Astragalus-mediated stimulation on antigen-presenting cells could result in higher IL-21 production from CXCR5+ Tfh-like cells and better IL-21-mediated effector functions.

T cells in renal cell carcinoma (RCC) patients display multiple features of impairment and exhaustion. Here, we hypothesize that Astragalus membranaceus, a herbal medicine commonly used to accompany chemotherapy, might have adjuvating effects on T cells from RCC patients. To investigate this, circulating T cells from healthy individuals and RCC patients were cocultured ex vivo with aqueous extract from Astragalus. Functional characteristics of T cells in the absence and presence of Astragalus extract were then compared. We first identified a downregulation of IL-21 expression in RCC patients in association with a functional dysregulation of CXCR5+ Tfh-like cells. Astragalus extract could significantly increase IL-21 expression in a dose-dependent manner. This Astragalus-mediated effect depended on the presence of antigen-presenting cells (APCs), as purified CXCR5+ Tfh-like cells presented little IL-21 upregulation following Astragalus stimulation. APCs primed by Astragalus extract also promoted IL-21 expression from Tfh-like cells. Interestingly, Astragalus-stimulated Tfh-like cells presented enhanced helper function and resulted in higher humoral responses and better CD8 T cell survival. This effect was dependent on the presence of IL-21. Overall, these data indicated that Astragalus could enhance IL-21 production and effector function from CXCR5+ Tfh-like cells in a manner that depended on the presence of APCs.

Inhibition of NLRP3 inflammasome-mediated pyroptosis in macrophage by cycloastragenol contributes to amelioration of imiquimod-induced psoriasis-like skin inflammation in mice.

Psoriasis is a common chronic inflammatory skin disease, and the infiltrated macrophages in psoriatic skin lesions play a key role in the progression of this uncontrolled cutaneous inflammation. However, the current therapeutic strategies for patients with psoriasis are not satisfactory. Here, we report that cycloastragenol (CAG), a natural active small compound isolated from Astragalus membranaceus, significantly ameliorated imiquimod (IMQ)-induced psoriasiform dermatitis in mice by targeting proinflammatory macrophages. CAG significantly reduced the clinical scores, decreased the epidermal thickness, and ameliorated the deteriorating histopathology observed in IMQ-induced mice. CAG treatment specifically reduced the dermal infiltration of macrophages, rather than of dendritic cells, neutrophils, or T lymphocytes, into psoriatic skin. CAG dose-dependently decreased the level of proinflammatory cytokines, including IL-1ß, TNF-α and IL-6, in murine psoriatic skin and serum, as well as in IMQ-stimulated, bone-marrow-derived macrophages. When compared to the control group, CAG significantly decreased IMQ-triggered NLRP3 inflammasome activation and gasdermin D-mediated cell pyroptosis in these proinflammatory macrophages. CAG also suppressed the assembly of the NLRP3 inflammasome complex. Taken together, the results show that CAG selectively modulates macrophage function by inhibiting NLRP3 inflammasome-mediated pyroptosis to ameliorate IMQ-induced psoriasis-like skin inflammation in mice. Our findings also identify an effective drug candidate for the treatment of psoriasis.

Baicalein Exerts Anticancer Effect in Nasopharyngeal Carcinoma In Vitro and In Vivo.

Baicalein, an active ingredient separated from Astragalus membranaceus, has shown its anticancer ability in various cancers. However, its effect on nasopharyngeal carcinoma has not been explored yet. The present study aimed to investigate the effect of baicalein on the growth, proliferation, apoptosis, and cell cycle of human nasopharyngeal carcinoma cells, as well as transplanted nude mouse xenograft. The results showed that baicalein inhibited the growth and proliferation of CNE1 and CNE2 cells in a time- and concentration-dependent manner. It also caused a significant increase in the number of cells in the G0/G1 phase and a decrease in the G2/M phase, thereby reducing the number of cells entering mitosis and inhibiting the proliferation of tumor cells. Baicalein also significantly induced apoptosis of CNE1 and CNE2 cells. Western blots showed that baicalein decreased the expression of Bcl-xl and Mcl-1 and increased the expression of Bax, Bad, and caspase 3, 8, and 9. In CNE1- and CNE2-transplanted tumors of mice, baicalein significantly inhibited tumor growth. In conclusion, baicalein could inhibit the growth and proliferation of human nasopharyngeal carcinoma cells, change their cell cycle, and induce apoptosis. Baicalein also effectively limits both CNE1- and CNE2-transplanted tumors in nude mice. Downregulation of Bcl-xl and Mcl-1 proteins and upregulation of Bax and Bad may be involved in the mechanism.

Are the Therapeutic Effects of Huangqi (Astragalus membranaceus) on Diabetic Nephropathy Correlated with Its Regulation of Macrophage iNOS Activity?

OBJECTIVE: To investigate the correlation between the clinical effects of Huangqi (Astragalus membranaceus) on different stages of diabetic nephropathy (DN) and the pharmacological effect of Huangqi on the activity of inducible nitric oxide synthase (iNOS) in macrophages in different states. METHODS: The PubMed, China National Knowledge Infrastructure, and Wanfang databases were searched. Clinical data was sourced from papers on treatment of different stages of DN with Huangqi, and pharmacological data was from papers on the effects of Huangqi on the iNOS activity of macrophages in a resting or an activated state. RESULTS: Meta-analysis of Huangqi injections on stages III and III-IV DN and randomized controlled trials on other stages showed that Huangqi had therapeutic effects on different stages of DN and on macrophages in different states: inducing normal macrophages in a resting state to generate nitric oxide (NO), tumor necrosis factor-α, and so forth upon iNOS activation; inhibiting NO generation by normal lipopolysaccharide- (LPS-) activated macrophages; and enhancing NO generation by LPS-induced macrophages from patients with renal failure. CONCLUSIONS: Huangqi can regulate iNOS activity of macrophages in different states in vitro. These biphasic or antagonistic effects may explain why Huangqi can be used to treat different stages of DN.

Astragaloside IV from Astragalus membranaceus ameliorates renal interstitial fibrosis by inhibiting inflammation via TLR4/NF-кB in vivo and in vitro.

Renal fibrosis is characterized by infiltration of inflammatory cells, activation and proliferation of fibroblasts, and accumulation of extracellular matrix (ECM). Astragalus membranaceus (AM) is traditional Chinese medicine and has a range of pharmacological effects. Astragaloside IV (As IV) is the main compound of AM and has anti-inflammation activities. Whether As IV ameliorates renal interstitial fibrosis by inhibiting inflammation remains unknown. Accordingly, this study investigated the ameliorating effect of As IV on renal fibrosis. Renal fibrosis was induced in vivo using the unilateral ureteral obstruction (UUO) model. UUO mice were administered intragastrically with As IV (20 and 40mg/kg/day). After a week, ECM including fibronectin and collagen I was examined by Immunohistochemistry and Western blot, inflammatory cells (CD68 and CD3) were detected by Immunohistochemistry, the release of inflammatory cytokines (tumor necrosis factor-α and interleukin-1ß) was inspected by polymerase chain reaction, and signaling pathway was determined by Western blot. In vitro, 100ng/ml lipopolysaccharide (LPS) stimulated epithelial cells to construct the inflammatory model; these cells were treated by As IV (10 and 20µM) with or without TAK-242 (1µM) for 48h. The released inflammatory cytokines were assayed by enzyme-linked immunosorbent assay, and signaling pathway was evaluated by Western blot. As IV decreased accumulation of ECM and infiltration of inflammatory cells in UUO-induced renal fibrosis. Furthermore, As IV markedly attenuated pro-inflammatory cytokines in UUO mouse and LPS-induced epithelial cells. As IV also inhibited the TLR4 and nuclear factor (NF)-кB signaling pathway in vivo and vitro. These results demonstrate that As IV protects against the progression of renal fibrosis by inhibiting inflammation via the TLR4/NF-кB signaling pathway.

Astragaloside IV alleviates E. coli-caused peritonitis via upregulation of neutrophil influx to the site of infection.

Astragaloside IV (AS-IV), an active saponin purified from Astragali Radix, has been identified with broad biological and pharmacological activities. In the present study, we continue to explore the potential effect of AS-IV on antibacterial response using an acute E. coli peritoneal infection model. Our findings implied that administration of AS-IV decreases mortality in mice challenged by lethal E. coli infection. The protection of AS-IV was related to promotion of neutrophil extravasation into the peritoneum and bacterial clearance. Toll-like receptor (TLR) activation in neutrophils has been reported to reduce CXCR2 expression and subsequent neutrophil migration. Our data indicated that AS-IV prevented the reduction of CXCR2 expression and neutrophil migration induced by LPS, the activator for TLR4. Moreover, we found that AS-IV blocks LPS-induced suppression of CXCR2 on neutrophils by inhibiting the expression of G protein-coupled receptor kinase-2 (GRK2), an agonist that regulates desensitization and internalization of chemokine receptors. Taken together, these data propose that AS-IV, through modulating GRK2-CXCR2 signal in neutrophils, offers an essential efficacy on host antibacterial immunity.

Protective effects of Astragalus polysaccharides against endothelial dysfunction in hypertrophic rats induced by isoproterenol.

Astragalus polysaccharide (APS) is an important bioactive component extracted from Chinese herb Astragalus membranaceus. It has been widely used in treatment of cardiovascular diseases. We have previously reported that APS could inhibit isoproterenol-induced cardiac hypertrophy. The present study was designed to evaluate the protective effect of APS on vascular endothelia in cardiac hypertrophy rats induced by isoproterenol (ISO). ISO (10mg×kg(-1)) was intraperitoneally injected once daily for 2weeks to induce cardiac hypertrophy. APS (400 and 800mg×kg(-1)) was intragastrically injected once daily along with ISO. The results showed that combination with APS significantly ameliorates the endothelial dysfunction while attenuates cardiac hypertrophy induced by ISO. We found that administration with APS could attenuate the increase in number of circulating endothelial cell (CEC). APS also decreases the superoxide anion generation and the protein expression of p65 and the levels of TNF-α and IL-6; while increases the cGMP levels, an activity marker for nitric oxide (NO) in aortas. In addition, APS improves the relaxation dysfunction in isolated aortic rings and increases the protein expression of IκBα and Cu/Zn-SOD in aortas. In conclusion, our results suggested that APS had a protective effect against endothelial dysfunction in hypertrophic rats induced by ISO. The underlining mechanisms may be contributed to the anti-inflammatory effects and the improvement of the imbalance between reactive oxygen species (ROS) and NO.

Astragaloside IV enhances diabetic wound healing involving upregulation of alternatively activated macrophages.

Astragaloside IV (AS-IV), one of the major active compounds extracted from Astragali Radix, has been used experimentally for its potent antiinflammatory and immunoregulatory activities. In this study, we further investigate the potential efficacy of AS-IV on impaired wound healing in streptozotocin-induced diabetic mice. A full-thickness skin wound was produced on the back of diabetic mice and treated with AS-IV or vehicle topically. Our results showed that AS-IV application promoted diabetic wound repair with wounds gaping narrower and exhibiting augmented reepithelialization. AS-IV enhanced the collagen deposition and the expression of extracellular matrix (ECM)-related genes such as fibronectin and collagen IIIa, which implies a direct effect of AS-IV on matrix synthesis. AS-IV also improved the new blood vessel formation in wound tissue with increased numbers of endothelial cells and enhanced expression of VEGF and vWF. Moreover, the beneficial effect of AS-IV was related to the development of polarized alternatively activated macrophages, which involved in resolution of inflammation and facilitation of wound repair. All together, these findings suggest that AS-IV may play a potential effect on maintenance of cutaneous homeostasis and acceleration of diabetic wound healing.

Astragaloside IV improves the isoproterenol-induced vascular dysfunction via attenuating eNOS uncoupling-mediated oxidative stress and inhibiting ROS-NF-κB pathways.

OBJECTIVE: Oxidative stress and inflammation are regarded as two important triggers of endothelial dysfunction and play pivotal role in progression of vascular damage associated with cardiac hypertrophy. Our previous studies demonstrated that astragaloside IV (AsIV) could protect against cardiac hypertrophy in rats induced by isoproterenol (Iso), but its effects on the aorta are not known. In present study, we aimed to assess the effects of AsIV on Isoinduced vascular dysfunction. METHODS: Sprague-Dawley (SD) rats were treated with Iso (10mg/kg/d) alone or in combination with AsIV (50mg/kg/d). RESULTS: Compared with Isotreated alone, AsIV significantly reduced the ratios of heart weight/body weight and left ventricular weight/body weight. AsIV ameliorated the increased vasoconstriction response to phenylephrine induced by Iso and suppressed superoxide anion generation in rat aorta, increased endothelial nitric oxide synthase (eNOS) dimer/monomer ratio and its critical cofactor tetrahydrobiopterin (BH4) content in aorta as well as the NO production in the serum, reduced the plasmatic peroxynitrite (ONOO-). Moreover, in contrast with Isotreatment alone, AsIV decreased the ratio of nuclear-to-cytosolic protein expression of the NF-κB p65 subunit while enhanced its inhibited protein expression of IκB-α, down-regulated mRNA expression of IL-1ß, IL-6 and TNF-α of the aorta. CONCLUSIONS: The present study suggested that AsIV protects against Isoinduced vascular dysfunction probably via attenuating eNOS uncoupling-mediated oxidative stress and inhibiting ROS-NF-κB pathways.

Effects of topical application of Astragalus membranaceus on allergic dermatitis.

Astragalus membranaceus (AM) is one of the most popular health-promoting herbs in East Asia, and has been used in traditional medicine for more than 2000 years. This study was performed to examine whether AM suppresses atopic dermatitis (AD)-like skin lesions in BALB/c mice. Seven-week-old female BALB/c mice were sensitized with 1-chloro-2,4-dinitrobenzene (DNCB) to induce allergic dermatitis. Skin sections were stained with hematoxylin and eosin (H&E) to assess epidermal and dermal hyperplasia, which were determined by measuring the thicknesses of the epidermis and dermis, respectively. The serum immunoglobulin G (IgE) concentration was quantified by enzyme-linked immunosorbent assay (ELISA). In addition, the levels of interleukins (IL)-4, -5, -6, and -13 and tissue necrosis factor (TNF)-α were measured in mouse serum. Significance was determined by one-way analysis of variance (ANOVA). Topical AM markedly improved the AD skin lesions in DNCB-induced mice. The AD skin lesions were significantly thinner in the AM treatment group compared with untreated controls, and the hyperkeratosis disappeared. Topical treatment of AM also restored nuclear factor-κB (NF-κB) expression. In addition, the serum IgE level was reduced. AM suppressed the expression of Th2 cytokines (IL-4, -5, -6, and -13) and significantly decreased the TNF-α level. AM is effective for treating AD by regulating cytokines. AM may be an alternative or complementary therapeutic option for treating patients with AD. More in-depth studies are necessary to clarify the mechanisms of AM.

Characterization of polysaccharide from Astragalus radix as the macrophage stimulator.

Astragalus polysaccharide (APS) was obtained by hot water extraction, alcohol precipitation, gel-permeation chromatography and ultrafiltration. Fluorescence material 2-aminoacridone (2-AMAC) labeled APS bind to macrophage in a time- dependent manner and the binding can be remarkably inhibited by APS. Furthermore, the effect of APS on RAW264.7 macrophage demonstrated APS increase the level of cytokines including TNF-α, GM-CSF and the production of NO. NF-κB protein levels are increased in response to APS. Blocking NF-κB with specific inhibitor resulted in decreased levels of NO and TNF-α. The results suggested that APS possess potent immunomodulatory activity by stimulating macrophage and could be used as an immunotherapeutic adjuvant.

The known immunologically active components of Astragalus account for only a small proportion of the immunological adjuvant activity when combined with conjugate vaccines.

The 95 % ethanol extract of Astragalus has been demonstrated to have potent activity as an immunological adjuvant when administered with vaccines of various types. We endeavor here to identify the components of this extract that are responsible for this adjuvant activity. Mice were immunized with KLH conjugated to cancer carbohydrate antigens globo H and GD3 and cancer peptide antigen MUC1 combined with different Astragalus fractions or with commercially available Astragalus saponins and flavonoids. The antibody responses against cancer antigens and KLH were quantitated in ELISA assays, and toxicity was calculated by weight loss. Astragalosides II and IV were the most active components, but the toxicity of these two differed dramatically. Astragaloside II was the most toxic Astragalus component with 5-10 % weight loss at a dose of 500 µg while astragaloside IV showed no weight loss at all at this dose, suggesting that astragaloside IV might be utilized as an immunological adjuvant in future studies. Several flavonoids also had significant adjuvant activity. However, when the activities of these known immunologically active components of Astragalus (and of endotoxin) are calculated based on the extent of their presence in the 95 % ethanol extract, they provide only a small proportion of the immunological activity. This raises the possibility that additional uniquely active components of Astragalus may contribute to adjuvant activity, or that the adjuvant activity of Astragalus is greater than the activity of the sum of its parts.

[Regulatory effect of Astragalus membranaceus on the immune disorder in rats with IgA nephropathy].

OBJECTIVE: To study the regulattory effect of Astragalus membranaceus on immune disturbance of the rats with IgA nephropathy. METHODS: Rats IgA nephropathy (IgAN) model was duplicated by oral feeding of bovine serum albumin (BSA), subcutaneous injection of carbon tetrachloride (CCl4) and injection of lipopolysaccharide (LSP) into vena caudalis. The rats were divided into three groups randomly for the normal, IgAN model group and the group treated with Astragalus membranaceus (treatment group). The treatment group was given the Astragalus membranaceus granules via intragastric administratsion, the normal group and the IgAN model group were given the equal amount of aqua destillata by gastric perfusion. The rats were examined for albuminuria, hematuria and pathological changes of renal tissue and the distribution of TGF-beta and interleukin-5 in renal tissue was determined by immunohistochemistry and the IFN-gamma and IL-4 of cytokine of Th1 and Th2 types were detected in rats IgA nephropathy model by sandwich enzyme linked immunosorbent assay (ELISA). RESULTS: (1) The hematuria in rats with IgA nephropathy significantly increased compared with normal control group and Astragalus treatment group (P < 0.05). There was significant increase in albuminuria in rats with IgA nephropathy, compared with normal control group and astragalus treatment group (P < 0.01). (2) The pathological change of glomerular mesangium, renal tubules and renal interstitia became serious in rats IgA nephropathy model when compared with normal control group and astragalus treatment group. Immumofluorescence showed renal IgA density in rats IgA nephropathy model was significantly higher than that in the normal control group (P < 0.001) and astragalus treatment group (P < 0.001). (3) The result of immuno histochemistry showed that there was only weak expression of TGF-beta and interleukin 5 in normal renal tissue. The expression of TGF-beta and interleukin 5 in IgA nephropathy model was significantly stronger than those in normal control group (P < 0.05) and astragalus treatment group (P < 0.05). (4) The serum IL-4 levels were (33.74 +/- 7.52) pg/ml in rats IgA nephropathy model, significantly higher than that in normal control group (2.36 +/- 0.85) pg/ml and astragalus treatment group (3.24 +/- 1.13) pg/ml. The IFN-gamma level in serum of rats IgA nephropathy model was (18.79 +/- 3.80) pg/ml, which was significantly higher than that in normal control group (46.53 +/- 5.56) pg/ml and astragalus treatment group (41.28 +/- 2.95) pg/ml. CONCLUSIONS: The astragalus could lower the level of hematuria and 24 hours-albuminuria of the IgAN model, and amelioratse the change of the renal pathology and reduce the deposit of IgA in glomerular mesangium. The possible mechanism of the effect is that astragalus could regulate the derangement of Th1, Th2, accordingly could improve the level of IL-4 and IFN-gamma in the serum and diminish the expression of cytokine Th2 TGF-beta1 and IL-5 of the renal tissue, and thereby could postpone the development of IgAN.