Qualitative and quantitative analysis of triterpenoids in different tissues of Pulsatilla chinensis

Pulsatilla chinensis (P.chinensis) is a traditional Chinese medicine used for the treatment of intestinal amebiasis diseases, vaginal trichomoniasis and bacterial infections. Tritepenoid saponins were important components of P.chinensis. Therefore, we asssessmented expression profiling of triterpenoids in different fresh tissues of P.chinensis by ultra high performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) and ultra high performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QQQ-MS). Firstly, we identified 132 triterpenoids, including 119 triterpenoid saponins, 13 triterpenoid acids and forty seven of them were first determined in Pulsatilla genus, including new aglycones and new ways of rhamnose linking to the aglycone. Secondly, we established the analytical method to analysis triterpenoids content of P.chinensis and comprehensively verified the analytical method by linearity, precision, repeatability, stability and recovery. At last, we quantified 119 triterpenoids simultaneously based on UHPLC-QQQ-MS. The results show that the types and contents of triterpenoids had obvious tissue distribution. New components like rhamnose directly linked to the aglycone mainely distributed in aboveground tissues. Additionally, We identified 15 chemical ingredients as differential components between the aboveground and underground tissues of P.chinensis. This study provides an efficient analysis strategy for the qualitative and quantitative analysis of triterpenoids in P.chinensis even in other traditional Chinese medicines. At the same time, it provides important informations to explain the biosynthetic pathway of triterpenoid saponins in P.chinensis.

The effect of plant compartment and geographical location on shaping microbiome of Pulsatilla chinensis

The plant-associated microbiome has an effect on plant growth. Pulsatilla chinensis (Bge.) Regel is an important Chinese medicinal plant. Currently, there is little understanding of the P. chinensis-associated microbiome and its diversity and composition. Here, the core microbiome associated with the root, leaf, and rhizospheric soil compartments of P. chinensis from five geographical locations was analyzed by the metagenomics approach. The alpha and beta diversity analysis showed that the microbiome associated with P. chinensis was shaped by the compartment, especially in the bacterial community. The geographical location had little influence on microbial community diversity associated with root and leaf. Hierarchical clustering distinguished the microbial communities of rhizospheric soil based on their geographical location and among the soil properties, pH was showed the more stronger effect on the diversity of rhizospheric soil microbial communities. Proteobacteria was the most dominant bacterial phylum in the root, leaf, and rhizospheric soil. Ascomycota and Basidiomycota were the most dominant fungal phyla in different compartments. Rhizobacter, Anoxybacillus, and IMCC26256 were the most important marker bacterial species for root, leaf, and rhizospheric soil screened by random forest, respectively. The fungal marker species for root, leaf, and rhizospheric soil were not only different across the compartments but also the geographical locations. Functional analysis showed that P. chinensis-associated microbiome had the similar function which had no obvious relationship with geographical location and compartment. The associated microbiome indicated in this study can be used for identifying microorganisms related to the quality and growth of P. chinensis. KEY POINTS: • Microbiome associated with P. chinensis was shaped by the compartment • Microbiome composition and abundance associated with rhizospheric soil were affected by the geographical location • Compared with fungi, bacterial associated with P. chinensis composition and diversity were more stable in different geographical locations and compartments.

Computational method for rapid screening of the metabolites of Pulsatilla chinensis in rats using UHPLC-Q-TOF/MS combined with mass spectrum-based orthogonal projection

Screening metabolites in vivo can be challenging due to the complexity of traditional Chinese medicine (TCM) and the ambiguous intracorporal process. To resolve this problem, we established the mass spectrum-based orthogonal projection (MSOP) method to differentiate prototype compounds from metabolites in vivo and applied it to the study of metabolites of Pulsatilla chinensis (PC). Initially, the validity and feasibility of the MSOP method were verified by using the ultra- high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) data of reference solution. Then, the MSOP method was applied to screen the metabolites of PC. A total of 63 metabolites were identified in vivo (urine, feces, bile, and plasma samples) and in vitro (intestinal bacteria biological sample). The results indicated that the main metabolic pathways of pentacyclic triterpenoids were demethylation, oxidation, dehydration, sulfation, and glucuronidation reactions. This study contributes to developing an integrated strategy based on chemometrics to characterize and classify the metabolism feature of pentacyclic triterpenoids of PC. This will support the scientific and rational application of PC in the clinic. The MSOP method based on the orthogonality of MS signals was used to differentiate the prototype compounds from metabolites in vivo. The method provides scientific and reliable support for fully understanding the metabolic fate of TCM.

The triterpenoid saponin content difference is associated with the two type oxidosqualene cyclase gene copy numbers of Pulsatilla chinensis and Pulsatilla cernua

Pulsatilla chinensis is an important medicinal herb, its dried radix is used to treat the inflammation since ancient China. Triterpenoid saponins are proved to be the main active compounds of Pulsatilla genus. The triterpenoid saponin contents vary widely in different Pulsatilla species. But no enzyme involved in the triterpenoid saponin biosynthetic pathway was identified in Pulsitilla genus. This seriously limits the explanation of the triterpene content difference of Pulsatilla species. In this article, we obtained two oxidosqualene cyclase (OSC) genes from P. chinensis and P. cernua by touchdown PCR and anchored PCR. These two OSCs converted 2,3-oxidosqualene into different triterpenoids. The OSC from P. cernua is a monofunctional enzyme for β-amyrin synthesis, while the OSC from P. chinensis is a multifunctional enzyme for lupeol and β-amyrin synthesis, and the lupeol is the main product. Then we identified the 260th amino acid residue was the key site for the product difference by gene fusion and site-directed mutant technology. When the 260th amino acid residue was tryptophan (W260) and phenylalanine (F260), the main catalysate was β-amyrin and lupeol, respectively. Then we found that the expression of these two genes was strongly correlated with the lupeol-type and β-amyrin-type triterpenoid contents in P. cernua and P. chinensis. Finally, we found the gene copy number difference of these two genotypes leaded to the triterpenoid diversity in P. cernua and P. chinensis. This study provides useful information for the molecular breeding and quality improvement of P. chinensis and a molecular marker to identify the P. chinensis decoction pieces.

Integrated transcriptomic and metabolomic analyses revealed the molecular mechanism of terpenoid formation for salicylic acid resistance in Pulsatilla chinensis callus

As a kind of traditional Chinese medicine, Pulsatilla chinensis (Bunge) Regel is well known for its anti-inflammation and anti-cancer activities, which are attributed to its active components including total saponins and monomers. To clarify the synthesis and metabolism mechanisms of class components in callus terpenes of P. chinensis, a certain concentration of salicylic acid (SA) hormone elicitor was added to the callus before being analysed by transcriptomic and metabolomic techniques. Results showed that the content of Pulsatilla saponin B4 in the callus suspension culture was significantly increased up to 1.99% with the addition of SA. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the differentially expressed genes were mainly enriched in 122 metabolic pathways, such as terpenoid metabolism-related pathways: terpenoid skeleton synthesis pathway, monoterpenoid biosynthesis pathways, diterpenoid biosynthesis pathways, and ubiquinone and other terpenoid-quinone biosynthesis pathways. A total of 31 differentially accumulated metabolites were obtained from four differential groups. Amongst 21 kinds of known chemical components in P. chinensis, deoxyloganic acid was the only monoterpenoid; the others are triterpenoids. In summary, this study found that SA elicitors can affect the metabolic changes of terpenoids in P. chinensis callus, which provided a basis for analysing the genetic regulation of terpenoid components of leucons.

Anemoside B4 protects against chronic relapsing colitis in mice by modulating inflammatory response, colonic transcriptome and the gut microbiota

BACKGROUND

Anemoside B4 (AB4) is reported to prevent acute colitis when given via intraperitoneal injection by two recent studies. However, whether oral AB4 protects against chronic colitis which resembles the clinical phenotype of ulcerative colitis (UC) and its mechanism of action are largely unknown.

PURPOSE

To systemically investigate the effects of oral AB4 against chronic colitis and illustrate the underlying mechanism of action.

METHODS

The preventive, therapeutic, and dose-dependent effects of AB4 against UC were examined in mice with acute or chronic relapsing colitis induced by dextran sulfate sodium (DSS). The inflammatory responses, colonic transcriptome, and 16S rDNA sequencing of the intestinal content of mice were analyzed.

RESULTS

Oral administration of AB4 alleviated disease severity and colon shortening in mice with chronic relapsing colitis in a dose-dependent manner. The effects of AB4 were comparable to those of two positive-control compounds: tofacitinib and berberine. Unlike tofacitinib, AB4 did not have a deleterious effect on DSS-induced splenic swelling and anemia. Furthermore, AB4 inhibited the inflammatory responses of colitis, as evidenced by in-vivo, ex-vivo, and in-vitro studies. Transcriptomics revealed that AB4 treatment reversed the DSS-mediated decrease in the expression of colonic Pelo, B3gat2 and Mir8010. In addition, AB4 reversed DSS-induced alterations in the intestinal microbiome in mice. Through fecal microbiota transplantation, we proved that AB4 partially exerted its anti-colitis effects by modulating the gut microbiota.

CONCLUSIONS

We demonstrated for the first time that AB4 has dose-dependent therapeutic effects against chronic relapsing colitis by modulating the inflammatory response, colonic gene expression, and intestinal microbiota.

Pharmacological activities and molecular mechanisms of Pulsatilla saponins

Saponins are found in a variety of higher plants and display a wide range of pharmacological activities, including expectorant, anti-inflammatory, vasoprotective and antimicrobial properties. Pulsatilla chinensis (P. chinensis, Bai Tou Weng, ) has been used medically in China for thousands of years for the treatment of diseases caused by bacteria, and it is rich in triterpenoid saponins. In recent decades, anemoside B4 (Pulchinenoside C) is well studied since it has been used as a quality control marker for P. chinensis. At the same time, more and more other active compounds were found in the genus of Pulsatilla. In this review, we summarize the pharmacological activities of Pulsatilla saponins (PS) and discuss the cellular or molecular mechanisms that mediate their multiple activities, such as inducing cancer cell apoptosis, inhibiting tumor angiogenesis, and protecting organs via anti-inflammatory and antioxidant measures. We aim to provide comprehensive analysis and summary of research progress and future prospects in this field to facilitate further study and drug discovery of PS.

Identification of Pulsatilla chinensis (Bge.) Regel and look-alike species by ultra-performance liquid chromatography/time-of-flight mass spectrometry using multivariate statistical analysis

Pulsatillae Radix, the root of Pulsatilla chinensis (Bge.) Regel, is recorded in the Pharmacopoeia of the People's Republic of China and has been widely used for its pharmacological activities, such as anti-inflammatory, antioxidant, antibacterial, antitumor, and cardiovascular benefits. However, there are several look-alike species that can be marketed as Pulsatillae Radix. To distinguish Pulsatilla chinensis (Bge.) Regel from its look-alikes, viz. Pulsatilla cernua (Thunb.) Bercht et Opiz., Pulsatilla dahurica (Fisch.) Spreng., Anemone tomeutosa (Maxim.) Pei., and Rhaponticum uniflorum (L.) DC, we used ultra-performance liquid chromatography/time-of-flight mass spectrometry combined with principal component analysis to compare their chemical compositions. Four ions, a (RT 8.98 min, m/z 1381.6671), b (RT 10.64 min, m/z 1219.6143), c (RT 11.52 min, m/z 1217.5978), and d (RT 13.6 min, m/z 749.4463) from Pulsatillae chinensis (Bge.) Regel were identified as potential chemical markers to distinguish it from look-alike species using an unsupervised statistical model combined with orthogonal partial least-squares discriminant analysis. The results of this study provide an effective method for identifying and distinguishing Pulsatilla chinensis (Bge.) Regel from similar plants. This article is protected by copyright. All rights reserved.

[Network pharmacological analysis and experimental study of Pulsatilla chinensis against inflammatory injury caused by pneumonia in mice infected with influenza virus FM_1]

Network pharmacology and the mouse model of viral pneumonia caused by influenza virus FM_1 were employed to explore the main active components and the mechanism of Pulsatilla chinensis against the inflammatory injury of influenza virus-induced pneumonia. The components and targets of P. chinensis were searched from TCMSP, and the targets associated with influenza virus-induced pneumonia were searched from GeneCards. The common targets between P. chinensis and influenza virus-induced pneumonia were identified with Venn diagram established in Venny 2.1. The herb-component-disease-target(H-C-D-T) network was constructed by Cytoscape 3.7.2. The above data were imported into STRING for PPI network analysis. Gene Ontology(GO) enrichment and KEGG pathway enrichment were performed with DAVID. BALB/cAnN mice were infected with the influenza virus FM_1 by nasal drip to gene-rate the mouse model of pneumonia. Immunohistochemistry was adopted to the expression profiling of inflammatory cytokines in the lung tissues of mice in the blank group, model group, and P. chinensis group 1, 3, 5, and 7 days after infection. The pathological changes of lung and trachea of mice in blank group, model group, and P. chinensis group were observed with light microscope and scanning electron microscope at all the time points. The network pharmacological analysis indicated that 9 compounds of P. chinensis were screened out, with a total of 57 targets, 22 of which were overlapped with those of influenza virus-induced pneumonia. A total of 112 GO terms(P<0.05) were enriched, including 81 terms of biological processes, 11 terms of cell components, and 20 terms of molecular functions. A total of 53 KEGG signaling pathways(P<0.05) were enriched, including TNF signaling pathway, influenza A signaling pathway, NF-κB signaling pathway, MAPK signaling pathway and other signaling pathways related to influenza/inflammation. In the P. chinensis group, the expression of TNF-α and IL-1 in the lung tissue was down-regulated on the 3 rd day after infection, and that of IL-6 in the lung tissue was down-regulated on the 5 th day after infection. Light microscopy and scanning electron microscopy showed that P. chinensis significantly alleviated the pathological damage of lung and trachea compared with the model group. This study reflects the multi-components, multi-targets, and multi-pathways of P. chinensis against influenza virus-induced pneumonia. P. chinensis may reduce the production of proinflammatory cytokines and mediators and block the pro-inflammatory signaling pathways to alleviate viral pneumonia, which provides reference for future research.

Therapeutic potential of triterpenoid saponin anemoside B4 from Pulsatilla chinensis

Pulsatilla Decoction (Bai-Tou-Weng-Tang) has been used medically in China for thousands of years for the treatment of diseases caused by bacteria. In recent decades, Pulsatilla Decoction is becoming a well-known formula prescription used for the treatment of ulcerative colitis in traditional Chinese medicine. Pulsatilla chinensis is the chief herbal source of Pulsatilla Decoction, and it is rich in triterpenoid saponins, such as anemoside B4, anemoside A3, and 23-hydroxybetulinic acid. Anemoside B4 is the most abundant of that group and has been used as a quality control marker for Pulsatilla chinensis. As the major active component of Pulsatilla chinensis, anemoside B4 has also received attention as a pure compound for its therapeutic potential. In this review, we systematically analyze the findings on triterpenoid saponins, especially anemoside B4, anemoside A3 and 23-hydroxybetulinic acid, included in Pulsatilla chinensis and Pulsatilla Decoction. We discuss the pharmacokinetics and tissue distribution of these triterpenoid saponins as well as their biological activities. We also summarize the pharmacological effects of anemoside B4 and its two possible metabolites, anemoside A3 and 23-hydroxybetulinic acid, as pure compounds. In summary, this review sketches a profile of the state of existing knowledge with regard to the pharmacological effects of anemoside B4, especially its anti-inflammatory and immunomodulatory effects. These findings point to the possibility that anemoside B4 has potential to be studied further as a natural compound-originated immunomodulatory agent for the treatment of inflammatory diseases such as ulcerative colitis and thus, may represent one of the most important active components of Pulsatilla Decoction responsible for its anti-ulcerative colitis efficacy.

CRH receptor antagonists from Pulsatilla chinensis prevent CRH-induced premature catagen transition in human hair follicles

BACKGROUND

There is a growing interest in the relationship among stress hormones, neuroendocrine signaling, and skin diseases, including hair loss. Previous reports showed that stress hormones inhibit human hair growth and induce early catagen transition. Moreover, a CRH receptor antagonist reversed CRH-induced alopecia in a mouse model, suggesting that antagonization of the CRH receptor is a key clinical strategy to treat stress-induced hair loss.

OBJECTIVES

The aim of this study was to investigate the protective effect of CRH receptor antagonists from Pulsatilla chinensis on human hair follicles (hHFs) and human dermal papilla cells (hDPCs).

METHODS

hHFs were observed and scored by hair cycle. The levels of cAMP, a second messenger, were measured in each group. In addition, the mRNA and protein levels of factors related to the hair cycle were measured. Furthermore, the expression levels of various members of the mitogen-activated protein kinase (MAPK) signaling pathway related to stress were measured.

RESULTS

CRH induced early catagen transition in an ex vivo hair organ culture model. In addition, CRH downregulated the levels of alkaline phosphatase (ALP) and hair anagen-related cytokines in cultured hDPCs. Moreover, CRH induced the phosphorylation of JNK, c-Jun, p38, ERK, and Akt in cultured hDPCs. CRH receptor antagonists isolated from P chinensis reversed these CRH-induced modulations in both ex vivo hair follicles (HFs) and cultured hDPCs.

CONCLUSIONS

These results indicate that P chinensis effectively blocks CRH receptor function and that saponin derivatives from P chinensis could be a pharmaceutical and cosmetic approach to treat stress-induced hair loss.

Comparative analysis of the complete chloroplast genome sequences of six species of Pulsatilla Miller, Ranunculaceae

BACKGROUND

Baitouweng is a traditional Chinese medicine with a long history of different applications. Although referred to as a single medicine, Baitouweng is actually comprised of many closely related species. It is therefore critically important to identify the different species that are utilized in these medicinal applications. Knowledge about their phylogenetic relationships can be derived from their chloroplast genomes and may provide additional insights into development of molecular markers.

METHODS

Genomic DNA was extracted from six species of Pulsatilla and then sequenced on an Illumina HiSeq 4000. Sequences were assembled into contigs by SOAPdenovo 2.04, aligned to the reference genome using BLAST, and then manually corrected. Genome annotation was performed by the online DOGMA tool. General characteristics of the cp genomes of the six species were analyzed and compared with closely related species. Additionally, phylogenetic trees were constructed, based on single nucleotide polymorphisms (SNPs) and 51 shared protein-coding gene sequences in the cp genome among all 31 species via maximum likelihood.

RESULTS

The size of cp genomes of P. chinensis (Bge.) Regel, P. chinensis (Bge.) Regel var. kissii (Mandl) S. H. Li et Y. H. Huang, P. cernua (Thunb.) Bercht. et Opiz f. plumbea J. X. Ji et Y. T. zhao, P. dahurica (Fisch.) Spreng, P. turczaninovii Kryl. et Serg, and P. cernua (Thunb.) Bercht. et Opiz. were 163,851 bp, 163,756 bp, 162,481 bp, 162,450 bp, 162,795 bp, and 162,924 bp, respectively. Each species included two inverted repeat regions, a small single-copy region, and a large single-copy region. A total of 134 genes were annotated, including 90 protein-coding genes, 36 tRNAs, and eight rRNAs across all species. In simple sequence repeat analysis, only P. dahurica was found to contain hexanucleotide repeats. A total of 26, 39, 32, 37, 32 and 43 large repeat sequences were identified in the genic regions of the six Pulsatilla species. Nucleotide diversity analysis revealed that the rpl36 gene and ccsA-ndhD region have the highest Pi value. In addition, two phylogenetic trees of the cp genomes were constructed, which laced all Pulsatilla species into one branch within Ranunculaceae.

CONCLUSIONS

We identified and analyzed the cp genome features of six species of P. Miller, with implications for species identification and phylogenetic analysis.

UPLC-Q-TOF-MS/MS-guided dereplication of Pulsatilla chinensis to identify triterpenoid saponins

INTRODUCTION

Triterpenoid saponins are the major bioactive constituents of Pulsatilla chinensis, playing an important role in various biological activities such as anti-tumour, cognition-enhancing, anti-biosis, anti-inflammatory, hypoglycemic and immunological adjuvant.

OBJECTIVE

To establish a systematic strategy based on ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) for the efficient characterisation and identification of triterpenoid saponins in crude extracts from Pulsatilla chinensis.

METHODOLOGY

In this work, the strategy includes two aspects: (1) positive mode: by target screening, we can deduce the aglycone type and the composition of sugar moiety according to the fragment ions; untargeted screening includes four steps, find unknown, formula finder, ChemSpider search and MS/MS identification; (2) negative mode: according to the MS/MS spectra, the composition of sugar chain bonded to C-28 is inferred reasonably. The extract of Pulsatilla chinensis was separated within 60 min on a C₁₈ column and eluted with methanol and water both containing 0.1% formic acid.

RESULTS

As a result, a total of 22 triterpenoid saponins (11 pairs of isomers) with four aglycone skeletons were tentatively identified or elucidated in crude extracts from Pulsatilla chinensis based on their retention times, the mass spectrometric fragmentation patterns, and MS and MS/MS data.

CONCLUSION

This study provides an efficient analysis strategy to rapidly identify the triterpenoid saponins in Pulsatilla species even in traditional Chinese medicines.

Validated rapid resolution LC-ESI-MS/MS method for simultaneous determination of five pulchinenosides from Pulsatilla chinensis (Bunge) Regel in rat plasma: application to pharmacokinetics and bioavailability studies

A simple, RRLC-ESI-MS/MS method was developed for the simultaneous determination of five oleanane pulchinenosides (B3, BD, B7, B10, and B11), in rat plasma following solid-phase extraction (SPE). Detection and quantitation were performed by MS/MS using electrospray ionization (ESI) and multiple reaction monitoring (MRM) mode. The MS/MS transitions of the triterpenoidal saponins: m/z 911.4→603.2, 749.4→471.3, 895.6→733.2, 733.5→455.3, and 579.3→371.1 were monitored for B3, BD, B7 and B10, B11 and internal standard (Forsythin), respectively. The method was validated in plasma samples, showed good linearity over a wide concentration range (r(2)>0.99), and with lower limits of quantification of 1.11 (B3), 0.751 (BD), 0.996 (B7), 0.415 (B10), and 0.332 (B11)ng/mL. The intra- and inter-day assay variability was less than 15% for all analytes. The mean extraction recoveries of analytes and IS from rats plasma were all more than 70.0%. The validation results demonstrate that this method is robust and specific. The validated method was successfully applied for the pharmacokinetic and bioavailability studies of the five pulchinenosides which are potentially active saponins present in P. chinensis saponins (PRS) extracts.