Rehmannia glutinosa polysaccharide functions as a mucosal adjuvant to induce dendritic cell activation in mediastinal lymph node

Application prospect of polysaccharide in the development of vaccine adjuvants

Vaccination is an effective strategy for preventing infectious diseases. Subunit vaccines offer more precise targeting and safer protection compared with traditional inactivated virus vaccines. However, due to their poor immunogenicity, subunit vaccines necessitate the use of adjuvants to stimulate the immune system. Adjuvants have long been incorporated into vaccines to enhance the body's immune response, allowing for reduced dosage and lower production costs. Despite the development of numerous vaccine adjuvants, few exhibit the necessary potency and low toxicity for clinical use, often due to limited efficacy or adverse side effects. This underscores the urgent need for novel human vaccine adjuvants that are safe, effective, and cost-efficient. Recent studies have identified certain natural polysaccharides as promising human vaccine adjuvants due to their immunostimulatory properties, low toxicity, and high safety profiles, which enhance both humoral and cellular immunity. These natural polysaccharides are primarily derived from traditional Chinese medicine (TCM) plants, bacteria, and yeast. This review comprehensively analyzes several promising polysaccharide adjuvants, discussing their clinical applications, market potential, and immunoregulatory activities. In summary, the future prospects of polysaccharides provide valuable insights for the application and development of vaccine adjuvants.

Structural characteristics, biological activities and market applications of Rehmannia Radix polysaccharides: A review

Rehmannia Radix Polysaccharides (RRPs) are biopolymers that are isolated and purified from the roots of Rehmannia glutinosa Libosch, which have attracted considerable attention because of their biological activities, such as anti-inflammatory, antioxidant, immunomodulatory, anti-tumor, hypoglycaemic etc. In this manuscript, the composition and structural characteristics of RRPs are reviewed. Moreover, the research progress on the conformational relationships and biological activities of RRPs is systematically summarized. Additionally, this manuscript also analyzes 155 patents using RRPs as the main raw materials to explore the status quo and bottleneck for the development and utilization of RRPs. In summary, this review not only provides a theoretical basis for future research on RRPs but also provides clear guidance for their market applications and innovation.

Rehmmannia glutinosa polysaccharide exerts antiviral activity against pseudorabies virus and antioxidant activity

Pseudorabies virus (PRV) is an important pathogen harming the global pig industry. Vaccines available for swine cannot protect against PRV completely. Furthermore, no antiviral drugs are available to treat PRV infections. Rehmmannia glutinosa polysaccharide (RGP) possesses several medicinal properties. However, its antiviral activity is not reported. In the present study, we found that RGP can inhibit PRV/XJ5 infection by western blotting, immunofluorescent assay (IFA), and TCID50 assay quantitative polymerase chain reaction (qPCR). We revealed RGP can inhibit virus adsorption and invasion into PK-15 cells in a dose-dependent manner via western blotting, IFA, TCID50 assay, and quantitative polymerase chain reaction (qPCR), and suppressed PRV/XJ5 replication through western blotting, and qPCR. Additionally, it also reduced PRV/XJ5-induced ROS, lipid oxidation, and improved SOD levels in PK-15 cells, which was observed by using corresponding test kits. To conclude, our findings suggest that RGP might be a novel therapeutic agent for preventing and controlling PRV infection and antioxidant agent.

Effects and core patterns of Chinese herbal medicines on hematologic manifestations in systemic lupus erythematosus: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis of randomized controlled trials (RCTs) aimed to evaluate the effects of Chinese herbal medicines (CHMs) on hematologic manifestations in patients with systemic lupus erythematosus (SLE).

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, and Airiti Library were searched for the period January 2000 to February 2022.

STUDY SELECTION

RCTs involving CHMs in patients with SLE with available hematologic data.

DATA EXTRACTION

The primary outcomes included white blood cell (WBC) count, hemoglobin level, and platelet count. The Cochrane risk of bias tool was used to assess the quality of the included RCTs. Sensitivity analysis of RCTs with abnormal hematologic data before intervention was performed to verify the robustness of the results. Subgroup analysis was also applied for results with high heterogenicity. Core patterns of used herbal drug pairs had also been analyzed and visualized.

DATA SYNTHESIS

Fifteen RCTs involving 1183 participants were included. The effects of elevating WBC count (weighted mean difference [WMD]: 0.69; 95% confidence interval [CI]: 0.33-1.06; p <0.001), hemoglobin levels (WMD: 0.64; 95% CI: 0.31-0.97; p <0.001), and platelet count (WMD: 0.61; 95% CI: 0.48-0.74; p <0.001) in the CHM group were significantly greater than those in the control group. In total, 23 single herbs and 152 herbal drug pairs were identified for core patterns network analysis.

CONCLUSIONS

We demonstrated significantly superior therapeutic effects achieved with CHMs and conventional therapy regarding leukopenia, anemia, and thrombocytopenia compared to that of conventional therapy alone in patients with SLE.

Preclinical pharmacokinetics-related pharmacological effects of orally administered polysaccharides from traditional Chinese medicines: A review

Polysaccharides (TCMPs) derived from traditional Chinese medicines (TCMs), such as Ganoderma lucidum, Astragalus membranaceus, Lycium barbarum, and Panax ginseng, are considered to be the main active constituents in TCMs. However, the significant pharmacological effects of orally administered TCMPs do not align well with their poor pharmacokinetics. This article aims to review the literature published mainly from 2010 to 2022, focusing on the relationship between pharmacokinetics and pharmacological effects. It has been found that unabsorbed TCMPs can exert local pharmacological effects in the gut, including anti-inflammation, anti-oxidation, regulation of intestinal flora, modulation of intestinal immunity, and maintenance of intestinal barrier integrity. Unabsorbed TCMPs can also produce systemic pharmacological effects, such as anti-tumor activity and immune system modulation, by regulating intestinal flora and immunity. Conversely, some TCMPs can be absorbed and distributed to various tissues, especially the liver, where they exhibit tissue-protecting effects against inflammation and oxidative stress-induced damage and improve glucose and lipid metabolism. In future studies, it is important to improve quality control and experimental design. Furthermore, research on enhancing the oral bioavailability of TCMPs, exploring the activity of TCMP metabolites, investigating pharmacokinetic interactions between TCMPs and oral drugs, and developing oral drug delivery systems using TCMPs holds great significance.

Progress of research into the pharmacological effect and clinical application of the traditional Chinese medicine Rehmanniae Radix

The traditional Chinese medicine (TCM) Rehmanniae Radix (RR) refers to the fresh or dried root tuber of the plant Rehmannia glutinosa Libosch of the family Scrophulariaceae. As a traditional Chinese herbal medicine (CHM), it possesses multiple effects, including analgesia, sedation, anti-inflammation, antioxidation, anti-tumor, immunomodulation, cardiovascular and cerebrovascular regulation, and nerve damage repair, and it has been widely used in clinical practice. In recent years, scientists have extensively studied the active components and pharmacological effects of RR. Active ingredients mainly include iridoid glycosides (such as catalpol and aucuboside), phenylpropanoid glycosides (such as acteoside), other saccharides, and unsaturated fatty acids. In addition, the Chinese patent medicine (CPM) and Chinese decoction related to RR have also become major research subjects for TCM practitioners; one example is the Bolus of Six Drugs, which includes Rehmannia, Lily Bulb and Rehmannia Decoction, and Siwu Decoction. This article reviews recent literature on RR; summarizes the studies on its chemical constituents, pharmacological effects, and clinical applications; and analyzes the progress and limitations of current investigations to provide reference for further exploration and development of RR.

Catalpol ameliorates inflammation and oxidative stress via regulating Sirt1 and activating Nrf2/HO-1 signaling against acute kidney injury

BACKGROUND

Septic acute kidney injury (SAKI) is usually caused by sepsis. It has been shown that catalpol (Cat) impairs sepsis-evoked organ dysfunction to a certain degree. The current work aims to evaluate the protective effects of Cat on SAKI and potential mechanisms in vivo and in vitro.

METHODS

SAKI cellular and murine model were set up using lipopolysaccharide (LPS) in vitro and in vivo. Cell apoptosis in cells was determined by TUNEL assay. Levels of inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). The levels of the markers of oxidative injury were evaluated by corresponding commercial kits. Protein levels were assayed via western blotting and immunohistochemistry (IHC) staining.

RESULTS

The results demonstrated that LPS upregulated TNF-α, IL-6, and malondialdehyde levels, and downregulated superoxide dismutase, whereas Cat treated cells have the opposite results. Functional assays displayed that Cat remarkably reversed the LPS-challenged damage as the impairment of TNF-α and IL-6 levels, oxidative stress, and the apoptosis in HK-2 cells. Moreover, knockdown of Sirtuin 1 (Sirt1) counteracted the suppressive impact of Cat on LPS-triggered inflammatory response, oxidative stress, and renal damage. Further, Cat elevated Sirt1 expression and activated the Nrf2/HO-1 signaling in LPS-engendered SAKI in vivo and in vitro.

CONCLUSION

Our study clearly proved that Cat protected against LPS-induced SAKI via synergic antioxidant and anti-inflammatory actions by regulating Sirt1 and Nrf2/HO-1 signaling pathways.

Purification and structural analysis of a novel polysaccharide from Rehmannia Radix Praeparata

In this paper, the purification, structure, and antioxidant activity of Rehmannia Radix Praeparata polysaccharide (RRPP) were studied. The RRPP was separated using DEAE-52 cellulose and Sephadex G-100. The RRPP consisted of xylose, glucose, rhamnose, galactose, and mannose in ratios of 10.64:5.58:3.52:1.39:1.0. No protein was detected in the RRPP fraction, and the molecular weight of RRPP was about 1.75 × 106  Da. The basic skeleton information was obtained using periodic acid oxidation-Smith degradation, and RRPP contained 1→, 1 → 2, 1 → 3, 1 → 4, 1 → 2,6, 1 → 4,6 or 1 → 6, 1 → 2,3, 1 → 2,3,4, and other glycosidic bonds. Fourier transform infrared spectroscopy also showed that RRPP has both α- and β-glycosidic bonds. The in vitro antioxidant activity test showed that RRPP could potentialize scavenging effect on ABTS+· and its scavenging rate was 91.3%.

Extraction, structure and bioactivities of polysaccharides from Rehmannia glutinosa: A review

ETHNOPHARMACOLOGIC RELEVANCE

Rehmannia glutinosa (Gaertn.) DC. (RG) is a widely used herb for clearing heat and cooling the blood. Polysaccharides from Rehmannia glutinosa (Gaertn.) DC. (RGPs) have a variety of biological activities, including antioxidation, hypoglycemia, immune enhancement, hematopoiesis promotion, and antianxiety.

AIM OF THE STUDY

This review provides up-to-date and comprehensive information on the extraction and separation methods, structural characteristics, and pharmacological activities of RGPs. A more in-depth study on the structure and clinical pharmacology of the RGPs was investigated. To further explore the pharmacological effects of RGPS, and lay a foundation for the safe clinical application and expansion of application scope.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the literature on extraction, separation, structural analysis and pharmacological activity of RGPs published before December 2022. The key words are "extraction", "isolation", "purification" and "pharmacological action" and "Rehmanniae polysaccharide".

RESULTS

Rehmannia glutinosa has been widely used in the treatment of diabetes since ancient times, and is known as one of the "Four Sacred Medicines" for the treatment of diabetes, along with Ginseng, Psidium Guajava and Pueraria Mirifica. The active ingredients of Rehmannia glutinosa that have been studied more in the treatment of diabetes are Rehmannia glutinosa polysaccharide and Rehmannia glutinosa oligosaccharide. The content of polysaccharides varies due to different extraction methods, and separation and purification methods. RGPs have a wide range of pharmacological activities, including antitumor, immunomodulatory, neuroprotective effect, hypoglycemic activity, cardioprotective and antioxidant activities. These pharmacological properties lay a foundation for the treatment of tumors, inflammation, hyperglycemia, myocardial ischemia, oxidative stress and other diseases with RGPs.

CONCLUSION

Based on its effects of promoting hematopoiesis, antitumor and enhancing immunity, RGPs have been clinically applied in the treatment of chronic aplastic anemia and esophageal cancer, but other effects of RGPs have not been reflected in the clinical practice. In the future, more in-depth research can be conducted on the molecular structure analysis, toxicity, side effects and clinical pharmacological effects of RGPs to further explore the pharmacological effects of RGPs and to lay the foundation for safe clinical application and expansion of application scope.

Structural Characteristics of Rehmannia glutinosa Polysaccharides Treated Using Different Decolorization Processes and Their Antioxidant Effects in Intestinal Epithelial Cells

Polysaccharide decolorization is a key determinant of polysaccharide structure. In this study, two purified Rehmannia glutinosa polysaccharides, RGP−1−A and RGP−2−A, were obtained after decolorization using the AB-8 macroporous resin and H₂O₂, respectively. RGP−1−A (molecular weight (Mw) = 18,964 Da) and RGP−2−A (Mw = 3305 Da) were acidic and neutral heteropolysaccharides, respectively, and were both polycrystalline in structure. FTIR analysis revealed that RGP−1−A was a sulfate polysaccharide, while RGP−2−A had no sulfate group. Experiments on IPEC-1 cells showed that RGPs alleviated oxidative stress by regulating the Nrf2/Keap1 pathway. These findings were confirmed by the upregulation of Nrf2, NQO1, and HO-1; the subsequent increase in the levels of antioxidant indicators (SOD, LDH, CAT, and MDA); and the restoration of mitochondrial membrane potential. Overall, the antioxidant capacity of RGP−1−A was significantly higher than that of RGP−2−A. These results suggest that RGPs may be a potential natural antioxidant and could be developed into functional foods.

Structural changes, and anti-inflammatory, anti-cancer potential of polysaccharides from multiple processing of Rehmannia glutinosa

Polysaccharides play important roles in the bioactivities of Rehmannia glutinosa. This study examined the physiochemical structure and biological activity of the polysaccharides of R. glutinosa during nine steps of processing. Characteristic study showed galactose, glucose, and fructose were the major sugars in the polysaccharides. The percentage of the high-molecular weight polysaccharide increased after processing. In addition, polysaccharides from repeated steam and dry processing of R. glutinosa can effectively increase the anti-inflammatory activity. Secretions of tumor necrosis factor (TNF-α), interleukin (IL)-6, and transforming growth factor (TGF)β after lipopolysaccharide (LPS) stimulation were detected in RAW264.7 macrophages because of its anti-inflammatory activity. RG-B9, a polysaccharide of the ninth steam and dry processing, showed the strongest inhibitory activity on bacterial LPS-induced macrophage IL-6 and TGFβ production. Mechanically, RG-B9 down-regulated the phosphorylation of AKT/ERK. The anti-inflammation of RG-B9 involved AKT/ERK/JNK signaling. In addition, RG-B9 inhibited the viability of lung cancer cells via EGFR/AKT signaling.

A systematic review on botany, processing, application, phytochemistry and pharmacological action of Radix Rehmnniae

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Rehmanniae (RR) is the tuber root of Rehmannia glutionsa Libosch, which was firstly recorded in Shennong's Classic of Materia Medica (⟪⟫). RR is a non-toxic and wide used traditional Chinese medicine. RR has the effect of clearing heat, generating essence, cooling blood, stopping bleeding, nourishing yin and blood, and filling marrow. It is used in clinic in the form of processed decoction pieces, including Dry Radix Rehmnniae (DRR) and Rehmanniae Radix Praeparata (RRP). The application of RR in traditional Chinese medicine (TCM) prescriptions can treat various diseases, such as anemia, irregular menstruation, deficiency of liver yin, renal failure and so on.

AIM OF REVIEW

This paper aims to provide a comprehensive and productive review of RR, which mainly contains botanical characteristics, processing methods, traditional application, chemical composition, quality control and pharmacological action.

MATERIALS AND METHODS

Literature search was conducted through the Web of Science, Baidu Scholar, ScienceDirect, PubMed, CNKI, and WanFang DATA using the keywords "Radix Rehmnniae", "Rehmanniae Radix Praeparata", "processing", "clinical application", "chemical composition", "quality control", and "pharmacological action". In addition, information was collected from relevant textbooks, reviews, and documents.

RESULTS

RR is a traditional Chinese herbal medicine with clinical value and rich resources. More than 100 components have been isolated and identified from RR. It has multiple pharmacological actions, such as hemostasis, antioxidation, anti-osteoporosis, lowering blood sugar, improving renal function, anti-inflammation, protecting neuronal function, antidepression and anti-anxiety. DRR and RRP are two different processed products of RR. After processing, there are great changes in property, taste, efficacy, clinical application, chemical composition and pharmacological action. At present, identifying chemical constituents of RR and its medicinal value has been deeply studied. However, there is a lack of research on the reasons for the differences in pharmacological effects between DRR and RRP. The reasons for these differences need to be further verified. Catalpol, the active component of RR, has been studied extensively in the literature, but the pharmacological effects of catalpol cannot represent the pharmacological effects of the whole RR. In the future, effective components such as rehmannioside D, polysaccharide, total glycosides, and effective parts in RR need to be further studied and developed. The pharmacodynamic material basis and mechanism of RR need to be further discussed. The scientific connotation and processing methods of RRP need to be studied and standardized.

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.

Intranasal Administration of Codium fragile Polysaccharide Elicits Anti-Cancer Immunity against Lewis Lung Carcinoma

Natural polysaccharides have shown promising effects on the regulation of immunity in animals. In this study, we examined the immune stimulatory effect of intranasally administered Codium fragile polysaccharides (CFPs) in mice. Intranasal administration of CFPs in C57BL/6 mice induced the upregulation of surface activation marker expression in macrophages and dendritic cells (DCs) in the mediastinal lymph node (mLN) and the production of interleukin-6 (IL-6), IL-12p70, and tumor necrosis factor-α in bronchoalveolar lavage fluid. Moreover, the number of conventional DCs (cDCs) was increased in the mLNs by the upregulation of C-C motif chemokine receptor 7 expression, and subsets of cDCs were also activated following the intranasal administration of CFP. In addition, the intranasal administration of CFPs promoted the activation of natural killer (NK) and T cells in the mLNs, which produce pro-inflammatory cytokines and cytotoxic mediators. Finally, daily administration of CFPs inhibited the infiltration of Lewis lung carcinoma cells into the lungs, and the preventive effect of CFPs on tumor growth required NK and CD8 T cells. Furthermore, CFPs combined with anti-programmed cell death-ligand 1 (PD-L1) antibody (Ab) improved the therapeutic effect of anti-PD-L1 Ab against lung cancer. Therefore, these data demonstrated that the intranasal administration of CFP induced mucosal immunity against lung cancer.

Ecklonia cava fucoidan has potential to stimulate natural killer cells in vivo

Fucoidan is a sulfated polysaccharide, derived from various marine brown seaweeds, that has immunomodulatory effects. In this study, we analyzed the effects of five different fucoidans, which were extracted from Ascophyllum nodosum, Undaria pinnatifida, Macrocystis pyrifera, Fucus vesiculosus, and Ecklonia cava, on natural killer (NK) cell activation in mice. Among these, E. cava fucoidan (ECF) promoted an increase in the number of NK cells in the spleen and had the strongest effect on the activation of NK cells. Additionally, we observed that DC stimulation was required for NK cell activation and that ECF had the most potent effect on splenic dendritic cells (DC). Finally, ECF treatment effectively prevented infiltration of CT-26 carcinoma cells in the lungs of BALB/c mice in an NK cell dependent manner. Collectively, these results suggest that ECF could be a suitable candidate for enhancing NK cell-mediated anti-cancer immunity.

Clinical research on traditional Chinese medicine treatment for bacterial vaginosis

Bacterial vaginosis (BV) is a common disease among women of reproductive age, with a serious impact on their daily life and health. At present, the most common treatment for BV is to take antibiotics, which results in good short-term treatment effects, but poor long-term effects. Traditional Chinese medicine (TCM) has been used to treat BV for over a millennium, with little risk of triggering drug resistance and adverse effects. Based on syndrome differentiation, there are three oral TCM treatment strategies for BV, including invigorating spleen, clearing dampness and heat, and nourishing kidney. The oral TCM prescriptions, such as Yi Huang decoction, Longdan Xiegan decoction, Zhibai Dihaung decoction, and so on are commonly used. Topical TCM treatment is also popular in China. According to the research results of pharmacological effects of active TCM ingredients, the most potential mechanisms of TCM for BV treatment are immune-enhancement effects, antibacterial activity, and estrogen-liked effects. Nonetheless, the multi-constituent of herbs may result in possible disadvantages to BV treatment, and the pharmacological mechanisms of TCM need further study. Here, we provide an overview of TCM compounds and their preparations used for BV, based on the pathogenesis and the potential therapeutic mechanisms, therefore providing a reference for further studies.

Polysaccharide from Astragalus membranaceus promotes the activation of human peripheral blood and mouse spleen dendritic cells

Astragalus membranaceus (A. membranaceus) is a widely used traditional herb in China and Korea. A. membranaceus polysaccharides (AMP), which make up a major part of the root extract, have been shown to modulate immune modulations, especially activation of bone marrow-derived dendritic cells (BMDCs) and T cells. However, the immune stimulatory effect of AMP in the mouse in vivo and human peripheral blood DCs (PBDCs) has not been well investigated. In this study, we found that intravenous (i.v.) injection of AMP in C57BL/6 mice induced remarkable elevations in co-stimulatory and MHC class I and II molecule levels in the splenic DCs and its subsets. The stimulatory effect of DCs by AMP was elevated 6 h after treatment, which rapidly decreased 18 h after injection. Furthermore, AMP promoted intracellular production of pro-inflammatory cytokines in spleen DC subsets, which contributed elevation of serum cytokine levels. Finally, the AMP promoted PBDC activation. Thus, these results demonstrate that AMP can be used as an immune stimulatory molecules in human and mouse.

Interleukin-10-Producing B Cells Help Suppress Ovariectomy-Mediated Osteoporosis

Osteoporosis is prevalent in elderly women and it may cause dental implant failure. In particular, estrogen deficiency in postmenopausal women leads to higher rates of osteoporosis prevalence. Immune cell-mediated effects involving the development of osteoporosis have been studied previously; however, the role of IL-10-producing regulatory B (B10) cells in osteoporosis is largely unclear. Here, we examined the role of B10 cells in osteoporosis. C57BL/6 mice were subjected to ovariectomy (OVX). Fifteen weeks after OVX surgery, the first molar of the right maxillary was extracted, and twenty-four weeks after OVX surgery, serous progression of osteoporosis was observed in the alveolar bone. Moreover, the proportion of CD19⁺CD5⁺CD1d^high regulatory B cells, B10, and CD4⁺CD25⁺FoxP3⁺ regulatory T cells from the spleen of OVX mice decreased during the progression of osteoporosis, compared to controls. In contrast to regulatory cells, IL-17-producing Th (Th17) cell levels were increased in OVX mice. Adoptive transfer of B10 cells to OVX mice led to a decrease in Th17 cell abundance and inhibited the development of osteoporosis in the alveolar bone from OVX mice. Thus, our results suggest that B10 cells may help suppress osteoporosis development.

PEGylated nano-Rehmannia glutinosa polysaccharide induces potent adaptive immunity against Bordetella bronchiseptica

Vaccines, in many cases, stimulate only too weak immunogenicity to prevent infection. Therefore, adjuvants are required during their preparation to boost the immune response. We herein developed a PEGylated nano-adjuvant based on Rehmannia glutinosa polysaccharide (RGP). The addition of PEG layer exhibits enhanced immune performance of the nano-RGP. Stimulation of dendritic cells (DCs) with PEGylated nano-RGP (pRL) led to increased proliferation and cytokine production (IL-6, IL-12, IL-1β and TNF-α). The pRL was internalized into DCs via a rapid and efficient method. The mice immunized with pRL exhibited enhanced antigen-specific serum IgG and Th1-(IFN-γ), Th2-(IL-4), and Th17-(IL-17, IL-6) cytokine production, contributing to a good anti-infection performance. Furthermore, the pRL could effectively deliver the antigen to the lymph nodes (LNs), activate DC in the LN and produce enhanced CD4⁺and CD8⁺ T-cells-derived memory (CD44^high CD62L^high), and effector (CD44^high CD62L^low) as well as functional phenotypes. Our results revealed that pRL can act as a promising adjuvant with targeted delivery of antigen due to its effective activation and robust adaptive immunity induction of DCs.

Alumina Ceramic Exacerbates the Inflammatory Disease by Activation of Macrophages and T Cells

(1) Background: Aluminum oxide (Al₂O₃) ceramic is one of the materials used for artificial joints, and it has been known that their fine particles (FPs) are provided by the wear of the ceramic. Al₂O₃ FPs have been shown to induce macrophage activation in vitro; however, the inflammatory effect in vivo has not been studied. (2) Methods: We examined the in vivo effect of Al₂O₃ FPs on the innate and adaptive immune cells in the mice. (3) Results: Al₂O₃ FPs promoted the activation of spleen macrophages; however, conventional dendritic cells (cDCs), plasmacytoid DCs (pDCs), and natural killer (NK) cells were not activated. In addition, increases in the CD4 and CD8 T cells was induced in the spleens of the mice treated with Al₂O₃ FPs, which differentiated into interferon-gamma (IFN-γ)-producing helper T1 (Th1) and cytotoxic T1 (Tc1) cells. Finally, the injection of Al₂O₃ FPs exacerbated dextran sulfate sodium (DSS)-induced inflammation in the colon, mediated by activated and increased number of CD4 and CD8 T cells. (4) Conclusions: These data demonstrate that FPs of Al₂O₃ ceramic may contribute to the exacerbation of inflammatory diseases in the patients.

Treatment with catalpol protects against cisplatin-induced renal injury through Nrf2 and NF-κB signaling pathways

Cisplatin (CP) is one of the most widely used chemotherapy drugs for cancer treatment, but it often leads to nephrotoxicity. It is well known that catalpol exhibits antioxidant and anti-inflammatory functions, thus the present study aimed to investigate the potential protective effects of catalpol on CP-induced kidney injury in rats, in addition to determining the underlying mechanisms. Sprague-Dawley rats were treated with 25, 50 or 100 mg/kg catalpol for two days, injected with 20 mg/kg cisplatin and catalpol on day 3 and sacrificed on day 4. The histological analysis of isolated kidney tissues was performed using hematoxylin and eosin staining, cleaved caspase-3 expression levels were analyzed using western blotting and the expression levels of inflammatory cytokines in the tissues, including tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6, IL-8, IL-10 and inducible nitric oxide synthase (iNOS) were evaluated using ELISAs. Furthermore, the mRNA and protein expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), kelch-like ECH-associated protein 1 (Keap1), NF-κB and inhibitory κB (IκB) were determined using reverse transcription-quantitative PCR and western blotting, respectively. The results revealed that the treatment with catalpol prevented the histopathological injury and renal dysfunction caused by CP. In addition, catalpol significantly suppressed the CP-induced apoptosis of tubular cells, inhibited the CP-induced upregulation of TNF-α, IL-1β, IL-6, IL-8 and iNOS and promoted the production of the anti-inflammatory cytokine IL-10. Additionally, the mRNA and protein expression levels of Nrf2, HO-1 and IκB in the kidney tissues were increased, whereas the expression levels of Keap1 and NF-κB were significantly decreased following the treatment with catalpol. In conclusion, these results suggested that catalpol may inhibit CP-induced renal injury and suppress the associated inflammatory response through activating the Nrf2 and inhibiting the NF-κB signaling pathways, respectively.

The Effects of Oral Rehmannia glutinosa Polysaccharide Administration on Immune Responses, Antioxidant Activity and Resistance Against Aeromonas hydrophila in the Common Carp, Cyprinus carpio L

The effects of the oral administration of Rehmannia glutinosa polysaccharide (RGP-1) on the immunoregulatory properties, antioxidant activity, and resistance against Aeromonas hydrophila in Cyprinus carpio L. were investigated. The purified RGP-1 (250, 500, and 1,000 μg/mL) was co-cultured with the head kidney cells of the common carp. The proliferation and phagocytosis activities of the head kidney cells, and the concentration of nitric oxide (NO) and cytokines in the culture medium were determined. Next, 300 common carps (47.66 ± 0.43 g) were randomly divided into five groups; the two control groups (negative and positive) were administered sterile PBS and the three treatment groups were administered different concentrations of RGP-1 (250, 500, and 1,000 μg/mL) for seven days. Subsequently, the positive and treatment groups were infected with A. hydrophila, and the negative group was administered sterile PBS for 24 h. The concentration of NO, cytokines, lysozyme (LZM), and alkaline phosphatase (AKP) in serum, the total antioxidant capacity (T-AOC), the levels of malonaldehyde (MDA) and glutathione (GSH), and the total activities of superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the hepatopancreas of the common carp were tested. We observed that RGP-1 could significantly enhance the proliferation and phagocytosis activities (P < 0.05), besides inducing the production of NO, pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12) and anti-inflammatory cytokines (IL-10, TGF-β) (P < 0.05) in vitro. The in vivo experimental results revealed that RGP-1 significantly enhanced NO production, protein levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-12), LZM and AKP activities, and the antioxidant content (T-AOC, SOD, CAT, GSH, GSH-Px, and MDA) compared to that observed in the negative group prior to A. hydrophila infection (P < 0.05). NO, pro-inflammatory cytokines, LZM and AKP activities were significantly lower than that in the positive group after infection (P < 0.05). However, whether infected or not, the expression of anti-inflammatory cytokines (IL-10, TGF-β) increased significantly in the RGP-1-treated groups (P < 0.05). Therefore, the results suggested that RGP-1 could enhance the non-specific immunity, antioxidant activity and anti-A. hydrophila activity of the common carp, and could be used as a safe and effective feed additive in aquaculture.

Optimum Preparation Method for Self-Assembled PEGylation Nano-Adjuvant Based on Rehmannia glutinosa Polysaccharide and Its Immunological Effect on Macrophages

BACKGROUND

Rehmannia glutinosa polysaccharide is the main reason that contributes to the immunological function of R. glutinosa. Due to its disadvantages in clinical use, here we designed the PEGylation nano-RGP (pRL) to improve the drug-targeting effect and the immunological function. Our present work aims to establish the optimum condition of preparing the pRL and to investigate its immunological function on macrophages.

METHODS

pRL was prepared by thin film hydration method combined with ultra-sonication technique. And its preparation conditions were optimized with response surface methodology. Also, the lyophilization method was optimized. The characteristics of the pRL were evaluated, including particle size, drug loading, encapsulation efficiency and morphology. The immunological function of pRL on macrophage was investigated through CCK-8 test, ELISA and flow cytometry.

RESULTS

The lipid-to-cholesterol molar ratio of 8:1, the addition of DSPE-PEG2000 of 9% and the lipid-to-drug ratio of 5.4:1 were the optimum preparation technology for pRL. The encapsulation efficiency (EE) of pRL under this preparation technology was 95.81±1.58%, with a particle size of 31.98 ± 2.6 nm. The lactose-to-lipid ratio (2:1) was the optimal lyophilization method. pRL promoted macrophage proliferation, which is significantly better than that of nano-RGP without PEGylation (RL). pRL-stimulated RAW264.7 cells showed a high secretion of pro-inflammatory cytokines, which is the characteristic indicator of M1 polarization. Enhanced cellular uptake through macropinocytosis-dependent and caveolae-mediated endocytosis was observed in pRL-treated RAW264.7 cells.

CONCLUSION

Our study concluded that PEGylation effectively overcame the poor targeting effect of Rehmannia glutinosa polysaccharide (RGP) and significantly improved the immunological profile of its nano-formulation, which suggested that pRL could serve as an immune adjuvant in clinical application.