Radix Astragali polysaccharide RAP directly protects hematopoietic stem cells from chemotherapy-induced myelosuppression by increasing FOS expression

Astragaloside IV accelerates hematopoietic reconstruction by improving the AMPK/PGC1α-mediated mitochondrial function in hematopoietic stem cells

BACKGROUND

Radiotherapy can damage hematopoietic stem cells (HSC) in bone marrow, leading to impaired hematopoietic function. Current treatments mainly target differentiated hematopoietic progenitor cells, which may accelerate their depletion. Astragaloside IV (AS-IV), derived from Astragalus membranaceus, shows potential in hematopoiesis, but its direct effects on HSC remain unclear.

METHODS

The study employed both in vitro and in vivo approaches. In vitro experiments utilized K562 cells and mouse bone marrow nucleated cells (BMNCs) to evaluate AS-IV's effects on cell proliferation and mitochondrial function. In vivo studies involved a 4.0 Gy total body irradiation mouse model treated with different doses of AS-IV (50 mg/kg and 100 mg/kg). The mechanism of action was investigated through Western blot, flow cytometry, and metabolomics analyses. The AMPK/PGC1α pathway regulation was verified using AMPK inhibitors and mutant plasmid, with molecular docking confirming AS-IV's direct binding to AMPK.

RESULTS

In vitro studies demonstrated that AS-IV significantly promoted the proliferation of K562 cells and BMNC while enhancing their mitochondrial membrane potential, mitochondrial mass, and ATP production. In the irradiated mouse model, AS-IV treatment led to significant improvements in peripheral blood cell counts, including white blood cells, red blood cells, and hemoglobin levels. Further investigation revealed that AS-IV increased the proportion of HSC in both bone marrow and spleen while improving their mitochondrial function. Transcriptomic sequencing and Western blot analysis identified the AMPK/PGC1α signaling pathway as the key mechanism underlying AS-IV-mediated mitochondrial enhancement. These findings were validated through pharmacological inhibition of AMPK and AMPKK45R mutation experiments.

CONCLUSION

AS-IV accelerates hematopoietic reconstruction following radiation injury via activation of the AMPK/PGC1α signaling pathway, which enhances HSC mitochondrial function.

Unraveling the pathogenesis of bone marrow hematopoietic injury and the therapeutic potential of natural products

Bone marrow hematopoietic injury encompasses a range of pathological conditions that disrupt the normal function of the hematopoietic system, primarily through the impaired production and differentiation of bone marrow hematopoietic cells. Key pathogenic mechanisms include aging, radiation damage, chemical induction, infection and inflammation, and cross-talk with non-hematopoietic diseases. These pathological factors often lead to myelosuppression and myeloid skewing. Furthermore, we explored the potential and application prospects of natural products in the treatment of bone marrow hematopoietic injury. Natural products, particularly those derived from Chinese herbal medicines and other natural sources, have emerged as promising therapeutic options due to their distinctive mechanisms and minimal side effects. A deeper understanding of the underlying mechanisms of bone marrow hematopoietic injury could illuminate how natural products exert their effects, thereby optimizing treatment strategies and offering safer, more effective options for patients. Future research should leverage emerging technologies to further elucidate the composition and interactions within the bone marrow microenvironment, as well as the specific pathways through which natural products modulate hematopoietic dysfunction.

Bletilla striata polysaccharide-mediated trained immunity drives the hematopoietic progenitors' expansion and myelopoiesis

Trained immunity represents a functional state of the innate immune response, characterized by enduring epigenetic reprogramming of innate immune cells. This phenomenon facilitates a sustained and advantageous reaction of myeloid cells to subsequent challenges. Bletilla striata polysaccharide (BSP) is the primary active component of Bletilla striata, mainly consisting of mannose and glucose in its chemical structure. Previous studies have demonstrated BSP's immunomodulatory properties, highlighting its effectiveness in enhancing the immune response. In the present study, we demonstrated that BSP administration induced the trained innate immunity, as evidenced by the BSP-induced generation of mature myeloid cells, especially neutrophils in the peripheral circulation in amouse model of chemotherapy-induced myelosuppression. Furthermore, we showed that BSP-induced trained immunity acts at the level of hematopoietic stem and progenitor cells (HSPCs) and induces the expansion of HSPCs. Mechanistically, our study demonstrated that BSP induced the activation of Notch signaling in HSPCs, and Notch signaling is indispensable for the BSP-mediated generation of trained HSPCs. Collectively, our data demonstrated for the first time that BSP induced trained immunity by regulating theexpansion of the myeloid progenitors. Harnessing trained immunity could be a promising strategy for protection from chemotherapy-induced myelosuppression.

Discovery of Potent and Selective CDK4/6 Inhibitors for the Treatment of Chemotherapy-Induced Myelosuppression

Chemotherapy-induced myelosuppression (CIM) significantly impairs hematopoiesis. Trilaciclib (TC), originally developed for oncology application, is the only FDA-approved CDK4/6 inhibitor for CIM, which effectively protects bone marrow cells by inhibiting their proliferation. In this study, a series of TC derivatives were designed and synthesized as CDK4/6 inhibitors (CDK4/6i) for alleviating CIM. Among these, 42 displayed potent CDK4/6 inhibitory activity (IC50 = 11 nM), lower cytotoxicity (CC50 > 100 μM) and showed high selectivity among 86 kinases. Additionally, 42 possessed strong bone marrow penetration, favorable pharmacokinetic properties, excellent safety profiles, and superior efficacy in mitigating myelosuppression caused by 5-fluorouracil (5-FU) in vivo. In conclusion, as the first oral small-molecule CDK4/6 inhibitor optimized specifically for myelosuppression treatment, 42 expands the therapeutic applications of CDK4/6i, optimizes the mode of administration, and offers significant translational value and clinical potential.

Along the gut-bone marrow signaling pathway: use of longan polysaccharides to regenerate blood cells after chemotherapy-induced myelosuppression

Although it has been established that polysaccharides have an effect on bone marrow haematopoiesis, it remains unclear how polysaccharides regulate bone marrow haematopoiesis during absorption and metabolism in vivo. In this study, the effect of a longan polysaccharide of large molecular weight (TLPL) on the gut microbiota of mice and its implications for the haematopoietic process in bone marrow was discussed. Here, the results show that after 21 days of TLPL consumption, the respective quantities of white blood cells, platelets, hemoglobin and bone marrow nucleated cells were determined to be 3.18 ± 1.71 (109 L-1), 1238.10 ± 164.41 (109 L-1), 135.10 ± 4.95 (g L-1), and 1.70 × 107, which reached 56.98%, 117.28%, and 47.74%, respectively, of the results for NC. TLPL both increased the thymus and spleen indexes by up to 2.08 ± 0.64 (mg g-1) and 6.49 ± 2.45 (mg g-1), respectively. Additionally, TLPL remodeled the gut microbiota with a significant increase in Lactobacillus in particular, and a significant increase in the level of the potential intestinal metabolite lactate was detected in the serum. Most importantly, a similarly significant up-regulation of the gene expression of the lactate receptor, Gpr81, in the myeloid cells was observed. These changes contributed to the activation of the secretion of various cytokines associated with haematopoiesis, with the levels of G-CSF, EPO, SCF and PF4 increased by 2.44 times, 1.14 times, 1.56 times and 1.13 times, respectively, compared to the MC group, which subsequently accelerated production of bone marrow cells and blood cells. The findings of this study reveal the unique mechanism of dried longan polysaccharides in ameliorating myelosuppression and provide a feasible strategy for the treatment of chemotherapy-induced myelosuppression with bioactive polysaccharides.

Alternative therapy for lymphoma with febrile neutropenia using traditional Chinese medicine: A case report

INTRODUCTION

Febrile neutropenia is a common complication in patients undergoing chemotherapy for hematologic malignancies and is associated with significant morbidity and mortality. Primary granulocyte colony-stimulating factor (G-CSF) prophylaxis is consistently associated with a notable reduction in the risk of febrile neutropenia. However, the use of G-CSF in patients who are already neutropenic from chemotherapy remains controversial. Studies have shown that 12.9 % of cancer patients incorporate traditional Chinese medicine (TCM) to alleviate chemotherapy side effects in Taiwan; thereby providing an alternative management strategy for febrile neutropenia in cancer patients.

CASE PRESENTATION

This is an 18-year-old female with newly diagnosed precursor T-lymphoblastic lymphoma. After chemotherapy, the patient developed febrile neutropenia. Despite the use of antibiotics and G-CSF, the febrile neutropenia persisted for two months. Approximately ten days after the initiation of traditional Chinese medicine decoction with the strategy of tonifying the spleen and stomach, clearing yin fire, and uplifting yang, her absolute neutrophil count (ANC) had gradually increased. Additionally, after two weeks of treatment, her fever subsided. The patient continued with chemotherapy and was discharged in stable condition.

DISCUSSION

Antibiotic use aligns with the TCM perspective of an "attack" approach. Conversely, our TCM decoction was designed to raise the ANC by tonifying the spleen and stomach, clearing Yin Fire, and uplifting Yang. Li Dongyuan, one of the four great masters of the Jin Yuan Dynasty, created the formula: Bupiwei Shengyang Sanhuo Decoction that is notable in this regard. The herbs in our decoction have shown hematopoietic and myelosuppression-alleviating effect. For many patients who do not respond adequately to G-CSF alone, integrative treatments involving both TCM and Western medicine can offer additional therapeutic benefits by increasing blood cell counts.

In vivo pharmacokinetics of Glycyrrhiza uralensis polysaccharides

Glycyrrhiza uralensis polysaccharides (GUPS) are widely applied in biomedicine and functional food due to their multiple pharmacological activities and low toxicity. Despite their widespread use, the in vivo metabolic profile of GUPS remains poorly understood. To address this gap, we developed a quantitative analysis method that involves labeling GUPS with visible fluorescein (5-DTAF) and near-infrared (NIR) fluorescein (Cy7), resulting in stable conjugates with substitution degrees of 0.81% for 5-DTAF and 0.39% for Cy7. The pharmacokinetic studies showed a biphasic elimination pattern in the blood concentration-time curve following both intravenous and oral administration, consistent with a two-compartment model. Using fluorescence quantification and NIR imaging, we observed that GUPS was distributed to various tissues, exhibiting higher concentrations particularly in liver, kidney and lung. Excretion studies indicated that feces were the major excretion pathway of GUPS after oral administration (60.98%), whereas urine was the main pathway after intravenous administration (31.16%). Notably, GUPS could be absorbed rapidly by gut (Tmax 1 ± 0.61 h) and showed a biological half-time t1/2 26.4 ± 7.72 h after oral administration. Furthermore, the Caco-2 cells uptake studies illustrated that macropinocytosis and clathrin-mediated endocytosis were participated in the transport of GUPS in intestine epithelium. This comprehensive analysis of the in vivo pharmacokinetics of GUPS not only enhances our understanding of its metabolic pathways but also establishes a foundational basis for its clinical application, optimizing its therapeutic potential and safety profile.

Investigating the protective effects of Astragalus polysaccharides on cyclophosphamide-induced bone marrow suppression in mice and bone mesenchymal stem cells

BACKGROUND

This study determines the role and mechanism of APS in cyclophosphamide-induced myelosuppression in mice and bone mesenchymal stem cells (BMSCs) cell model.

METHODS

Cy-induced myelosuppression mice and BMSCs cell model were established. Fifty C57BL/6 mice (weighing 20 ± 2 g) were randomly divided into five groups. Femur and tibia samples, bone marrow samples, and blood samples were collected 3 days after the last injection of Cy. Histopathology changes and cell apoptosis were detected. Cell viability, apoptosis, cycle distribution, reactive oxygen species activity, osteogenesis ability, and protein levels were detected. γ-H2AX and senescence-associated β-galactosidase activity expression was detected by immunofluorescence. Cy-induced senescence and Wnt/β-catenin related protein levels were detected using western blotting.

RESULTS

The results showed that APS effectively induced Cy-induced histological injury and cell apoptosis rate. After treated with APS, ROS and ALP levels were significantly increased. In BMSCs, cell viability, apoptosis, and cell cycle distribution were also influenced by APS treatment. Compared with the control group, cell viability was significantly increased, the cell apoptosis rate was decreased while the number of cells remained in the G0-G1 phase was increased. Meanwhile, ROS levels were significantly increased in APS group. Cell senescence and Wnt/β-catenin related protein (γ-H2AX, SA-β-gal, p21, p16, p-β-catenin/ β-catenin, c-Myc, and AXIN2) levels were also altered both in vivo and in vitro. Interestingly, the effects of APS were reversed by BML-284.

CONCLUSION

Our results indicate that APS protected Cy-induced myelosuppression through the Wnt/β-catenin pathway and APS is a potential therapeutic drug for Cy-induced myelosuppression.

Structural characterization of Russula griseocarnosa polysaccharide and its improvement on hematopoietic function

The hematopoietic function of a polysaccharide derived from Russula griseocarnosa was demonstrated in K562 cells, and subsequently purified through chromatography to obtain RGP1. RGP1 is a galactan composed of 1,6-α-D-Galp as the main chain, with partial substitutions. A -CH3 substitution was detected at O-3 of 1,6-α-D-Galp. The possible branches at O-2 of 1,6-α-D-Galp was α-L-Fucp. In mice with cyclophosphamide (CTX)-induced hematopoietic dysfunction, RGP1 alleviated bone marrow damage and multinucleated giant cell infiltration of the spleen, increased the number of long-term hematopoietic stem cells, and regulated the levels of myeloid cells in the peripheral blood. Furthermore, RGP1 promoted the differentiation of activated T cells and CD4+ T cells without affecting natural killer cells and B cells. Proteomic analysis, detection of cytokines, and western blotting revealed that RGP1 could alleviate hematopoietic dysfunction by promoting the activation of CD4+ T cells and the Janus kinase/ signal transducer and activator of transcription 3 pathway. The present study provides experimental evidence to support the application of RGP1 in CTX-induced hematopoietic dysfunction.

Unveiling the Mechanisms of Bone Marrow Toxicity Induced by Lead Acetate Exposure

Lead (Pb), a widespread heavy metal, causes severe toxicity in human and animal organs (e.g., bone marrow), whereas the mechanisms of the bone marrow toxicity induced by Pb exposure are unclear. Hence, this study was designed to reveal the hub genes involved in Pb-induced bone marrow toxicity. GSE59894 dataset obtained from Gene Expression Omnibus (GEO) was composed of lead acetate (PbAc2)-treated and control bone marrow samples. Totally 120 and 85 differentially expressed genes (DEGs) were identified on the 1st day, while 153 and 157 DEGs on the 3rd day in the bone marrow treated with 200 and 600 mg/kg of PbAc2, respectively. Notably, a total of 28 and 32 overlapping DEGs were identified in the bone marrow on the 1st and 3rd day treated with PbAc2, respectively. Biological process analysis suggested that the common DEGs were primarily participated in cell differentiation, the response to drug, xenobiotic stimulus, and organic cyclic compound. Pathway analysis demonstrated that the overlapping DEGs were primarily linked to PI3K-Akt, TGF-β, MAPK, and osteoclast differentiation signaling pathways. Moreover, the hub genes, including PLD2, DAPK1, ALB, TNF, FOS, CDKN1A, and TGFB3, might contribute to PbAc2-induced bone marrow toxicity. Overall, our study offers an important insight into the molecular mechanisms of Pb-induced bone marrow toxicity.

Impact of macrophage differentiation on hematopoietic function enhancement by Shenzhu ErKang Syrup

Shenzhu Erkang Syrup (SZEK) is a traditional Chinese medicine that improves spleen and stomach function, tonifying the Qi and activating the blood; however, its therapeutic effects in hematopoietic dysfunction and their underlying mechanism remain unexplored. In this study, mice were given cyclophosphamide (100 mg/kg) by intraperitoneal injections for three days to produce hematopoietic dysfunction model. We investigated the hematopoietic effect and mechanism of SZEK in mice with hematopoietic dysfunction via histopathological examination, flow cytometry, enzyme-linked immunosorbent assay, and Western blotting combined with intestinal flora and serum metabolomics analysis. In mice with hematopoietic dysfunction, SZEK (gavage, 0.3 mL/25 g) alleviated pathological damage to the bone marrow and spleen; increased the number of naïve cells (Lin-), hematopoietic stem cells (Lin-Sca-1+c-Kit+), long-term self-renewing hematopoietic stem cells (Lin-Sca-1+c-Kit+CD48-CD150+), B lymphocytes (CD45+CD19+), and macrophages (CD11b+F4/80+) in the bone marrow; and reduced inflammation. Preliminary intestinal flora and serum metabolome analyses indicated that the pro-hematopoietic mechanism of SZEK was associated with macrophage differentiation. Further validation revealed that SZEK promoted hematopoiesis by decreasing the number of M2 macrophages and inhibiting the secretion of negative hematopoietic regulatory factors in mice with hematopoietic dysfunction.

Effectiveness and safety of Shenqi Fuzheng injection combined with platinum-based chemotherapy for treatment of advanced non-small cell lung cancer: a systematic review and meta-analysis

Objective

To evaluate the efficacy and safety of Shenqi Fuzheng Injection (SFI) combined with platinum-based chemotherapy (PBC) for the treatment of advanced non-small cell lung cancer (NSCLC).

Methods

Seven electronic databases, including CNKI and Wanfang, were comprehensively searched to screen randomized controlled trials (RCTs) until May 1, 2022. The quality of each trial was evaluated according to the Cochrane Handbook for Systematic Reviews of Interventions, and systematic reviews were conducted according to the PRISMA guidelines. Statistical analysis was performed using Review Manager 5.3, and the results were expressed as relative risk (RR) and 95% confidence interval (95% CI). The primary outcome measures were objective response rate (ORR) and disease control rate (DCR). The secondary outcome measures were quality of life and toxicity. Subgroup analysis was performed according to the number of days of SFI single-cycle treatment and combined PBC regimen.

Results

A total of 44 RCTs involving 3475 patients were included in the study. The meta-analysis results showed that, compared with PBC alone, SFI combined with PBC significantly improved the ORR (RR = 1.27, 95% CI = 1.18-1.37, P < 0.00001), DCR (RR = 1.12, 95% CI = 1.08-1.15, P < 0.00001), and quality of life (RR = 1.41, 95% CI = 1.31-1.52, P < 0.00001). It also reduced chemotherapy-induced hemoglobin reduction (RR = 0.57, 95% CI = 0.48-0.67, P < 0.00001), leukopenia (RR = 0.61, 95% CI = 0.53-0.71, P < 0.00001), thrombocytopenia (RR = 0.62, 95% CI = 0.55-0.70, P < 0.00001), and simple bone marrow suppression (RR = 0.55, 95% CI = 0.41-0.73, P < 0.0001). Nausea and vomiting (RR = 0.63, 95% CI = 0.52-0.77, P < 0.00001), diarrhea (RR = 0.48, 95% CI = 0.37-0.64, P < 0.00001), and simple digestive tract reactions (RR = 0.63, 95% CI = 0.49-0.80, P = 0.0002) also decreased with the treatment of SFI.

Conclusion

SFI combined with PBC for the treatment of advanced NSCLC improved the ORR, DCR, and quality of life, and reduced the incidence of myelosuppression and gastrointestinal adverse reactions. However, considering the limitations of existing evidence, further verification using high-quality RCTs is required.

Systematic review registration

https://inplasy.com/inplasy-2022-7-0026, identifier INPLASY202270026.

Biosynthesis and Pharmacological Activities of Flavonoids, Triterpene Saponins and Polysaccharides Derived from Astragalus membranaceus

Astragalus membranaceus (A. membranaceus), a well-known traditional herbal medicine, has been widely used in ailments for more than 2000 years. The main bioactive compounds including flavonoids, triterpene saponins and polysaccharides obtained from A. membranaceus have shown a wide range of biological activities and pharmacological effects. These bioactive compounds have a significant role in protecting the liver, immunomodulation, anticancer, antidiabetic, antiviral, antiinflammatory, antioxidant and anti-cardiovascular activities. The flavonoids are initially synthesized through the phenylpropanoid pathway, followed by catalysis with corresponding enzymes, while the triterpenoid saponins, especially astragalosides, are synthesized through the universal upstream pathways of mevalonate (MVA) and methylerythritol phosphate (MEP), and the downstream pathway of triterpenoid skeleton formation and modification. Moreover, the Astragalus polysaccharide (APS) possesses multiple pharmacological activities. In this review, we comprehensively discussed the biosynthesis pathway of flavonoids and triterpenoid saponins, and the structural features of polysaccharides in A. membranaceus. We further systematically summarized the pharmacological effects of bioactive ingredients in A. membranaceus, which laid the foundation for the development of clinical candidate agents. Finally, we proposed potential strategies of heterologous biosynthesis to improve the industrialized production and sustainable supply of natural products with pharmacological activities from A. membranaceus, thereby providing an important guide for their future development trend.

Extraction of polysaccharides from Maca enhances the treatment effect of 5-FU by regulating CD4+T cells

In our previous studies, we used a graded alcohol precipitation method to extract four maca polysaccharide components (MCP1, MCP2, MCP3, and MCP4) from maca with various molecular weights. Compared to other three components, MCP2 had stronger immunoregulatory abilities on CD4⁺T cells. To avoid the immunosuppressive effect of 5-fluorouracil (5-FU), maca polysaccharides in combination with 5-FU treatment were investigated in this study. The results show that 500 mg/kg and 1000 mg/kg MCP2 could significantly delay the growth of tumor and enhance the anti-tumor effect of 5-FU in vivo. Furthermore, MCP2 can partly recover the proliferation of CD4⁺T cells after being suppressed by 5-FU in vitro. Additionally, in order to explore the mechanism in which MCP2 acts on CD4⁺T cells, the MCP2 is marked with FITC fluorescence and synthesis MCP2-Tyr-FITC for the first time. Confocal microscope results show that MCP2-Tyr-FITC can directly bind to the surface of CD4⁺T cells. Together, our work demonstrates that maca polysaccharides could enhance the anti-tumor effect when combined with 5-FU by regulating CD4⁺T cells, suggesting a novel potential immunomodulator in tumor therapy.

Purification, Structural Analysis and Cardio-Protective Activity of Polysaccharides from Radix Astragali

Two polysaccharides, named APS2-I and APS3-I, were purified from the water extract of Radix Astragali. The average molecular weight of APS2-I was 1.96 × 10⁶ Da and composed of Man, Rha, GlcA, GalA, Glc, Gal, Xyl, and Ara in a molar ratio of 2.3:4.8:1.7:14.0:5.8:11.7:2.8:12.6, while the average molecular weight of APS3-I was 3.91 × 10⁶ Da and composed of Rha, GalA, Glc, Gal, and Ara in a molar ratio of 0.8:2.3:0.8:2.3:4.1. Biological evaluation showed APS2-I and APS3-I had significant antioxidant activity and myocardial protection activity. Furthermore, total polysaccharide treatment could significantly enhance hemodynamic parameters and improve cardiac function in rat ischemia and reperfusion isolated heart models. These results provided important information for the clinical application of APS in the field of cardiovascular disease and implied that Astragalus polysaccharides (APS) could be considered as a reference for the quality control of Radix Astragali.

Astragalus polysaccharide: a review of its immunomodulatory effect

The Astragalus polysaccharide is an important bioactive component derived from the dry root of Astragalus membranaceus. This review aims to provide a comprehensive overview of the research progress on the immunomodulatory effect of Astragalus polysaccharide and provide valuable reference information. We review the immunomodulatory effect of Astragalus polysaccharide on central and peripheral immune organs, including bone marrow, thymus, lymph nodes, spleen, and mucosal tissues. Furthermore, the immunomodulatory effect of Astragalus polysaccharide on a variety of immune cells is summarized. Studies have shown that Astragalus polysaccharide can promote the activities of macrophages, natural killer cells, dendritic cells, T lymphocytes, B lymphocytes and microglia and induce the expression of a variety of cytokines and chemokines. The immunomodulatory effect of Astragalus polysaccharide makes it promising for the treatment of many diseases, including cancer, infection, type 1 diabetes, asthma, and autoimmune disease. Among them, the anticancer effect is the most prominent. In short, Astragalus polysaccharide is a valuable immunomodulatory medicine, but further high-quality studies are warranted to corroborate its clinical efficacy.

Extraction, structure, and activity of polysaccharide from Radix astragali

Radix astragali polysaccharide (RAP) is a water-soluble heteropolysaccharide. It is an immune promoter and regulator, and has antivirus, antitumor, anti-aging, anti-radiation, anti-stress, anti-oxidation and other activitys. The extraction, separation, purification, structure, activity and modification of RAP were summarized. Some extraction methods of RAP had been introduced, and the separation and purification methods of RAP were reviewed, and the structure and activity of RAP were highly discussed. Current derivatization of RAP was outlined. Through the above discussion that the yield of crude polysaccharides from Radix astragali by enzyme-assisted extraction was significantly higher than that by other extraction methods, but each extraction method had different extraction effects under certain conditions, and the activity efficiency of RAP was also different. Therefore, it is particularly important to optimize the extraction method with known better yield for the study of RAP. In addition, the purification and separation of RAP are the key factors affecting the yield and activity of RAP. At the same time, there are still few studies on the derivatiration of Radix astragali polysaccharide, but the researches in this area are very important. RAP also has many important pharmacological effects on human body, but its practical application needs further study. Finally, studies on the structure-activity relationship of RAP still need to be carried out by many scholars. This review would provide some help for further researches on various important applications of RAP.

Radix Astragalus Polysaccharide Accelerates Angiogenesis by Activating AKT/eNOS to Promote Nerve Regeneration and Functional Recovery

Peripheral nerve injury (PNI) results in loss of neural control and severe disabilities in patients. Promoting functional nerve recovery by accelerating angiogenesis is a promising neuroprotective treatment strategy. Here, we identified a bioactive Radix Astragalus polysaccharide (RAP) extracted from traditional Chinese medicine (TCM) as a potent enhancer of axonal regeneration and remyelination. Notably, RAP promoted functional recovery and delayed gastrocnemius muscle atrophy in a rat model of sciatic nerve crush injury. Further, RAP treatment may induce angiogenesis in vivo. Moreover, our in vitro results showed that RAP promotes endothelial cell (EC) migration and tube formation. Altogether, our results show that RAP can enhance functional recovery by accelerating angiogenesis, which was probably related to the activation of AKT/eNOS signaling pathway, thereby providing a polysaccharide-based therapeutic strategy for PNI.

Structural Characterization of Polysaccharides Isolated from Panax notoginseng Medicinal Residue and Its Protective Effect on Myelosuppression Induced by Cyclophosphamide

This study aims to establish the isolation and purification method of polysaccharides from medicinal residue of Panax notoginseng (PPN). The structure and protective effect of PPN on myelosuppression mice were investigated. One neutral polysaccharide (NPPN) and five acidic polysaccharides (APPN I, APPN II-A, APPN II-B, APPN III-A, and APPN III-B) were obtained. The results confirmed that NPPN, APPN I and APPN II-A are glycan with 1, 4 main chains. APPN III-A is a glycan. APPN II-B and APPN III-B are homogalacturonan pectin with 1, 4 main chains. This study demonstrated that NPPN played a bone marrow protective role in myelosuppression mice induced by cyclophosphamide. NPPN could relieve cell cycle arrest, reduce the apoptosis rate of marrow cells, and improve granulocyte-macrophage colony-stimulating (GM-CSF), thermoplastic polyolefin (TPO) and erythropoietin (EPO) serum level, which contributes to promoting the proliferation of hematopoietic cells.