Optimization of angelica sinensis polysaccharide-loaded Poly (lactic-co-glycolicacid) nanoparticles by RSM and its immunological activity in vitro

Application of plant-derived products as adjuvants for immune activation and vaccine development

Vaccines are one of the most important means to prevent and control the epidemic of infectious diseases. Commercial vaccines not only include corresponding antigens, but also need vaccine adjuvants. Immune adjuvants play an increasingly important role in the research, development and manufacture of vaccines. Adjuvants combined with antigens can improve the stability, safety and immune efficiency of vaccines. Some substances that can enhance the immune response have been found in nature(mainly plants) and used as adjuvants in vaccines to improve the immune effect of vaccines. These plant-derived immune adjuvants often have the advantages of low toxicity, high stability, low price, etc., providing more possibilities for vaccine development. We summarized and analyzed the advantages, application research, particulate delivery systems, existing problems and future research focus of botanical adjuvant. It is hoped to provide new ideas for the research and development of immune adjuvants in the future.

The angelica Polysaccharide: a review of phytochemistry, pharmacology and beneficial effects on systemic diseases

Angelica sinensis is a perennial herb widely distributed around the world, and angelica polysaccharide (APS) is a polysaccharide extracted from Angelica sinensis. APS is one of the main active components of Angelica sinensis. A large number of studies have shown that APS has hematopoietic, promoting blood circulation, radiation resistance, lowering blood glucose, enhancing the body immunity and other pharmacological effects in a variety of diseases. However, different extraction methods and extraction sites greatly affect the efficacy of APS. In recent years, with the emerging of new technologies, there are more and more studies on the combined application and structural modification of APS. In order to promote the comprehensive development and in-depth application of APS, this narrative review systematically summarizes the effects of different drying methods and extraction sites on the biological activity of APS, and the application of APS in the treatment of diseases, hoping to provide a scientific basis for the experimental study and clinical application of APS.

Extraction, purification, structural characteristics, biological activities, and applications of polysaccharides from the genus Lilium: A review

The genus Lilium (Lilium) has been widely used in East Asia for over 2000 years due to its rich nutritional and medicinal value, serving as both food and medicinal ingredient. Polysaccharides, as one of the most important bioactive components in Lilium, offer various health benefits. Recently, polysaccharides from Lilium plants have garnered significant attention from researchers due to their diverse biological properties including immunomodulatory, anti-oxidant, anti-diabetic, anti-tumor, anti-bacterial, anti-aging and anti-radiation effects. However, the limited comprehensive understanding of polysaccharides from Lilium plants has hindered their development and utilization. This review focuses on the extraction, purification, structural characteristics, biological activities, structure-activity relationships, applications, and relevant bibliometrics of polysaccharides from Lilium plants. Additionally, it delves into the potential development and future research directions. The aim of this article is to provide a comprehensive understanding of polysaccharides from Lilium plants and to serve as a basis for further research and development as therapeutic agents and multifunctional biomaterials.

The Application of Nanovaccines in Autoimmune Diseases

Autoimmune diseases are diseases caused by the body's chronic immune responses to self-antigens and attacks on the host's own cells, tissues and organs. The dysfunction of innate immunity and adaptive immunity leads to the destruction of autoimmune tolerance, which is the most basic factor leading to pathogenesis. The optimal strategy for autoimmune diseases is to modify the host immune system to restore tolerance. The ideal effect of therapeutic autoimmune diseases is to eliminate the autoantigen-specific spontaneous immune response without interfering with the immune response against other antigens. Therapeutic nanovaccines that produce immune tolerance conform to this principle. Nanomaterials provide a platform for antigen loading and modification due to their unique physical and chemical properties. Nanovaccines based on nanomaterial technology can simultaneously enable antigens and adjuvants to be absorbed by immune cells and induce rapid and durable immunity. Nanovaccines have the advantages of being able to be designed and loaded and of better protecting antigens from premature degradation. Nanovaccines also have the ability to target specific tissues or cells through optimized design. We review the latest research progress of nanovaccines for autoimmune diseases and the design strategies of nanovaccines to promote the development of more effective nanovaccines for autoimmune diseases.

Purification processes of polymeric nanoparticles: How to improve their clinical translation?

Polymeric nanoparticles, as revolutionary nanomedicines, have offered a new class of diagnostic and therapeutic solutions for a multitude of diseases. With its immense potential, the world witnesses the new age of nanotechnology after the COVID-19 vaccines were developed based on nanotechnology. Even though there are countless benchtop research studies in the nanotechnology world, their integration into commercially available technologies is still restricted. The post-pandemic world demands a surge of research in the domain, which leaves us with the fundamental question: why is the clinical translation of therapeutic nanoparticles so restricted? Complications in nanomedicine purification, among other things, are to blame for the lack of transference. Polymeric nanoparticles, owing to their ease of manufacture, biocompatibility, and enhanced efficiency, are one of the more explored domains in organic-based nanomedicines. Purification of nanoparticles can be challenging and necessitates tailoring the available methods in accordance with the polymeric nanoparticle and impurities involved. Though a number of techniques have been described, there are no available guidelines that help in selecting the method to better suit our requirements. We encountered this difficulty while compiling articles for this review and looking for methods to purify polymeric nanoparticles. The currently accessible bibliography for purification techniques only provides approaches for a specific type of nanomaterial or sometimes even procedures for bulk materials, that are not fully relevant to nanoparticles. In our research, we tried to summarize the available purification techniques using the approach of A.F. Armington. We divided the purification systems into two major classes, namely: phase separation-based techniques (based on the physical differences between the phases) and matter exchange-based techniques (centered on physicochemical induced transfer of materials and compounds). The phase separation methods are based on either using nanoparticle size differences to retain them on a physical barrier (filtration techniques) or using their densities to segregate them (centrifugation techniques). The matter exchange separation methods rely on either transferring the molecules or impurities across a barrier using simple physicochemical phenomena, like the concentration gradients (dialysis method) or partition coefficients (extraction technique). After describing the methods in detail, we highlight their advantages and limitations, mainly focusing on preformed polymer-based nanoparticles. Tailoring a purification strategy takes into account the nanoparticle structure and its integrity, the method selected should be suited for preserving the integrity of the particles, in addition to conforming to the economical, material and productivity considerations. In the meantime, we advocate the use of a harmonized international regulatory framework to define the adequate physicochemical and biological characterization of nanomedicines. An appropriate purification strategy serves as the backbone to achieving desired characteristics, in addition to reducing variability. As a result, the present review aspires to serve as a comprehensive guide for researchers, who are new to the domain, as well as a synopsis of purification strategies and analytical characterization methods used in preclinical studies.

Research progress in the development of natural-product-based mucosal vaccine adjuvants

Mucosal vaccines have great potential and advantages in preventing infection caused by multiple pathogens. In developing mucosal vaccines, the biggest challenge comes from finding safe and effective adjuvants and drug delivery systems. Great progress has been made in the generation of mucosal adjuvants using detoxified bacterial toxin derivatives, pathogen-related molecules, cytokines, and various vaccine delivery systems. However, many problems, relating to the safety and efficacy of mucosal vaccine adjuvants, remain. Certain natural substances can boost the immune response and thus could be used as adjuvants in vaccination. These natural-product-based immune adjuvants have certain advantages over conventional adjuvants, such as low toxicity, high stability, and low cost of production. In this review, we summarize the latest natural-product-based immune adjuvants, and discuss their properties and clinical applications.

Amomum longiligulare polysaccharide 1- PLGA nanoparticle promotes the immune activities of T lymphocytes and dendritic cells

Amomum longiligulare polysaccharide 1 (ALP1) was extracted from Amomum longiligulare T.L. Wu fruits and the poly (lactic-co-glycolic acid) nanoparticle enveloping ALP1 (ALPP) showed a good promoting effect on the activation of macrophages in our previous study. To further understand the immunomodulatory property of ALPP, the effect of ALPP on T lymphocytes and dendritic cells was investigated in the present study. The proliferation rates of chicken T lymphocytes and chicken bone marrow dendritic cells (chBM-DCs) that were treated with ALP1 or ALPP were determined by using MTT method. Meanwhile, the relative mRNA levels of cytokines from T lymphocytes and surface molecules of chBM-DCs were determined by using qRT-PCR method. In addition, the drug uptake capacity of chBM-DCs was also tested. As a result, the promoting effect on the proliferation of T lymphocytes and the Th1-type immune response of ALPP was better than that of ALP1. In addition, ALPP was much more effectively swallowed by chBM-DCs so that its promoting effect on the proliferation and maturation of chBM-DCs was higher than that of ALP1. To conclude, ALPP had a stronger immunomodulatory activity than ALP1, and showed the potential to become a new type of immune booster.

Herb Polysaccharide-Based Drug Delivery System: Fabrication, Properties, and Applications for Immunotherapy

Herb polysaccharides (HPS) have been studied extensively for their healthcare applications. Though the toxicity was not fully clarified, HPS were widely accepted for their biodegradability and biocompatibility. In addition, as carbohydrate polymers with a unique chemical composition, molecular weight, and functional group profile, HPS can be conjugated, cross-linked, and functionally modified. Thus, they are great candidates for the fabrication of drug delivery systems (DDS). HPS-based DDS (HPS-DDS) can bypass phagocytosis by the reticuloendothelial system, prevent the degradation of biomolecules, and increase the bioavailability of small molecules, thus exerting therapeutic effects. In this review, we focus on the application of HPS as components of immunoregulatory DDS. We summarize the principles governing the fabrication of HPS-DDS, including nanoparticles, micelles, liposomes, microemulsions, hydrogels, and microneedles. In addition, we discuss the role of HPS in DDS for immunotherapy. This comprehensive review provides valuable insights that could guide the design of effective HPS-DDS.

Preparation and sulfate modified of Lagenaria siceraria (Molina) Standl polysaccharide and its immune-enhancing adjuvant activity

Herbal polysaccharides and their modifiers used as vaccine adjuvants have been widely investigated due to their safety and good immunoenhancing activity. In this study, the 50% ethanol concentration precipitated Lagenaria siceraria(Molina) standl polysaccharide (LSP50) and sulfated modified LSP50 (sLSP50) was prepared, and their characterization was investigated. LSP50 and sLSP50_-1.5 were used as vaccine adjuvants to immunize chickens, and the strength and type of immune responses induced by different adjuvants were detected. Our results showed that LSP50 was homogeneous polysaccharides, and the carbohydrate content was 98.6%. The sLSP50_-1.5 with the DS value of 1.5 was optimized by response surface methodology. The sLSP50_-1.5 has both characteristics of polysaccharide functional groups and sulfate functional groups. Adjuvant activity of LSP50 and sLSP50_-1.5 showed that LSP50 and sLSP50_-1.5 could induce long-lasting and high hemagglutination (HI) titers, antigen-specific lgG-NDV antibody, splenic lymphocyte proliferation, high immune organ index. Moreover, chicken immunized with sLSP50_-1.5 showed a strong mixed Th1-type (IFN-γ and TNF-α) and Th2-type (IL-4 and IL-6) cytokines expression. Thus, these findings demonstrated that sLSP50_-1.5 as a vaccine adjuvant can induce a mixed cellular and humoral immune response and can potentially serve as an effective vaccine adjuvant for NDV antigen.

Polysaccharides derived from Chinese medicinal herbs: A promising choice of vaccine adjuvants

Adjuvants have been used in vaccines for a long time to promote the body's immune response, reducing vaccine dosage and production costs. Although many vaccine adjuvants are developed, the use in human vaccines is limited because of either limited action or side effects. Therefore, the development of new vaccine adjuvants is required. Many studies have found that natural polysaccharides derived from Traditional Chinese medicine (TCM) possess good immune promoting effects and simultaneously improve humoral, cellular and mucosal immunity. Recently polysaccharide adjuvants have attracted much attention in vaccine preparation because of their intrinsic characteristics: immunomodulation, biocompatibility, biodegradability, low toxicity and safety. This review article systematically analysed the literature on polysaccharides possessing vaccine adjuvant activity from TCM plants, such as Astragalus polysaccharide (APS), Rehmannia glutinosa polysaccharide (RGP), Isatis indigotica root polysaccharides (IRPS), etc. and their derivatives. We believe that polysaccharide adjuvants can be used to prepare the vaccines for clinical use provided their mechanisms of action are studied in detail.

Lentinan PLGA-stabilized pickering emulsion for the enhanced vaccination

Lentinan (LNT), a β-1,3-linked-d-glucan with β-1,6 glucose branches, is the main bioactive component extracted from Lentinus edodes. As a carbohydrate polymer, it has attracted increasingly attention because of immune enhancement effect. Pickering emulsion has been widely used in biomedicine due to its great stability, high loading capacity, and appreciable biocompatibility. The aim of this study is to construct an adjuvant delivery system (LNTPP/OVA) (Lentinan PLGA-stabilized Pickering emulsion loading OVA antigen) which can enhance the immune activity of LNT and can together deliver model protein antigen ovalbumin (OVA) into the organism. The characterization of the LNTPP/OVA was demonstrated that the size of LNTPP/OVA was around 1050.68 nm and was stable to store at least 28 days. Pickering emulsion was spherical shape like the raspberry with the high antigen load rate at around 82.53%. Moreover, the adjuvant effect of LNTPP/OVA formulation was detected. Compared with LNT/OVA formulation, our experimental results showed that LNTPP/OVA could promote the uptake of the OVA-antigen by macrophages in vitro. In vivo experiments, LNTPP/OVA facilitated the activation of dendritic cells (DCs) and induced strong humoral and cellular immune responses carrying a Th1 and Th2 immune responses. Therefore, LNTPP/OVA formulation have the latent capacity as a vaccine transmission system.

A Novel Nanomedicine Ameliorates Acute Inflammatory Bowel Disease by Regulating Macrophages and T-Cells

Ramulus mori polysaccharide (RMP), one of the most important active components of R. mori, has been attracting increasing interest because of its potent bioactive properties, including anti-inflammatory, antitumor, and antidiabetic effects. Despite the great therapeutic potential of RMP, its inherent properties of low bioavailability and brief biological half-life have limited its applications to the clinic. Thus, RMP was packaged by poly(lactic-co-glycolic acid) (PLGA) nanoparticles to develop a novel anti-inflammatory nanomedicine (PLGA-RMP) in this study. The nanoparticles were synthesized via a double-emulsion solvent evaporation technique, and the average diameter of PLGA-RMP was about 202 nm. PLGA-RMP nanoparticles reduced the expression of inflammatory cytokines while promoting the production of IL-10, and boosted the phenotypic shift in macrophages in vitro. Furthermore, lipopolysaccharide (LPS)-induced inflammatory bowel disease (IBD) in mouse was used to examine the anti-inflammatory effect of PLGA-RMP in vivo. Oral administration of PLGA-RMP in LPS-induced IBD mice substantially mitigated the intestinal inflammation compared to treatment with LPS alone, as evidenced by attenuation of disease activity index scores and inflammatory damage in the intestine. Meanwhile, PLGA-RMP suppressed the expression and secretion of specific inflammatory cytokines including TNF-α, IL-6, IL-1β, and PGE2 in the inflamed intestine while inhibiting the activation of CD3⁺CD8⁺ T-cells and increasing the number of activated T_regs in the intestine. These results indicated that PLGA-RMP deserves further consideration as a potential therapeutic nanomedicine to treat various inflammatory diseases, including IBD.

Preparation of Amomum longiligulare polysaccharides 1- PLGA nanoparticle and its immune enhancement ability on RAW264.7 cells

Amomum longiligulare polysaccharides 1 (ALP1) was a glucosan that possessed an immune enhancement ability. However, disadvantages including short biological half-life hindered the application of ALP1. To solve these shortcomings, ALP1 was successfully prepared to nanoparticles (ALPP) with poly (lactic-co-glycolic acid) in the present study. And the optimal preparation conditions were developed by using the response surface method with a Box-Behnken design. The results showed that the encapsulation efficiency of ALPP reached a high level (79.88%) when the volume ratio of the water phase to the organic phase was 1:7, the volume ratio of the primary emulsion to the external water phase was 1:7, and the concentration of F68 was 0.7%. ALPP showed a controlled and sustained release. Meanwhile, the scanning electron microscope results showed that ALPP was a kind of nanoparticles with a diameter of 389.77 nm. In addition, the activating effect of ALPP on macrophages was studied. The results indicated that ALPP showed a better activity on promoting the RAW264.7 cells' activities and polarizing RAW264.7 cells into both M1 type and M2 type macrophages, compared to ALP1.

Nanocarriers in the Enhancement of Therapeutic Efficacy of Natural Drugs

Abstract Since time immemorial, plant derived natural products have been used for the treatment of various human diseases before the intervention of modern medicine. The basis of modern medicine is still being inspired from traditional medicine and therapies. However, despite their tremendous therapeutic potential, these natural drugs often have poor bioavailability, metabolic instability, and aqueous insolubility. These factors greatly impede a natural drug’s commercialization potential as a mainstream medicine. Therefore, the development of nanocarrier drug delivery systems is indispensable in overcoming the various constraints of the bottlenecks which occur with natural drugs. Of particular interest in this review are four plant materials endogenous to China with the common names of barrenwort or horny goat weed (Epimedium), Shu Di Huang (Rehmannia glutinosa, RG), ginseng (Panax ginseng), and Dong Quai or female ginseng (Angelica sinensis, AS), each having been scientifically investigated for a wide range of therapeutic uses as has been originally discovered from the long history of traditional usage and anecdotal information by local population groups in Asia. The integration of natural drugs from the East and nanocarrier drug delivery systems developed from the West is paving the way towards further accurate and efficient medicine therapy. We further discuss the potential benefits of these plants and the enhancement of their therapeutic efficacy by nanotechnology intervention.

Ramulus mori polysaccharide-loaded PLGA nanoparticles and their anti-inflammatory effects in vivo

In this study, ramulus mori polysaccharide (RMP) was encapsulated into Poly (lactic-co-glycolicacid) (PLGA) to form PLGA-RMP (PR). The aim of study is to investigate anti-inflammatory effects of PR. The particle size of PR nanoparticles was approximately 205.6 ± 1.86 nm. PR nanoparticles showed significant therapeutic effects on colitis mice model, evidenced by attenuation of the loss of body weight, reduction of the DAI score, and restoration of the colon length. From the histopathological analysis, alleviation of the histopathological damage, less production of IFN-γ and IL-6, and improvement of IL-10 were observed with the treatment of PR. Meanwhile, the treatment of PR not only promoted the expression of ZO-1 and occludin, but also improved the contents of acetate, propionate, and butyrate in the colitis colon. Furthermore, PR extenuated the reduction of the diversity and richness of gut microbiota induced by DSS, and decreased the ratio of Firmicutes to Bacteroidetes while increasing the proportion of Clostridium XIVa, Mucispirillum, and Paraprevotella in the gut microbiota. What's more, PR nanoparticles attenuated the metabolic disorders in the colitis colon induced by DSS. These results indicated that PR nanoparticles could serve as a potent nanomedicine to treat IBD and be used as potential prebiotics.

Extraction, structure, pharmacological activities and drug carrier applications of Angelica sinensis polysaccharide

Angelica sinensis polysaccharide (ASP) is one of the main active components of Angelica sinensis (AS) that is widely used in traditional Chinese medicine. ASP is water-soluble polysaccharides, and it is mainly composed of glucose (Glc), galactose (Gal), arabinose (Ara), rhamnose (Rha), fucose (Fuc), xylose (Xyl) and galacturonic acid (GalUA). The extraction methods of ASP include hot water extraction and ultrasonic wave extraction, and different extraction methods can affect the yield of ASP. ASP has a variety of pharmacological activities, including hematopoietic activity, promoting immunity, antitumor, anti-inflammatory, antioxidant, anti-aging, anti-virus, liver protection, and so on. As a kind of natural polysaccharide, ASP has potential application as drug carriers. This review provides a comprehensive summary of the latest extraction and purification methods of ASP, the strategies used for monosaccharide compositional analysis plus polysaccharide structural characterization, pharmacological activities and drug carrier applications, and it can provide a basis for further study on ASP.

The Bioactivities and Potential Clinical Values of Angelica Sinensis Polysaccharides

Angelica sinensis Radix (ASR), one of the most commonly used traditional Chinese medicines, contains many chemical components such as polysaccharides, volatile oil, flavonoids, amino acids, and organic acids, among which polysaccharides play an indispensable role in the therapeutic effect of ASR. A. sinensis polysaccharide (ASP) has many biological activities, for instance, hematopoietic, anti-tumor, and liver protection, which are closely related to the treatment of human diseases such as chronic anemia, leukemia, and diabetes. In addition, there are excellent application prospects for drug delivery in nanoparticles. This paper reviews the chemical compositions, extraction methods, biological activity, action mechanism, potential clinical applications, nanoparticles, and research prospect of ASP from 2010 to 2020, so as to provide references for its further development.

Angelica Polysaccharide Ameliorates Sepsis-Induced Acute Lung Injury through Inhibiting NLRP3 and NF-κB Signaling Pathways in Mice

Objective. This study aimed to explore the role of angelica polysaccharide (AP) in sepsis-induced acute lung injury (ALI) and its underlying molecular mechanism. Methods. A sepsis model of cecal ligation and puncture (CLP) in male BALB/C mice was used. Then, 24 h after CLP, histopathological changes in lung tissue, lung wet/dry weight ratio, and inflammatory cell infiltration were analyzed. Next, levels of inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-18), as well as the activity of myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH), were measured to assess the role of AP. The protein expression of NF-κB p65, p-NF-κB p65, IκBα, p-IκBα, nucleotide-binding domain- (NOD-) like receptor protein 3 (NLRP3), ASC, and caspase-1 was detected by western blot. In addition, the expression of p-NF-κB p65 and NLRP3 was detected by immunohistochemistry. Results. AP treatment ameliorated CLP-induced lung injury and lung edema, as well as decreased the number of total cells, neutrophils, and macrophages in bronchoalveolar lavage fluid (BALF). AP reduced the levels of TNF-α, IL-1β, IL-6, and IL-18 in BALF, as well as in serum. Moreover, AP decreased MPO activity and MDA content, whereas increased SOD and GSH levels. AP inhibited the expression of p-NF-κB p65, p-IκBα, NLRP3, ASC, and caspase-1, while promoted IκBα expression. Conclusion. This study demonstrated that AP exhibits protective effects against sepsis-induced ALI by inhibiting NLRP3 and NF-κB signaling pathways in mice.

Extraction and structural analysis of Angelica sinensis polysaccharide with low molecular weight and its lipid-lowering effect on nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the prevalent and typical chronic liver diseases. In this study, we extracted a novel Angelica sinensis polysaccharide (ASP) with low molecular weight (MW) of 3.2 kDa through optimized "one-step" purification process. The major monosaccharide components of ASP were mannose, rhamnose, glucuronic acid, galactose, arabinose, and xylose with weight ratio of 0.23:0.17:14.41:0.39:1.68:0.87, respectively. Herein, "small" ASP could serve as an effective therapeutic option for NAFLD both in free fatty acid-induced L02 models and in high-fat diet-induced mice models. Results revealed that low MW ASP dose-dependently decreased TG, TC in vitro and TG, TC, ALT, HDL-C, and LDL-C in vivo. Oil Red O-positive area and Nile red fluorescence intensity decreased in ASP treatment groups both in vitro and in vivo which suggested ASP could reduce lipid accumulation and fatty regeneration. Hematoxylin-eosin staining results shown a decrease in hepatocytes ballooning indicating that ASP could ameliorate liver lipid degeneration. Briefly, a novel polysaccharide with low MW was successfully obtained which can prospectively act as NAFLD therapy.

Angelica sinensis polysaccharide prevents mitochondrial apoptosis by regulating the Treg/Th17 ratio in aplastic anemia

Background

Angelica sinensis polysaccharide (ASP) is an effective medicine for aplastic anemia (AA). The present study aims to investigate whether mitochondrial apoptosis in aplastic anemia could be corrected by ASP by adjusting an abnormal level of regulatory T cell (Treg)/ IL-17 secreting CD4 T cell (Th17) ratio.

Methods

BALB/c mice were treated with 5.0 Gy Co60 γ -radiation. Then 2 × 10⁶ lymph node cells from DBA/2 donor mice were transplanted within 4 h after radiation. The mice in the various groups were fed saline or ASP for 2 weeks. For the in vitro experiment, bone marrow nucleated cells (BMNCs) and Treg cells were sorted from the mice on the 2nd day of modeling, and then cultured with or without ASP.

Results

The mice treated with the medium dose of ASP for 14 days showed increased white blood cell (WBC), red blood cell (RBC), platelet (PLT), BMNC counts and Lin–Sca-1 + c-Kit+ (LSK) populations viability compared with the mice in the AA group mice. The data showed that ASP decreased damage to the mitochondrial outer membrane, improved the stabilization of the mitochondrial membrane, and corrected the abnormal levels of ROS and mitochondrial-associated apoptosis proteins, including the Bcl-2/Bax ratio and caspase-3 and caspase-9 expression, in BMNCs which were sorted from the bone marrow cells of AA mice. The changes to the p-P38/P38 and Treg/Th17 ratios induced by AA were also reversed by the medium dose of ASP. The same ASP effect including the Bcl-2/Bax and p-P38/P38 ratio, caspase-3 and caspase-9 expression of BMNCs were observed in vivo. The viability of Treg cells were increased by treatment of ASP in vivo.

Conclusions

ASP might prevent mitochondrial apoptosis to restore the function of hematopoietic stem cells by suppressing abnormal T-cell immunity in AA.

Enhancing the Enzymatic Saccharification of Grain Stillage by Combining Microwave-Assisted Hydrothermal Irradiation and Fungal Pretreatment

Grain stillage from the liquor industry was pretreated by using microwave-assisted hydrothermal pretreatment, fungal pretreatments, and their combination to enable efficient enzymatic hydrolysis for sugar production. The microwave-assisted hydrothermal (MH) pretreatment was optimized by using a response surface methodology, and the respective maximum reducing sugar yield and saccharification efficiency of 17.59 g/100 g and 33.85%, respectively, were achieved under the pretreatment conditions of microwave power = 120 W, solid-to-liquid ratio = 1:15 (g·mL^-1), and time = 3.5 min. The fungal pretreatment with Phanerochaete chrysosporium digestion (PC) achieved the maximum ligninolytic enzyme activities in 6 days with 10% inoculum size at which the reducing sugar yield and saccharification efficiency reached 19.74 g/100 g and 36.29%, respectively. To further improve the pretreatment efficiency, MH and PC pretreatments were combined, but the sequence of MH and PC mattered on the saccharification efficiency. The MH + PC pretreatment (the MH prior to the PC) was better than PC + MH (the PC prior to the MH) in terms of saccharification efficiency. Overall, the MH + PC pretreatment achieved superior reducing sugar yield and saccharification efficiency (25.51 g/100 g and 66.28%, respectively) over all other studied pretreatment methods. The variations of chemical compositions and structure features of the raw and pretreated grain stillage were characterized by using scanning electron microscopy and Fourier transform infrared spectroscopy. The results reveal that both MH and PC pretreatments mainly functioned on delignification and decreasing cellulose crystallinity, thus enhancing the enzymatic saccharification of the pretreated grain stillage. The combined MH and PC pretreatment could be a promising method to enable cost-efficient grain stillage utilization for downstream applications such as biofuels.

Activation of RAW264.7 macrophage by Exopolysaccharide from Aphanothece halaphytica (EPSAH) and the underlying mechanisms

Exopolysaccharide from Aphanothece halophytica (EPSAH), a potent antitumor agent and immunological adjuvant, was investigated for the activation effect on RAW264.7 macrophages and the underlying mechanisms. EPSAH could significantly enhance macrophage phagocytosis and the secretion of nitric oxide, increase the mRNA expression levels of the pro-inflammatory cytokines (IL-1β, IL-6, IL-12, and TNF-α), anti-inflammatory cytokine IL-10, and chemokines (MCP-1 and MIP-1α). When RAW264.7 cells were treated with EPSAH, the mRNA expression of TLR4 and its downstream molecules TRAF6 and MyD88 were upregulated. When TLR4 was blocked using a TLR4-specific neutralizing antibody, nitric oxide secretion from the macrophages was significantly inhibited. EPSAH was further shown to induce phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK, JNK, and p38, and promote cytoplasmic IκB phosphorylation and increase nuclear NF-κB p65 levels remarkably in RAW264.7 cells. These data demonstrate the capacity of EPSAH to induce macrophage activation possibly via TLR4/MyD88 pathway, which leads to the activation of its main signaling downstream molecules MAPKs and NF-κB.

Designing selenium polysaccharides-based nanoparticles to improve immune activity of Hericium erinaceus

In previous researches, the results showed that selenium Hericium erinaceus polysaccharide and Hericium erinaceus polysaccharide-loaded poly (lactic-co-glycolic acid) nanoparticles enhanced immune responses. In order to further enhance the immune adjuvant activity and phagocytosis of the nanoparticles, two way of combination (selenium-HEP loaded PLGA nanoparticles and selenium modified HEP-PLGA nanoparticles) were prepared to investigate the effects on macrophages in vitro. After treatment with the nanoparticles, the effects of phagocytosis, co-stimulatory molecules expression, nitric oxide (NO), and cytokines secretion were evaluated. The results showed that the particle size, PDI and zeta potential of the selenium-HEP loaded PLGA nanoparticles (Se-HEP-PLGA) and selenium modifified HEP-PLGA nanoparticles (HEP-PLGA-Se) were presented. Se-HEP-PLGA and HEP-PLGA-Se nanoparticles significantly stimulated phagocytic activity, CD40 and CD86 expression of macrophages. In addition, the levels of NO, TNF-α, IL-1β and IL-6 were enhanced in the peritoneal macrophages by stimulation with Se-HEP-PLGA and HEP-PLGA-Se nanoparticles. Among them, Se-HEP-PLGA showed the best effects on the expression of co-stimulatory molecules, secretions of NO and cytokines. These results indicated that Se-HEP-PLGA could enhance the activation of macrophages, and it could be potentially used as an HEP delivery system for the induction of strong immune responses.

Optimization of Degradation Conditions with PRG, a Polysaccharide from Phellinus ribis, by RSM and the Neuroprotective Activity in PC12 Cells Damaged by Aβ25-35

In the previous work, we found PRG, a polysaccharide from Phellinus ribis, exhibited neurotrophic activity. To obtain an active structural unit with lower molecular weight, PRG was degraded to prepare the degraded PRG (DPRG) using ascorbic acid and H₂O₂. The aim of the paper was to obtain DPRG by optimizing the degradation conditions using response surface methodology (RSM) and to study its protective effects of PC12 cells induced by Aβ_25–35. The optimum conditions were as follows; the concentration of H₂O₂-Vc was 17 mM and degradation temperature was 50 °C; when degradation time was 1.6 h, the experimental response value of PC12 cell viability was 83.4 ± 0.15%, which was in accordance with the predicted value (83.5%). We also studied the protective effects of DPRG against the Aβ_25–35-induced neurotoxicity and explored the underlying mechanism. The results showed that treatment with DPRG could attenuate PC12 cells death. The mechanism was relative to the inhibition of cell apoptosis by increasing the MMP level and decreasing the protein expression of cytochrome C (Cytc) in PC12 cells. In conclusion, DPRG with lower molecular weight was obtained successfully. It possessed neuroprotective properties and might be a candidate for neurodegenerative disease treatment.

Polyethylenimine-coated PLGA nanoparticles-encapsulated Angelica sinensis polysaccharide as an adjuvant to enhance immune responses

Nanoparticle delivery systems have been widely investigated as new vaccines strategy to enhance the immune responses to antigens against infectious diseases. The positively charged nanoparticles could efficiently improve the immune responses due to targeting and activating the antigen-presenting cells. In this study, the immunopotentiator Angelica sinensis polysaccharide (ASP) was encapsulated into Poly (lactic-co-glycolic acid) (PLGA) nanoparticles, and the polyethylenimine, one of the cationic polymers, was used to coat nanoparticles to develop a new nanoparticle delivery system (ASP-PLGA-PEI) with positively charged. The ASP-PLGA-PEI nanoparticles significantly activated macrophages, and promoted the expression of the MHCII and CD86 and the production of IL-1β and IL-12p70 cytokines of macrophages. Furthermore, the antigen adsorbed on the surface of the ASP-PLGA-PEI nanoparticles enhanced the antigen uptake by macrophages. Moreover, the mice immunized with PCV2 antigen adsorbed ASP-PLGA-PEI nanoparticles significantly enhanced PCV2-specific IgG immune response and the levels of cytokines, induced a mixed Th1/Th2 immune response with Th1 bias compared with other groups. These findings demonstrate that the positively charged nanoparticles (ASP-PLGA-PEI) have the potential to serve as an effective vaccine delivery and adjuvant system to induce vigorous and long-term immune responses.

Cationic polymer modified PLGA nanoparticles encapsulating Alhagi honey polysaccharides as a vaccine delivery system for ovalbumin to improve immune responses

Background: Poly (lactic-co-glycolic acid) (PLGA) nanoparticles and surface modified PLGA nanoparticles have been widely studied as antigens or drugs carriers due to their controlled release characteristics and biocompatibility. However, most PLGA nanoparticles have lower antigens loading efficiency and adjuvanticity.

Purpose: The aim of this study was to improve the antigen loading efficiency and adjuvant activity of PLGA nanoparticles.

Materials and methods: Surface cationic polymer modification can improve the antigens loading efficiency of PLGA nanoparticles by surface adsorption. Therefore, in this study, chitosan modified PLGA nanoparticles (CS-AHPP/OVA), polyethyleneimine modified PLGA nanoparticles (PEI-AHPP/OVA), and ε-Poly-L-lysine modified PLGA nanoparticles (εPL-AHPP/OVA) were prepared as antigen delivery carriers to investigate the characterization and stability of these nanoparticles. These nanoparticles were evaluated for their efficacies as adjuvants pre- and post-modification.

Results: The AHP and OVA-loaded PLGA nanoparticles (AHPP/OVA) were positively charged after surface cationic polymers modification, and their structural integrity was maintained. Their antigen loading capacity and stability of nanoparticles were improved by the surface cationic polymers modification. Increased positive surface charge resulted in greater OVA adsorption capacity. Among AHPP/OVA and the three surface cationic polymers synthesized from modified PLGA nanoparticles, PEI-AHPP/OVA showed the highest antigen loading efficiency and good stability. AHPP/OVA, CS-AHPP/OVA PEI-AHPP/OVA, and εPL-AHPP/OVA formulations significantly enhanced lymphocyte proliferation and improved the ratio of CD4+/CD8+ T cells. In addition, AHPP/OVA, PEI-AHPP/OVA and εPL-AHPP/OVA formulations induced secretion of cytokines (TNF-α, IFN-γ, IL-4, and IL-6), antibodies (IgG) and antibody subtypes (IgG1 and IgG2a) in immunized mice. These results demonstrate that these formulations generated a strong Th1-biased immune response. Among them, PEI-AHPP/OVA induced the strongest Th1-biased immune response.

Conclusion: In conclusion, PEI-AHPP/OVA nanoparticles may be a potential antigen delivery system for the induction of strong immune responses.

RETRACTED: Angelica polysaccharide protects PC-12 cells from lipopolysaccharide-induced injury via down-regulating microRNA-223

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concerns were initially raised regarding the Western Blots from Figures 1C, 1G, 2B, 2D, 4D, 4F, 5 (left panel), 6C and 6E. Given also the comments of Dr Elisabeth Bik regarding this article “… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated”, the journal requested the authors to provide the raw data. The authors have not provided raw data of sufficient quality and detail to support the authors’™ claim and therefore the Editor-in-Chief decided to retract the article.

Angelica sinensis polysaccharide encapsulated into PLGA nanoparticles as a vaccine delivery and adjuvant system for ovalbumin to promote immune responses

Nanoparticles (NPs)-based vaccine delivery systems are widely used for their ability to control the release of antigens and promote immune responses against cancer or infectious diseases. In this study, the immunopotentiator Angelica sinensis polysaccharide (ASP) and model protein antigen ovalbumin (OVA) were encapsulated into Poly(lactic-co-glycolic acid) (PLGA) to formulate the novel NPs-based vaccine delivery system (ASP-PLGA/OVA). These formulations were subcutaneously administered to mice, then the magnitude and kinetics of antibody and cellular immune responses were assessed. The ASP-PLGA/OVA NPs were pherical in shape with smooth surfaces, approximately 225.2 nm in average size, negatively charged (around -11.27 mV), and the encapsulation efficiency of OVA at around 66.28%, respectively. Furthermore, ASP-PLGA/OVA NPs could keep stable at 4 °C over 30 days and provide a sustained and controlled release of OVA from the NPs. The results demonstrated that mice immunized with ASP-PLGA/OVA NPs could significantly enhance lymphocyte proliferation and improve the ratio of CD4⁺ to CD8⁺ T cells, thereby ASP-PLGA/OVA NPs could induce a strong cellular immune response. Moreover, the ASP-PLGA/OVA NPs could induce vigorous and long-term IgG immune responses with a mixed Th1 and Th2 responses and up-regulate the levels of Th-associated cytokines. These results suggested that ASP-PLGA/OVA NPs, which stimulated strong and continuous antibody responses and induced cellular immune responses, could potentially serve as an efficient and safe vaccine delivery and adjuvant system against infections and diseases.

Polysaccharides as vaccine adjuvants

Adjuvant is a substance added to vaccine to improve the immunogenicity of antigens, and it can induce stronger immune responses and reduce the dosage and production cost of vaccine in populations responding poorly to vaccination. Adjuvants in development or in use mainly include aluminum salts, oil emulsions, saponins, immune-stimulating complexes, liposomes, microparticles, nonionic block copolymers, polysaccharides, cytokines and bacterial derivatives. Polysaccharide adjuvants have attracted much attention in the preparation of nano vaccines and nano drugs because natural polysaccharides have the characteristics of intrinsic immunomodulating, biocompatibility, biodegradability, low toxicity and safety. Moreover, it has been proved that a variety of natural polysaccharides possess better immune promoting effects, and they can enhance the effects of humoral, cellular and mucosal immunities. In the present study, we systematically reviewed the recent studies on polysaccharides with vaccine adjuvant activities, including chitosan-based nanoparticles (NPs), glucan, mannose, inulin polysaccharide and Chinese medicinal herb polysaccharide. The application and future perspectives of polysaccharides as adjuvants were also discussed. These findings lay a foundation for the further development of polysaccharide adjuvants. Collectively, more and more polysaccharide adjuvants will be developed and widely used in clinical practice with more in-depth investigations of polysaccharide adjuvants.