Transcriptome Level Reveals the Triterpenoid Saponin Biosynthesis Pathway of Bupleurum falcatum L.

Bupleurum falcatum L. is frequently used in traditional herbal medicine in Asia. Saikosaponins (SSs) are the main bioactive ingredients of B. falcatum, but the biosynthetic pathway of SSs is unclear, and the biosynthesis of species-specific phytometabolites is little known. Here we resolved the transcriptome profiles of B. falcatum to identify candidate genes that might be involved in the biosynthesis of SSs. By isoform sequencing (Iso-Seq) analyses of the whole plant, a total of 26.98 Gb of nucleotides were obtained and 124,188 unigenes were identified, and 81,594 unigenes were successfully annotated. A total of 1033 unigenes of 20 families related to the mevalonate (MVA) pathway and methylerythritol phosphate (MEP) pathway of the SS biosynthetic pathway were identified. The WGCNA (weighted gene co-expression network analysis) of these unigenes revealed that only the co-expression module of MEmagenta, which contained 343 unigenes, was highly correlated with the biosynthesis of SSs. Comparing differentially expressed gene analysis and the WGCNA indicated that 130 out of 343 genes of the MEmagenta module exhibited differential expression levels, and genes with the most "hubness" within this module were predicted. Manipulation of these genes might improve the biosynthesis of SSs.

The Polysaccharides from the Aerial Parts of Bupleurum chinense DC Attenuate Epilepsy-Like Behavior through Oxidative Stress Signaling Pathways.

Bupleurum chinense DC. is a traditional Chinese medicine with a long medicinal history and is often used as the main ingredient in prescription drugs for epilepsy. The aerial parts of B. chinense DC. have similar efficacy and composition to B. chinense DC. Therefore, we speculated that the aerial parts of B. chinense DC. could be used in the treatment of epilepsy. Polysaccharides from the aerial parts of B. chinense DC. were selected to explore their therapeutic effects on epilepsy and their potential mechanism of action. The study is aimed at clarifying the antiepileptic effects of the polysaccharides from the aerial parts of B. chinense DC. and their potential underlying mechanisms. The chemical profile of the aerial parts of B. chinense DC. polysaccharides (ABP) was characterized by FT-IR spectrum and HPLC chromatogram. To determine the therapeutic effects of ABPs on epilepsy, we established a kainic acid- (KA-) induced rat model of epilepsy, and through H&E staining, Nissl staining, immunohistochemistry, biochemical analysis, ELISA, and Western blot analysis, we explored the mechanisms underlying the therapeutic effects of ABPs on epilepsy. The monosaccharide content of ABP included galacturonic acid (45.19%), galactose (36.63%), arabinose rhamnose (12.13%), and mannose (6.05%). Moreover, the average molecular weight of ABP was 1.38 × 103 kDa. ABP could improve hippocampal injuries and neuronal function in the KA-induced epilepsy rat model. ABP significantly inhibited oxidative stress in the hippocampus of KA-induced rats. More importantly, ABP could regulate TREM2 activation in the PI3K/Akt/GSK-3ß pathway to inhibit neuronal apoptosis, including increasing the expression of superoxide dismutase and lactate dehydrogenase and decreasing the expression of malondialdehyde. The current study defined the potential role of ABP in inhibiting the development of epilepsy, indicating that ABP could upregulate TREM2 to alleviate neuronal apoptosis, by activating the PI3K/Akt/GSK-3ß pathway and oxidative stress in epilepsy.

Overexpression of BcERF3 increases the biosynthesis of saikosaponins in Bupleurum chinense.

Chaihu, the dried roots of some species of Bupleurum L., is a famous Chinese herbal medicine for treatment of liver- and cold-related diseases, in which saikosaponins (SSs) are the major active compounds. Many of the genetic components upstream of SS biosynthetic pathways have been characterized; however, the regulatory mechanisms remain elusive. In this study we identified the APETALA2/Ethylene Responsive Factor family transcription factor gene BcERF3 from B. chinense. The expression of BcERF3 was induced in methyl-jasmonate-treated adventitious root of B. chinense; it was also expressed at higher levels in roots than in other tissues (stem, leaf, flower, and tender fruit of early fruiting plants). Transient expression of BcERF3 in the leaves of Nicotiana benthamiana resulted in intracellular localization of the protein in the nucleus. It was also demonstrated that the number of SSs was greater in BcERF3-overexpressing hairy roots of B. chinense than in plants treated with empty vector controls. This coincided with upregulation of ß-AS, which encodes a key enzyme involved with triterpenoid biosynthesis. In conclusion, BcERF3 plays a positive regulatory role in the biosynthesis of SSs.

Antitumor Effect of Saikosaponin A on Human Neuroblastoma Cells.

OBJECTIVE: Neuroblastoma (NB) is a highly metastatic tumor in children that develops in the sympathetic nervous system and has a low curative rate. Saikosaponin A (SSA), an active ingredient isolated from the root of Radix Bupleuri, is a natural compound with various pharmacological activities and shows good application prospects in antitumors. This study investigated the antihuman NB activity of SSA and underlying mechanisms associated with its actions. MATERIALS AND METHODS: The MTT method was used to detect the activity of SSA in inhibiting human NB cell SK-N-AS proliferation. Cell morphology was observed. The flow cytometry technology was used in analyzing the cell apoptosis rate. The Transwell assay evaluated cell migration and invasion following SSA treatment, apoptosis-related protein expression, and angiogenesis-related protein expression, and EMT-related proteins were detected by western blot analysis. RESULTS: SSA showed an inhibitory effect on SK-N-AS cells with the IC50 values of 14.14 µM at 24 h and 12.41 µM at 48 h. Results indicated that SSA has proapoptotic activity, and its proapoptotic activity is positively correlated with the Bax/Bcl-2/caspase-9/caspase-7/PARP pathway. Furthermore, SSA inhibited the invasion and migration of SK-N-AS cells via regulating the angiogenesis-related VEGFR2/Src/Akt pathway and the epithelial-mesenchymal transition- (EMT-) related protein expression. CONCLUSION: SSA exerts an antihuman NB effect and thus provides foundations for NB treatment.

Comparison of chemical constituents of Bupleurum marginatum var. stenophyllum and Bupleurum chinense DC. using UHPLC-Q-TOF-MS based on a metabonomics approach.

The overall chemical composition of Bupleurum marginatum var. stenophyllum and Bupleurum chinense DC. was compared in this study. Metabolites were identified using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Multivariate statistical analysis techniques such as principal component analysis were used to conduct metabonomics analysis and study the correlation between different components. Principal component analysis results showed a clear distinction among medicinal materials of different origins and divided them into different categories, consistent with the results of hierarchical cluster analysis. Both partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA) showed that the two materials could be distinguished clearly. Using PLS-DA and OPLS-DA combined with the S-plot and a variable importance in the projection (VIP) score >1, 24 differential metabolites were screened and identified; all of the metabolites were triterpenoid saponins. In addition, SPSS 25.0 and Metabo Analyst 4.0 were used to analyze significant differences in the relative contents of different compounds in the two materials. This study has successfully provided not only a new direction for research based on the chemical substances identified and the quality evaluation of Bupleuri Radix but also a better theoretical basis for the expansion of medicinal sources and their clinical application.

Recent Progress in Saikosaponin Biosynthesis in Bupleurum.

BACKGROUND: Chaihu is a popular traditional Chinese medicine that has been used for centuries. It is traditionally used to treat cold fever and liver-related diseases. Saikosaponins (SSs) are one of the main active components of chaihu, in addition to essential oils, flavonoids, and polysaccharides. Considerable effort is needed to reveal the biosynthesis and regulation of SSs on the basis of current progress. OBJECTIVE: The aim of this study is to provide a reference for further studies and arouse attention by summarizing the recent achievements of SS biosynthesis. METHODS: All the data compiled and presented here were obtained from various online resources, such as PubMed Scopus and Baidu Scholar in Chinese, up to October 2019. RESULTS: A few genes of the enzymes of SSs participating in the biosynthesis of SSs were isolated. Among these genes, only the P450 gene was verified to catalyze the SS skeleton ß-amyrin synthase. Several UDP-glycosyltransferase genes were predicted to be involved in the biosynthesis of SSs. SSs could be largely biosynthesized in the phloem and then transported from the protoplasm, which is the biosynthetic site, to the vacuoles to avoid self-poisoning. As for the other secondary metabolites, the biosynthesis of SSs was strongly affected by environmental factors and the different species belonging to the genus of Bupleurum. Transcriptional regulation was studied at the molecular level. CONCLUSION: Profound discoveries in SSs may elucidate the mechanism of diverse the monomer formation of SSs and provide a reference for maintaining the stability of SS content in Radix Bupleuri.

Multi-scale Gaussian/Haar wavelet strategies coupled with sub-window factor analysis for an accurate alignment in nontargeted metabolic profiling to enhance herbal origin discrimination capability.

Metabolic dataset can provide an overview of different herbal origin, which is conducted by some statistical procedures. Such results often deviate to a certain degree, due to peaks shifts in chromatographic signals. In order to solve this problem, an improved algorithm of combining sub-window factor analysis with the mass spectrum information is proposed. The algorithm uses a peak detection approach derived either from multi-scale Gaussian function or Haar wavelet to locate the peaks with different application scope; the candidate drift points at each peak are estimated by Fast Fourier transform cross correlation; Specifically, the best drift points at each candidate peaks are confirmed by sub-window factor analysis and mass spectrum information in nontargeted metabolic profiling. Finally, the peak regions were aligned against a reference chromatogram, and the non-peak regions were used linear interpolation. The chromatographic signals of 30 Bupleurum samples were aligned as an illustration of this algorithm, and they could be well distinguished using some statistical procedures. The result demonstrates that the presented method is stronger than other mass-spectra based algorithms, when facing the alignment of some co-eluted peaks.

Large-scale analysis of small RNAs derived from traditional Chinese herbs in human tissues.

Plant-derived microRNAs have recently been reported to function in human blood and tissues. Controversy was immediately raised due to possible contamination and the lack of large sample sizes. Here, we report thousands of unique small RNAs derived from traditional Chinese medicine (TCM) herbs found in human blood cells and mouse lung tissues using a large-scale analysis. We extracted small RNAs from decoctions of 10 TCM plants (Ban Zhi Lian, Chai Hu, Chuan Xin Lian, Di Ding Zi Jin, Huang Qin, Jin Yin Hua, Lian Qiao, Pu Gong Ying, Xia Ku Cao, and Yu Xing Cao) and obtained millions of RNA sequences from each herb. We also obtained RNA-Seq data from the blood cells of humans who consumed herbal decoctions and from the lung tissues of mice administered RNAs from herbal decoctions via oral gavage. We identified thousands of unique small RNA sequences in human blood cells and mouse lung tissues. Some of these identified small RNAs from Chuan Xin Lian and Hong Jing Tian could be mapped to the genomes of the herbs, confirming their TCM plant origin. Small RNAs derived from herbs regulate mammalian gene expression in a sequence-specific manner, and thus are a superior novel class of herbal drug components that hold great potential as oral gene-targeted therapeutics, highlighting the important role of herbgenomics in their development.

Triple herbal extract DA-9805 exerts a neuroprotective effect via amelioration of mitochondrial damage in experimental models of Parkinson's disease.

Moutan cortex, Angelica Dahurica root, and Bupleurum root are traditional herbal medicines used in Asian countries to treat various diseases caused by oxidative stress or inflammation. Parkinson's disease (PD) has been associated with mitochondrial dysfunction, but no effective treatment for mitochondrial dysfunction has yet been identified. In this study we investigated the neuroprotective effects of the triple herbal extract DA-9805 in experimental models of PD. DA-9805 was prepared by extracting three dried plant materials (Moutan cortex, Angelica Dahurica root, and Bupleurum root in a 1:1:1 mixture) with 90% ethanol on a stirring plate for 24 h at room temperature and fingerprinted using high-performance liquid chromatography. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its active metabolite 1-methyl-4-phenylpyridinium (MPP+), which both exert neurotoxic effects on dopaminergic neurons by inhibiting mitochondrial oxidative phosphorylation (OXPHOS) complex I, were used to make experimental models of PD. In MPP+-treated SH-SY5Y cells, DA-9805 ameliorated the suppression of tyrosine hydroxylase expression and mitochondrial damage on OXPHOS complex 1 activity, mitochondrial membrane potential, reactive oxygen species (ROS) generation, and oxygen consumption rate. In the MPTP-induced subacute PD model mice, oral administration of DA-9805 recovered dopamine content as well as bradykinesia, as determined by the rotarod test. DA-9805 protected against neuronal damage in the substantia nigra pars compacta (SNpc) and striatum. In both in vitro and in vivo models of PD, DA-9805 normalized the phosphorylation of AKT at S473 and T308 on the insulin signaling pathway and the expression of mitochondria-related genes. These results demonstrate that the triple herbal extract DA-9805 showed neuroprotective effects via alleviating mitochondria damage in experimental models of PD. We propose that DA-9805 may be a suitable candidate for disease-modifying therapeutics for PD.

Radix Bupleuri: A Review of Traditional Uses, Botany, Phytochemistry, Pharmacology, and Toxicology.

Radix Bupleuri (Chaihu) has been used as a traditional medicine for more than 2000 years in China, Japan, Korea, and other Asian countries. Phytochemical studies demonstrated that this plant contains essential oils, triterpenoid saponins, polyacetylenes, flavonoids, lignans, fatty acids, and sterols. Crude extracts and pure compounds isolated from Radix Bupleuri exhibited various biological activities, such as anti-inflammatory, anticancer, antipyretic, antimicrobial, antiviral, hepatoprotective, neuroprotective, and immunomodulatory effects. However, Radix Bupleuri could also lead to hepatotoxicity, particularly in high doses and with long-term use. Pharmacokinetic studies have demonstrated that the major bioactive compounds (saikosaponins a, b2, c, and d) were absorbed rapidly in rats after oral administration of the extract of Radix Bupleuri. This review aims to comprehensively summarize the traditional uses, botany, phytochemistry, pharmacology, toxicology, and pharmacokinetics of Radix Bupleuri reported to date with an emphasis on its biological properties and mechanisms of action.

[Expression of key enzyme genes and content of saikosaponin in saikosaponin biosynthesis under drought stress in Bupleurum chinense].

To research the expression of key enzymes in saikosaponin biosynthesis and the content of saikosaponin under the drought stress, the study focused on the gene-level and the end product responses to environmental change. Taking the five months of Bupleurum chinense as research materials, the contents of saikosaponin A and saikosaponin D under different stress levels were measured by HPLC. The drought was simulated by poly ethylene glycol. The real-time fluorescence quantitative PCR was used to analyze the expression of four key enzymes genes HMGR, IPPI, FPS, ß-AS and the expression of ß-tubulin was set as a reference gene. The results showed that drought stress significantly improved the content of saikosaponin. The contents of SSa and SSd were highest researching 0.648% and 0.781%, respectively when the concentration of PEG was 10%. Meanwhile, the results reflected that the expression of four key enzymes had risen differently and FPS, ß-AS raised significantly(P<0.01). In addition, the results of correlation analysis showed that there was a significant positive correlation between the expression of the four key enzymes genes and the content of saikosaponin. In a word, the contents of secondary metabolites were regulated by the expression of key enzymes genes under the drought stress in B. chinense.

[Effect of combined application of zinc, boron and molybdenum on yield and saikosaponin a, saikosaponin d contents of Bupleurum chinense].

This research use "3414" fertilizer effect experiments to handle zinc, boron and molybdenum trace element fertilizer, determined the dry matter accumulation and content of saikosaponion a and d, to investigate the different ratio of zinc, boron and molybdenum on yield and saikosaponin a, saikosaponin d contents of Bupleurum chinense. Found The suitable ratio of zinc, boron and molybdenum play an active role on dry matter accumulation and distribution, the treatment Zn2B2Mo3 is the best one to promote the dry matter accumulation and transfer to the underground part; in a certain range, only use zinc or molybdenum can promote the yield of B. chinense, the yield of treatment Zn2B2Mo1 is the highest one. According to the results of regression analysis: in accordance with Zn 48.45 g x hm(-2), B 355.05 g x hm(-2), Mo 86.40 g x hm(-2), can obtain the yield with 3313.05 kg x hm(-2); the treatment Zn2BMo2 is most effective to promote the total saikosaponin a and d accumulated, according to the results of regression analysis: in accordance with Zn 36.15 g x hm(-2), B 343.05 g x hm(-2), Mo 106.35 g x hm(-2), the content of total saikosaponin a and d can reach 1.23%. This research first discovered the suitable ratio of zinc, boron and molybdenum can promote the yield and saikosaponin a, saikosaponin d contents on B. chinense.

[Studies on high efficient plant regeneration system from anther callus of Bupleurum chinense].

The callus of Bupleurum chinense with anthers at the stage of uninucleate was induced. After several subcultures, anther calli of B. chinense were cultured at 20 MS culture mediums with different plant hormones to differentiate into plantlets. Differentiation of callus was detected after 21 and 49 days to select the most effective medium. There were 19 culture mediums in which anther callus could differentiate into plantlets with differentiation rate range from 3% to 60% , and most less than 20%. MS + KT 0.5 mg x L(-1) + sucrose 30 g c L(-1) + phytagel 5 g x L(-1) was the best differentiation medium with the differentiation rate of 60%, followed by MS + ZT 1.0 mg x L(-1) + sucrose 30 g x L(-1) + phytagel 5 g x L(-1) with the differentiation rate of 58%. Then plantlets were transferred to rooting medium to obtain whole plant. All plantlets could root in the rooting medium of MS + sucrose 30 g x L(-1) + phytagel 5 g x L(-1) and 1/2 MS + NAA 0.5 mg x L(-1) + sucrose 30 g x L(-1) + phytagel of 5 g L(-1) with the rooting rate of 100%. As a result, the high efficient and stable plant regeneration system was established from anther callus of B. chinense.

[Comprehensive yield and quality comparison of Bupleurum chinense' s seeds of different harvesting time from Qingchuan County with Topsis approach].

In order to investigate the comprehensive quality differences of the seeds harvested in different growing time, and offer theoretical guide for the optimization of seeds' production technology, we analyzed the apparent size, 1 000-grain weight, water absorbency, germination indexes, postharvest embryo rate change, relatively contents of coumarins and the yield of single plant of its seeds of different harvesting time, and compared their comprehensive quality by Topsis analysis. The results showed that there existed obvious differences in yield and quality between seeds of 3 harvesting times. While the harvesting time postponed, the yield of single plant raised, and the shrunken seeds rate decreased, the quality of seedlings increased, while the contents of coumarins showed a steady increase, and the germination rate decreased. The comprehensive quality of the seeds harvested in the black ripe time rank the first place, followed by the brown ripe time and the yellow ripe time. As the harvesting time delays, the seeds' comprehensive quality increases, therefore, we could put off the seeds' harvesting time properly for the high efficient seed production.

Metabolic fingerprinting by 1HNMR for discrimination of the two species used as Radix Bupleuri.

Radix Bupleuri is a traditional Chinese medicine harvested from two Bupleurum species (B. chinense and B. scorzonerifolium). It is widely used and is sourced from different regions of China. 1H NMR spectroscopy and multivariate data analysis were applied to 67 Radix Bupleuri samples to discriminate the two species, and explore the influences of habitat and culture method on the quality of Radix Bupleuri based on their metabolomics profiles. Metabolites responsible for the differences between the two species were higher levels of arginine, citric acid, sucrose, saikosaponin b1/b2 analogs, volatile oil with an (E)-2-olefin aldehyde fragment, and fatty acids in B. scoreonerifolium, and more saikosaponin a/c/d analogs in B. chinense. The variances of two cultivation areas were observed due to the higher amount of saikosaponins a/c/d in samples from Shaanxi and lipidsin samples from Shanxi. No obvious difference was detected between cultivars and wild type. 1HNMR metabolomics can simultaneously detect saikosaponins and hydrocarbon aldehydes, and also differentiate the two main saikosaponin skeletons, making it a suitable tool for the species discrimination and quality evaluation of Radix Bupleuri.

Transcriptome analysis of Bupleurum chinense focusing on genes involved in the biosynthesis of saikosaponins.

BACKGROUND: Bupleurum chinense DC. is a widely used traditional Chinese medicinal plant. Saikosaponins are the major bioactive constituents of B. chinense, but relatively little is known about saikosaponin biosynthesis. The 454 pyrosequencing technology provides a promising opportunity for finding novel genes that participate in plant metabolism. Consequently, this technology may help to identify the candidate genes involved in the saikosaponin biosynthetic pathway. RESULTS: One-quarter of the 454 pyrosequencing runs produced a total of 195, 088 high-quality reads, with an average read length of 356 bases (NCBI SRA accession SRA039388). A de novo assembly generated 24, 037 unique sequences (22, 748 contigs and 1, 289 singletons), 12, 649 (52.6%) of which were annotated against three public protein databases using a basic local alignment search tool (E-value ≤1e-10). All unique sequences were compared with NCBI expressed sequence tags (ESTs) (237) and encoding sequences (44) from the Bupleurum genus, and with a Sanger-sequenced EST dataset (3, 111). The 23, 173 (96.4%) unique sequences obtained in the present study represent novel Bupleurum genes. The ESTs of genes related to saikosaponin biosynthesis were found to encode known enzymes that catalyze the formation of the saikosaponin backbone; 246 cytochrome P450 (P450s) and 102 glycosyltransferases (GTs) unique sequences were also found in the 454 dataset. Full length cDNAs of 7 P450s and 7 uridine diphosphate GTs (UGTs) were verified by reverse transcriptase polymerase chain reaction or by cloning using 5' and/or 3' rapid amplification of cDNA ends. Two P450s and three UGTs were identified as the most likely candidates involved in saikosaponin biosynthesis. This finding was based on the coordinate up-regulation of their expression with ß-AS in methyl jasmonate-treated adventitious roots and on their similar expression patterns with ß-AS in various B. chinense tissues. CONCLUSIONS: A collection of high-quality ESTs for B. chinense obtained by 454 pyrosequencing is provided here for the first time. These data should aid further research on the functional genomics of B. chinense and other Bupleurum species. The candidate genes for enzymes involved in saikosaponin biosynthesis, especially the P450s and UGTs, that were revealed provide a substantial foundation for follow-up research on the metabolism and regulation of the saikosaponins.

Introgression of Swertia mussotii gene into Bupleurum scorzonerifolium via somatic hybridization.

BACKGROUND: The wild herb Swertia mussotii is a source of the anti-hepatitis compounds swertiamarin, mangiferin and gentiopicroside. Its over-exploitation has raised the priority of producing these compounds heterologously. Somatic hybridization represents a novel approach for introgressing Swertia mussotii genes into a less endangered species. RESULTS: Protoplasts derived from calli of Bupleurum scorzonerifolium and S. mussotii were fused to produce 194 putative hybrid cell lines, of which three (all derived from fusions where the S. mussotii protoplasts were pre-treated for 30 s with UV light) later differentiated into green plants. The hybridity of the calli was confirmed by a combination of isozyme, RAPD and chromosomal analysis. The hybrid calli genomes were predominantly B. scorzonerifolium. GISH analysis of mitotic chromosomes confirmed that the irradiation of donor protoplasts increased the frequency of chromosome elimination and fragmentation. RFLP analysis of organellar DNA revealed that mitochondrial and chloroplast DNA of both parents coexisted and recombined in some hybrid cell lines. Some of the hybrid calli contained SmG10H from donor, and produced swertiamarin, mangiferin and certain volatile compounds characteristic of S. mussotii. The expression of SmG10H (geraniol 10-hydroxylase) was associated with the heterologous accumulation of swertiamarin. CONCLUSIONS: Somatic hybrids between B. scorzonerifolium and S. mussotii were obtained, hybrids selected all contained introgressed nuclear and cytoplasmic DNA from S. mussotii; and some produced more mangiferin than the donor itself. The introgression of SmG10H was necessary for the accumulation of swertiamarin.

Effects of SYJN, a Chinese herbal formula, on chronic unpredictable stress-induced changes in behavior and brain BDNF in rats.

AIM OF THE STUDY: Suyu-Jiaonang (SYJN) is a Chinese herbal formula that contains four herbs: Bupleurum chinense DC, Curcuma aromatica Salisb., Perilla frutescens (Linn.) Britt., and Acorus tatarinowii Schott. Previous studies conducted in our laboratory have revealed an antidepressant-like effect of the formula in various mouse models of behavioral despair. The present study aimed to investigate whether SYJN could produce antidepressant-like effects in chronic unpredictable stress (CUS)-induced depression model in rats and its possible mechanism(s). MATERIALS AND METHODS: Rats were subjected to an experimental setting of CUS. The effect of SYJN treatment on CUS-induced depression was examined using behavioral tests including the sucrose consumption and open field tests. The mechanism underlying the antidepressant-like action of SYJN was examined by measuring brain-derived neurotrophic factor (BDNF) protein and mRNA expression in brain tissues of CUS-exposed rats. RESULTS: Exposure to CUS for 4 weeks caused depression-like behavior in rats, as indicated by significant decreases in sucrose consumption and locomotor activity (assessed in the open field test). In addition, it was found that BDNF protein and mRNA levels in the hippocampus and frontal cortex were lower in CUS-treated rats, as compared to controls. Daily intragastric administration of SYJN (1300 or 2600 mg/kg) during the 4-week period of CUS significantly suppressed behavioral changes and attenuated the CUS-induced decrease in BDNF protein and mRNA levels in the hippocampus and frontal cortex. CONCLUSION: The results suggest that SYJN alleviates depression induced by CUS. The antidepressant-like activity of SYJN is likely mediated by the increase in BDNF expression in brain tissues.

Ultrastructure and secretion of secretory canals in vegetative organs of Bupleurum chinense DC.

The development of secretory canals in vegetative organs of Bupleurum chinense DC. and the accumulation of essential oils were investigated by transmission electron microscopy (TEM) analysis. The secretion mechanism of the essential oil was also discussed. The results indicate that the plastid, ground substances of cytoplasm and mitochondria took part in the biosynthesis of oil or oil precursor. The endoplasmic reticulum involved in the transport of essential oil to the secretory lumen. At latter stages of development of secretory cells, numerous different sized vesicles fused with the plasmalemma along the boundary between two neighbor secretory cells and secreted the substance into the wall. Thus, the wall between two neighbor secretory cells near the lumen became loosely structured. Then, the wall lined the lumen near two neighbor secretory cells extruded numerous grey vesicles with various sizes on the side facing the lumen, and released these vesicles into the lumen. As a result, the manner of secretion in secretory canals of Bupleurum chinense DC. appeared to be exocytosis.

[Preliminary study on the characteristics of Bupleurum chinense in nutrition uptake].

It was studied that the characteristics of Bupleurum chinense DC. in nutrition uptake based on potted and field experiment to provide a properly fertilizer application measure. The result showed that the absorption amounts of N, P and K were in the order of K > N > P under field condition. For one-year-old B. chinesnse DC., the average N, P2O5 and K2O absorption per 100 kg dry matter of root were 11.77 kg, 2.43 kg, 14.07 kg respectively; for two-year-old, the average N, P2O5 and K2O absorption amount per 100 kg dry matter of root were 12.11 kg, 2.74 kg, 18.39 kg respectively. The total absorption amount of N, P2O5 and K2O were lower in the first year, while the percentage of content was higher, that was to say, the demand for N, P and K was urgent in the first year. The accumulation peak of N, P2O5 and K2O occurred regreening to later elongation stage in the second year. The ratio of N, P and K were differential in different growth stages.