Rehmannia Glutinosa Polysaccharide Research Articles

Antioxidant and anti-aging effects of purified Rehmannia glutinosa polysaccharide in Caenorhabditis elegans

Oxidative stress has been linked to the onset and progression of aging. Natural polysaccharides have attracted considerable attention in the field of antioxidants and anti-aging products owing to their exceptional biological activity and low toxicity. In this study, a homogeneous (glucogalactan-structured) polysaccharide (RGP70–1) was purified from the roots of Rehmannia glutinosa Libosch. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), monosaccharide composition, methylation, and nuclear magnetic resonance analyses were employed to characterize structure. RGP70–1 (3.6 kDa) was composed of glucose, galactose. RGP70–1's primary chain consisted of α-D-Galp connected by 1,4-linkages, α-D-Galp connected by 1,6-linkages, and β-D-Galp connected by 1,3,4,6-linkages.The side branches included α-D-Galp linked in a 1,4 position, α-D-Galp linked in a 1,6 position, and α-D-Glcp linked at the terminal end. In vivo, the effects of RGP70–1 on aging were examined using a Caenorhabditis elegans model. The findings demonstrated that RGP70–1 enhanced the performance of antioxidant enzymes, decreased reactive oxygen species levels, and prolonged the lifespan of Caenorhabditis elegans. The results of the quantitative real-time polymerase chain reaction indicated that RGP70–1 might demonstrate anti-aging properties by influencing insulin/insulin-like signaling pathway. In general, these findings highlight the possibility of RGP70–1 being utilized in dietary supplements for its anti-aging properties.

Rehmannia Glutinosa Polysaccharide Regulates Bone Marrow Microenvironment via HIF-1α/NF-κB Signaling Pathway in Aplastic Anemia Mice.

Aplastic anemia (AA), a rare disorder, is associated with bone marrow microenvironment (BMM). Presently, AA treatment is of great difficulty. This study aimed to explore the mechanism of action of Rehmannia glutinosa polysaccharide (RGP) in AA. Busulfan was used to induce AA in BALB/c mice; blood cell count and Ray's Giemsa staining were used to assess the severity of hematopoietic failure; HE was performed to assess the pathological state of the marrow cavity; ELISA was performed to assess IL-4, IL-10, IL-6, IL-12, IL-1β, TNF-α, MCP-1, VEGF, and EPO; and WB was performed to evaluate the effects of RGP on the HIF-1α/NF-κB signaling. Significant downregulation of hemocyte levels in the blood and nucleated cells in the bone marrow was reversed by RGP and Cyclosporine A (CA). Compared with the AA group, dilating blood sinusoids, inflammation, hematopoiesis, decreased bone marrow cells and megakaryocytes were alleviated by RGP and CA, and the HIF-1α/NF-κB signaling was inhibited too. Notably, RGP was more effective when used in combination with CA. In this study, we established a relationship between BMM and the HIF-1α/NF-κB signaling pathway and found that RGP regulates BMM by suppressing the activation of the HIF-1α/NF-κB signaling. Thus, RGP exerts a pharmacological effect on AA.

Rehmannia glutinosa polysaccharides attenuates colitis via reshaping gut microbiota and short-chain fatty acid production.

Ulcerative colitis is a gastrointestinal disease closely related to intestinal epithelial barrier damage and intestinal microbiome imbalance; however, effective treatment methods are currently limited. Rehmannia glutinosa polysaccharide (RGP) is an important active ingredient with a wide range of pharmacological activities, although its protective effect on colitis remains to be explored. In the present study, we verified the in vitro anti-inflammatory effect of RGP, and observed the ameliorating effect of RGP on dextran sulfate sodium-induced colitis in mice. The results showed that (i) RGP attenuates lipopolysaccharide-induced overexpression of inflammatory factors in RAW264.7 cells; (ii) RGP improves the pathological damage caused by DSS, including weight loss, increased disease activity index and intestinal tissue ulcers; (iii) RGP improves tight junction proteins to protects the tightness of the intestinal epithelium; (iv) RGP inhibits the expression of inflammatory factors through the nuclear factor-kappa B pathway, and improved the of intestinal tissues inflammation; and (v) RGP can maintain the species diversity of intestinal microbes, increase the content of short-chain fatty acids and then restore the imbalance of intestinal microecology. RGP can improve the intestinal microbiota to strengthen the intestinal epithelial barrier and protect against DSS-induced colitis. © 2022 Society of Chemical Industry.

Deciphering the mechanism of Fang-Ji-Di-Huang-Decoction in ameliorating psoriasis-like skin inflammation via the inhibition of IL-23/Th17 cell axis

Ethnopharmacological relevanceIn the theory of traditional Chinese medicine (TCM), the etiology of psoriasis is assigned to damp-heat internal depression, blood poisoning, Yin deficiency and loss of nourishment. Fang-Ji-Di-Huang-Decoction (FJDH), a well-known Chinese traditional formula, is recorded in Synopsis of the Golden Chamber (in the Eastern Han Dynasty). This decoction is composed of dried roots of Rehmannia glutinosa (Gaertn.) DC., dried roots of Stephania tetrandra S. Moore, roots of Saposhnikovia divaricata (Turcz.) Schischk., dried twigs of Cinnamomum cassia (L.) J. Presl and dry roots and rhizomes of Glycyrrhiza uralensis Fisch. FJDH has the function of clearing heat, removing dampness, and nourishing blood. Therefore, in modern medical theory, FJDH can regulate the infiltration of inflammatory cells and the secretion of inflammatory cytokines in the process of psoriasis. Aim of the studyThis study evaluated whether FJDH treated psoriasis and its specific mechanism for the efficacy in mice. At the same time, it clarified s what important role of the copperware played s in the curative effect of FJDH. Methods and materialsWe used imiquimod (IMQ) to induce psoriasis-like skin inflammation in mice. Mice were treated with imiquimod for one week, and FJDH was given by intragastric administration one week in advance. Record the weight change and psoriasis Area and Severity Index (PASI) score of the mouse during the whole process to assess the severity of psoriasis were recored mouse. Hematoxylin-eosin staining was used to evaluate skin tissue structure change. Immunohistochemistry was performed to observe the expressions of Ki67 and proliferating cell nuclear antigen (PCNA) in skin tissue. In order to further explore the mechanism of FJDH in the treatment of psoriasis, we used network pharmacology to predict the therapeutic target. TCMSP and Uniprot were used to collect compounds and genes of FJDH. Genecards was used for obtaining genes of psoriasis. String was used to analyze the relationship between genes. Metascape was used for gene enrichment and pathway prediction. Using molecular biological detection methods, we verified whether FJDH could regulate Interleukin 17 signaling pathway and T helper cell 17 (Th17) cell differentiation. Flow cytometry was used to detect Th17 cell differentiation in mouse spleen. Quantitative Real-time PCR was used to detect mRNA expression of IL-17 signaling pathway-related inflammatory factors in mouse skin tissues. UPLC-Triple TOF-MS/MS and Phenol-Sulphate colorimetry were used to explore the main components of FJDH, and further elaborate the mechanism of FJDH in the treatment of psoriasis. ResultsFJDH with copper was found to improve psoriasis-related pathological symptoms in a dose-dependent manner, possibly by inhibiting IL-23/Th17 cell axis and reducing inflammatory cytokines such as IL-17A, IL-17F, IL-22 and TNF-α. Furthermore, R. glutinosa polysaccharide in FJDH was the main substance that exerted the drug effect and it work by forming a complex with copper. Experimental data proved that Rehmannia glutinosa polysaccharide and copper complex had the same pharmacological activity and therapeutic effect as FJDH. ConclusionsFJDH may attenulated imiquimod-induced psoriasis-like skin inflammation in mice by inhibiting IL-23/Th17 cell axis. The material basis for the therapeutic effect may be the formation of complexes between the polysaccharides of R. glutinosa and copper in FJDH to produce the effect. These findings suggest that FJDH can be used as an effective Chinese medicine to treat psoriasis.

Rehmannia glutinosa polysaccharide increases the expression of erythropoietin and vascular endothelial growth factor in rats with chronic renal failure by activating hypoxia-inducible factor-2α

Background: To investigate the effect of Rehmannia glutinosa polysaccharide (RGP) in rats with chronic renal failure. Materials and Methods: In this study, we established a rat model of adenine-induced chronic renal failure. Hemoglobin (Hb), red blood cells (RBCs), total protein (TP), serum albumin (ALB), blood urea nitrogen (BUN), cystatin C (Cys C), and serum creatinine anhydride (SCA) were detected in the blood samples of rats. Hematoxylin and eosin staining was used to observe the pathological changes. Immunohistochemical was used to detect the protein expression of hypoxia-inducible factor (HIF)-2α, erythropoietin (EPO), and vascular endothelial growth factor (VEGF) and calculate the value of microvessel density (MVD) in renal tissues. M1001 and GPRRP + PT2385 groups were added to further validate the mechanism of RGP. Results: In the case of rats with chronic renal failure, GPRRP and EPO contributed to the repairment of renal tissue. The level of Hb, TP, and ALB, as well as RBC counts was significantly increased, and the renal function indexes, including BUN, SCA, and Cys C, were significantly decreased, and HIF-2α, EPO, VEGF, and MVD were significantly increased. The effects observed in M1001 group was similar to those in GPRRP group, but compared with GPRRP + PT2385 group, the biochemical indicators and renal function indexes were significantly decreased, which means HIF-2α inhibitor antagonized the protective effect of RGP. Conclusion: RGP played an essential role in repairing the renal injury in rats with chronic renal failure. The therapeutic mechanism of action may be related to the activation of HIF-2α, thereby increasing the expression of EPO and VEGF and then reducing renal anemia and renal tissue damage.

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 (CD44high CD62Lhigh), and effector (CD44high CD62Llow) 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.

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.

BackgroundRehmannia 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.MethodspRL 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.ResultsThe 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.ConclusionOur 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.

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

In our previous study, we showed that Rehmannia glutinosa polysaccharide (RGP) treatment induced activation of dendritic cells (DCs) in human and mouse subjects. In this study, we evaluated the effect of RGP as a mucosal adjuvant for inducting activation of DCs in the mediastinal lymph node (mLN) in the mouse. The C57BL/6 mice were intranasally (i.n.) treated with RGP and activation of DC in the mLN was analyzed. The treatment with RGP induced a substantial increase in the number of DCs in the mLN due to the up-regulation of C-C motif chemokine receptor 7 (CCR7) in the DCs. Moreover, the expression of co-stimulatory molecules in the mLN DCs and the concentration of pro-inflammatory cytokines in the lung were up-regulated by RGP treatment. Also, RGP treatment induced interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) production in the mLN T cells. The combination treatment of RGP and ovalbumin (OVA) induced OVA-specific TCR transgenic I (OT-I) and OT-II cell proliferation in the mLN. Finally, the combination treatment of RGP and tyrosinase-related protein 2 (TRP2) peptide, a melanoma self-antigen, protected mice from melanoma challenge. Thus, these data demonstrated that RGP can be used as a mucosal adjuvant for inducing activation of immune responses in the lung.

Rehmannia glutinosa polysaccharide promoted activation of human dendritic cells

In our previous study, we showed that Rehmannia glutinosa polysaccharide (RGP) treatment induced maturation of dendritic cells (DCs) and that it had an anticancer effect in mice. The effect of RGP has not been studied in human DCs, including monocyte-derived DCs (MDDCs) and peripheral blood DCs (PBDCs). In this study, we examined DC activation by RGP in human cells. The dendritic morphology of RGP-treated MDDCs was substantially altered as compared with that of phosphate-buffered saline (PBS)-treated control cells. Moreover, RGP treatment markedly decreased phagocytic activity and increased expression levels of co-stimulatory molecules in MDDCs. In addition, RGP treatment elevated the production of proinflammatory cytokines. Furthermore, RGP-induced activation of MDDCs was dependent on the phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). RGP-treated MDDCs promoted upregulation of T-cell activation, including proliferation and interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) production. Analysis of the effect of RGP in PBDC subsets revealed that it induced upregulation of co-stimulatory molecule expression and proinflammatory cytokine production. These data suggest that RGP may function as an immune stimulatory molecule in humans.

Rehmannia glutinosa polysaccharide induced an anti-cancer effect by activating natural killer cells

Rehmannia glutinosa polysaccharide (RGP) has exhibited an immune stimulatory effect, such as dendritic cell activation, but it has not been studied in terms of the activation capacity of natural killer (NK) cells in mice in vivo. In this study, we examined the effect of RGP on the proliferation and activation of NK cells in the spleen, mesenteric lymph node (mLN), and blood in vivo and compared that function with that of Escherichia coli lipopolysaccharide. The administration of RGP to C57BL/6 mice induced the increase in circulating blood NK cell numbers and in the proliferation of NK cells in the spleen, mLN, and blood. Moreover, RGP treatment promoted the toll-like receptor-4-dependent production of interferon-gamma and the up-regulation of CD69 expression in spleen NK cells. RGP-treated NK cells enhanced the cytotoxic activity with type I IFN production against target Yac-1 cells. Finally, RGP treatment inhibited the CT26 tumor growth in the lung. These findings demonstrated that RGP promoted the activation of NK cells and inhibited tumor growth in mice in vivo.

The enhanced immune response of PCV-2 vaccine using Rehmannia glutinosa polysaccharide liposome as an adjuvant

Liposomes, one kind of vaccine adjuvants, have been demonstrated as effective adjuvants and vaccine delivery system. Immunization against PCV-2 has been studied intensely and found to be the most effective strategy for protecting pigs against PCV-2 infection. Inactivated vaccines represent a complex mixture of viral antigens closely resembling the native virion. In the present study, PCV-2 attenuated antigen was encapsulated within Rehmannia glutinosa polysaccharide liposome, instead of oil adjuvant which is the mainstream adjuvant. Our results showed that RGPL could elicit a strong IgG response and significantly increased the production of Th1 and Th2 associated IgG subtypes and cytokines. R. glutinosa polysaccharide liposome showed excellent particle stability. In vitro, R. glutinosa polysaccharide liposome could also significantly promote phagocytic activity of macrophage and the levels of cytokines it produced. Overall, the results demonstrated that R. glutinosa polysaccharide liposome has the potential to be developed into a more effective and safer vaccine adjuvant.

Immunoenhancement effect of rehmannia glutinosa polysaccharide on lymphocyte proliferation and dendritic cell

The aim of this study is to investigate immunomodulatory effect of rehmannia glutinosa polysaccharide (RGP) on murine splenic lymphocyte and bone marrow derived dendritic cells (DCs). Splenic lymphocytes obtained from mice were co-cultured with RGP for 48h and then harvested for analyzing with MTT method. The cytokine production of T lymphocytes was measured by ELISA. Effects of RGP treatment on DCs were investigated and assessed by MTT method. The results showed RGP significantly stimulated lymphocyte proliferation and the growth rate of T cell was more significant. The IL-2 and IFN-γ production of T lymphocyte were significantly upregulated after being stimulated with RGP. DCs stimulating on proliferation of T cells and the ability of antigen presenting of DCs have been enhanced under the stimulation of RGP. In conclusion, these findings provided valuable information that RGP possessed strong immunoenhancement activity, which provided the theoretical basis for the further experiment.

Rehmannia glutinosa polysaccharide induces maturation of murine bone marrow derived Dendritic cells (BMDCs)

Purified Rehmannia glutinosa polysaccharide (RGP) is used as functional foods for the prevention and treatment of various diseases. In this study, we examined the effects of RGP on phenotypic and functional maturation of murine bone marrow derived Dendritic cells (BMDCs). Phenotypic maturation of BMDCs was confirmed by conventional scanning electron microscopy (SEM), flow cytometry (FCM) and functional maturation by transmission electron microscopy (TEM), cytochemistry assay, Acid phosphatase (ACP) activity, FITC-dextran, bio-assay and enzyme linked immunosorbent assay (ELISA).We found that RGP up-regulated the expression of CD40, CD80, CD83, CD86 and MHC II molecules of BMDCs, down-regulated pinocytosis and phagocytosis activity, induced IL-12 and TNF-α production of BMDCs. It is therefore concluded that RGP can effectively promote the maturation of DCs. Our study provides evidence and rationale on using RGP in various clinical conditions to enhance host immunity and suggests RGP as a potent adjuvant for the design of DC-based vaccines.