Transcriptomic and metabolomic analyses provide new insights into the appropriate harvest period in regenerated bulbs of Fritillaria hupehensis

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.

Combined metabolomics and transcriptomics reveal the secondary metabolite networks in different growth stages of Bletilla striata (Thunb.) Reichb.f

BACKGROUND

Bletilla striata (Thunb.) Reichb.f. (B. striata) is a traditional Chinese medicinal herb. B. striata polysaccharides (BSP), stilbenes and 2-isobutyl malic acid glucosoxy-benzyl ester compounds are the main active ingredients in B. striata. However, there is limited report on the changes of medicinal components and their biosynthesis regulation mechanisms in the tubers of B. striata at different stages.

METHOD

The tubers of B. striata were collected during the flowering period, fruiting period, and harvest period to determine the total polysaccharide content using the phenol sulfuric acid method. The changes in secondary metabolites in the tubers at these stages were analyzed by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS), and transcriptomics was conducted for further exploration of their biosynthetic pathways.

RESULT

The BSP content gradually increases from the flowering period to the fruiting period as the tubers develop, reaching its peak, but subsequently decreases at harvest time, which may be associated with the germination of B. striata buds in later stage. A total of 294 compounds were identified in this study. Among them, a majority of the compounds, such as 2-isobutyl malate gluconoxy-benzyl ester, exhibited high content during the fruit stage, while stilbenes like coelonin, 3'-O-methylbatatasin III, and blestriarene A accumulated during the harvesting period. The transcriptome data also revealed a substantial number of differentially expressed genes at various stages, providing a partial explanation for the complex changes in metabolites. We observed a correspondence between the expression pattern of GDP-Man biosynthesis-related enzyme genes and cumulative changes in BSP. And identified a positive correlation between 9 transcription factors and genes associated with polysaccharide biosynthesis, while 5 transcription factors were positively correlated with accumulation of 2-isobutyl malate gluconoxy-benzyl ester compounds and 5 transcription factors exhibited negative correlated with stilbene accumulation.

CONCLUSION

It is imperative to determine the appropriate harvesting period based on the specific requirements of different active ingredients and the accumulation patterns of their metabolites. Considering the involvement of multiple transcription factors in the biosynthesis and accumulation of its active ingredients, a comprehensive investigation into the specific regulatory mechanisms that facilitate high-quality cultivation of B. striata is imperative.

Exploring regulatory network of icariin synthesis in Herba Epimedii through integrated omics analysis

Herba Epimedii's leaves are highly valued in traditional Chinese medicine for their substantial concentration of flavonoids, which play a crucial role in manifesting the plant's therapeutic properties. This study investigated the metabolomic, transcriptomic and proteomic profiles of leaves from two Herba Epimedii cultivars, Epipremnum sagittatum (J) and Epipremnum pubescens (R), at three different developmental stages. Metabolite identification and analysis revealed a total of 1,412 and 1,421 metabolites with known structures were found. Flavonoids made up of 33%, including 10 significant accumulated icariin analogues. Transcriptomic analysis unveiled totally 41,644 differentially expressed genes (DEGs) containing five encoded genes participated in icariin biosynthesis pathways. Totally, 9,745 differentially expressed proteins (DEPs) were found, including Cluster-47248.2.p1 (UDP-glucuronosy/UDP-glucosyltransferase), Cluster-30441.2.p1 (O-glucosyltransferase), and Cluster-28344.9.p1 (anthocyanidin 3-O-glucoside 2 "-O-glucosyltransferase-like) through proteomics analysis which are involved to icariin biosynthesis. Protein-protein interaction (PPI) assay exhibited, totally 12 proteins showing a strong relationship of false discovery rate (FDR) <0.05 with these three proteins containing 2 leucine-rich repeat receptor kinase-like protein SRF7, and 5 methyl jasmonate esterase 1. Multi-omics connection networks uncovered 237 DEGs and 72 DEPs exhibited significant associations with the 10 icariin analogues. Overall, our integrated omics approach provides comprehensive insights into the regulatory network underlying icariin synthesis in Herba Epimedii, offering valuable resources for further research and development in medicinal plant cultivation and pharmaceutical applications.

Integrated Metabolomic and Transcriptomic Analysis of Puerarin Biosynthesis in Pueraria montana var. thomsonii at Different Growth Stages

Puerarin, a class of isoflavonoid compounds concentrated in the roots of Puerarias, has antipyretic, sedative, and coronary blood-flow-increasing properties. Although the biosynthetic pathways of puerarin have been investigated by previous researchers, studies focusing on the influence of different growth stages on the accumulation of metabolites in the puerarin pathway are not detailed, and it is still controversial at the last step of the 8-C-glycosylation reaction. In this study, we conducted a comprehensive analysis of the metabolomic and transcriptomic changes in Pueraria montana var. thomsonii during two growing years, focusing on the vigorous growth and dormant stages, to elucidate the underlying mechanisms governing the changes in metabolite and gene expression within the puerarin biosynthesis pathway. In a comparison of the two growth stages in the two groups, puerarin and daidzin, the main downstream metabolites in the puerarin biosynthesis pathway, were found to accumulate mainly during the vigorous growth stage. We also identified 67 common differentially expressed genes in this pathway based on gene expression differences at different growth stages. Furthermore, we identified four candidate 8-C-GT genes that potentially contribute to the conversion of daidzein into puerarin and eight candidate 7-O-GT genes that may be involved in the conversion of daidzein into daidzin. A co-expression network analysis of important UGTs and HIDs along with daidzein and puerarin was conducted. Overall, our study contributes to the knowledge of puerarin biosynthesis and offers information about the stage at which the 8-C-glycosylation reaction occurs in biosynthesis. These findings provide valuable insights into the cultivation and quality enhancement of Pueraria montana var. thomsonii.