Astragaloside IV Research Articles

Astragaloside IV exhibits anti-tumor function in gastric cancer via targeting circRNA dihydrolipoamide S-succinyltransferase (circDLST)/miR-489-3p/ eukaryotic translation initiation factor 4A1(EIF4A1) pathway

ABSTRACT Astragaloside IV (AS-IV) is an inartificial saponin separated from astragalus membranaceus, which has exhibited key anti-tumor regulation in some cancers. Circular RNAs (circRNAs) are important regulators in malignant development of gastric cancer (GC). Herein, we focused on the molecular mechanism of AS-IV with circRNA dihydrolipoamide S-succinyltransferase (circDLST) in GC. CircDLST, microRNA-489-3p (miR-489-3p), and eukaryotic translation initiation factor 4A1 (EIF4A1) levels were detected by quantitative real-time polymerase-chain reaction and western blot. Cell functions were assessed by cell counting kit-8 assay, ethynyl-2’-deoxyuridine assay, colony formation assay, and transwell assay. The interaction between miR-489-3p and circDLST or EIF4A1 was analyzed by dual-luciferase reporter assay. Xenograft tumor assay was adopted to check the role of circDLST and AS-IV in vivo. CircDLST and EIF4A1 were upregulated but miR-489-3p was downregulated in GC cells. AS-IV restrained cell proliferation and metastasis in GC cells by downregulating circDLST. CircDLST served as a miR-489-3p sponge, and miR-489-3p inhibition reversed anti-tumor function of AS-IV. EIF4A1 was a target for miR-489-3p and circDLST sponged miR-489-3p to regulate EIF4A1. AS-IV suppressed GC cell progression via circDLST-mediated downregulation of EIF4A1. Also, AS-IV recued tumor growth in vivo via targeting circDLST to regulate miR-489-3p/EIF4A1 axis. AS-IV inhibited the development of GC through circDLST/miR-489-3p/EIF4A1 axis.

Panax notoginseng glycosides with astragaloside IV improve cerebral ischemic injury through autophagy-NLRP3 inflammasome pathway

Autophagy-NLRP3 pathway participates in cerebral ischemia injury. However, whether Panax notoginsenoside (PN) combined with astragaloside IV (A-IV) plays an anti-inflammatory role in cerebral ischemia injury remains unclear. SD rats were in this study divided into sham operation group, model group, combination drug low-dose group (PN 40 mg/kg+ A-IV 14 mg/kg), medium dose group (80 mg/kg+ 28 mg/kg), high dose group (160 mg/kg+ 56 mg/kg), control group (propofol 4–6 mg/kg) followed by analysis of cerebral ischemia injury and PINK1/Parkin signaling. The model group presented increased infarct volume and NLRP3 level compared to drug and sham operation group. However, the higher the dose, the smaller was the infarct volume and lower NLRP3 expression (P < 0.05). LC3-II/LC3-I ratio increased with ischemia injury, while the ratios of P62, COX4 II and TomM20 were contrary. P62 presented declined level in treatment group compared to model group (P < 0.05). P62, COX4 II and TOMM20 levels were lower in the high-dose group and higher in the P62 group (P < 0.01). After 3-MA and mdivi-1 intervention, NLRP3-related pathway, LC3-II/LC3-I and P62 abundance in mitochondria were highest in the model group with downregulated COX4 II and TOMM20. The neurological deficit score and infarct volume were highest in the model group and improved in medium dose group. The cerebral infarction volume and neurological deficit score were elevated in the drug group combined with 3-MA and MIDIV-1 (P < 0.05). The higher the dose was, the lower were the expressions of PINK and Parkin (P < 0.01). In conclusion, Panax notoginsenoside combined with astragaloside IV effectively alleviated cerebral ischemia injury in rats and improved mitochondrial autophagy by inhibiting inflammasome activation.

Astragaloside IV inhibits cell invasion and metastasis in vulvar squamous cell carcinoma through the TGF-β1/FAK/AKT signaling pathway.

To investigate the mechanism of astragaloside IV (AS-IV) inhibiting the invasion and metastasis of vulvar squamous cell carcinoma (VSCC). MTT and plate colony-formation assays were used to examine the cell proliferation of VSCC (SW962 cell line). Transwell and scratch wound-healing assays were used to analyse cell migration and invasion. Western blot was used to detect the expression of relevant proteins in terms of cell proliferation, invasion and metastasis, as well as the TGF-β1/FAK/AKT signaling pathway. The results showed that AS-IV inhibited the proliferation of SW962 cells in a concentration-dependent manner, as demonstrated by the upregulation of P53 and P21 expression and the downregulation of cyclin D1 expression. AS-IV decreased the ability of cell invasion and metastasis by the downregulation of MMP-2 and MMP-9 expression. When TGF-β1 was added to SW962 cells, the expression of the N-cadherin and Vimentin were upregulated and that of the E-cadherin was downregulated. Subsequently, fibroblast-like elongated spindle-shaped cells appeared, which suggests that TGF-β1 could induce EMT in SW962 cells. Furthermore, the expression of p-FAK, p-AKT, MMP-2 and MMP-9 were upregulated. The expression of these proteins exhibited the opposite effect after AS-IV intervention. Cell invasion and metastasis were suppressed. AS-IV inhibits cell invasion and metastasis in VSCC through the TGF-β1/FAK/AKT signalling pathway.

Chinmedomics Strategy for Elucidating the Pharmacological Effects and Discovering Bioactive Compounds From Keluoxin Against Diabetic Retinopathy.

Keluoxin (KLX) is an active agent in the treatment of diabetic retinopathy (DR). However, its mechanism, targets, and effective constituents against DR are still unclear, which seriously restricts its clinical application. Chinmedomics has the promise of explaining the pharmacological effects of herbal medicines and investigating the effective mechanisms. The research results from electroretinography and electron microscope showed that KLX could reduce retinal dysfunction and pathological changes by the DR mouse model. Based on effectiveness, we discovered 64 blood biomarkers of DR by nontargeted metabolomics analysis, 51 of which returned to average levels after KLX treatment including leukotriene D4 and A4, l-tryptophan, 6-hydroxymelatonin, l-phenylalanine, l-tyrosine, and gamma-linolenic acid (GLA). The metabolic pathways involved were phenylalanine metabolism, steroid hormone biosynthesis, sphingolipid metabolism, etc. Adenosine monophosphate-activated protein kinase (AMPK), extracellular signal-regulated protein kinase1/2 (ERK1/2), phosphatidylinositol-3-kinase (PI3K), and protein 70 S6 kinase (p70 S6K) might be potential targets of KLX against DR. This was related to the mammalian target of rapamycin (mTOR) signaling and AMPK signaling pathways. We applied the chinmedomics strategy, integrating serum pharm-chemistry of traditional Chinese medicine (TCM) with metabolomics, to discover astragaloside IV (AS-IV), emodin, rhein, chrysophanol, and other compounds, which were the core effective constituents of KLX when against DR. Our study was the first to apply the chinmedomics strategy to discover the effective constituents of KLX in the treatment of DR, which fills the gap of unclear effective constituents of KLX. In the next step, the research of effective constituents can be used to optimize prescription preparation, improve the quality standard, and develop an innovative drug.

In vitro demonstration of herbal exacerbation of paracetamol-induced hepatotoxicity

BackgroundParacetamol (acetaminophen) is one of the most accessible pharmaceutical analgesic and antipyretic agents. Similarly, traditional herbal medicines including Psoralea corylifolia, Astragalus propinquus and Atractylodes macrocephala have been used for centuries to treat cold and flu-like symptoms. As herbal medicines are ‘natural and safe’, likelihood of combination with over-the-counter pharmaceuticals is high. Paracetamol and herbal medicines are associated with many adverse effects, hepatotoxicity being a common complication. PurposeTo determine whether concomitant use of paracetamol with phytochemicals commonly found in herbal medicines, including psoralen, astragaloside IV (AST-IV) and atractylenolide I (ATR-I) may produce synergistic hepatotoxicity. MethodsParacetamol (0–50 mM), psoralen (0–1000 µM) and AST-IV and ATR-I (0–300 µM) were tested on a human hepatocellular carcinoma cell line (HepG2) individually and in combination. Interactions were determined using fixed concentrations of 200 µM psoralen with paracetamol (0 – 50 mM), and 10 mM paracetamol with AST-IV or ATR-I (0 – 300 µM). ResultsParacetamol and psoralen demonstrated significant concentration-dependent toxicity individually (P < 0.05), however AST-IV and ATR-I alone or in combination with each other had little effect (P > 0.05). Fixed 200 µM psoralen in 20 mM – 50 mM paracetamol had approximately 20% increase in cell death compared to paracetamol with no psoralen; thus, paracetamol and psoralen demonstrated increased toxicity through synergistic interactions (P < 0.01; CI < 1). ConclusionsThis study highlights the potential risks that herbal medicines can have on paracetamol-induced liver injury and may explain the underlying mechanisms where patients have developed liver failure and necrosis in the presence of low levels of paracetamol.

Implications for herbal polypharmacy: coumarin-induced hepatotoxicity increased through common herbal phytochemicals astragaloside IV and atractylenolide I

Hepatotoxicity is a well-known adverse effect of many substances, with toxicity often resulting from interactions of drugs with other drug-like substances. With the increased availability of complementary and alternative medicines, including herbal medicines, the likelihood of adverse interactions between drugs and drug-like substances in herbs increases. However, the impact of potential herb-herb interactions is little understood. To assess the potential of two cytochrome P450 enzyme modulating phytochemicals common to many herbal medicines, atractylenolide I (ATR-I) and astragaloside IV (AST-IV), to interact with coumarin, another phytochemical common in many foods, a hepatocyte function model with a liver carcinoma cell line, HepG2, was exposed to these agents. To determine the effects of cytochrome P450 modulation by these phytochemicals certain cells were induced with rifampicin to induce cytochrome P450. Increasing concentrations of ATR-I combined with a fixed, nontoxic concentration of coumarin (200 µM), demonstrated significant additive interactions. 300 µM ATR-I produced a 31% reduction in cell viability (p < 0.01) with coumarin in rifampicin uninduced cells. In rifampicin-induced cells, ATR-I (100–300 µM) produced a significant reduction in cell viability (p < 0.01) with coumarin (200 µM). AST-IV with fixed coumarin (200 µM) showed 27% toxicity at 300 µM AST-IV in rifampicin uninduced cells (p < 0.05) and 30% toxicity in rifampicin induced cells (p < 0.05). However, when fixed coumarin and AST-IV were combined with increasing concentrations of ATR-I no further significant increase in toxicity was observed (p > 0.05). These results demonstrate the potential toxic interactive capabilities of common traditional Chinese herbal medicine phytochemicals and underline the potential importance of coumarin-mediated toxicity.

Astragaloside IV protects against C/EBP homologous protein-mediated apoptosis in oxidized low-density lipoprotein-treated macrophages by promoting autophagy

Astragaloside Ⅳ (AS-Ⅳ) is one of the main active components extracted from Astragalus membranaceus that exerts an antiatherosclerotic effect. Our study explored the underlying anti-apoptotic effects and the mechanisms of action of AS-Ⅳ in oxidized low-density lipoprotein (oxLDL)-stimulated macrophages and in vulnerable plaques. The results showed that AS-Ⅳ lowered the oxLDL-induced lipid content and reversed the oxLDL-induced reduction in cell viability and elevation in lactate dehydrogenase (LDH) leakage and apoptosis in RAW264.7 macrophages, similar to the effects of 4-phenylbutyric acid (PBA, an ER stress inhibitor). In addition, consistent with the effect exerted by PBA, AS-Ⅳ inhibited oxLDL-triggered ER stress activation by decreasing the level of inositol-requiring enzyme1 phosphorylation and transcription factor 6 nuclear translocation and upregulating the protein and mRNA expression of glucose-regulated protein 78 (GPR78) and C/EBP homologous protein (CHOP). As expected, autophagy activation was induced by AS-IV, evidenced by increased expression of microtubule-associated protein 1 light chain 3-Ⅱ (LC3-Ⅱ), autophagy-related gene 5, and beclin-1 in macrophages. Furthermore, after pretreatment with 3-methyladenine and beclin-1 small interfering RNA, the inhibitory role played by AS-Ⅳ in oxLDL-induced ER stress-CHOP-mediated macrophage apoptosis was weakened, while its inhibitory effect was further enhanced by rapamycin pretreatment. Moreover, administration of AS-Ⅳ or rapamycin to Apoe−/− mice upregulated LC3-Ⅱ expression and collagen content but decreased CHOP expression, macrophage apoptosis, and lipid areas. Overall, by promoting autophagy, AS-Ⅳ effectively protects macrophages from oxLDL-induced apoptosis mediated by ER stress-CHOP, which may reinforce the stability of atherosclerotic plaques.

Therapeutic Potential of Astragaloside IV Against Adriamycin-Induced Renal Damage in Rats via Ferroptosis.

Adriamycin (ADR) has been utilized to treat cancer for several decades. However, ADR-induced renal injury is one of the most common side effects accompanying ADR therapy. In the present study, we revealed that astragaloside IV (ASIV) was beneficial for renal injury caused by Adriamycin. We demonstrated that ASIV significantly ameliorated kidney injury, improved renal dysfunction, reduced oxidative stress, alleviated iron accumulation, and inhibited the induction of ferroptosis by ADR. ASIV also rescued the intracellular levels of nuclear factor-erythroid-2-related factor 2 (Nrf2) and promoted nuclear translocation of Nrf2. These protective effects of ASIV on renal injury might be attained through the ASIV-induced activation of the Pi3K/Akt signaling pathway. In vitro, the treatment of the HK-2 cells with fer-1 or deferoxamine mesylate obviously improved cell viability during Adriamycin administration. On the other hand, the protective role of ASIV can be abrogated by RSL3 to some extent. Moreover, ASIV lowered the expression of transferrin receptor 1 and divalent metal transporter 1 while enhancing the expression of ferropotin 1 and glutathione peroxidase 4 in ADR administrated cells, the effects of which were akin to those of deferoxamine mesylate. Furthermore, ASIV increased the phosphorylation of Pi3K, Akt, and the expression of Nrf2 and glutathione peroxidase 4 compared to HK-2 cells stimulated by ADR. However, Pi3K inhibitor LY294002 abrogated these activations. In conclusion, ferroptosis may involve in ADR-induced nephrotoxicity, and ASIV might protect nephrocytes against ADR-induced ferroptosis, perhaps via activations of the Pi3K/Akt and Nrf2 signaling pathways.

Astragaloside-IV alleviates high glucose-induced ferroptosis in retinal pigment epithelial cells by disrupting the expression of miR-138-5p/Sirt1/Nrf2

ABSTRACT Astragaloside-IV (AS-IV) (C41H68O14) is a high-purity natural product extracted from Astragalus, which has demonstrated biological activities. However, the effect of AS-IV on retinal pigment epithelial (RPE) cells in diabetic retinopathy (DR) remains unclear. In this study, high glucose (HG) was shown to promote ARPE-19 RPE cell death, increase the contents of reactive oxygen species (ROS) and oxidized glutathione (GSSG), and enhance lipid peroxidation density of mitochondrial membrane. In contrast, AS-IV decreased glutathione (GSH) content, mitochondria size and ridge. Addition of ferroptosis inhibitor Ferrostatin-1 (Fer-1) to RPE cells decreased cell dead rate, thus indicating that HG-induced mitochondrial damage occurred due to ferroptosis. AS-IV alleviated HG-induced RPE cell damage. Furthermore, HG decreased levels of silent information regulator 1 (Sirt1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in the nucleus of RPE cells; AS-IV could alleviate these effects and increased expression of glutathione peroxidase 4 (GPX4), glutamate cysteine ligase (GCLM) and glutamate cysteine ligase catalytic subunit (GCLC), which are Nrf2 downstream genes. Mechanistically, AS-IV was shown to alleviate the effects of HG by increasing mir-138-5p expression in RPE cells and promoting expression of Sirt1 and Nrf2 in the nucleus. Transfection of mir-138-5p agonist inhibited the regulatory effects of AS-IV on Sirt1 and Nrf2, accompanied by decreased GPX4, GCLM and GCLC levels, and restoration of ferroptosis-related changes. Collectively, HG increased ferroptosis rate in RPE cells. In addition, AS-IV inhibited miR-138-5p expression, subsequently increasing Sirt1/Nrf2 activity and cellular antioxidant capacity to alleviate ferroptosis, resulting decreased cell death, which potentially inhibits the DR pathological process.

Astragaloside IV Improves the Barrier Damage in Diabetic Glomerular Endothelial Cells Stimulated by High Glucose and High Insulin.

Objective To investigate the protective effect and mechanism of astragaloside IV (AS-IV) on damage in human glomerular endothelial cells (GEnCs) stimulated by high glucose and high insulin. Methods The transwell method was used to detect the integrity of the cell barrier after AS-IV intervention in a high glucose and high insulin environment for 24 h; immunofluorescence and Western blot methods were used to detect the tight junction protein ZO-1 and claudin-5 expression; intracellular and extracellular 1β (IL-1β) and tumor necrosis factor α (TNFα) were determined by ELISA; expression and activation of AKT, p-AKT, GSK3α/β, and p-GSK3α/β were evaluated by Western blot. Results The results showed that AS-IV had a significant protective effect on the cell barrier of GEnCs. High glucose or insulin inhibited cell viability in a concentration-dependent manner. High glucose or insulin significantly inhibited glucose uptake and promoted release of reactive oxygen species in GEnCs. Administration with AS-IV dramatically preserved viability of the cells; moreover, the expression of intracellular tight junction proteins was upregulated, inflammatory cytokines including IL-1β and TNFα were decreased, and the AKT-GSK3 pathway participated in modulation of AS-IV in GEnCs cells. Conclusion We found in the present study that AS-IV can preserve filtration barrier integrity in glomerular endothelial cells under diabetic settings, its effects on increasing the cell energy metabolism and cell viability, inhibiting inflammation and oxidative stress damage, and enhancing tight junction between cells play a role in it; and the intracellular signaling pathway AKT-GSK modulated the above function. Our present finding supplied a new understanding towards development of DN and provided an alternative method on ameliorating DN.

Implication of IGF1R signaling in the protective effect of Astragaloside IV on ischemia and reperfusion-induced cardiac microvascular endothelial hyperpermeability

BackgroundMyocardial ischemia-reperfusion (I/R) causes damage to coronary capillary endothelial barrier and microvascular leakage (MVL), aggravating tissue injury and heart dysfunction. However, the effective strategy for protecting endothelium barrier of cardiac vasculature remains limited. PurposeThis study aimed to explore the effect of Astragaloside IV (ASIV) on coronary MVL after cardiac I/R and the underlying mechanism. Study designSprague-Dawley (SD) rats were used for assessment of the efficacy of Astragaloside IV in protection of myocardial I/R injury, while human cardiac microvascular endothelial cells were applied to gain more insight into the underlying mechanism. MethodsSprague-Dawley rats with or without pretreatment by ASIV at 10 mg/kg were subjected to occlusion of left coronary anterior descending artery followed by reperfusion. Endothelial cells were exposed to hypoxia and re-oxygenation (H/R). The distribution of junction proteins was detected by immunofluorescence staining and confocal microscope, the content of junction proteins was detected by Western blot, the level of adenosine triphosphate (ATP) was detected by ELISA, and the signal pathway related to permeability was detected by siRNA infection. The fluorescence intensity of FITC-albumin and FITC-Dextran was measured to evaluate the permeability of endothelial cells. ResultsASIV exhibited protective effects on capillary damage, myocardium edema, albumin leakage, leucocyte infiltration, and the downregulated expression of endothelial junction proteins after I/R. Moreover, ASIV displayed ability to protect ATP from depletion after I/R or H/R, and the effect of ASIV on regulating vascular permeability and junction proteins was abolished once ATP synthase was inhibited. Notably, ASIV activated the insulin-like growth factor 1 receptor (IGF1R) and downstream signaling after reoxygenation. Knocking IGF1R down abolished the effect of ASIV on restoration of ATP, junction proteins and endothelial barrier after H/R. ConclusionASIV was potential to prevent MVL after I/R in heart. Moreover, the study for the first time demonstrated that the beneficial role of ASIV depended on promoting production of ATP through activating IGF1R signaling pathway. This result provided novel insight for better understanding the mechanism underlying the potential of ASIV to cope with cardiac I/R injury.

Astragaloside IV alleviates oxidative stress-related damage via inhibiting NLRP3 inflammasome in a MAPK signaling dependent pathway in human lens epithelial cells.

Oxidative stress alters cellular microenvironment, facilitating cell apoptosis and inflammatory response, and oxidation of lens constituents may ultimately result in cataracts. Astragaloside IV (AS-IV) exhibits a variety of pharmacological activities, such as antioxidative and anti-inflammatory activity via regulating various signaling pathways. However, the effect of AS-IV on lens epithelial cells and its potential therapeutic role in cataracts remained to be investigated. In this study, AS-IV prevented H2 O2 -induced injury and inflammatory response in human lens epithelial cell line HLE-B3 through inhibiting NLRP3 inflammasome in a mitogen-activated protein kinase-dependent pathway, providing a potential novel therapeutic strategy for cataracts.

Astragaloside IV Relieves Atherosclerosis and Hepatic Steatosis via MAPK/NF-κB Signaling Pathway in LDLR-/- Mice.

Astragaloside IV (AS-IV) is the main active compound of Astragalus membranaceus. In this study, we investigated whether AS-IV could attenuate atherosclerosis and hepatic steatosis in LDLR−/−mice and its potential mechanisms. After 12 weeks of high fat diet, the LDLR−/−mice were randomly divided into four groups. Then, the mice were administrated with 0.9% saline or AS-IV (10 mg/kg) or atorvastatin (1.3 mg/kg) for 12 weeks. Serum lipid profiles and inflammatory cytokines were detected by ELISA, hepatic TC and TG by colorimetric enzymatic kits, gene expression by RT-qPCR, plaque sizes by H&E staining, Oil Red O, liver pathology by H&E staining, collagen content by Masson, α-SMA, caspase-3 and NF-κB p65 production by immunofluorescence staining. MAPK/NF-κB pathway and inflammation related proteins were detected by Western Blot. The results showed that AS-IV decreased the levels of serum lipids, reduced plaque area and increased plaque stability in HFD-induced LDLR−/− mice. AS-IV also decreased the levels of inflammatory cytokines in the serum, aortas and liver tissue, and NF-κB p65 in aortic roots. The phosphorylation of JNK, ERK1/2, p38 and NF-κB, and inflammatory proteins (iNOS, VCAM-1and IL-6) was inhibited in AS-IV-treated group. In summary, AS-IV inhibited inflammation to attenuate atherosclerosis and hepatic steatosis via MAPK/NF-κB signaling pathway in LDLR−/− mice.

Astragaloside IV Alleviates Infarction Induced Cardiomyocyte Injury by Improving Mitochondrial Morphology and Function.

The protective effect of astragaloside IV (AS-IV) on myocardial injury after myocardial infarction has been reported. However, the underlying mechanism is still largely unknown. We established a myocardial infarction model in C57BL/6 mice and injected intraperitoneally with 10 mg/kg/d AS-IV for 4 weeks. The cardiac function, myocardial fibrosis, and angiogenesis were investigated by echocardiography, Masson's trichrome staining, and CD31 and smooth muscle actin staining, respectively. Cardiac mitochondrial morphology was visualized by transmission electron microscopy. Cardiac function, infarct size, vascular distribution, and mitochondrial morphology were significantly better in AS-IV-treated mice than in the myocardial infarction model mice. In vitro, a hypoxia-induced H9c2 cell model was established to observe cellular apoptosis and mitochondrial function. H9c2 cells transfected with silent information regulator 3 (Sirt3) targeting siRNA were assayed for Sirt3 expression and activity. Sirt3 silencing eliminated the beneficial effects of AS-IV and abrogated the inhibitory effect of AS-IV on mitochondrial division. These results suggest that AS-IV protects cardiomyocytes from hypoxic injury by maintaining mitochondrial homeostasis in a Sirt3-dependent manner.

Suppressing NK Cells by Astragaloside IV Protects Against Acute Ischemic Stroke in Mice Via Inhibiting STAT3.

Natural killer (NK) cells, a key member of innate lymphocytes, are a promising immunotherapeutic target for ischemic stroke. Astragaloside IV (ASIV) is isolated from Astragalus mongholicus Bunge (Fabaceae), a herbal medicine possessing immunomodulatory ability. This study investigated the effect of ASIV on NK cells during the acute stage of brain ischemic injury in a mouse model of middle cerebral artery occlusion (MCAO). MCAO mice treated with ASIV had better functional outcomes, smaller brain infarction and less NK cell brain infiltration. NK cell depletion echoed the protective effect of ASIV. Notably, ASIV did not enhance the protective effect of NK cell depletion against brain ischemic injury. ASIV inhibited glial cell-derived CCL2-mediated chemotaxis to prevent post-ischemic NK cell brain recruitment. Meanwhile, ASIV also abrogated NK cell-mediated cytolytic killing of neurons subjected to oxygen-glucose deprivation and suppressed NK cell-derived IFN-γ and NKG2D expression in the ischemic brain. The inhibitory effect of ASIV on NK cell brain infiltration and activation was mimicked by cryptotanshinone, a STAT3 inhibitor. There was no additive effect when ASIV and cryptotanshinone were used together. In conclusion, ASIV inhibits post-ischemic brain infiltration and activation of NK cells through STAT3 suppression, and this inhibitory effect of ASIV on NK cells plays a key role in its protection against acute ischemic brain injury. Our findings suggest that ASIV is a promising therapeutic candidate in NK cell-based immunotherapy for the treatment of acute ischemic stroke and pave the way for potential clinical trials.

Astragaloside IV suppresses migration and invasion of TGF-β1-induced human hepatoma HuH-7 cells by regulating Nrf2/HO-1 and TGF-β1/Smad3 pathways.

Astragaloside IV (AS-IV), one of the major compounds extract from Astragalus membranaceus, has shown attractive anti-cancer effects in certain malignancies. Oxidative stress (OS) is considered as a crucial factor in promoting the progression of hepatocellular carcinoma (HCC). In response to OS, nuclear factor erythroid 2-related factor 2 (Nrf2) upregulates and induces heme oxygenase 1 (HO-1) to combat oxidative damages. The phosphorylation of the COOH-terminal of Smad3 (pSmad3C) activates p21 to resist HCC progression, while the phosphorylation of the linker region of Smad3 (pSmad3L) up-regulates c-Myc transcription to exert promoting effect towards HCC. This study aimed to explore whether AS-IV suppresses migration and invasion of human hepatoma HuH-7 cells by regulating Nrf2/HO-1 and TGF-β1/Smad3 pathways. HuH-7 cells were induced with TGF-β1 (9 or 40pM) to establish HCC model in vitro and pretreated with AS-IV at different concentration (5, 10, and 20μM) for 24h. Cell proliferation, migration, invasion, and intracellular reactive oxygen species (ROS) of HuH-7 cells were measured. The expression of Nrf2, pSmad3C, Nrf2/pNrf2, HO-1, pSmad3C/3L, c-Myc, and p21 were detected. Exposure of HuH-7 cells to TGF-β1 enhanced the cell proliferation, migration, invasion, and ROS production. Pretreatment with AS-IV (5, 10, and 20μM) significantly reduced the cell proliferation, migration, invasion, and ROS production in HuH-7 cells. Furthermore, AS-IV increased the expressions of Nrf2/pNrf2, HO-1, pSmad3C, and p21, meanwhile reduced the expressions of pSmad3L and c-Myc. In conclusion, our study suggested that AS-IV inhibit HuH-7 cells migration and invasion, which related to activate Nrf2/HO-1 pathway, up-regulation pSmad3C/p21 pathway, and down-regulation pSmad3L/c-Myc pathway. The present research supports the notion that AS-IV may be a latent agent for the treatment of HCC.

Astragaloside IV ameliorates peripheral immunosuppression induced by cerebral ischemia through inhibiting HPA axis

Post-ischemic peripheral immunosuppression increases vulnerability to infection which is a common complication and worsens outcome in ischemic stroke patients. Hypothalamic-pituitary-adrenal (HPA) axis plays a key role in post-ischemic immunosuppression. Astragaloside IV (ASIV), isolated from Astragalus membranaceus, possesses immunomodulatory and neuroprotective effects against cerebral ischemic injury. This study investigated the effect of ASIV on cerebral ischemia-induced peripheral immunosuppression and the underlying mechanism in a mouse model of middle cerebral artery occlusion (MCAO). Our results showed that ASIV significantly prevented the atrophy of spleen and the reduction of splenic cell count. Meanwhile, ASIV preserved cell numbers of splenic NK, T, and B cells in the spleen. ASIV also suppressed apoptosis of splenic cells and preserved their proliferation ability. In addition, ASIV robustly reduced the mRNA expression of TNF-α, IL-1β, IL-6 and CRH in the hypothalamus, as well as the enlargement of adrenal gland and the increase of corticosterone in blood, indicating the inhibition of HPA axis by ASIV. Furthermore, ASIV did not enhance the effect of HPA inhibition on reducing splenic atrophy and preserving splenic NK, T, and B cell numbers in MCAO mice. Of note, ASIV did not attenuate splenic cell apoptosis induced by prednisolone, suggesting that ASIV may ameliorate splenic apoptosis through reducing peripheral glucocorticoid level. Our findings demonstrate that ASIV ameliorates post-ischemic peripheral immunosuppression through inhibiting the activation of HPA axis and targeting HPA activation to ameliorate peripheral immunosuppression may be a promising strategy to improve clinical outcomes of ischemic stroke.

Regulatory Effects of Astragaloside IV on Hyperglycemia-Induced Mitophagy in Schwann Cells.

Objective This study aimed to observe the regulatory effects of astragaloside IV (AS-IV) on hyperglycemia-induced mitochondrial damage and mitophagy in Schwann cells and to provide references for clinical trials on AS-IV in the treatment of diabetic peripheral neuropathy. Methods Schwann cells were grown in a high-glucose medium to construct an autophagy model; the cells were then treated with AS-IV and N-acetylcysteine (control) to observe the regulatory effects of AS-IV on oxidative stress and mitophagy. Results AS-IV exhibited antioxidant activity and inhibited the overactivation of autophagy in Schwann cells, significantly reducing the level of reactive oxygen species and downregulating the expression of autophagy-related proteins (LC3, PINK, and Parkin) under hyperglycemic conditions, thereby exerting a protective effect on mitochondrial morphology and membrane potential. Conclusion AS-IV can maintain the mitochondrial function of Schwann cells under hyperglycemic conditions by effectively alleviating oxidative stress and overactivation of mitophagy. The evidence from this study supports an AS-IV-based therapeutic strategy against diabetic peripheral neuropathy.

Protective Effects of Astragaloside IV on Uric Acid-Induced Pancreatic β-Cell Injury through PI3K/AKT Pathway Activation.

Background Elevated uric acid (UA) has been found to damage pancreatic β-cell, promote oxidative stress, and cause insulin resistance in type 2 diabetes (T2D). Astragaloside IV (AS-IV), a major active monomer extracted from Astragalus membranaceus (Fisch.) Bunge. which belongs to TRIB. Galegeae (Br.) Torrey et Gray, Papilionaceae, exhibits various activities in a pathophysiological environment and has been widely employed to treat diseases. However, the effects of AS-IV on UA-induced pancreatic β-cell damage need to be investigated and the associating mechanism needs to be elucidated. This study was designed to determine the protective effects and underlying mechanism of AS-IV on UA-induced pancreatic β-cell dysfunction in T2D. Methods UA-treated Min6 cells were exposed to AS-IV or wortmannin. Thereafter, the 3-(45)-dimethylthiahiazo(-z-y1)-35-di-phenytetrazoliumromide (MTT) assay and flow cytometry were employed to determine the effect of AS-IV on cell proliferation and apoptosis, respectively. Insulin secretion was evaluated using the glucose-stimulated insulin secretion (GSIS) assay. Finally, western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were performed to determine the effect of AS-IV on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway in UA-treated cells. Results AS-IV had no cytotoxic effects on Min6 cells. UA significantly suppressed Min6 cell growth, promoted cell apoptosis, and enhanced caspase-3 activity; however, AS-IV abolished these effects in a dose-dependent manner. Further, decreased insulin secretion was found in UA-treated Min6 cells compared to control cells, and the production of insulin was enhanced by AS-IV in a dose-dependent manner. AS-IV significantly increased phosphorylated (p)-AKT expression and the ratio of p-AKT/AKT in Min6 cells exposed to UA. No evident change in AKT mRNA level was found in the different groups. However, the effects of AS-IV on UA-stimulated Min6 cells were reversed by 100 nM wortmannin. Conclusion Collectively, our data suggest that AS-IV protected pancreatic β-cells from UA-treated dysfunction by activating the PI3K/AKT pathway. Such findings suggest that AS-IV may be an efficient natural agent against T2D.

Preliminary study of astragaloside IV on oxaliplatin-induced peripheral neurotoxicity in rats

Objective: As an effective component of Astragalus membranaceus, astragaloside IV (AS-IV) has a history of thousands of years in China. Many evidences have indicated that AS-IV has a potential neuroprotective effect. In this study, we aimed to preliminarily study the effects of AS-IV on oxaliplatin-induced peripheral neurotoxicity (OIPN) in rats. Methods: Intraperitoneal injection of oxaliplatin for 4 weeks (4 mg/kg, twice a week) was used to establish peripheral neurotoxicity in rats. 40 Sprague Dawley rats were randomly divided into five groups, eight rats in each group, including control group, model group, and three AS-IV treated groups. Different doses of AS-IV (5 mg/kg, 10 mg/kg, and 20 mg/kg, daily) were orally administrated to OIPN rats once a day for 4 weeks at beginning of oxaliplatin administration. Behaviors and histologic evaluation of sciatic nerve and dorsal root ganglia (DRG) were performed to assess the changes of peripheral neurotoxicity through mechanical allodynia and cold allodynia, immunofluorescence, H&amp;E staining, myelin staining, and Nissl staining. Results: AS-IV treatments were able to significantly reduce oxaliplatin induced mechanical and cold allodynia. Moreover, AS-IV administration could increase the levels of NGF, but decrease the levels of TNF-α and IL-6 in oxaliplatin induced rats. AS-IV suppressed the activation of Iba-1 in anterior horn of spinal cord of OIPN rats. The myelin sheath degenerations in the sciatic nerve of OIPN rats were repaired after AS-IV administration. Through observation of sciatic nerves and DRG, AS-IV treatments improved the oxaliplatin induced pathologic injuries in a dose-dependent. Conclusion: AS-IV administration was able to attenuate the oxaliplatin-induced peripheral neurotoxicity in rats.