Effect of total astragalosides on diabetic non-healing wound by regulating immune microenvironment

Aim

The aim of the research was to analyse the regulatory effect of astragaloside (AST) on the immune microenvironment of diabetic non-healing wound (DNHW), and to analyse the clinical efficacy and mechanism of wound repair in multiple layers.

Material and methods

Ninety adult male Wistar rats, which were kept healthy (SPF) under natural infection, were randomly divided into three groups, namely, blank, control and observation groups, with 30 rats in each group. After adaptive feeding for 7 days, the diabetes model was established. After the model was formed, the wounds were uniformly prepared, and then the blank group only was shaved. Both the control group and the observation group were treated with moist exposure therapy. The control group was covered with physiological saline gauze, while the observation group was covered with AST gauze. The healing status of the wounds in both groups was observed and recorded on the 1st, 7th, and 14th days after formation. And the levels of α-smooth muscle actin (α-SMA) and collagen I (COL-1) in the wound tissue were measured.

Results

On the 1st day after wound formation, the wound healing area, α-SMA, and COL-1 levels in the three groups were consistent (p > 0.05). On the 7th and 14th days after wound formation, the wound healing area in the three groups increased compared within the group, but only the control and observation groups had significantly higher wound healing area than on the 1st day after wound formation (p < 0.05). In addition, the blank group had lower levels of α-SMA and COL-1, while the control and observation groups had higher levels of α-SMA and COL-1 (p < 0.05). In the comparison between groups, the wound healing area, α-SMA, and COL-1 levels in the control and observation groups were higher than those in the blank group, while the wound healing area, α-SMA, and COL-1 levels in the observation group were higher than those in the control group (p < 0.05).

Conclusions

AST can regulate the immune microenvironment of DNHW, improve α-SMA and COL-1, and accelerate the wound healing of DNHW.

Astragaloside in cancer chemoprevention and therapy

ABSTRACT

Tumor chemoprevention and treatment are two approaches aimed at improving the survival of patients with cancers. An ideal anti-tumor drug is that which not only kills tumor cells but also alleviates tumor-causing risk factors, such as precancerous lesions, and prevents tumor recurrence. Chinese herbal monomers are considered to be ideal treatment agents due to their multi-target effects. Astragaloside has been shown to possess tumor chemoprevention, direct anti-tumor, and chemotherapeutic drug sensitization effects. In this paper, we review the effects of astragaloside on tumor prevention and treatment and provide directions for further research.

To study the mechanism of Scutellariae Radix and Astragaloside in the treatment of lung cancer based on network pharmacology

The aim of the study wasto explore the target and potential mechanism of Scutellariae Radix and Astragaloside in the treatment of lung cancer infection by network pharmacology. The target information of baicalein and flavonin was mined from CTD database and Swiss database. Genecards database, DRUGBANK database, and OMIM database were used to search for lung cancer related genes. The target protein network map (PPI) was drawn by using the STRING database analysis and Cytoscape3.7.1 software. With the help of Perl language, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis and gene function analysis (GO) enrichment analysis were carried out by using the biological program package of R language. In total, 347 biological targets of Astragaloside and Scutellariae Radix were identified through the collection and analysis of multiple databases. In total, 1526 lung cancer targets were obtained from a multi-disease database. The "component-target" network of Astragaloside and Scutellariae Radix was constructed, and the protein interaction network (PPI) of the overlapping targets was analyzed to identify the key targets of drug-influenced diseases. In addition, KEGG pathway analysis and GO enrichment analysis were performed on the overlapping targets to explore the mechanism of Scutellariae Radix and Astragaloside in the treatment of lung cancer. Scutellariae Radix and Astragaloside have the characteristics of multi-component, multi-target and multi-pathway in the treatment of lung cancer, which provides a new idea and scientific basis for further research on the molecular mechanism of the antilung cancer effect of Scutellariae Radix and Astragaloside.

Astragaloside IV enhances the sensibility of lung adenocarcinoma cells to bevacizumab by inhibiting autophagy

Bevacizumab (BV) has an inhibitory effect on tumor growth including lung adenocarcinoma. However, its efficacy is greatly affected by drug resistance. Astragaloside IV (AST-IV) is effective in combination with other drugs is effective to treat cancer. This study aimed to investigate the effect of AST-IV on enhancing the sensibility of lung adenocarcinoma cells to BV. A549 cells were treated by different concentrations of BV and AST-IV. Cell viability, cell cycle, and apoptosis were detected by thiazolyl blue tetrazolium bromide (MTT) and flow cytometry, respectively. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting were performed to detect the expression levels of autophagy- and apoptosis-related proteins, protein kinase B (AKT), and mammalian target of rapamycin (mTOR). The results showed that BV or AST-IV could inhibit the viability and promote the apoptosis of A549 cells in a concentration-dependent manner. Moreover, BV or AST-IV inhibited Bcl-2 expression and increased the expressions of Bax and Cleaved caspase-3, and promoted apoptosis. BV and AST-IV in combination acted synergistically on viability and apoptosis of A549 cells. However, BV alone down-regulated P62 expression, LC3I/LC3II level, the number of cells arrested at S phase and the phosphorylation levels of AKT and mTOR, but upregulated the number of cells arrested at G0/G1 phase and Beclin1 expression, whereas AST-IV alone could reverse the effect of BV on autophagy-related proteins, the phosphorylation levels of AKT and mTOR. This paper demonstrates that AST-IV enhances the effect of BV on inhibiting proliferation and promoting apoptosis of lung adenocarcinoma cells through inhibiting autophagy pathway.

Quantification by LC-MS/MS of astragaloside IV and isoflavones in Astragali radix can be more accurate by using standard addition

INTRODUCTION

Astragali radix (AR), the root of Astragalus, is an important medical herb widely used in traditional Chinese medicine. Bioactive components include isoflavones and a unique class of triterpenoid saponins (named astragalosides).

OBJECTIVES

Accurate measurement of bioactive components, especially astragaloside IV, is necessary for confirming AR authenticity, quality control and future medical research.

METHODOLOGY

Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is a suitable technique but suffers from ion suppression effects due to sample matrix. This can be corrected by using isotopic labelled internal standards, but these are not available for many phytochemicals. We explored the use of standard addition to circumvent this issue.

RESULTS

LC-MS/MS and liquid chromatography coupled with ultraviolet (LC-UV) detection provided linear calibration curves (R² > 0.99). LC-MS/MS provided superior selectivity and detection limits below 10 ng/mL, which was 2-3 magnitudes lower than LC-UV detection. Precision and accuracy were overall improved by using LC-MS/MS with diluted sample extracts, resulting in an inter series coefficient of variation (CV) of 12% or less and mean recovery estimates in the 85-115% range. LC-MS/MS quantification by standard addition resulted in significantly higher concentrations of astragaloside IV measured in the samples. Concentrations calculated by standard addition were unaffected by large variation in signal response caused by matrix effects, independent of variation in slope of the standard addition curves.

CONCLUSION

Sample dilution was helpful but not sufficient for reducing effects of ion suppression. We have shown that LC-MS/MS quantification by standard addition can be a powerful approach for accurate measurement of phytochemicals in the absence of isotopic labelled internal standards.

Astragaloside regulates lncRNA LOC100912373 and the miR‑17‑5p/PDK1 axis to inhibit the proliferation of fibroblast‑like synoviocytes in rats with rheumatoid arthritis

Previous studies have confirmed that astragaloside (AST) exerts a positive effect on alleviating synovial and joint injury in rheumatoid arthritis (RA). However, the precise mechanisms through which AST acts in the treatment of RA remain unclear. Long non-coding RNA (lncRNA) LOC100912373 was identified as a key gene related to RA and has been proven to interact with miR-17-5p, in order to regulate the pyruvate dehydrogenase kinase 1 and protein kinase B axis (PDK1/AKT axis). The present study aimed to determine whether AST may treat RA through the interaction between lncRNA LOC100912373 and the miR-17-5p/PDK1 axis. MTT assays and flow cytometry were used to detect the proliferation and cell cycle progression of AST-treated fibroblast-like synoviocytes (FLSs). The expression of lncRNA LOC100912373 and miR-17-5p, as well as relative the mRNA expression of the PDK1 and AKT genes following AST intervention was detected by reverse transcription-quantitative PCR (RT-qPCR), immunofluorescence and western blot analysis. The results revealed that AST inhibited FLS proliferation, reduced lncRNA LOC100912373 expression levels, increased miR-17-5p expression levels, and decreased the PDK1 and p-AKT expression levels. Additionally, consecutive rescue experiments revealed that AST counteracted the effects of lncRNA LOC100912373 overexpression on FLS proliferation and cell cycle progression. On the whole, the present study demonstrates that AST inhibits FLS proliferation by regulating the expression of lncRNA LOC100912373 and the miR-17-5p/PDK1 axis.

Astragaloside alleviates alcoholic fatty liver disease by suppressing oxidative stress

Alcoholic fatty liver disease (AFLD) is the most common liver disease and can progress to fatal liver cirrhosis and carcinoma, affecting millions of patients worldwide. The functions of astragaloside on the cardiovascular system have been elucidated. However, its role in AFLD is unclear. Ethanol-treated AML-12 cells were used as a cell model of alcoholic fatty liver. Real-time quantitative reverse transcription-PCR and Western blotting detected genes and proteins expressions. Reactive oxygen species (ROS), triglyceride, total cholesterol, low-density lipoprotein, albumin, ferritin, bilirubin, superoxide dismutase, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were examined using commercial kits. Lipid accumulation was assessed by Oil red O staining. MTT and flow cytometry measured cell viability and apoptosis. JC-1 was used to analyze mitochondrial membrane potential. A rat model of AFLD was established by treating rats with ethanol. Astragaloside suppressed ethanol-induced lipid accumulation, oxidative stress, and the production of AST and ALT in AML-12 cells. Ethanol induced TNF-α and reduced IL-10 expression, which were reversed by astragaloside. Ethanol promoted Bax expression and cytochrome C release and inhibited Bcl-2 and ATP expression. Astragaloside hampered these apoptosis effects in AML-12 cells. Impaired mitochondrial membrane potential was recovered by astragaloside. However, all these astragaloside-mediated beneficial effects were abolished by the ROS inducer pyocyanin. Ethanol-induced activation of NF-κB signaling was suppressed by astragaloside in vitro and in vivo, suggesting that astragaloside inhibited oxidative stress by suppressing the activation of NF-κB signaling, thus improving liver function and alleviating AFLD in rats. Our study elucidates the pharmacological mechanism of astragaloside and provides potential therapeutic strategies for AFLD.

Effect of astragaloside on diaphragm cell apoptosis in chronic obstructive pulmonary disease

PURPOSE

This study aimed to discuss the effects and relative mechanisms of astragaloside (AST) on diaphragm cell apoptosis in mice with chronic obstructive pulmonary disease (COPD).

MATERIALS AND METHODS

The mouse models of COPD were established by passive smoking. The pathological changes in lung and diaphragm tissues were observed by hematoxylin and eosin staining and evaluating the number of apoptotic cells of the diaphragm via a terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The relative protein expression levels of AKT, p-AKT, caspase-3, and caspase-9 were measured through immunohistochemistry and Western blot assay.

RESULTS

In comparison with the normal control mice, the pathological change and number of apoptotic cells deteriorated in the lung and diaphragm tissues of COPD model mice. With AST supplement, the pathological change and the number of apoptotic cells significantly improved (p < .05). With AKT inhibitor intervention, the effects of AST treatment disappeared. p-AKT, caspase-3, and caspase-9 protein expression was stimulated in the model group but was depressed in the AST-treated groups.

CONCLUSION

Our in vivo study revealed that AST improved COPD-induced diaphragm apoptosis by regulating and depressing AKT activities.

In Silico Studies on Triterpenoid Saponins Permeation through the Blood-Brain Barrier Combined with Postmortem Research on the Brain Tissues of Mice Affected by Astragaloside IV Administration

As the number of central nervous system (CNS) drug candidates is constantly growing, there is a strong need for precise a priori prediction of whether an administered compound is able to cross the blood–brain barrier (BBB). The aim of this study was to evaluate the ability to cross the BBB of triterpenoid saponins occurring in Astragalus mongholicus roots. The research was carried out using in silico methods combined with postmortem studies on the brain tissues of mice treated with isolated astragaloside IV (AIV). Firstly, to estimate the ability to cross the BBB by the tested saponins, new quantitative structure–activity relationship (QSAR) models were established. The reliability and predictability of the model based on the values of the blood–brain barrier penetration descriptor (logBB), the difference between the n-octanol/water and cyclohexane/water logP (ΔlogP), the logarithm of n-octanol/water partition coefficient (logP_ow), and the excess molar refraction (E) were both confirmed using the applicability domain (AD). The critical leverage value h* was found to be 0.128. The relationships between the standardized residuals and the leverages were investigated here. The application of an in vitro acetylcholinesterase-inhibition test showed that AIV can be recognized as the strongest inhibitor among the tested compounds. Therefore, it was isolated for the postmortem studies on brain tissues and blood using semi-preparative HPLC with the mobile phase composed of water, methanol, and ethyl acetate (1.7:2.1:16.2 v/v/v). The results of the postmortem studies on the brain tissues show a regular dependence of the final concentration of AIV in the analyzed brain samples of animals treated with 12.5 and 25 mg/kg b.w. of AIV (0.00012299 and 0.0002306 mg, respectively, per one brain). Moreover, the AIV logBB value was experimentally determined and found to be equal to 0.49 ± 0.03.

Astragaloside attenuates the progression of prostate cancer cells through endoplasmic reticulum stress pathways

Astragaloside (As) has been demonstrated extensively to serve roles in a variety of tumor types, including glioma, lung cancer, colorectal cancer, breast cancer and cervical cancer, and has therefore been widely used in Traditional Chinese Medicine. To the best of our knowledge, the present study was the first to investigate the efficacy of the Traditional Chinese Medicine astragaloside on tumor growth and the apoptosis of prostate cancer cells. In addition, further investigation into the underlying molecular mechanisms via the endoplasmic reticulum (ER) stress pathway was also performed. In the present study, the human prostate cancer DU-145 cell line was employed as an experimental model in vitro and cells were divided into five treatment groups: Dimethyl sulfoxide (DMSO) group (control), low-dose astragaloside group (L-As; 20 nmol/l), moderate-dose astragaloside group (M-As; 50 nmol/l), high-dose astragaloside group (H-As, 100 nmol/l) and ER stress suppressor group (tauroursodeoxycholic acid; TUDCA). The proliferative ability and apoptosis rate of the DU-145 cells were detected via Cell Counting kit-8 methods and flow cytometry, respectively. Furthermore, the ER stress factors [binding immunoglobulin protein (BiP), C/EBP homologous protein (CHOP) and caspase-12] were assessed through reverse transcription polymerase chain reaction. Additionally, the protein expression levels of inositol-requiring enzyme 1 (IRE1), phosphorylated protein kinase R-like ER kinase (p-PERK), iron-regulated transcriptional activator Aft (AFT)4 and AFT6 were measured detected by western blot analysis. Administration of As significantly reduced the cell viability and promoted apoptosis (P<0.05) in a dose-dependent manner. Expression of ER-stressed genes BiP, CHOP and caspase-12 mRNA was increased by As administration, while TUDCA treatment led to a lower mRNA expression of these genes, compared with the control group. Results of western blot analysis indicated that the protein expression of IRE1, AFT4 and AFT6 was upregulated in the H-As group, and that the ratio of p-PERK/PERK was also higher than in the other groups. The administration of As demonstrated significant therapeutic effects on the proliferation of prostate cancer cells, as well as the expression of related proteins and genes. The results of the present study suggested future clinical potential of As for the treatment of prostate cancer.

The Effect of Astragaloside on Pacemaker Current and the Cytoskeleton in Rabbit Sinoatrial Node Cells Under the Ischemia and Reperfusion Condition

Objective: We investigated the role of astragaloside in the treatment of sick sinus syndrome (SSS). Methods: Neonatal New Zealand rabbits were selected for the study. Rabbit sinoatrial node (SAN) cells were isolated by the method of dual enzymatic digestion and differential adherence. The injury model was prepared through simulated ischemia and reperfusion (I/R), and changes in the pacemaker current (I_f) were recorded using the whole-cell patch-clamp technique. The proteins F-actin and vinculin were examined between various groups of SAN cells using a microplate reader and laser scanning confocal microscopy. The mRNA level and protein expression of hyperpolarization-activated cyclic nucleotide gated potassium channel 4 (HCN4) were assessed by q-PCR and western blot method. Results: The peak current density of I_f was decreased to -19.64 ± 2.14 pA/pF in SAN cells after simulated I/R, and the difference was highly significant (P < 0.01). Following simulated I/R, 100, 200, or 300 μmol L^-1 astragaloside was added to the extracellular solution of SAN cells; the peak current density of the I_f increased to -30.43 ± 1.98, -34.83 ± 1.6, and -52.72 ± 1.7 pA/pF, respectively (P < 0.01). Adding 100 μmol L^-1 astragaloside to normal SAN cells also led to an enhanced peak current density of the I_f (P < 0.05). In a concentration-dependent manner, especially at 300 μmol/L, astragaloside was capable of increasing the expression of HCN4 and protecting the structural stability of F-actin and vinculin in the damaged SAN cells. Conclusion: We estimated that astragaloside could shorten the action potential duration 20 (APD20) and APD50 in damaged SAN cells of neonatal rabbits, thereby increasing the expression of HCN4 and the I_f current density in damaged SAN cells of neonatal rabbits in a voltage-dependent manner, accelerating the steady-state activation of the I_f channels, and protecting damaged cytoskeleton.

Astragaloside IV ameliorates early diabetic nephropathy by inhibition of MEK1/2-ERK1/2-RSK2 signaling in streptozotocin-induced diabetic mice

Objective The aim of this study was to investigate the renoprotective effects and molecular mechanisms of astragaloside IV (AS-IV) in streptozotocin (STZ)-induced diabetic mice. Methods Male C57BL/6 mice were injected intraperitoneally with STZ at 200 mg/kg body weight. AS-IV was administered for 8 consecutive weeks, beginning 1 week after STZ injection. Body weight, 24-hour urinary albumin excretion, and fasting blood glucose were measured. Kidney tissues were examined by histopathological analyses. Total levels and phosphorylation of mitogen-activated protein kinase 1/2 (MEK1/2), extracellular signal-regulated kinases 1 and 2 (ERK1/2), and ribosomal S6 kinase 2 (RSK2) were determined by Western blotting analysis. Results AS-IV treatment significantly reduced albuminuria and serum creatinine levels, ameliorated mesangial matrix expansion and greater foot process width, and decreased the levels of urinary N-acetyl-beta-D-glucosaminidase, neutrophil gelatinase-associated lipocalin, and transforming growth factor-beta 1 in STZ-induced diabetic mice. AS-IV also inhibited renal cortical phosphorylation of MEK1/2, ERK1/2 and RSK2. Conclusion Our results suggest that AS-IV attenuates renal injury in STZ-induced diabetic mice. This effect might be partially associated with inhibition of the activation of the MEK1/2-ERK1/2-RSK2 signaling pathway.

[Effect of astragaloside on mRNA expression of PI3K/Akt/mTOR signal transduction in anemia model mice induced by chemotherapy]

To study the influence of astragaloside on mRNA expression of PI3K/Akt/mTOR signal transduction in anemia model mice induced by chemotherapy, 48 male BALB/c mice which were 6-7 week old were picked as the research objects and randomly divided into four groups, blank group, model group, astragaloside group and astragaloside IV group. Each group was 12 mice. Chemotherapy anemia model was established by cyclophosphamide. The mice were drawn blood from eyeball after 14 days treatment. The QPCR was used to test the mRNA concentrations of Akt, PI3K, BCL-xl, bad, FoxO, mTOR, PTEN in mouse spleen. In comparison of blank group, astragaloside group and astragaloside IV group,the erythrocyte counting and values of Hb in model group were significantly lower (P<0.05). The volumes mRNA of Akt,PI3K,BCL-xl,bad,mTOR were lower in blank group, compared with other groups (P<0.05 or P<0.01). The similar trend in astragaloside IV group except PI3K, comparing with blank group (P<0.05 or P<0.01). The contents of these five genes were no significant differentiations between astragaloside group and blank group. The statistics were obvious between astragaloside group and astragaloside IV group (P<0.05 or P<0.01). The concentrations of FoxO, PTEN were higher in model group,compared with blank group and astragaloside group (P<0.05 or P<0.01), but no difference with astragaloside IV group. Comparing with blank group, the volumes of these two genes were increased in astragaloside IV group (P<0.05), FoxO was higher in astragaloside group (P<0.05), but PTEN was not significant. There was no the same as astragaloside group and Astragaloside IV group. Therefore, astragaloside could increase the contents of Akt, PI3K, BCL-xl, bad, mTOR (P<0.01), decrease the concentrations of FoxO, PTEN (P<0.05). The changes in cyclophosphamide-induced anemia were highly significant by astragaloside. It could be related to the mRNA expression of PI3K/Akt/mTOR Signal Transduction.

Astragaloside protects myocardial cells from apoptosis through suppression of the TLR4/NF-κB signaling pathway

Astragaloside is a monomer isolated from Astragalus membranaceus, a flowering plant in the family Fabaceae. The aim of the present study was to investigate the anti-apoptotic affect of astragaloside on myocardial cells through the TLR4/NF-κB signaling pathway. Astragaloside, NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) and Toll-like receptor 4 (TLR4) blocking antibody solution were prepared in vitro, and myocardial cells were incubated and cultured in serum-free medium overnight. Cells were divided into five groups: the normal control group, serum-free group, astragaloside group, TLR4 blocking antibody group and NF-κB inhibitor PDTC group. The myocardial cell apoptosis in each group was detected using flow cytometry, and the expression levels of TLR4 and NF-κB were detected via western blotting. The apoptosis rate in the serum-free group was significantly higher than that in the normal control group. The apoptosis rate of myocardial cells in the TLR4 blocking antibody group and NF-κB inhibitor PDTC group was lower than that in the serum-free group. In addition, the myocardial cell apoptosis was more obviously decreased in the astragaloside group, and the protein expression levels of TLR4 and NF-κB in the serum-free group were significantly higher than those in normal control group. The protein expression levels of TLR4 and NF-κB in the astragaloside group were obviously lower than those in the serum-free group, and the protein expression levels of TLR4 and NF-κB in the TLR4 blocking antibody group and NF-κB inhibitor PDTC group were decreased. In conclusion, astragaloside reduced myocardial cell apoptosis and protected myocardial cells, which may be one of the mechanisms of a traditional Chinese medicine monomer in treating heart failure.

Astragaloside attenuates myocardial injury in a rat model of acute myocardial infarction by upregulating hypoxia inducible factor‑1α and Notch1/Jagged1 signaling

The present study aimed to investigate the mechanisms underlying the cardioprotective effect of Astragaloside against myocardial injury following myocardial infarction (MI) in a rat model. Male Wistar rats were subjected to left anterior descending branch ligation. The rats that survived 24 h (n=18) were randomly and equally assigned to three groups: MI model group, and 2.5 and 10 mg/kg/day Astragaloside group. A further six rats underwent identical surgical procedures without artery ligation, serving as sham controls. Following 28 days of treatment, the left ventricle was harvested for morphological analysis, and mRNA and protein expression levels of hypoxia inducible factor‑1α (HIF‑1α), Notch1 and Jagged1 were measured. Treatment with Astragaloside attenuated pathological changes in the myocardium. Compared with untreated MI rats, rats treated with Astragaloside exhibited significantly increased mRNA expression levels of HIF‑1α, Notch1 and Jagged1 (all P<0.01). HIF‑1α demonstrated a dose‑dependent effect (P<0.05). Astragaloside (10 mg/kg/day) significantly increased HIF‑1α (P<0.05), Notch1 (P<0.01) and Jagged1 (P<0.01) protein expression levels. Additionally, 2.5 mg/kg Astragaloside significantly increased Jagged1 protein expression levels compared with untreated MI rats. Furthermore, there was a dose‑dependent effect of Astragaloside treatment (P<0.01). These findings suggested that the cardioprotective effects of Astragaloside against myocardial injury following MI may involve upregulation of HIF‑α, Notch1 and Jagged1 signaling, implicating these molecules as therapeutic targets for the treatment of MI.

Transcriptional Profiling and Molecular Characterization of Astragalosides, Calycosin, and Calycosin-7-O-β-D-glucoside Biosynthesis in the Hairy Roots of Astragalus membranaceus in Response to Methyl Jasmonate

We used the next-generation Illumina/Solexa HiSeq2000 platform on RNA analysis to investigate the transcriptome of Astragalus membranaceus hairy roots in response to 100 μM methyl jasmonate (MeJA). In total, 77,758,230 clean reads were assembled into 48,636 transcripts (average length of 1398 bp), which were clustered into 23,658 loci (genes). Of these, 19,940 genes were annotated by BLASTx searches. In addition, DESeq analysis showed that 2127 genes were up-regulated, while 1247 genes were down-regulated by MeJA. Seventeen novel astragaloside (AST) biosynthetic genes and seven novel calycosin and calycosin-7-O-β-D-glucoside (CG) biosynthetic genes were isolated. The accumulation of ASTs, calycosin, and CG increased significantly in MeJA-treated hairy roots compared with control hairy roots. Our findings will provide a valuable resource for molecular characterization of AST, calycosin, and CG biosynthetic pathways and may lead to new approaches to maximize their production and biomass productivity in the hairy roots of A. membranaceus.