Astragaloside Research Articles

Beneficial Effect of Astragaloside on Alzheimer's Disease Condition Using Cultured Primary Cortical Cells Under β-amyloid Exposure.

β-amyloid (Aβ)-mediated neuronal apoptosis contributes to the pathogenesis of Alzheimer's disease (AD). This study aimed to investigate whether astragalosides (AST) could inhibit Aβ-induced apoptosis in vivo and in vitro and to explore the underlying mechanisms. Amyloid β-protein fragment 25-35 (Aβ25-35) was administered to cerebral lateral ventricle of rats to make the AD models in vivo. AST was able to attenuate both cortical cell degeneration and memory deficits in the AD rats. AST also inhibited Aβ25-35-induced cytotoxicity (e.g., decreased cell viability); apoptosis (e.g., increased caspase-3 expression, increased DNA fragmentation, and Tau hyperphosphorylation); synaptotoxicity (e.g., increased loss of both a dendritic marker, microtubule-associated protein 2 (MAP-2) and synaptic proteins, synaptophysins); and mitochondrial dysfunction (e.g., increased mitochondrial membrane potential) in cultured primary rat cortical cells. The beneficial effect of AST in reducing Aβ-induced cytotoxicity, apoptosis, and mitochondrial dysfunction in cortical cells were blocked by inhibition of phosphoinositide 3-kinase (PI3K)-dependent protein kinase B (PKB, as known as AKT) activation with LY294002. In addition, inhibition of extracellular protein kinase (ERK) with U0126 shared with the AST the same beneficial effects in reducing Aβ-induced apoptosis. Our data suggest that the cortical PI3K/AKT and MAPK (or ERK) pathways as appealing therapeutic targets in treating AD, and AST may have a positive impact on AD treatment via modulation of both PI3K/AKT and ERK pathways.

Enhanced astragaloside production and transcriptional responses of biosynthetic genes in Astragalus membranaceus hairy root cultures by elicitation with methyl jasmonate

In this work, the elicitation of Astragalus membranaceus hairy root cultures (AMHRCs) with methyl jasmonate (MJ), salicylic acid (SA) and acetylsalicylic acid (ASA) was conducted to boost astragaloside (AG) biosynthesis. MJ was found to be the most effective inducer for AG production among all elicitor treatments. The highest enhancement of AG accumulation was achieved in 34 day-old AMHRCs elicited by 157.4μM MJ for 18.4h. The resulting AG yield was 5.5±0.13mg/g dry weight (DW), which was 2.1-fold higher than that of non-treated control (2.7±0.05mg/g DW). Moreover, transcriptional analyses revealed that MVD, IDI, FPS and SS were the potential key regulated genes in AG biosynthetic pathway. Overall, this study offered a feasible approach of utilizing MJ elicitation for the enhanced production of valuable AGs in AMHRCs, and also provided a basis for AG biosynthesis via metabolic engineering strategies in the future.

Triterpene and Flavonoid Biosynthesis and Metabolic Profiling of Hairy Roots, Adventitious Roots, and Seedling Roots of Astragalus membranaceus.

Astragalus membranaceus is an important traditional Chinese herb with various medical applications. Astragalosides (ASTs), calycosin, and calycosin-7-O-β-d-glucoside (CG) are the primary metabolic components in A. membranaceus roots. The dried roots of A. membranaceus have various medicinal properties. The present study aimed to investigate the expression levels of genes related to the biosynthetic pathways of ASTs, calycosin, and CG to investigate the differences between seedling roots (SRs), adventitious roots (ARs), and hairy roots (HRs) using quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR study revealed that the transcription level of genes involved in the AST biosynthetic pathway was lowest in ARs and showed similar patterns in HRs and SRs. Moreover, most genes involved in the synthesis of calycosin and CG exhibited the highest expression levels in SRs. High-performance liquid chromatography (HPLC) analysis indicated that the expression level of the genes correlated with the content of ASTs, calycosin, and CG in the three different types of roots. ASTs were the most abundant in SRs. CG accumulation was greater than calycosin accumulation in ARs and HRs, whereas the opposite was true in SRs. Additionally, 40 metabolites were identified using gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). Principal component analysis (PCA) documented the differences among SRs, ARs, and HRs. PCA comparatively differentiated among the three samples. The results of PCA showed that HRs were distinct from ARs and SRs on the basis of the dominant amounts of sugars and clusters derived from closely similar biochemical pathways. Also, ARs had a higher concentration of phenylalanine, a precursor for the phenylpropanoid biosynthetic pathway, as well as CG. TCA cycle intermediates levels including succinic acid and citric acid indicated a higher amount in SRs than in the others.

Astragalosides promote angiogenesis via vascular endothelial growth factor and basic fibroblast growth factor in a rat model of myocardial infarction.

The aim of the present study was to evaluate the effect of astragalosides (ASTs) on angiogenesis, as well as the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) following myocardial infarction (MI). MI was induced in rats by ligation of the left coronary artery. Twenty-four hours after surgery, the rats were divided into low-dose, high-dose, control and sham surgery groups (n=8 per group). The low- and high-dose groups were treated with ASTs (2.5 and 10 mg/kg/day, respectively, via intraperitoneal injection), while, the control and sham surgery group rats received saline. Serum levels, and mRNA and protein expression levels of VEGF and bFGF, as well as the microvessel density (MVD) were determined four weeks post-treatment. Twenty-four hours post-surgery, VEGF and bFGF serum levels were observed to be comparable between the groups; while at four weeks, the VEGF and bFGF levels were higher in the AST-treated rats (P<0.01). Similarly, VEGF and bFGF mRNA and protein expression levels were higher following AST treatment (P<0.05). No difference in VEGF mRNA expression between the low- and high-dose groups was noted, however, an increase in the bFGF expression levels was detected in the high-dose group. Newly generated blood vessels were observed following MI, with a significant increase in MVD observed in the AST-treated groups (P<0.05). AST promotes angiogenesis of the heart and increases VEGF and bFGF expression levels. Thus, it is hypothesized that increased VEGF and bFGF levels may contribute to the AST-induced increase in angiogenesis in rat models 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.

Astragaloside prevents BDL-induced liver fibrosis through inhibition of notch signaling activation

Ethnopharmacological relevanceHuangqi decoction was first described in Prescriptions of the Bureau of Taiping People׳s Welfare Pharmacy in the Song Dynasty (AD1078). It consists of Radix Astragali (Astragalus membranceus (Fisch.) Bge. Root, Huangqi) and Radix Glycyrrhizae (Glycyrrhiza uralensis Fisch., root and rhizome, Gancao), and it is an effective recipe that is usually used to treat consumptive disease and chronic liver diseases. Astragaloside (AS) is a main component of Radix Astragali had an effect similar to the Huangqi decoction on hepatic fibrosis. Aim of the studyCholestasis is associated with a number of chronic liver diseases and Notch signaling has been demonstrated to be involved in ductular reaction. Previous studies have shown that AS can prevent the progression of cholestatic liver fibrosis, however, whether AS affects the Notch signaling pathway is unclear. Materials and methodsCholestatic liver fibrosis was established by common bile duct ligation (BDL) in rats. At first weekend, the rats were randomly divided into a model group (BDL), an AS group, and a Sorafenib positive control group (SORA) and treated for 3 weeks. Bile duct proliferation and liver fibrosis were determined by tissue staining. Activation of the Notch signaling pathway was evaluated by analyzing expressions of Notch-1, -2, -3, -4, Jagged 1 (JAG1), Delta-like (DLL)-1, -3, -4, Hes1, Numb and RBP-Jκ. Activation of the Wnt signaling pathway was evaluated by analyzing expressions of Wnt-4, -5a, -5b, Frizzled (Fzd)-2, -3, -6 and β-catenin. Results(1) Compared with the BDL group, AS significantly reduced the deposition of collagen and the Hyp content of liver tissue and inhibited the activation of HSCs. In addition, AS significantly decreased the protein and mRNA expressions of TGF-β1 and α-SMA. In contrast, AS significantly enhanced expression of the Smad 7 protein. AS also reduced biliary epithelial cell proliferation, and reduced the mRNA and protein expressions of CK7, CK8, CK18, CK19, OV6, Sox9 and EpCAM. (2) The mRNA and protein expressions of Notch-2, -3, -4 and JAG1 were significantly reduced in the AS compared to the BDL group. In contrast, the mRNA and protein level of Numb was clearly enhanced after AS treatment. ConclusionAS may prevent biliary liver fibrosis via inhibition of the Notch signaling pathway, thereby inhibiting the abnormal proliferation of biliary epithelial cells. Results indicate that AS may be a potential therapeutic drug for cholestatic liver disease.

Protective effect of astragaloside IV against ultraviolet B-induced photodamage to human HaCaT keratinocytes and its mechanisms

Objective To evaluate the protective effect of astragaloside Ⅳ against ultraviolet B (UVB)-induced photodamage to human HaCaT keratinocytes,and to investigate its mechanisms.Methods Culturedimmortalized human HaCaT keratinocytes were divided into four groups:blank control group receiving untreated,UVB group irradiated with 50 mJ/cm2 UVB,astragaloside Ⅳ group treated with astragaloside Ⅳ,UVB + astragalosideⅣ group treated with astragaloside Ⅳ for 24 hours before and after 50 mJ/cm2 of UVB radiation.The concentration ofastragaloside Ⅳ ranged from 10 to 200 mg/L in cell proliferation assay,and according to the results of proliferationassay,20 mg/L was determined as the optimal concentration in the other assays.At 24 hours after UVB radiation,cellcounting kit-8 (CCK8) assay was performed to evaluate cellular proliferative activity,flow cytometry to determineintracellular reactive oxygen species (ROS) levels,and Western blot to measure the expression levels of p53,p38,matrix metalloproteinase-9 (MMP-9) and high mobility group Al (HMGA-1) protein in HaCaT cells.ResultsCompared with the control group,astragaloside Ⅳ at 10 and 20 mg/L had no inhibitory effect (F =1.32,P ＞ 0.05),while astragaloside Ⅳ at 50,100 and 200 mg/L showed significantly inhibitory effect (F =20.20,P ＜ 0.05),on theproliferation of HaCaT cells.In addition,cellular proliferative activity in the UVB group was significantly lower thanthat in the control group (F =99.00,P ＜ 0.01).Compared with the UVB group,cellular proliferative activityincreased to different degrees in HaCaT cells treated with both UVB and astragaloside Ⅳ of 10-200 mg/L (F =19.08,P ＜ 0.01),with the strongest increase observed in those treated with UVB and astragaloside Ⅳ of 20 mg/L.Further experiments revealed reduced intracellular ROS levels in the UVB + astragaloside Ⅳ (20 mg/L) groupcompared with the UVB group (t =21.12,P ＜ 0.01).Western blot assay showed that the expression levels of p53,p38,MMP-9 and HMGA-1 protein were significantly higher in the UVB group than in the control group (all P ＜0.01),but significantly lower in the UVB + astragaloside Ⅳ (20 mg/L) group than in the UVB group (all P ＜ 0.01).Conclusion Astragaloside Ⅳ can effectively protect keratinocytes from UVB-induced photodamage. Key words: Astragalus membranaceus; Ultraviolet rays; Keratinocytes; Reactive oxygen species

Optimization of Astragalus membranaceus hairy roots induction and culture conditions for augmentation production of astragalosides

In this study, an efficient and reliable Agrobacterium rhizogenes-mediated hairy root system in A. membranaceus was developed. An optimal transformation rate of 66.84 % was obtained after 13 days by inoculating A. rhizogenes LBA9402 onto 3-week-old leaf explants followed by a co-cultivation period of 2 days with acetosyringone (100 μM). Among eight representative A. membranaceus hairy root lines (AMHRL), AMHRL VI was found to be the lead line and confirmed by PCR amplification of rolB, rolC and aux1 genes. Culture parameters of AMHRL VI were systematically optimized by central composite design and slogistic kinetic models, and six main astragalosides (AG) were quail-quantitatively determined by liquid chromatography–tandem mass spectrometry. Under optimal conditions (inoculum size 1.54 %, culture temperature 27.8 °C, sucrose concentration 3.24 % and harvest time 36 days), A. membranaceus hairy root cultures (AMHRCs) in MS medium gave the optimal biomass production of 15.79 g/L dry weight (DW) with total AG accumulation of 2.657 mg/g DW. This yield was significantly superior to that of 3-year-old field grown roots (2.435 mg/g DW). Overall, this investigation provided the generation of a high-productive AMHRCs that is capable of augmentation production of AG, offering a promising and continuous product platform for naturally derived, high quality and valuable phytochemicals.

A optimization of astragaloside IV extraction process from methanolic extracts of Astragali Mongholici Radix by HPLC-ELSD detection

s / European Journal of Integrative Medicine 6 (2014) 686–745 717 Table 1 (Continued ) No. tR (min) Cyclopamine analogs Formula [M+H]+ Experimental m/z [M+H]+ Theoretical m/z [M+H]+ Error

The effect and mechanism of Astragaloside IV on immune function of regulatory T cell mediated by high mobility group box 1 protein in vitro

Objective Based the previous studies, the present study was performed to investigate the antagonistic effects of different doses of Astragaloside IV on the immune function of Treg mediated by HMGB1 in vitro and its potential mechanism.Methods CD4＋CD25-T cells isolated from the spleens of male BABL/c mice by magnetic beads were seeded on 48-well cell culture plates and were randomly divided into four groups as follows（12 holes per group）. Normal control group： CD4＋CD25-T cells were cultured merely. Treg group： Tregs（100μl） and CD4＋CD25-T cells were co-cultured in ratio of 1：10. HMGB1＋Treg group： Tregs（100μl） stimulated by HMGB1（1μg/ml） for 72 h and CD4＋CD25-T cells were co-cultured in ratio of 1∶10. HMGB1＋AST IV＋Treg group： Tregs（100μl） stimulated by HMGB1（1μg/ml） and AST IV（100μg/ml）for 72 h were co-cultured with CD4＋CD25-T cells in ratio of 1：10. CD4＋CD25-T cells and supernatants were again collected on post-culture 72 hour. The proliferation of CD4＋CD25- T cells was analyzed by MTT test, the activity of NFAT and the contents of cytokines of IL-2 released into supernatants were also determined by means of ELISA. Results When CD4＋CD25-T cells were co-cultured with Tregs, the cell proliferation（0.166±0.039） and the levels of NFAT（0.156±0.035） and IL-2（2.38±0.58） in supernatant were markedly decreased as compared with those in the control group（P〈0.01）. However, the contrary results were found when CD4＋CD25-T cells were co-cultured with Treg stimulated by HMGB1. Compared with those in the（HMGB1＋Treg） group, the contrary results were showed with a dose-dependent in the（HMGB1＋ASTⅣ＋Treg） group.Conclusion ASTⅣcan rivalry the effects of HMGB1 on immune function of Treg in vitro, this result indicate that ASTⅣhas the therapeutic action on inflammation promoted by HMGB1. Key words: High mobility group box-1 protein Regulatory T cell AstragalosideⅣ Immune suppression Sepsis

Astragalosides from Radix Astragali benefits experimental autoimmune encephalomyelitis in C57BL /6 mice at multiple levels.

BackgroundRadix Astragali is famous for its beneficial effect on inflammation associated diseases. This study was to assess the efficacy of astragalosides (AST) extracted from Radix Astragali, on the progression of experimental autoimmune encephalomyelitis (EAE), and explore its possible underlying molecular mechanisms.MethodsEAE was induced by subcutaneous immunization of MOG35–55. Infiltration of inflammatory cells was examined by HE staining. ROS level was detected by measuring infiltrated hydroethidine. Leakage of blood brain barrier (BBB) was assessed using Evan’s blue dye extravasation method. Levels of inflammatory cytokines were measured using ELISA kits. Activities of total-SOD, GSH-Px, and iNOS and MDA concentration were measured using biochemical analytic kits. Gene expression was detected using real-time PCR method. Protein expression was assayed using western blotting approach.ResultsAST administration attenuated the progression of EAE in mice remarkably. Further studies manifested that AST treatment inhibited infiltration of inflammatory cells, lessened ROS production and decreased BBB leakage. In peripheral immune-systems, AST up-regulated mRNA expression of transcriptional factors T-bet and Foxp3 but decreased that of RORγt to modulate T cell differentiation. In CNS, AST stopped BBB leakage, reduced ROS production by up-regulation of T-SOD, and reduced neuroinflammation by inhibition of iNOS and other inflammatory cytokines. Moreover, AST inhibited production of p53 and phosphorylation of tau by modulation of the Bcl-2/Bax ratio.ConclusionsAST orchestrated multiple pathways, including immuno-regulation, anti-oxidative stress, anti-neuroinflammation and anti-neuroapoptosis involved in the MS pathogenesis, to prevent the deterioration of EAE, which paves the way for the application of it in clinical prevention/therapy of MS.

Beneficial effect of astragalosides on stroke condition using PC12 cells under oxygen glucose deprivation and reperfusion.

Astragalosides (AST) are reported to be neuroprotective in focal cerebral ischemic models in vivo. In this study, the direct effect of AST against oxygen and glucose deprivation (OGD) including neuronal injury and the underlying mechanisms in vitro were investigated. 5 h OGD followed by 24 h of reperfusion [adding back oxygen and glucose (OGD-R)] was used to induce in vitro ischemia reperfusion injury in differentiated rat pheochromocytoma PC12 cells. AST (1, 100, and 200 µg/mL) were added to the culture after 5 h of the OGD ischemic insult and was present during the reoxygenation phases. A key finding was that OGD-R decreased cell viability, increased lactate dehydrogenase, increased reactive oxygen species, apoptosis, autophagy, functional impairment of mitochondria, and endoplasmic reticulum stress in PC12 cells, all of which AST treatment significantly reduced. In addition, AST attenuated OGD-R-induced cell loss through P38 MAPK activation a neuroprotective effect blunted by SB203580, a specific inhibitor of P38 MAPK. Our data suggest that both apoptosis and autophagy are important characteristics of OGD-R-induced PC12 death and that treating PC12 cells with AST blocked OGD-R-induced apoptosis and autophagy by suppressing intracellular oxidative stress, functional impairment of mitochondria, and endoplasmic reticulum stress. Our data provide identification of AST that can concomitantly inhibit multiple cells death pathways following OGD injuries in neural cells.

Astragalosides attenuate learning and memory impairment in rats following ischemia-reperfusion injury

Astragalosides (ASTs) have been traditionally used in the treatment of various cardiovascular and cerebrovascular diseases. The aim of the present study was to investigate the neuroprotective effects of AST on learning and memory following focal cerebral ischemia/reperfusion in a rat model. A Morris water maze was used to measure the effect of AST on learning and memory impairments. A histological examination and Hoechst 33258 staining was used to observe the neuronal changes and apoptosis in the hippocampus. The activity of phospho-extracellular signal‑regulated kinases (p‑ERK), p‑c-Jun N-terminal kinases (JNK) and p‑Akt was measured by western blotting. The data revealed that AST improved the rats learning and memory abilities, attenuated neuronal cells apoptosis, increased the expression of p‑ERK and p‑Akt, and decreased the expression of p‑JNK. These findings indicated that AST has protective effects that may be correlated with the inhibition of neuronal cell apoptosis and the regulation of p‑ERK, p‑Akt and p‑JNK expression.

Using high performance liquid chromatography (HPLC) fingerprint distinguish producing area and grown years of Shanxi Astragalus

So far, there has been no advanced method to assure the quality control for Astragalus. However, this paper summarizes a fingerprinting approach, which based on developed high performance liquid chromatography to provide reference for the scientific evaluation of the intrinsic quality of Astragalus. To assess the chemical content of Astragalus in different years and different producing areas, we determined 22 batches of samples through cluster analysis and similar calculations. According to the clustering analysis, we group the two-year-old Astragalus into three categories, which established the common model of RP-HPLC Fingerprint of Astragalus, and identified 12 peaks, two of which were Astragaloside (No. 15 peak) and Formononetin (No. 17 peak) respectively. In addition, from the fingerprints, the variation of chemical composition of Astragalus from the same producing area but different years was also summed up. In conclusion, not only is this method simple, fast and reproducible, but also the established fingerprints have a strong exclusion, providing evidences for the quality control and evaluation of Astragalus. Key words: Astragalus, HPLC, fingerprint.

Protective effects of astragaloside IV on high-glucose-induced damage of retinal ganglion cells

To explore the protective effects of astragaloside IV on retinal ganglion cells (RGC) incubated under high glucose. Cultured RGC-5 were divided into 3 groups: control, high glucose and high glucose+astragaloside IV. The survival rate of cell was measured by CCK-8 kit and flow cytometry. The changes of mitochondrial membrane potential were monitored by confocal laser scanning microscopy while those of RGC-5 mitochondria observed by electron microscopy. When the cell survival rate was 100% in the control group, the survival rate improved after 1 h 5, 10, 50, 100, 200 µg/ml astragaloside IV pretreatment and high-glucose culture. The cell survival rates for 100 mg/L, 200 mg/L of astragaloside IV were 81.6%, 80.0%, the difference from the high glucose group (66%) was significant (P < 0.05) and 100 mg/L of astragaloside IV was the best protection concentration. The apoptotic rate for 100 mg/L astragaloside IV pretreated group of RGC-5 cell was 6.1%. And it could partially inhibit the RGC-5 cell apoptosis caused by high glucose (8.2%) (P < 0.05). In the high-glucose group, the cells showed marked increases in mitochondrial swelling, especially for cristae. Numerous normal mitochondria were observed in 100 mg/L astragaloside IV pretreated group. Astragaloside IV could elevate mitochondrial membrane potential and alleviate mitochondrial swelling. Astragaloside IV can protect RGC from high-glucose induced damage and may benefit the patients with diabetic retinopathy.

Study on compatibility of traditional Chinese medicine active constituents with antioxidant activity

To find a research method suitable to multi-component multi-index composition-activity relationship of traditional Chinese medicines (TCMs) with the antioxidant activity of four compatible active constituents of TCMs as the subject. LARS-based regression algorithm and comprehensive weight coefficient method were adopted to study in vitro clearance of DPPH and polyaromatic hydrocarbon with different doses of four compatible active constituents--total flavonoids of Glycyrrhizae Radix et Rhizoma (TFG), Ginkgo Folium extract (GBE), total flavonoids of Epimedii Folium (TFE) and astragaloside (AST) according to the comprehensive efficacy assessment procedures, that is test design, efficacy test and mathematical modeling (model verification). LARS and comprehensive weight coefficient method was adopted to assess the optimal comprehensive efficacy of clearing DPPH and polyaromatic hydrocarbon. The results showed that the optimal dose combination of compatible constituents is TFG-GBE-TFE-AST 1: 0.2545: 0.007 6:0.011 5. The above compatibility of TCMs constituents can effectively clear polyaromatic hydrocarbon and DPPH with a good antioxidation. The uniform design adopted in this experiment, in combination of synthetic weight method, is suitable to the data analysis of "non-linear and small-sample" biotic experiment and the study on screening and assessment of compatibility of TCMs constituents.

Protective effects of astragalosides on dexamethasone and Aβ25–35 induced learning and memory impairments due to decrease amyloid precursor protein expression in 12-month male rats

Alzheimer’s disease (AD) is a chronic neurodegenerative disorder of the elderly characterized by learning and memory impairment. Stress level glucocorticoids (GCs) and β-amyloid (Aβ) peptide deposition are found to be correlated with dementia progression in patients with AD. The astragalosides (AST) was extracted from traditional Chinese herb Astragalus membranaceous. In this study, 12months male rats were treated with Aβ25–35 (10μg/rat, hippocampal CA1 injection) and dexamethasone (DEX, 1.5mg/kg, ig) and AST (8, 16 and 32mg/kg, ig) or ginsenoside Rg1 (Rg1, 5mg/kg, ig) for 14days. We investigated the protective effect of AST against DEX+Aβ25–35 injury in rats and its mechanisms of action. Our results indicate that DEX+Aβ25–35 can induce learning and memory impairments and increase APP and Aβ1–40 expression. AST (16, 32mg/kg) or Rg1 (5mg/kg) treatment significantly improve learning and memory, down-regulate the mRNA levels of APP and β-secretase, decrease expression of APP and Aβ1–40 in hippocampus. The results indicated that DEX might increase hippocampal vulnerability to Aβ25–35 and highlight the potential neuronal protection of AST.

Effects of Astragalosides on Cultured Islets After Cryopreservation in Rats

Objective To explore the effects of AST (astragalosides) on cultured rat islet yield, purity, and function after cryopreservation in rats. Methods Pancreatic islets were isolated from 30 Sprague-Dawley rats using the standard technique of collagenase P digestion and discontinuous Ficoll gradient purification. After thaw, the islets were randomly divided into AST group and control group ( n = 15). Next, the islet cells were cultured in AST-containing medium or standard medium for 7, 14, and 21 days after cryopreservation and thaw. The quantity, purity, and survival rate were calculated in the two groups before and after culture. Then the in vitro and in vivo function was observed in diabetic rats after islet transplantation. Results The quantity and purity of islets had no difference between the two groups before culture ( P > .05) while the difference after culture was significantly ( P < .05). The survival rate of islets was 48% in AST group and 32% in the control group 21 days after thaw ( P < .05). After 3 days, there was significantly a higher simulation index in the AST group than in the control group ( P < .05). There was a significant difference in blood glucose and insulin concentrations between the groups after 3 days ( P < .05). Conclusion AST can be added to the culture medium to reduce the loss of islet cryopreservation and be intravenously injected to improve culture islet function in vitro and prolong islet graft survival in diabetic rats.

Astragalosides Rescue Both Cardiac Function and Sarcoplasmic Reticulum Ca2+ Transport in Rats with Chronic Heart Failure

The study investigated the beneficial effects of astragalosides (AS) on cardiac performance in rats with chronic heart failure. Chronic heart failure was produced by left anterior descending coronary artery ligation, and the therapeutic efficacy of astragalosides at 10, 20 and 40 mg/kg was evaluated. Five weeks after the operation, cardiac function was deficient and sarcoplasmic reticulum Ca²⁺-ATPase (SERCA) activity was significantly reduced. Moreover, SERCA mRNA decreased, while expression of the SERCA down-regulator phospholamban (PLB) was significantly increased. Phosphorylated phospholamban (P-PLB), the form that does not inhibit SERCA, was also reduced by chronic heart failure. Treatment with AS improved left ventricle function and cardiac structure, reversed the depression of SERCA activity, and increased P-PLB. These results suggest that the cardioprotective effect of AS may be due to the increase in P-PLB protein, which disinhibits SERCA activity. Rescue of sarcoplasmic reticulum Ca²⁺ cycling by astragalosides could normalize excitation-contraction coupling and improve overall cardiac function.

Research of antitumor immunity of gastric carcinoma by DC vaccine with AIV in vitro

Objective Through experiments in vitro,we explored the role of Chinese medicine monomer-Astragaloside Ⅳ with DC vaccine in the body immunologic function.Methods Peripheral blood mononuclear cells (PBMCs)from healthy volunteers were isolated,cultured and generated in vitro,pulsed with tumor antigen from SGC7901 gastric carcinoma cell lysates,produced DC vaccine.Observe T-cell proliferation responses stimulated by DC vaccine with AⅣ group,DC vaccine group and AⅣ group respectively,and the anti-tumor effects on SGC7901 cells in vitro.Results ①The T-cell proliferation rate of DC vaccine with AⅣ group and DC vaccine group were significantly higher than AⅣ group and T-cell group(negative control group)(P=0.000).The stimulating efficacy on T-cell proliferation of DC vaccine with AⅣ group was higher than that of DC vaccine group(S/R 1∶5,1∶10,1∶50,1∶100,P=0.013,0.014,0.017,0.019).Compared with T-cell group,the T-cell proliferation rate of AⅣ group had no statistically significance(P=0.185).②The killing rate of effector cells actived by DC vaccine with AⅣ group and DC vaccine group against SGC7901 gastric carcinoma cells were higher than that of AⅣ group and T-cell group(P=0.000).The Killing power of DC vaccine with AⅣ group was stronger than that of DC vaccine(E/T 5∶1,10∶1,20∶1,50∶1,P=0.023,0.012,0.016,0.011);while the group of AⅣ group and T-cell group cannot killing tumor cells.Both had no statistically significance(P=0.267).Conclusion AⅣ can stimulate T-cell proliferation and enhance the activity of killing tumor cells by DC,which induced specific antitumor response against stomach carcinoma cells effectively. Key words: Dendritic cell; Astragaloside Ⅳ; Gastric carcinoma; Antitumor immunity