Extraction, characterization, antioxidation and anti-inflammatory activity of polysaccharides from Bupleurum chinense based on different molecular weights.

Bupleurum chinense polysaccharide has a wide range of biological activities. In this study, Bupleurum chinense polysaccharides (BPs), BPs-1 (30 kDa) and BPs-2 (2000 kDa) with different molecular weights were isolated and prepared by ultrafiltration interception method. The structures of BPs, BPs-1 and BPs-2 were characterised by monosaccharide composition, GC-MS, Fourier transform infra-red spectroscopy and nuclear magnetic resonance. The results showed that the monosaccharide composition of BPs with different molecular weights was the same, but the proportion was different. BPs, BPs-1 and BPs-2 were mainly connected by Glup-(1→,→2,4)-Araf-(1→,→6)-Glup-(1→). The anti-inflammatory activity screening experiment in vitro showed that BPs-1 had stronger anti-inflammatory effect. Antioxidant experiments showed that BPs-2 had high free radical scavenging activity. This study laid a foundation for elucidating the fine structure and structure-activity relationship of Bupleurum chinense polysaccharides and will promote the product development of Bupleurum chinense polysaccharides.

Intercropping with maize and sorghum-induced saikosaponin accumulation in Bupleurum chinense DC. by liquid chromatography-mass spectrometry-based metabolomics.

Bupleuri Radix is an important medicinal plant, which has been used in China and other Asian countries for thousands of years. Cultivated Bupleurum chinense DC. (B. chinense) is the main commodity of Bupleuri Radix. The benefits of intercropping with various crops for B. chinense have been recognized; however, the influence of intercropping on the chemical composition of B. chinense is still unclear yet. In this study, intercropping with sorghum and maize exhibited little effect on the root length, root diameter, and single root mass of B. chinense. Only the intercropping with sorghum increased the root length of B. chinense slightly compared to the monocropping. In addition, 200 compounds were identified by UHPLC-Q-TOF-MS, and metabolomic combined with the Venn diagram and heatmap analysis showed apparent separation between the intercropped and monocropped B. chinense samples. Intercropping with sorghum and maize could both increase the saikosaponins, fatty acyls, and organic acids in B. chinense while decreasing the phospholipids. The influence of intercropping on the saikosaponin biosynthesis was probably related with the light intensity and hormone levels in B. chinense. Moreover, we found intercropping increased the anti-inflammatory activity of B. chinense. This study provides a scientific reference for the beneficial effect of intercropping mode of B. chinense.

Study on characterization of Bupleurum chinense polysaccharides with antioxidant mechanisms focus on ROS relative signaling pathways and anti-aging evaluation in vivo model.

This study explored the structures of three polysaccharides from Bupleurum chinense DC. (BCPRs), and evaluated their antioxidant and anti-aging properties. The HPGPC and ion chromatography analyses revealed that the molecular weights of the BCPRs ranged from 12.05 to 21.20 kDa, and were primarily composed of rhamnose, arabinose, xylose, galactose, glucose and galacturonic acid. Methylation and NMR studies identified 10 PMAAs, establishing the various backbones of BCPRs 1-3. BCPR-3 demonstrated potent antioxidant activities, including DPPH, ABTS, hydroxy, and superoxide radicals scavenging in vitro. At concentrations between 125 and 500 µg/mL, BCPR-3 increased T-AOC, SOD and GSH-Px activities, while decreasing MDA levels in H2O2-induced SH-SY5Y cells. In addition, RNA-seq results indicated that BCPR-3 considerably downregulated the expression of 49 genes and upregulated five genes compared with the control group. KEGG analysis suggested that these differentially expressed genes (DEGs) were predominantly involved in the TNF and PI3K/Akt signaling pathways. Furthermore, in vivo experiment with Drosophila melanogaster showed that BCPR-3 could extend the average lifespan of flies. In conclusion, polysaccharides from B. chinense exhibited potential antioxidant and anti-aging activities, which could be developed as new ingredients to combat oxidative stress damage and slow the aging process.

Homotherapy-for-heteropathy of Bupleurum Chinense DC.-Scutellaria baicalensis Georgi in treating depression and colorectal cancer: A network pharmacology and animal model approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Bupleurum chinense DC.-Scutellaria baicalensis Georgi (BS) is a classic drug pair that has good clinical effects on depression and many tumors. However, the concurrent targeting mechanism of how the aforementioned drug pair is valid in the two distinct diseases, has not been clarified yet. AIM OF THE STUDY: The components of BS were detected by LC-MS, combined with network pharmacology to explore the active ingredients and common targeting mechanism of its multi-pathway regulation of BS in treating depression and CRC, and to validate the dual effects of BS using the CUMS mice model and orthotopic transplantation tumor mice model of CRC. RESULTS: Twenty-nine components were screened, 84 common gene targets were obteined, and the top 5 key targets including STAT3, PIK3R1, PIK3CA, AKT1, IL-6 were identified by PPI network. GO and KEGG analyses revealed that PI3K/AKT and JAK/STAT signaling pathways might play a crucial role of BS in regulating depression and CRC. BS significantly modulated CUMS-induced depressive-like behavior, attenuated neuronal damage, and reduced serum EPI and NE levels in CUMS model mice. BS improved the pathological histological changes of solid tumors and liver tissues and inhibited solid tumors and liver metastases in tumor-bearing mice. BS significantly decreased the proteins' expression of IL-6, p-JAK2, p-STAT3, p-PI3K, p-AKT1 in hippocampal tissues and solid tumors, and regulated the levels of IL-2, IL-6 and IL-10 in serum of two models of mice. CONCLUSION: BS can exert dual antidepressant and anti-CRC effects by inhibiting the expression of IL-6/JAK2/STAT3 and PI3K/AKT pathway proteins and regulating the release of inflammatory cytokines.

Quantitative and Differential Analysis between Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd. Using HPLC-MS and GC-MS Coupled with Multivariate Statistical Analysis.

Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd. have different clinical efficacies, with the former typically used to treat typhoid fever and the latter mainly used to clear liver heat. The differences in their clinical efficacy are closely related to their complex chemical composition, especially the active components. In this study, the saponins and volatile oils in two varieties of Radix Bupleuri grown in different regions were extracted and analyzed using high-performance liquid chromatography (HPLC) and gas chromatography coupled with mass spectrometry (MS), and the absolute contents of five saikosaponins were accurately quantified using an established HPLC-MS method in the multiple reaction monitoring mode. Multivariate statistical analysis was performed to reveal the difference in the active components between the two varieties. The saikosaponin content was significantly affected by variety and growing region, with all five saikosaponins being significantly higher in Bupleurum chinense DC. than in Bupleurum scorzonerifolium Willd. The results of principal component analysis and hierarchical cluster analysis show a clear distinction between the two varieties in terms of both saponins and volatile oils. Twenty-one saponins, including saikosaponin b2 and b1, and fifty-two volatile oils, including 2-tetradecyloxirane and chloromethyl cyanide, were screened and identified as differential compounds contributing to the significant difference between the two varieties. These compounds may also be responsible for the difference in clinical efficacy between Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd. All the results suggest that the accumulation and diversity of active components in Radix Bupleuri are significantly affected by the variety. In contrast to previous reports, this study provides the absolute contents of five saikosaponins in Radix Bupleuri of different varieties and reduces the influence of the growing region on the analytical results by collecting samples from different regions. The results of this study may provide a reference for the identification and quality evaluation of different varieties of Radix Bupleuri.

Bupleurum chinense exerts a mild antipyretic effect on LPS-induced pyrexia rats involving inhibition of peripheral TNF-α production.

ETHNOPHARMACOLOGICAL RELEVANCE: Bupleuri Radix, the dried roots of Bupleurum chinense DC. (BC) or Bupleurum scorzonerifolium Willd., is one of the most frequently used traditional Chinese medicines. As the species in Xiao-Chai-Hu decoction, BC has been used as an antipyretic medicine with a long history. However, its antipyretic characteristics and underlying mechanism(s) remain unclear. AIM OF THE STUDY: To elucidate the antipyretic characteristics and mechanism(s) of BC used in its traditional way. METHODS: The water extract of BC (BCE) was prepared according to the traditional decocting mode. Murine fever and endotoxemia models were induced by intravenous injection of lipopolysaccharide (LPS). In vitro complement activation assay and the levels of TNF-α, IL-6, IL-1ß, and C5a were determined by ELISA. RESULTS: BCE exerted a confirmed but mild antipyretic effect on LPS-induced fever of rat. In vitro, it significantly lowered LPS-elevated TNF-α in the supernatant of rat complete blood cells and THP-1 cells, but failed to decrease IL-6 and IL-1ß. In murine endotoxemia models, BCE markedly decreased serum TNF-α, but had no impact on IL-6 and IL-1ß. BCE also restricted complement activation in vitro and in vivo. Nevertheless, the mixture of saikosaponin A and D could not suppress supernatant TNF-α of monocytes and serum TNF-α of endotoxemia mice. CONCLUSIONS: The present study dissects the peripheral mechanism for the antipyretic effect of BC used in the traditional way. Our findings indicate that BCE directly suppresses monocyte-produced TNF-α, thus decreasing circulating TNF-α, which may be responsible for its mild but confirmed antipyretic action.

Comparative Transcriptome Analysis Provides Insights into the Molecular Mechanism Underlying the Effect of MeJA Treatment on the Biosynthesis of Saikosaponins in Bupleurum chinense DC.

Bupleurum chinense DC. is a well-known traditional Chinese medicinal plant that produces saikosaponins (SSs), which possess hepatoprotective, antipyretic, and anti-inflammatory activities. Methyl jasmonate (MeJA) is a signalling phytohormone that can increase the accumulation of SSs in the root of Bupleurum plants. However, the molecular understanding of MeJA-mediated SS biosynthesis is not clear. Therefore, it is necessary to explore the molecular mechanism underlying the response of B. chinense DC. to MeJA in roots. In this study, we performed comparative transcriptome analysis of B. chinense DC. roots with different MeJA treatment times. In total, 104,057 unigenes were identified, of which 4053 were differentially expressed genes (DEGs). Most of the DEGs were downregulated after MeJA treatment, and GO enrichment analysis showed that they were mainly related to biological processes involved in stress responses and development. A total of 88 DEGs encoding enzymes known to be involved in the SS synthesis pathway were found, and most were significantly downregulated within 24 h. Based on the DEGs, 99 transcription factors (TFs) belonging to the AP2/ERF, WRKY, bZIP, ZFP, and bHLH families with different expression patterns were also identified. Further integrated analysis indicated that 20 DEGs involved in the SS synthesis pathway and 12 DEGs encoding TFs presented strong correlations with the SS contents, and these DEGs may be critical for the biosynthesis and regulation of SSs. These findings will be critical for further study of the response of B. chinense DC. to MeJA for SS biosynthesis.

Structure and potential anti-fatigue mechanism of polysaccharides from Bupleurum chinense DC.

Two polysaccharides, BCP-1 and BCP-2, were obtained from Bupleurum chinense DC. by water extraction and ultrafiltration. BCP-1 (1.04 × 105 Da) and BCP-2 (2.14 × 104 Da) were composed of Mannose, Rhamnose, Glucose, Galactose, Arabinose, and Galacturonic acid in different proportions. They both contained oligogalacturonides in their main chain. Besides, the backbone of BCP-1 was composed of 4-ß-Galp and 4,6-ß-Glcp, and branched at C4 of 4,6-ß-Glcp. While BCP-2 contained a backbone of 3,5-α-Araf residues with branches at C3. BCP-2 effectively extended the forced swimming time, improved the glycogen reserves and antioxidant system, decreased the levels of blood urea nitrogen, lactic acid, lactate dehydrogenase and creatinine kinase expression. It alleviated physical fatigue through regulating 5'-AMP-activated protein kinase (AMPK) and Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) signalling pathway in skeletal muscles. This study demonstrated that BCP-2 exhibited more effective anti-fatigue activity than BCP-1 potentially associated with its primary and higher structures.

Saikosaponin A and Its Epimers Alleviate LPS-Induced Acute Lung Injury in Mice.

The purpose of this work was to illustrate the effect of processing with vinegar on saikosaponins of Bupleurum chinense DC. (BC) and the protective effects of saikosaponin A (SSA), saikosaponin b1 (SSb1), saikosaponin b2 (SSb2), and saikosaponin D (SSD) in lipopolysaccharide (LPS)-induced acute lung injury (ALI) mice. We comprehensively evaluated the anti-inflammatory effects and potential mechanisms of SSA, SSb1, SSb2, and SSD through an LPS-induced ALI model using intratracheal injection. The results showed that SSA, SSb1, SSb2, and SSD significantly decreased pulmonary edema; reduced the levels of IL-6, TNF-α, and IL-1ß in serum and lung tissues; alleviated pulmonary pathological damage; and decreased the levels of the IL-6, TNF-α, and IL-1ß genes and the expression of NF-κB/TLR4-related proteins. Interestingly, they were similar in structure, but SSb2 had a better anti-inflammatory effect at the same dose, according to a principal component analysis. These findings indicated that it may not have been comprehensive to only use SSA and SSD as indicators to evaluate the quality of BC, especially as the contents of SSb1 and SSb2 in vinegar-processed BC were significantly increased.

Molecular cloning, functional characterization and expression of the ß-amyrin synthase gene involved in saikosaponin biosynthesis in Bupleurum chinense DC.

Bupleurum chinense DC. is a commonly used plant in traditional Chinese medicine, and saikosaponins(SSs) are the main active oleanane-typetriterpene saponins in B. chinense. ß-Amyrin synthase (ß-AS) is an important enzyme in oleanane-type triterpenoid saponin synthesis, but its role in saikosaponin synthesis has rarely been studied. Here, the putative ß-AS gene BcBAS1(Accession No.ON890382) selected according to metabolomic and transcriptomic analyses was cloned and functionally characterized by heterologous expression in Escherichia coli and Pichia pastoris, and its subcellular localization and expression patterns were examined. The molecular weight of the BcBAS1 recombinant protein was approximately 87 kDa, and this protein could catalyse the production of ß-amyrin, the precursor of SSs. Furthermore, BcBAS1 was located in the cytosol, and relative expression in four tissues of the four genotypes was positively correlated with SSa and SSd contents. Our results indicate that BcBAS1 is a ß-AS gene and may play an important role in saikosaponin biosynthesis and regulation. This study sheds light on the role of ß-AS genes in the synthesis of SSs and provides insights for the metabolic engineering of SSs.

Plant regeneration via callus-mediated organogenesis in commercial variety of Chuanbeichai No. 1 in Bupleurum chinense DC.

Bupleurum chinense DC is an important medicinal plant with many active ingredients that are used for the treatment of different types of diseases and valued in pharmaceutical markets. In vitro shoot regeneration can efficiently contribute to the improvement of B. chinense. In the present study, we investigated the effects of the explant type and plant growth regulators (PGRs) on embryogenic callus induction and plant regeneration in B. chinense. Our investigation demonstrated that 2 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) combined with 1 mg/L thidiazuron (TDZ) played a major role in promoting callus induction from leaf, hypocotyl and stem 2 explants, whereas the most effective treatment for stem 1 callus formation was Murashige and Skoog (MS) medium supplemented with 1 mg/L 2,4-D, 0.5 mg/L 6-benzyladenine (BA) and 0.5 mg/L kinetin (Kin). The highest shoot regeneration rate (57.14%) was obtained from hypocotyl-induced calli in MS medium with 0.5 mg/L Kin after 12 weeks of cultivation. This regeneration protocol can be used in large-scale cultivation and may be useful for future genetic modifications of B. chinense .

Study on the intestinal absorption characteristics of saikosaponins / 中国药房

OBJECTIVE To explore the intestinal absorption characteristics of saikosaponins. METHODS Based on everted intestinal sac model， using accumulative absorption amount （Q） and absorption rate constant （Ka） as indexes， UHPLC-MS/MS technique as a method， the absorption of saikosaponin A， B2， C， D and F from total saponins of Bupleurum chinense （8 g/mL， by crude drug） in the duodenum， jejunum and ileum was detected. RESULTS The correlation coefficients （r） of the regression equations for the absorption of saikosaponins A， B2， C and F in the duodenum， jejunum and ileum were all higher than 0.95， while the r of saikosaponin D in the above intestinal segments was lower than 0.95； compared with the absorption of the same composition in the duodenum， the Q and Ka of saikosaponin A and C circulating in jejunum and ileum for 120 min， as well as the Q and Ka of saikosaponin F circulating in the ileum for 120 min were significantly decreased （P＜0.05）. CONCLUSIONS Saikosaponin A and the other 4 saikosaponins are all absorbed in the duodenum， jejunum and ileum； among them， saikosaponin A， B2， C and F are linearly absorbed， which conforms to the zero-order absorption characteristics， but saikosaponin D shows non- linear absorption.

Rapid determination of microbial contamination of Bupleurum chinense DC. decoction slices by ATP bioluminescence technology combined with statistical analysis methods / 药学学报

This study focuses on the microbial quality control of the Chinese herbal decoction pieces. In view of the shortcomings of traditional culture methods such as slow detection speed and inability to detect unculturable microorganisms, a new method based on ATP bioluminescence technology combined with statistical analysis methods was established to rapidly predict and quantitatively detect the total aerobic microbial count (TAMC) and total yeast and mold count (TYMC) contaminated Bupleurum chinense DC. decoction pieces. Based on the optimized ATP bioluminesence detection system, accurate detection of pure bacterial solution of Escherichia coli, Bacillus subtilis and Staphylococcus aureus can be achieved, with detection limits of 47.86, 89.13 and 1 862.09 CFU·mL-1, respectively. The detection time was 6.5 h, and the detection cost was as low as 2 yuan/time. The upper and lower warning limits of TAMC were determined by the misjudgment rates of 10% and 20%, respectively. And the warning limit of TYMC was determined by the misjudgment rate of 20%. The proposed crossing method could quickly predict the amount of microbial contamination in Bupleurum chinense DC. decoction pieces. The constructed partial least squares regression (PLSR) model could accurately quantify the quantity of microbial contamination in Bupleurum chinense DC. decoction pieces. The optimal PLSR prediction model for TAMC had a correction coefficient (R2) of 0.826, a root mean square error of correction set (RMSEE) of 0.468 and a root mean square error of cross-validation set (RMSECV) of 0.465. The R2, RMSEE and RMSECV in the prediction model of TYMC were 0.778, 0.543 and 0.541, respectively. The aim of this study is to establish a kind of rapid detection method and prediction models for the microbial limit of traditional Chinese medicine and Chinese herbal decoction pieces, and to provide a more convenient and sensitive detection technology for the microbial quality process control of traditional Chinese medicine products.

Quantitative analysis of multi-components by single marker method combined with UPLC-PAD fingerprint analysis based on saikosaponin for discrimination of Bupleuri Radix according to geographical origin.

Background: Saikosaponins are regarded as one of the most likely antipyretic constituents of Bupleuri Radix, establishing a comprehensive method that can reflect both the proportion of all constituents and the content of each saikosaponin is critical for its quality evaluation. Methods: In this study, the combination method of quantitative analysis of multiple components with a single marker (QAMS) and fingerprint was firstly established for simultaneous determination of 7 kinds of saikosaponins in Bupleuri Radix by ultra-high performance liquid chromatography (UPLC). Results: The results showed that saikosaponin d was identified as the optimum IR by evaluating the fluctuations and stability of the relative calibration factors (RCFs) under four different conditions. The new QAMS method has been confirmed to accurately quantify the 7 kinds of saikosaponins by comparing the obtained results with those obtained from external standard method and successfully classify the 20 batches of Bupleuri Radix from 8 provinces of China. The experimental time of fingerprint was significantly reduced to approximate 0.5 h through UPLC-PAD method, a total of 17 common peaks were identified. Conclusion: The QAMS-fingerprint method is feasible and reliable for the quality evaluation of Bupleuri Radix. This method could be considered to be spread in the production enterprises of Bupleuri Radix.

A Review of Antidepressant Effects and Mechanisms of Three Common Herbal Medicines: Panax ginseng, Bupleurum chinense, and Gastrodia elata.

OBJECTIVES: Major depressive disorder (MDD) has been reported to affect an increasing number of individuals due to the modern lifestyle. Because of its complicated mechanisms and recurrent attacks, MDD is considered a refractory chronic disease. Although the mainstream therapy for MDD is chemical drugs, they are not a panacea for MDD because of their expensiveness, associated serious adverse reactions, and endless treatment courses. Hence, we studied three kinds of herbal medicines, namely, Panax ginseng C. A. Mey (PGM), Bupleurum chinense DC (BCD), and Gastrodia elata Blume (GEB), and reviewed the mechanisms underlying their antidepressant properties to provide a reference for the development of antidepressants and clinical medications. METHODS: An extensive range of medicinal, clinical, and chemistry databases and search engines were used for our literature search. We searched the literature using certain web literature search engines, including Google Scholar, PubMed, Science Direct, CNKI (China National Knowledge Infrastructure), and Web of Science. RESULTS: Experimental research found that active compounds of these three medicines exhibited good antidepressant effects in vivo and in vitro. Clinical investigations revealed that single or combined treatment of these medicines improved certain depressive symptoms. Antidepressant mechanisms are summarized based on this research. CONCLUSION: The antidepressant mechanism of these three medicines includes but is not limited to ameliorating inflammation within the brain, reversing the hypothalamic-pituitary adrenal axis (HPA) system hyperfunction, inhibiting monoamine neurotransmitters reuptake, anti-neuron apoptosis and preventing neurotoxicity, and regulating depressive-related pathways such as the BDNF pathway and the PI3K/Akt/mTOR pathway.

Effects of Trichoderma harzianum biofertilizer on growth, yield, and quality of Bupleurum chinense.

The use of chemical fertilizers and pesticides led to a decline in the quality and yield of Bupleurum chinense. The aim of this study was to determine the effects of Trichoderma harzianum biofertilizer on the growth, yield, and quality of radix bupleuri and microbial responses. The results showed that T. harzianum biofertilizer promoted the growth of B. chinense and increased the yield and quality of radix bupleuri. In addition, it increased the contents of NH4 +-N, NO3 --N, available K, and available P and increased the activities of sucrase and catalase in the rhizosphere soil. High-throughput analysis showed that the dominant bacteria in the rhizosphere were Proteobacteria (28%), Acidobacteria (23%), and Actinobacteria (17%), whereas the dominant fungi were Ascomycota (49%), Zygomycota (30%), and Basidiomycota (6%). After the application of T. harzianum biofertilizer, the abundance of Proteobacteria and Actinobacteria (relative to total bacteria) and Ascomycota and Basidiomycota (relative to total fungi) increased, but the relative abundance of Acidobacteria decreased. Canonical correlation analysis (CCA) showed that the relative abundance of Pseudarthrobacter, Streptomyces, Rhizobium, Nocardioides, Minimedusa, and Chaetomium were positively correlated with NO3 --N, NH4 +-N, available K, available P, sucrase, and catalase in microbial communities, whereas Aeromicrobium and Mortierella were positively correlated with soil organic matter and urease. These results suggest that T. harzianum biofertilizer could significantly improve the yield and quality of radix bupleuri by changing the structure of soil microbial flora and soil enzyme activity. Therefore, it could be recommended for commercial scale production of Bupleurum.

Drought Stress Stimulates the Terpenoid Backbone and Triterpenoid Biosynthesis Pathway to Promote the Synthesis of Saikosaponin in Bupleurum chinense DC. Roots.

Bupleurum chinense is an important medicinal plant in China; however, little is known regarding how this plant transcribes and synthesizes saikosaponins under drought stress. Herein, we investigated how drought stress stimulates the transcriptional changes of B. chinense to synthesize saikosaponins. Short-term drought stress induced the accumulation of saikosaponins, especially from the first re-watering stage (RD_1 stage) to the second re-watering stage (RD_2 stage). Saikosaponin-a and saikosaponin-d increased by 84.60% and 75.13%, respectively, from the RD_1 stage to the RD_2 stage. Drought stress also stimulated a rapid increase in the levels of the hormones abscisic acid, salicylic acid, and jasmonic acid. We screened 49 Unigenes regarding the terpenoid backbone and triterpenoid biosynthesis, of which 33 differential genes were significantly up-regulated during drought stress. Moreover, one P450 and two UGTs are possibly involved in the synthesis of saikosaponins, while some transcription factors may be involved in regulating the expression of key enzyme genes. Our study provides a reference for the cultivation of B. chinense and a practical means to ensure the quality (safety and effectiveness) of B. chinense for medicinal use, as well as insights into the modernization of the China Agriculture Research System.

Response of soil microecology to different cropping practice under Bupleurum chinense cultivation.

The effects of cropping practices on the rhizosphere soil physical properties and microbial communities of Bupleurum chinense have not been studied in detail. The chemical properties and the microbiome of rhizosphere soil of B. chinense were assessed in the field trial with three cropping practices (continuous monocropping, Bupleurum-corn intercropping and Bupleurum-corn rotation). The results showed cropping practices changed the chemical properties of the rhizosphere soil and composition, structure and diversity of the rhizosphere microbial communities. Continuous monocropping of B. chinense not only decreased soil pH and the contents of NO3--N and available K, but also decreased the alpha diversity of bacteria and beneficial microorganisms. However, Bupleurum-corn rotation improved soil chemical properties and reduced the abundance of harmful microorganisms. Soil chemical properties, especially the contents of NH4+-N, soil organic matter (SOM) and available K, were the key factors affecting the structure and composition of microbial communities in the rhizosphere soil. These findings could provide a new basis for overcoming problems associated with continuous cropping and promote development of B. chinense planting industry by improving soil microbial communities.

Assembly and comparative analysis of the complete mitochondrial genome of Bupleurum chinense DC.

BACKGROUND: Bupleurum chinense(B. chinense) is a plant that is widely distributed globally and has strong pharmacological effects. Though the chloroplast(cp) genome of B. chinense has been studied, no reports regarding the mitochondrial(mt) genome of B. chinense have been published yet. RESULTS: The mt genome of B.chinense was assembled and functionally annotated. The circular mt genome of B. chinense was 435,023 bp in length, and 78 genes, including 39 protein-coding genes, 35 tRNA genes, and 4 rRNA genes, were annotated. Repeat sequences were analyzed and sites at which RNA editing would occur were predicted. Gene migration was observed to occur between the mt and cp genomes of B. chinense via the detection of homologous gene fragments. In addition, the sizes of plant mt genomes and their GC content were analyzed and compared. The sizes of mt genomes of plants varied greatly, but their GC content was conserved to a greater extent during evolution. Ka/Ks analysis was based on code substitutions, and the results showed that most of the coding genes were negatively selected. This indicates that mt genes were conserved during evolution. CONCLUSION: In this study, we assembled and annotated the mt genome of the medicinal plant B. chinense. Our findings provide extensive information regarding the mt genome of B. chinense, and help lay the foundation for future studies on the genetic variations, phylogeny, and breeding of B. chinense via an analysis of the mt genome.

Metabolomics Analysis Reveals the Differences Between Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd.

Bupleurum chinense DC. and Bupleurum scorzonerifolium Willd. are two varieties of Bupleuri Radix in Chinese Pharmacopoeia 2020. The clinical efficacy of the two bupleurum species is different. The difference in clinical efficacy is closely related to the composition of plant metabolites. In order to analyze the difference in metabolites, we used liquid chromatography coupled with mass spectrometry (LC-MS) for untargeted metabolome and gas chromatography coupled with mass spectrometry (GC-MS) for widely targeted metabolome to detect the roots (R), stems (S), leaves (L), and flowers (F) of two varieties, and detected 1,818 metabolites in 25 classes. We performed a statistical analysis of metabolites. Differential metabolites were screened by fold-change and variable importance in the projection values of the OPLS-DA model, and significant differences were found among different groups. The content of active components (triterpenoid saponins) was found to be high in the BcR group than in the BsR group. Other pharmacological metabolites were significantly different. By Kyoto Encyclopedia of Genes and Genomes annotation and enrichment analysis, we found that differential metabolites of the aboveground parts mainly concentrated in monoterpenoid biosynthesis, while the differential metabolites of the root mainly concentrated in sesquiterpenoid and triterpenoid biosynthesis. Differences in metabolic networks may indirectly affect the metabolic profile of Bc and Bs, leading to differences in clinical efficacy. Our study provides a scientific basis for subsequent biosynthesis pathway and related bioactivity research, and provides a reference for developing non-medicinal parts and guiding the clinical application of Bupleuri Radix.