Activation of murine macrophages by G1-4A, a polysaccharide from Tinospora cordifolia, in TLR4/MyD88 dependent manner

Systematic Review of Chemical Compounds with Immunomodulatory Action Isolated from African Medicinal Plants

A robust, well-functioning immune system is the cornerstone of good health. Various factors may influence the immune system's effectiveness, potentially leading to immune system failure. This review aims to provide an overview of the structure and action of immunomodulators isolated from African medicinal plants. The research was conducted according to PRISMA guidelines. Full-text access research articles published in English up to December 2023, including plant characteristics, isolated phytochemicals, and immuno-modulatory activities, were screened. The chemical structures of the isolated compounds were generated using ChemDraw® (version 12.0.1076), and convergent and distinctive signaling pathways were highlighted. These phytochemicals with demonstrated immunostimulatory activity include alkaloids (berberine, piperine, magnoflorine), polysaccharides (pectin, glucan, acemannan, CALB-4, GMP90-1), glycosides (syringin, cordifolioside, tinocordiside, aucubin), phenolic compounds (ferulic acid, vanillic acid, eupalitin), flavonoids (curcumin, centaurein, kaempferin, luteolin, guajaverin, etc.), terpenoids (oleanolic acid, ursolic acid, betulinic acid, boswellic acids, corosolic acid, nimbidin, andrographolides). These discussed compounds exert their effects through various mechanisms, targeting the modulation of MAPKs, PI3K-Akt, and NF-kB. These mechanisms can support the traditional use of medicinal plants to treat immune-related diseases. The outcomes of this overview are to provoke structural action optimization, to orient research on particular natural chemicals for managing inflammatory, infectious diseases and cancers, or to boost vaccine immunogenicity.

Characterization and anti-tumor activities of polysaccharide isolated from Brassica rapa L. via activation of macrophages through TLR2-and TLR4-Dependent pathways

We have previously shown the immunostimulatory effects by Nozawana (Brassica rapa L.). In this report, we determined the characteristics of Nozawana polysaccharide (NPS) and evaluated the immunomodulatory effects and anti-tumor activity of NPS mediated by macrophage activation. The molecular weight of NPS was determined by gel filtration chromatography with an average molecular weight of approximately 100.6 kDa. HPLC analysis showed that NPS contained glucose, galacturonic acid, galactose, and arabinose. NPS increased cytokine and nitric oxide (NO) production by macrophages in a Toll-like receptor (TLR)2 and TLR4-dependent manner. Furthermore, NPS induced apoptosis significantly against 4T1 murine breast cancer cells cultured in conditioned medium from NPS-treated macrophages through tumor necrosis factor-α. In tumor-bearing mouse model, tumor growth was significantly reduced in NPS-treated mice compared with control mice. These results support the potential use of NPS as an immunotherapeutic material found in health food products.

Corrigendum: Immunomodulatory function and anti-tumor mechanism of natural polysaccharides: a review

[This corrects the article DOI: 10.3389/fimmu.2023.1147641.].

Unveiling Various Facades of Tinospora cordifolia Stem in Food: Medicinal and Nutraceutical Aspects

Natural products with curative properties are gaining immense popularity in scientific and food research, possessing no side effects in contrast to other drugs. Guduchi, or Tinospora cordifolia, belongs to the menispermaceae family of universal drugs used to treat various diseases in traditional Indian literature. It has received attention in recent decades because of its utilization in folklore medicine for treating several disorders. Lately, the findings of active phytoconstituents present in herbal plants and their pharmacological function in disease treatment and control have stimulated interest in plants around the world. Guduchi is ethnobotanically used for jaundice, diabetes, urinary problems, stomachaches, prolonged diarrhea, skin ailments, and dysentery. The treatment with Guduchi extracts was accredited to phytochemical constituents, which include glycosides, alkaloids, steroids, and diterpenoid lactones. This review places emphasis on providing in-depth information on the budding applications of herbal medicine in the advancement of functional foods and nutraceuticals to natural product researchers.

Microanalysis Characterization and Immunomodulatory Effect for Selenium-Enriched Polysaccharide from Morchella esculenta (L.) Pers

Morchella esculenta (L.) Pers., referred to as Morel, is a medicinal and edible homologous fungus, which contains many bioactive substances. In Morel, polysaccharides are the most abundant and have various bioactivities. In the present work, two novel polysaccharides, Se-MPS and MPS, were prepared and purified from selenium-enriched (Se-enriched) and common Morel mycelia, respectively, and their structural and immunomodulatory properties were evaluated. The results show that Se-enriched treatment significantly changed the polysaccharides' chemical composition, molecular weight, and sugar chain configuration. In addition, the Se-enriched treatment also improved the polysaccharides' fragmentation and thermal stability. Importantly, Se-enriched Morel polysaccharide (Se-MPS) could significantly enhance phagocytosis of RAW 264.7 macrophage cells and, remarkably, activate their immune response via activating the TLR4-TRAF6-MAPKs-NF-κB cascade signaling pathway, finally exerting an immunomodulatory function. Based on these findings, selenium-enriched Morel polysaccharide appears to have more potential for development and utilization in functional foods or medicines than ordinary Morel polysaccharide.

Immunomodulatory function and anti-tumor mechanism of natural polysaccharides: A review

Polysaccharides extracted from natural resources have attracted extensive attention in biomedical research and pharmaceutical fields, due to their medical values in anti-tumor, immunomodulation, drug delivery, and many other aspects. At present, a variety of natural polysaccharides have been developed as adjuvant drugs in clinical application. Benefit from their structural variability, polysaccharides have great potential in regulating cellular signals. Some polysaccharides exert direct anti-tumor effects by inducing cell cycle arrest and apoptosis, while the majority of polysaccharides can regulate the host immune system and indirectly inhibit tumors by activating either non-specific or specific immune responses. As the essential of microenvironment in the process of tumor development has been gradually revealed, some polysaccharides were found to inhibit the proliferation and metastasis of tumor cells via tumoral niche modulation. Here, we focused on natural polysaccharides with biomedical application potential, reviewed the recent advancement in their immunomodulation function and highlighted the importance of their signaling transduction feature for the antitumor drug development.

Tinospora cordifolia (Willd.) Hook.f. & Thomson polysaccharides: A review on extraction, characterization, and bioactivities

Human awareness of the need for health and wellness practices that enhance disease resilience has increased as a result of recent health risks. Plant-derived polysaccharides with biological activity are good candidates to fight diseases because of their low toxicity. Tinospora cordifolia (Willd.) Hook.f. & Thomson polysaccharides extract from different plant parts have been reported to possess significant biological activity such as anti-oxidant, anti-cancer, immunomodulatory, anti-diabetic, radioprotective and hepatoprotective. Several extraction and purification techniques have been used to isolate and characterize T. cordifolia polysaccharides. Along with hot-water extraction (HWE), other novel techniques like microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), pulsed electric field (PEF), supercritical-fluid extraction (SFE), and enzyme-assisted extraction (EAE) are used to extract T cordifolia polysaccharides. SFE is a revolutionary technology that gives the best yield and purity of low-molecular-weight polysaccharides. According to the findings, polysaccharides extracted and purified from T. cordifolia have a significant impact on their structure and biological activity. As a result, the methods of extraction, structural characterization, and biological activity of T. cordifolia polysaccharides are covered in this review. Research on T. cordifolia polysaccharides and their potential applications will benefit greatly from the findings presented in this review.

Effects of Sparassis latifolia neutral polysaccharide on immune activity via TLR4-mediated MyD88-dependent and independent signaling pathways in RAW264.7 macrophages

Background

Sparassis latifolia (S. latifolia) is a precious edible fungus with multiple biological activities. To date, no study has been investigated the underlying molecular mechanism of immunoregulation caused by the neutral polysaccharide of S. latifolia.

Materials and methods

To investigate immunomodulatory mechanism of S. latifolia neutral polysaccharide (SLNP), SLNP was obtained from S. latifolia and its structure, immune receptors and regulation mechanism were studied.

Results

S. latifolia neutral polysaccharide consisted of arabinose, galactose, glucose, xylose, and mannose with a molar ratio of 6:12:63:10:5. SLNP was a pyran polysaccharide with a relative molecular weight of 3.2 × 105 Da. SLNP promoted the proliferation of RAW264.7, which further induced the secretions of nitric oxide, TNF-α, IL-6, and IFN-β, and upregulated the immune receptor TLR4 expression. Moreover, SLNP increased remarkably the levels of TRAF6, IRF3, JNK, ERK, p38, and p38 mRNA and protein mediated by TLR4.

Conclusion

S. latifolia neutral polysaccharide regulated the immune function of RAW264.7 through MyD88-dependent and -independent signaling pathways mediated by TLR4 receptor, which suggests that SLNP is a new immunomodulator.

NLRP3 inflammasome up-regulates major histocompatibility complex class I expression and promotes inflammatory infiltration in polymyositis

Objective

This study was designed to investigate the role of the nucleotide-binding-domain -and leucine-rich repeat -containing (NLR) family, pyrin-domain-containing 3 (NLRP3) inflammasome in the pathogenesis of polymyositis (PM).

Methods

Immunochemistry was performed to analyze the NLRP3, caspase-1 and interleukin-1 beta (IL-1β) expression in the muscle tissue of PM patients. Rat model of PM and C2C12 cell were used to investigate the potential role of NLRP3 inflammasome in PM.

Results

The percentage of CD 68+ macrophages, and the expression levels of NLRP3, caspase-1 and IL-1β in the muscle tissue were elevated in 27 PM patients. LPS/ATP treatment resulted in activation of NLRP3 inflammasome and secretion of IL-1β as well as interferons (IFNs) and monocyte chemotactic protein-1 (MCP-1) in the Raw 264.7 macrophages. Meanwhile, LPS/ATP challenged activation of NLRP3 inflammasome induced overexpression of major histocompatibility complex class I (MHC-I), a key molecular of PM in the co-cultured C2C12 cells. The effect was decreased by treatment of NLRP3 inflammasome inhibitor MCC950 or siRNA of NLRP3 inflammasome. These findings suggested certain levels of IL-1β rather than IFNs up-regulated MHC-I expression in C2C12 cells. IL-1β blockade using neutralizing IL-1β monoclonal antibody or siRNA of IL-1β suppressed MHC-I overexpression. In vivo, NLRP3 inflammasome inhibition by MCC950 reduced the expression of NLRP3, IL-1β and MHC-I in the muscle tissue of PM modal rats. Also, it attenuated the intensity of muscle inflammation as well as the CRP, CK, and LDH levels in the serum.

Conclusion

NLRP3/caspase-1/IL-1β axis may play an important role in the development of PM. Inhibition of NLRP3 activation may hold promise in the treatment of PM.

Salvia miltiorrhiza polysaccharide activated macrophages and improved the disease resistance of sturgeon against Aeromonas hydrophila

The use of plant polysaccharides in aquaculture is recognized as a healthy strategy to enhance disease resistance and reduce medication use. Salvia miltiorrhiza polysaccharide (SMP) can regulate the immune function of higher vertebrates. However, the effects of SMP on fish have not been fully investigated. In this study, the ability of SMP to activate the macrophages of Siberian sturgeon (Acipenser bareii) was analyzed in vitro. The effects of SMP on immune cell activity of hybrid sturgeon (A. baerii ♀ × Acipenser schrenckii ♂) and resistance to Aeromonas hydrophila were further detected in vivo. The in vitro results showed that SMP up-regulated phagocytosis, respiratory burst, inducible nitric oxide synthase activity, nitric oxide (NO) concentration, and cytokine mRNA expression of macrophages. The in vivo results showed that dietary supplementation with SMP enhanced the respiratory burst of macrophages and proliferative activity of lymphocytes. Dietary supplementation with SMP increased serum concentrations of lysozyme and NO, and improved the survival rate of hybrid sturgeon challenged with A. hydrophila. Collectively, these results suggest that SMP can improve the immune function and disease resistance of sturgeon. This study provides a theoretical basis for the application of SMP for healthy farming of sturgeon.

Swelling, Protein Adsorption, and Biocompatibility In Vitro of Gel Beads Prepared from Pectin of Hogweed Heracleum sosnówskyi Manden in Comparison with Gel Beads from Apple Pectin

The study aims to develop gel beads with improved functional properties and biocompatibility from hogweed (HS) pectin. HS4 and AP4 gel beads were prepared from the HS pectin and apple pectin (AP) using gelling with calcium ions. HS4 and AP4 gel beads swelled in PBS in dependence on pH. The swelling degree of HS4 and AP4 gel beads was 191 and 136%, respectively, in PBS at pH 7.4. The hardness of HS4 and AP4 gel beads reduced 8.2 and 60 times, respectively, compared with the initial value after 24 h incubation. Both pectin gel beads swelled less in Hanks’ solution than in PBS and swelled less in Hanks’ solution containing peritoneal macrophages than in cell-free Hanks’ solution. Serum protein adsorption by HS4 and AP4 gel beads was 118 ± 44 and 196 ± 68 μg/cm² after 24 h of incubation. Both pectin gel beads demonstrated low rates of hemolysis and complement activation. However, HS4 gel beads inhibited the LPS-stimulated secretion of TNF-α and the expression of TLR4 and NF-κB by macrophages, whereas AP4 gel beads stimulated the inflammatory response of macrophages. HS4 gel beads adsorbed 1.3 times more LPS and adhered to 1.6 times more macrophages than AP4 gel beads. Thus, HS pectin gel has advantages over AP gel concerning swelling behavior, protein adsorption, and biocompatibility.

The regulating effect of Tibet Opuntia ficus-indica (Linn.) Mill. polysaccharides on the intestinal flora of cyclophosphamide-induced immunocompromised mice

The stem of Opuntia species, a traditional medicinal plant, is widely used as food and functional raw material because of its rich polysaccharide content. There have been many studies on the immune function of polysaccharides from Opuntia stem, but only few have examined this function with respect to intestinal microbes. In this study, the effects of different concentrations of Opuntia stem polysaccharides on the immunity and intestinal microflora of cyclophosphamide (CTX)-induced immunocompromised mice were explored. The results showed that Tibet Opuntia ficus-indica (Linn.) Mill. polysaccharides (ODPs) could effectively increase the white blood cells (WBC) count index of mice and improve their thymus and spleen indices, while effectively promoting the secretion of IL-4, IL-1β, TNF-α and IFN-γ, with these effects being dependent on the concentration of crude polysaccharides. The intake of ODPs significantly regulated the relative abundance of Lactobacillus, Bacteroides and Akkermansia, and the new dominant intestinal bacterial species were Deferribacteres, Actinomycetes, Firmicutes, Tenericutes, Actinomycetes and Pasteurella. In addition, the ODPs could effectively enhance the metabolic level of lysine synthesis and decomposition, regulate the gene expression level after immune disorders, and enhance the overall health of the immunodeficient mice.

Tinospora cordifolia (Willd.) Miers: Protection mechanisms and strategies against oxidative stress-related diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Tinospora cordifolia (Willd.) Miers (Menispermaceae) is a Mediterranean herb, used in Ayurvedic, Siddha, Unani, and folk medicines. The herb is also used in conventional medicine to treat oxidative stress-related diseases and conditions, including inflammation, pain, diarrhea, asthma, respiratory infections, cancer, diabetes, and gastrointestinal disorders.

AIM OF THE REVIEW

The taxonomy, botanical classification, geographical distribution, and ethnobotanical uses of T. cordifolia, as well as the phytochemical compounds found in the herb, the toxicology of and pharmacological and clinical studies on the effects of T. cordifolia are all covered in this study.

MATERIALS AND METHODS

To gather information on T. cordifolia, we used a variety of scientific databases, including Scopus, Google Scholar, PubMed, and Science Direct. The information discussed focuses on biologically active compounds found in T. cordifolia, and common applications and pharmacological activity of the herb, as well as toxicological and clinical studies on its properties.

RESULTS

The findings of this study reveal a connection between the use of T. cordifolia in conventional medicine and its antioxidant, anti-inflammatory, antihypertensive, antidiabetic, anticancer, immunomodulatory, and other biological effects. The entire plant, stem, leaves, root, and extracts of T. cordifolia have been shown to have a variety of biological activities, including antioxidant, antimicrobial, antiviral, antiparasitic, antidiabetic, anticancer, anti-inflammatory, analgesic and antipyretic, hepatoprotective, and cardioprotective impact. Toxicological testing demonstrated that this plant may have medicinal applications. T. cordifolia contains a variety of biologically active compounds from various chemical classes, including alkaloids, terpenoids, sitosterols, flavonoids, and phenolic acids. Based on the reports researched for this review, we believe that chemicals in T. cordifolia may activate Nrf2, which leads to the overexpression of antioxidant enzymes such as CAT, GPx, GST, and GR, and thereby induces the adaptive response to oxidative stress. T. cordifolia is also able to reduce NF-κB signalling by inhibiting PI3K/Akt, activating AMPK and sirtuins, and downregulating PI3K/Akt.

CONCLUSIONS

Our findings indicate that the pharmacological properties displayed by T. cordifolia back up its conventional uses. Antimicrobial, antiviral, antioxidant, anticancer, anti-inflammatory, antimutagenic, antidiabetic, nephroprotective, gastroprotective, hepatoprotective, and cardioprotective activities were all demonstrated in T. cordifolia stem extracts. To validate pharmacodynamic targets, further research is needed to evaluate the molecular mechanisms of the known compounds against gastrointestinal diseases, inflammatory processes, and microbial infections, as immunostimulants, and in chemotherapy. The T. cordifolia safety profile was confirmed in a toxicological analysis, which prompted pharmacokinetic assessment testing to confirm its bioavailability.

Protective Effects of Natural Polysaccharides on Intestinal Barrier Injury: A Review

Owing to their minimal side effects and effective protection from oxidative stress, inflammation, and malignant growth, natural polysaccharides (NPs) are a potential adjuvant therapy for several diseases caused by intestinal barrier injury (IBI). More studies are accumulating on the protective effects of NPs with respect to IBI, but the underlying mechanisms remain unclear. Thus, this review aims to represent current studies that investigate the protective effects of NPs on IBI by directly maintaining intestinal epithelial barrier integrity (inhibiting oxidative stress, regulating inflammatory cytokine expression, and increasing tight junction protein expression) and indirectly regulating intestinal immunity and microbiota. Furthermore, the mechanisms underlying IBI development are briefly introduced, and the structure-activity relationships of polysaccharides with intestinal barrier protection effects are discussed. Potential developments and challenges associated with NPs exhibiting protective effects against IBI have also been highlighted to guide the application of NPs in the treatment of intestinal diseases caused by IBI.

Characterization and Biocompatibility Properties In Vitro of Gel Beads Based on the Pectin and κ-Carrageenan

This study aimed to investigate the influence of kappa (κ)-carrageenan on the initial stages of the foreign body response against pectin gel. Pectin-carrageenan (P-Car) gel beads were prepared from the apple pectin and κ-carrageenan using gelling with calcium ions. The inclusion of 0.5% κ-carrageenan (Car0.5) in the 1.5 (P1.5) and 2% pectin (P2) gel formulations decreased the gel strength by 2.5 times. Car0.5 was found to increase the swelling of P2 gel beads in the cell culture medium. P2 gel beads adsorbed 30–42 mg/g of bovine serum albumin (BSA) depending on pH. P2-Car0.2, P2-Car0.5, and P1.5-Car0.5 beads reduced BSA adsorption by 3.1, 5.2, and 4.0 times compared to P2 beads, respectively, at pH 7. The P1.5-Car0.5 beads activated complement and induced the haemolysis less than gel beads of pure pectin. Moreover, P1.5-Car0.5 gel beads allowed less adhesion of mouse peritoneal macrophages, TNF-α production, and NF-κB activation than the pure pectin gel beads. There were no differences in TLR4 and ICAM-1 levels in macrophages treated with P and P-Car gel beads. P2-Car0.5 hydrogel demonstrated lower adhesion to serous membrane than P2 hydrogel. Thus, the data obtained indicate that the inclusion of κ-carrageenan in the apple pectin gel improves its biocompatibility.

Interaction between polysaccharides and toll-like receptor 4: Primary structural role, immune balance perspective, and 3D interaction model hypothesis

Various structural types of polysaccharides are recognized by toll-like receptor 4 (TLR4). However, the mechanism of interaction between the polysaccharides with different structures and TLR4 is unclarified. This review summarized the primary structure of polysaccharides related to TLR4, mainly including molecular weight, monosaccharide composition, glycosidic bonds, functional groups, and branched-chain structure. The optimal primary structure for interacting with TLR4 was obtained by the statistical analysis. Besides, the dual-directional regulation of TLR4 signaling cascade by polysaccharides was also elucidated from an immune balance perspective. Finally, the 3D interaction model of polysaccharides to TLR4-myeloid differentiation factor 2 (MD2) complex was hypothesized according to the LPS-TLR4-MD2 dimerization model and the polysaccharides solution conformation. The essence of polysaccharides binding to TLR4-MD2 complex is a multivalent non-covalent bond interaction. All the arguments summarized in this review are intended to provide some new insights into the interaction between polysaccharides and TLR4.

Polysaccharides confer benefits in immune regulation and multiple sclerosis by interacting with gut microbiota

Pharmacological and clinical studies have consistently demonstrated that polysaccharides exhibit great potential on immune regulation. Polysaccharides can interact directly or indirectly with the immune system, triggering cell-cell communication and molecular recognition, leading to immunostimulatory responses. Gut microbiota is adept at foraging polysaccharides as energy sources and confers benefits in the context of immunity and chronic autoimmune disease, such as multiple sclerosis. A compelling set of interconnectedness between the gut microbiota, natural polysaccharides, and immune regulation has emerged. In this review, we highlighted the available avenues supporting the existence of these interactions, with a focus on cytokines-mediated and SCFAs-mediated pathways. Additionally, the neuroimmune mechanisms for gut microbiota communication with the brain in multiple sclerosis are also discussed, which will lay the ground for ameliorate multiple sclerosis via polysaccharide intervention.

Porous particles and novel carrier particles with enhanced penetration for efficient pulmonary delivery of antitubercular drugs

This study aimed to design dry powder inhaler formulations using a hydrophilic polymeric polysaccharide, phytoglycogen (PyG), as a multi-functional additive that increases the phagocytic activity of macrophage-like cells and enhances pulmonary delivery of drugs. The safety and usefulness of PyG were determined using in vitro cell-based studies. Dry powder inhaler formulations of an antitubercular drug, rifampicin, were fabricated by spray drying with PyG. The cytotoxicity, effects on phagocytosis, particle size, and morphology were evaluated. The aerosolization properties of the powder formulations were evaluated using an Andersen cascade impactor (ACI). Scanning electron microscope images of the particles on each ACI stage were captured to observe the deposition behavior. PyG showed no toxicity in A549, Calu-3, or RAW264.7 cell lines. At concentrations of 0.5 and 1 g/L, PyG facilitated the cellular uptake of latex beads and the expression of pro-inflammatory cytokine genes in RAW264.7 cells. Formulations with outstanding inhalation potential were produced. The fine particle fraction (aerodynamic size 2-7 µm) of the porous particle batch reached nearly 60%, whereas in the formulation containing wrinkled carrier particles, the extra-fine particle fraction (aerodynamic particle size < 2 μm) was 25.0% ± 1.7%. The deposition of porous and wrinkled particles on individual ACI stages was distinct. The inclusion of PyG dramatically improved the inhalation performance of porous and wrinkled powder formulations. These easily inhaled immunostimulatory carrier particles may advance the state of research by enhancing the therapeutic effect and alveolar delivery of antitubercular drugs.

A polysaccharide extracted from alfalfa activates splenic B cells by TLR4 and acts primarily via the MAPK/p38 pathway

Alfalfa polysaccharide (APS) has been proposed to exhibit growth-promoting and immune-enhancing bodily functions in vivo. However, little is known about its downstream immunomodulatory and intrinsic molecular mechanisms. Herein, mouse splenic lymphocytes were isolated to characterize the immunomodulatory effects and molecular mechanisms of APS in vitro. The results demonstrated that APS selectively improved the cell viability and IgM production of B cells, but no effects on T cell viability or secretion of IL-2, IL-4 and IFN-γ were observed in vitro. The receptor blocking assay showed that TLR4 was the primary receptor involved in APS-mediated B cell activation, which was confirmed by the results obtained using C57BL/10ScNJ (TLR4 gene-deficient) mice. Moreover, APS activated the TLR4-MyD88 signaling pathway at the translational level by significantly increasing the protein expression of TLR4 and MyD88. Downstream pathway blocking assay demonstrated that both the MAPK and NF-κB pathways were involved in APS-induced B cell activation. Additionally, APS significantly enhanced the phosphorylation of p38, ERK, and JNK and activated the nuclear translocation of the NF-κB p65 subunit. Therefore, we concluded that APS specifically activates the immune functions of splenic B cells by TLR4, acting through the MAPK and NF-κB signaling pathways, and potently activates the p38 pathway.

Molecular mechanisms underlying macrophage immunomodulatory activity of Rubus chingii Hu polysaccharides

The present study was to investigate the mechanisms involved in macrophage activation by polysaccharides from the fruits of Rubus chingii Hu (RFPs). The results showed that RFPs enhanced pinocytic and phagocytic activity, promoted the expression and secretion of inflammatory factors (ROS, PTGS2, iNOS, IL-6, IL-10 and TNF-α) and chemokines (CCL2 and CXCL10), and boosted the expression of accessory and costimulatory molecules (CD40, CD80, CD86, MHC-I and MHC-II). RNA-Seq analysis identified 2564 DEGs, 1710 GO terms and 101 KEGG pathways. TNF was identified as the core gene via analysis of pathway information integration and PPI network. The western blot analysis combined with functional verification assay confirmed that MAPK, NF-κB and Jak-STAT pathways were essential to RFPs-mediated macrophage activation. TLR2 was revealed to be the functional receptor and involved in the early recognition of RFPs. These results indicated that RFPs modulated macrophage immune response mainly through TLR2-dependent MAPK, NF-κB and Jak-STAT pathways.

Promising traditional Indian medicinal plants for the management of novel Coronavirus disease: A systematic review

Traditional Indian medical practices (Ayurveda, Siddha, Unani, and homeopathy) are a vast reservoir of knowledge about medicinal plants. The promising pharmacological properties of these plants have paved the way for developing therapy against novel Coronavirus (CoV) infection. The current review will summarize published works of literature on the effects of traditional Indian medicinal plants against acute respiratory infection (COVID‐19, SARS, Influenza, and Respiratory syncytial virus infection) and registered clinical trials of traditional Indian herbal medicines in COVID‐19. The current study aims to comprehensively evaluate the data of traditional Indian medicinal plants to warrant their use in COVID‐19 management. PubMed, Embase, and Cochrane databases were searched along with different clinical trial databases. A total of 22 relevant traditional Indian medicinal plants (35 relevant studies) were included in the current study having potential antiviral properties against virus‐induced respiratory illness along with promising immunomodulatory and thrombolytic properties. Further, 36 randomized and nonrandomized registered clinical trials were also included that were aimed at evaluating the efficacy of herbal plants or their formulations in COVID‐19 management. The antiviral, immunomodulatory, and thrombolytic activities of the traditional Indian medicinal plants laid down a strong rationale for their use in developing therapies against SARS‐CoV‐2 infection. The study identified some important potential traditional Indian medicinal herbs such as Ocimum tenuiflorum, Tinospora cordifolia, Achyranthes bidentata, Cinnamomum cassia, Cydonia oblonga, Embelin ribes, Justicia adhatoda, Momordica charantia, Withania somnifera, Zingiber officinale, Camphor, and Kabusura kudineer, which could be used in therapeutic strategies against SARS‐CoV‐2 infection.

Activation of RAW264.7 cells by PCp-I, a polysaccharide from Psoralea corylifolia L, through NF-κB/MAPK signalling pathway

PCp-I is a polysaccharide isolated and identified from the Psoralea corylifolia L. by our research group. In this study, the immunomodulatory effects of PCp-I on RAW264.7 cells was evaluated. PCp-I could enhance the level of NO along with up-regulation of iNOS mRNA in RAW264.7 cells. The PCp-I could significantly up-regulate the mRNA expression of TNF-α and IL-6 in RAW264.7 cells, and then the expression of TNF-α, IL-6, ROS and the phagocytic activity were increased. Additionally, PCp-I could significantly up-regulate the phosphorylation level of p65, p38, ERK and JNK proteins, which proved that PCp-I could activate the macrophages by MAPKs and NF-κB signalling pathway and the TLR4 may be one of the receptors of PCp-I regulate the RAW264.7 cells.

A review on antiviral and immunomodulatory polysaccharides from Indian medicinal plants, which may be beneficial to COVID-19 infected patients

The emergence of the novel coronavirus, SARS-CoV-2 has pushed forward the world to experience the first pandemic of this century. Any specific drug against this RNA virus is yet to be discovered and presently, the COVID-19 infected patients are being treated symptomatically. During the last few decades, a number of polysaccharides with potential biological activities have been invented from Indian medicinal plants. Many polysaccharides, such as sulfated xylomannan, xylan, pectins, fucoidans, glucans, glucoarabinan, and arabinoxylan from Indian medicinal plants, have been shown to exhibit antiviral and immunomodulating activities. Plant polysaccharides exhibit antiviral activities through interference with the viral life cycle and inhibition of attachment of virus to host cell. Intake of certain immune stimulating plant polysaccharides may also protect from the virus to a certain extent. In process of continuous search for most potent drug, Indian plant polysaccharides may emerge as significant biomaterial to combat COVID-19. This review explores a number of polysaccharides from Indian medicinal plants which showed antiviral and immunomodulating activities. It is aimed to provide an overview about the composition, molecular mass, branching configuration and related bioactivities of polysaccharides which is crucial for their classification as possible drug to induce immune response in viral diseases.

Potent anti-mycobacterial and immunomodulatory activity of some bioactive molecules of Indian ethnomedicinal plants that have the potential to enter in TB management

Tuberculosis (TB) is one of the deadliest infectious diseases of human civilization. Approximately one-third of global population is latently infected with the TB pathogen Mycobacterium tuberculosis (M.tb). The discovery of anti-TB antibiotics leads to decline in death rate of TB. However, the evolution of antibiotic-resistant M.tb-strain and the resurgence of different immune-compromised diseases re-escalated the death rate of TB. WHO has already cautioned about the chances of pandemic situation in TB endemic countries until the discovery of new anti-tubercular drugs, that is, the need of the hour. Analysing the pathogenesis of TB, it was found that M.tb evades the host by altering the balance of immune response and affects either by killing the cells or by creating inflammation. In the pre-antibiotic era, traditional medicines were only therapeutic measures for different infectious diseases including tuberculosis. The ancient literatures of India or ample Indian traditional knowledge and ethnomedicinal practices are evidence for the treatment of TB using different indigenous plants. However, in the light of modern scientific approach, anti-TB effects of those plants and their bioactive molecules were not established thoroughly. In this review, focus has been given on five bioactive molecules of different traditionally used Indian ethnomedicinal plants for treatment of TB or TB-like symptom. These compounds are also validated with proper identification and their mode of action with modern scientific approaches. The effectiveness of these molecules for sensitive or drug-resistant TB pathogen in clinical or preclinical studies was also evaluated. Thus, our specific aim is to highlight such scientifically validated bioactive compounds having anti-mycobacterial and immunomodulatory activity for future use as medicine or adjunct-therapeutic molecule for TB management.

Tinospora Cordifolia: A review of its immunomodulatory properties

Emergent health threats have heightened human awareness of the need for health and wellness measures that promote resilience to disease. In addition to proper nutrition and exercise, health-conscious consumers are seeking natural-based modalities, e.g. botanical preparations, that positively impact the immune system. In Ayurvedic ethnomedicine, Tinospora cordifolia (T. cordifolia), a deciduous climbing shrub indigenous to India, has been used to historically to combat acute and chronic inflammation as well as to promote a balanced immune response. As a dietary supplement, T. cordifolia has been administered most often as a decoction either alone or in compositions containing other medicinal plant extracts of the Terminalia and Phyllanthus species. Extensive phytochemical characterization of aqueous and alcoholic extracts of different Tinospora species has identified over two hundred different phytochemicals from non-overlapping chemical classes with the most abundant being diterpenoids containing the clerodane-type skeleton. Numerous pharmacology studies have demonstrated that T. cordifolia modulates key signaling pathways related to cell proliferation, inflammation, and immunomodulation. However, rigorous dereplication studies to identify active constituents in various T. cordifolia extracts and their fractions are lacking. In this review, we will summarize the current information regarding T. cordifolia's ethnomedicinal uses, phytochemistry, pharmacological activities, and safety in order to highlight its potential as an immunomodulatory dietary supplement.

<i>Tinospora cordifolia</i> (Giloy): Phytochemistry, Ethnopharmacology, Clinical Application and Conservation Strategies

Tinospora cordifolia (Giloy) is a medicinal plant used in folk and Ayurvedic medicines throughout India since ancient times. All the parts of the plant are immensely useful due to the presence of different compounds of pharmaceutical importance belonging to various groups as alkaloids, diterpenoid lactones, glycosides, steroids, sesquiterpenoid, and phenolics. These compounds possess pharmacological properties, which make it anti-diabetic, antipyretic, anti-inflammatory, anti-oxidant, hepato-protective, and immuno-modulatory. However, due to the increasing population, there is an inadequate supply of drugs. Therefore, this review focuses on phytochemistry, ethnopharmacology, clinical application and its conservation strategies so that the plant can be conserved for future generations and utilized as alternative medicine as well as to design various pharmacologically important drugs.

Immunomodulatory Potential of Tinospora cordifolia and CpG ODN (TLR21 Agonist) against the Very Virulent, Infectious Bursal Disease Virus in SPF Chicks

Infectious bursal disease (IBD), caused by infectious bursal disease virus (IBDV), is characterized by severe immunosuppression in young chicks of 3 to 6 week age group. Although vaccines are available to prevent IBD, outbreaks of disease are still noticed in the field among vaccinated flocks. Further, the birds surviving IBD become susceptible to secondary infections caused by various viral and bacterial agents. This study assessed the immunoprophylactic potential of Cytosine-guanosinedeoxynucleotide (CpG) oligodeoxynucleotides (ODN) and Tinospora cordifolia stem aqueous extract in the specific pathogen free (SPF) chicks, experimentally infected with very virulent IBDV (vvIBDV). Both of these agents (CpG ODN and herbal extract) showed significant increase in the IFN-γ, IL-2, IL-4, and IL-1 levels in the peripheral blood mononuclear cells (PBMCs) (p < 0.05) of chickens in the treatment groups following IBD infection.Further we found significant reduction in mortality rate in vvIBDV infected chicks treated with either, or in combination, compared with the birds of control group. Additionally, the adjuvant or immune enhancing potential of these two immunomodulatory agents with the commercially available IBDV vaccine was determined in chicks. The augmentation of vaccine response in terms of an enhanced antibody titer after vaccination, along with either or a combination of the two agents was noticed. The findings provide a way forward to counter the menace of IBDV in the poultry sector through use of these herbal or synthetic immunomodulatory supplements.

Enhanced corrosion resistance of zinc-containing nanowires-modified titanium surface under exposure to oxidizing microenvironment

Titanium (Ti) and its alloys as bio-implants have excellent biocompatibilities and osteogenic properties after modification of chemical composition and topography via various methods. The corrosion resistance of these modified materials is of great importance for changing oral system, while few researches have reported this point. Recently, oxidative corrosion induced by cellular metabolites has been well concerned. In this study, we explored the corrosion behaviors of four common materials (commercially pure Ti, cp-Ti; Sandblasting and acid etching-modified Ti, Ti-SLA; nanowires-modified Ti, Ti-NW; and zinc-containing nanowires-modified Ti, Ti-NW-Zn) with excellent biocompatibilities and osteogenic capacities under the macrophages induced-oxidizing microenvironment. The results showed that the materials immersed into a high oxidizing environment were more vulnerable to corrode. Meanwhile, different surfaces also showed various corrosion susceptibilities under oxidizing condition. Samples embed with zinc element exhibited more excellent corrosion resistance compared with other three surfaces exposure to excessive H₂O₂. Besides, we found that zinc-decorated Ti surfaces inhibited the adhesion and proliferation of macrophages on its surface and induced the M2 states of macrophages to better healing and tissue reconstruction. Most importantly, zinc-decorated Ti surfaces markedly increased the expressions of antioxidant enzyme relative genes in macrophages. It improved the oxidation microenvironment around the materials and further protected their properties. In summary, our results demonstrated that Ti-NW-Zn surfaces not only provided excellent corrosion resistance properties, but also inhibited the adhesion of macrophages. These aspects were necessary for maintaining osseointegration capacity and enhancing the corrosion resistance of Ti in numerous medical applications, particularly in dentistry.

Advances in Research on Immunoregulation of Macrophages by Plant Polysaccharides

Polysaccharides are among the most important members of the biopolymer family. They are natural macromolecules composed of monosaccharides. To date, more than 300 kinds of natural polysaccharide compounds have been identified. They are present in plants, animals, and microorganisms, and they engage in a variety of physiological functions. In the 1950s, due to the discovery of their immunoregulatory and anti-tumor activities, polysaccharides became a popular topic of research in pharmacology, especially in immunopharmacology. Plants are an important source of natural polysaccharides. Pharmacological and clinical studies have shown that plant polysaccharides have many functions, such as immune regulation, anti-tumor activity, anti-inflammatory activity, anti-viral functions, anti-radiation functions, and a hypoglycaemic effect. The immunomodulatory effects of plant polysaccharides have received much attention. Polysaccharides with these effects are also referred to as biological response modifiers (BRMs), and research on them is one of the most active areas of polysaccharide research. Thus, we summarize immunomodulatory effects of botanical polysaccharides isolated from different species of plants on the macrophage. The primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, including increasing reactive oxygen species (ROS) production, and enhancing secretion of cytokines and chemokines. Therefore, it is believed that botanical polysaccharides have significant therapeutic potential, and represent a new method for discovery and development of novel immunomodulatory medicine.

The impacts of natural polysaccharides on intestinal microbiota and immune responses – a review

This paper presents a comprehensive review of the impacts of natural polysaccharides on gut microbiota and immune responses as well as their interactions.

Polysaccharide from alfalfa activates RAW 264.7 macrophages through MAPK and NF-κB signaling pathways

Alfalfa polysaccharide (APS), a bioactive compound extracted from alfalfa, has been proposed to exhibit potential growth-promoting and immune-enhancing functions. But, little is known about the cellular immunomodulatory and intrinsic molecular mechanisms. Here we extracted the APS, and performed in vitro experiments to characterize the immunomodulatory functions as well as the molecular mechanisms of APS on RAW 264.7 macrophages cells. Chemical analyses showed that APS was mainly composed of fucose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid and glucuronic acid. The results of in vitro assays demonstrated that 50 and 100 μg/mL APS increased the cell viability of RAW 264.7 cells. The secretion and gene expression of NO/iNOS, IL-6 and TNF-α in APS-induced macrophage cell were significantly enhanced. However, APS-induced TNF-α production was decreased by blocking the MAPK or NF-κB signaling pathways, especially for the blockade of p38. Moreover, APS enhanced the phosphorylation of p38, ERK, and JNK, promoted the degradation of IκBα, and increased the nuclear translocation of NF-κB p65 subunit. Therefore, we demonstrated that APS could improve the immune functions of RAW 264.7 macrophages cells by promoting the cell viability and increasing secretion and gene expressions of NO/iNOS, IL-6 and TNF-α through the MAPK and NF-κB signaling pathways.

Polysaccharide rich extract (PRE) from Tinospora cordifolia inhibits the intracellular survival of drug resistant strains of Mycobacterium tuberculosis in macrophages by nitric oxide induction

Plethora of clinical and scientific information obtained in recent past has strengthened the idea that targeting critical constituents of host immune system may have beneficial outcomes for the treatment of tuberculosis. Macrophages being the primary host for Mycobacterium tuberculosis, offer an attractive target for modulation. Owing to their negligible toxicity, plant derived polysaccharides with the ability to activate macrophages; are suitable candidates for immunomodulation. In the present study, effects of polysaccharide rich extract (PRE) isolated from Tinospora cordifolia, on the survival of intracellular MTB strains and activation of macrophages were investigated. PRE treatment up regulated the expression of pro-inflammatory cytokines such as IL-β, TNF-α, IL-6, IL-12, and IFN-γ in RAW 264.7 cell line. Up regulation in the expression of NOS2 was observed along with concomitant enhanced nitric oxide production post PRE treatment. Surface expression of MHC-II and CD-86 was up regulated after PRE treatment. Above results suggested the classical activation of macrophages by PRE treatment. Furthermore, PRE treatment led to the activation of all the three classes of MAPK i.e p38, ERK and JNK MAPKs. Further, PRE up regulated the expression of cytokines, NOS-2, MHC-II and CD-86 in MTB infected macrophages. PRE treatment inhibited the intracellular survival of drug resistant MTB in macrophages which was partially attributed to PRE mediated NO induction. Thus our data demonstrate classical activation of macrophages by PRE treatment and killing of intracellular MTB by NO induction.

Macrophage immunomodulatory activity of the polysaccharide isolated from Collybia radicata mushroom

Polysaccharides from Collybia radicata mushroom (CRP) possess many functions, such as antiviral, anti-aging and hypolipidemic activities. However, little is known about their immunomodulatory activity. To address this issue, we did a thorough research into their immune effects on murine macrophages. The results showed that the 14942Da polysaccharide not only obviously improved the proliferation and phagocytosis of macrophages, but also induced the secretion of nitric oxide (NO), inducible nitric oxide synthase (iNOS) and cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin factors (IL-1β, IL-6 and IL-10). At a concentration of 850.0μgmL^-1, the polysaccharide stimulated their proliferation and phagocytosis to 2.1 and 3.4 times, respectively, as compared to the negative group. Meanwhile, it raised the production of NO by inducing iNOS in a concentration-dependent manner. Furthermore, it enhanced the release of these cytokines to multiples from 2.3 to 3.6 times. As an inhibitor of TLR4 (Toll-like Receptor 4), TAK242 suppressed the secretion of NO, iNOS and cytokines above 51%, and ORP acted on the cells mainly via TLR4. Consequently, the polysaccharide has a potent immunomodulatory activity by stimulating macrophages and can be considered as a novel potential immunopotentiator in medical and food industries.

Structural Characterization and Immunostimulatory Activity of Polysaccharides from Brassica rapa L.

Two neutral polysaccharides (BRNP-1, 6.9 kDa; BRNP-2, 4.8 kDa) were purified from the common edible plant Brassica rapa L. via the combined techniques of ion-exchange chromatography and high-performance gel permeation chromatography. Monosaccharide composition analysis showed that BRNP-1 and BRNP-2 were composed of glucosyl residues. Methylation and 1D- and 2D-NMR analyses revealed that both BRNP-1 and BRNP-2 contained a backbone chain that was composed of α-D-(1 → 4)-linked Glcp residues and side chains that were composed of terminally linked Glcp residues attached at the O-6 position of backbone-glycosyl residues. BRNP-1 and BRNP-2, however, differed in branch degree and molecular weight. Bioassay results showed that treatment with the higher dosage (400 μg/mL) of BRNP-1 and BRNP-2 stimulated the proliferation, NO release, and cytokine secretion (IL-6 and TNF-α) of RAW264.7 macrophages. These results suggested that BRNP-1 and BRNP-2 may enhance macrophage-mediated immune responses.