can not also be ignored. Given that toxicity is a critical issue limiting the clinical application of V. nigrum, more toxicological studies on V. nigrum and its active ingredients, especially steroid alkaloids, should be conducted in the future to further explore its toxicity targets and the underlying mechanisms and to provide more evidence and recommendations to enhance the safety of its clinical application.

Ruminant metabolism of zygacine, the major toxic alkaloid in foothill death camas (Zigadenuspaniculatus)

Death Camas (Zigadenus spp.) are common poisonous plants distributed throughout North America. The toxic alkaloids in foothill death camas are zygadenine and a series of zygadenine esters, with zygacine, the 3-acetyl ester of zygadenine, being the most abundant. Both cattle and sheep can be poisoned by grazing death camas, however, sheep consume death camas more readily and are most often poisoned. We hypothesized that the presence of enzymes, including esterases present in the rumen, liver, and blood of livestock would metabolize zygacine. The objective of this study was to investigate the metabolism of zygacine in sheep and cattle using in-vitro and in-vivo systems. Results from experiments where zygacine was incubated in rumen culture, plasma, liver S9 fractions, and liver microsomes and from the analysis of rumen and sera from sheep and cattle dosed death camas plant material demonstrated that zygacine is metabolized to zygadenine in the rumen, liver and blood of sheep and cattle. The results from this study indicate that diagnosticians should analyze for zygadenine, and not zygacine, in the rumen and sera for the diagnosis of livestock suspected to have been poisoned by foothill death camas.

Quality Assessment and Antioxidant Activities of the Blossoms of Inula Nervosa Wall

BACKGROUND

Currently, although Inula nervosa Wall is substantially investigated, little is understood about blossoms of Inula nervosa Wall (BINW).

OBJECTIVE

In this work, we systematically investigated the antioxidant activity of the extract from BINW by various standard assays including 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical ability, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt radical cation (ABTS), and ferric reducing antioxidant potential (FRAP).

METHODS

Chemical compounds were tentatively identified through an UHPLC-QTOF-MS system. Furthermore, the contents of nine compounds were detected with UHPLC method coupled with photodiode array (PDA) detector. By carefully analyzing the quantitative data via clusters analysis and principal component analysis (PCA).

RESULTS

Forty-six compounds were tentatively identified, and our results showed that nine compound samples in 21 batches of BINW collected from different areas could be differentiated and analyzed by a heatmap visualization. In addition, the contents of nine compounds (flavonoids, phenolic acids) exhibited a total of higher amounts and better antioxidant activities from Yunnan than those from the other three origins.

CONCLUSIONS

Our study not only developed a powerful platform to explain the difference between traditional Chinese medicines species that are closely related through the chemometric and chemical profiling, but also presented a useful method to establish quality criteria of BINW with multiple origins.

HIGHLIGHTS

To characterize the BINW in detail, we not only performed DPPH, FRAP, and ABTS assays to investigate its antioxidant activity, but also established UHPLC-QTOF-MS/MS- and UHPLC-PDA-based methods to comprehensively identify and qualitatively analyze its components.

UPLC-MS/MS Method for the Simultaneous Quantification of Eight Compounds in Rat Plasma and Its Application to a Pharmacokinetic Study after Oral Administration of Veratrum (Veratrum nigrum L.) Extract

Veratrum nigrum L. is a well-known traditional Chinese medicine with a lot of pharmacological activities including antihypertensive, anticancer, and antifungal effects. In the current experiment, a rapid and sensitive UPLC-MS/MS method that takes only 7 min run time has been established and validated for simultaneous determination of eight bioactive compounds including cyclopamine, jervine, veratramine, polydatin, quercetin, apigenin, resveratrol, and veratrosine in rat plasma. The chromatographic separation of analytes and internal standard was performed on a Phenyl-Hexyl column (2.1 × 100 mm, 1.7 μm) with the mobile phase consisting of water (0.1% formic acid) and acetonitrile at a flow rate of 0.3 mL/min. An electrospray ionization (ESI) source was used to detect the samples in both positive and negative ion modes. The intra- and interday precisions of the compounds were less than 9.5% and the accuracy ranged from -10.8% to 10.4%. The extraction recoveries of the compounds were in the range of 85.1 ± 1.5% to 102.6 ± 8.0%, and the matrix effect ranged from 91.2 ± 4.5% to 113.8 ± 1.5%. According to the results of the stability test, the eight compounds have good stability under various conditions and the relative standard deviation (RSD) less than 13.2%. The pharmacokinetic parameters of the eight compounds in rat plasma after oral administration of Veratrum nigrum L. extract were successfully determined by the established UPLC-MS/MS method.

A Structure-Activity Relationship between the Veratrum Alkaloids on the Antihypertension and DNA Damage Activity in Mice

Veratrum plant contains a family of compounds called steroidal alkaloids which have been previously reported to cause DNA damage and blood pressure decrease in vivo. In this study, the antihypertensive effects and DNA damage in brain cells of 12 steroidal alkaloids separated from Veratrum plant were all evaluated to develop a relationship among chemical structure, antihypertensive activity and neurotoxicity by utilization of chemical principal component analysis (PCA) and hierarchical cluster analysis (HCA). Twelve steroidal alkaloids markedly reduced high blood pressure of hypertensive mice and also similarly induced varying degrees of DNA single-strand breaks in mouse cerebellum and cerebral cortex after oral administration. On the basis of the PCA and HCA results, it was suggested that the 3-carboxylic esters and benzene group play a core role in the DNA damage of brain cells, while more hydroxy groups in the A-ring and B-ring structure of jervine-type alkaloid led to stronger antihypertensive activity. The primary structure, activity and neurotoxicity relationship were discussed briefly.