Sarcodon imbricatus polysaccharides protect against cyclophosphamide-induced immunosuppression via regulating Nrf2-mediated oxidative stress

Isolation, structural characterization and immunomodulatory activity on RAW264.7 cells of a novel exopolysaccharide of Dictyophora rubrovalvata

Fungal polysaccharides have been explored by many for both structural studies and biological activities, but few studies have been done on the extracellular polysaccharides of Dictyophora rubrovalvata, so a new exopolysaccharide was isolated from Dictyophora rubrovalvata and its structure and its immunological activity were investigated. The crude exopolysaccharide (EPS) was purified by DEAE52 cellulose and Sephadex G-200 to obtain a new acidic polysaccharide (DR-EPS). DR-EPS (2.66 × 103 kDa) was consisted mainly of mannose, glucose, galactose and glucuronic acid with a molar ratio of 1: 0.86: 0.20: 0.01. In addition, DR-EPS increased the phagocytic activity of RAW264.7 cells up to 2.67 times of the blank control group. DR-EPS improved intracellular nucleic acid and glycogen metabolism as observed by AO and PAS staining. DR-EPS(40 μg/mL) promoted NO production up to 30.66 μmol, enhanced acid phosphatase (ACP) and superoxide dismutase (SOD) activities, with activity maxima of 660 U/gprot and 96.27 U/mgprot, respectively, and DR-EPS (160 μg / mL) significantly increased the lysozyme content as 2.73 times of the control group. The good immunological activity of extracellular polysaccharides of Dictyophora rubrovalvata provides directions for the use of fermentation broths.

Sciadonic acid ameliorates cyclophosphamide-induced immunosuppression by modulating the immune response and altering the gut microbiota

BACKGROUND

Cyclophosphamide (Cy) is a frequently used chemotherapeutic drug, but long-term Cy treatment can cause immunosuppression and intestinal mucosal damage. The intestinal mucosal barrier and gut flora play important roles in regulating host metabolism, maintaining physiological functions and protecting immune homeostasis. Dysbiosis of the intestinal flora affects the development of the intestinal microenvironment, as well as the development of various external systemic diseases and metabolic syndrome.

RESULTS

The present study investigated the influence of sciadonic acid (SA) on Cy-induced immunosuppression in mice. The results showed that SA gavage significantly alleviated Cy-induced immune damage by improving the immune system organ index, immune response and oxidative stress. Moreover, SA restored intestinal morphology, improved villus integrity and activated the nuclear factor κB signaling pathway, stimulated cytokine production, and reduced serum lipopolysaccharide (LPS) levels. Furthermore, gut microbiota analysis indicated that SA increased t beneficial bacteria (Alistipes, Lachnospiraceae_NK4A136_group, Rikenella and Odoribacter) and decreased pathogenic bacteria (norank-f-Oscillospiraceae, Ruminococcus and Desulfovibrio) to maintain intestinal homeostasis.

CONCLUSION

The present study provided new insights into the SA regulation of intestinal flora to enhance immune responses. © 2024 Society of Chemical Industry.

Fucosylated chondroitin sulfate from sea cucumber Stichopus chloronotus alleviate the intestinal barrier injury and oxidative stress damage in vitro and in vivo

This study aimed to investigate the alleviative effects of fucosylated chondroitin sulfate from sea cucumber Stichopus chloronotus (fCSSc) on the intestinal barrier injury and oxidative stress damage in vitro and in vivo. The results showed that fCS-Sc protected the intestinal barrier and improved the antioxidant function in H2O2 damaged Caco-2 cells via up-regulating the tight junction proteins and activating Keap1-Nrf2-ARE antioxidant pathway. Furthermore, administration fCS-Sc could ameliorate the weight loss and spleen index decrease in Cyclophosphamide (Cy) treated mice, improve the expressions of ZO-1, Claudin-1, Nrf2, SOD, and NQO-1 in Cy damaged colon tissue, showing significant protective effects against intestinal barrier damage and oxidative stress in vivo. fCS-Sc intervention also alleviated the gut microbiota disorder though increasing the richness and diversity of intestinal bacteria, regulating the structural composition of gut microbiota. fCS-Sc promoted the relative abundance of beneficial microbiota and inhibited the growth of harmful bacteria. This study provided a theoretical basis for the application of fCS-Sc as a prebiotic in chemotherapy.

Carboxymethylated Abrus cantoniensis polysaccharide prevents CTX-induced immunosuppression and intestinal damage by regulating intestinal flora and butyric acid content

As a Chinese folk health product, Abrus cantoniensis exhibits good immunomodulatory activity because of its polysaccharide components (ACP), and carboxymethylation of polysaccharides can often further improve the biological activity of polysaccharides. In this study, we explored the impact of prophylactic administration of carboxymethylated Abrus cantoniensis polysaccharide (CM-ACP) on immunosuppression and intestinal damage induced by cyclophosphamide (CTX) in mice. Our findings demonstrated that CM-ACP exhibited a more potent immunomodulatory activity compared to ACP. Additionally, CM-ACP effectively enhanced the abundance of short-chain fatty acid (SCFA)-producing bacteria in immunosuppressed mice and regulated the gene expression of STAT6 and STAT3 mediated pathway signals. In order to further explore the relationship among polysaccharides, intestinal immunity and intestinal flora, we performed a pseudo-sterile mouse validation experiment and fecal microbiota transplantation (FMT) experiment. The findings suggest that CM-FMT and butyrate attenuate CTX-induced immunosuppression and intestinal injury. CM-FMT and butyrate show superior immunomodulatory ability, and may effectively regulate intestinal cell metabolism and repair the damaged intestine by activating STAT6 and STAT3-mediated pathways. These findings offer new insights into the mechanisms by which CM-ACP functions as functional food or drug, facilitating immune response regulation and maintaining intestinal health.

Pre-treatment with galectin-1 attenuates lipopolysaccharide-induced myocarditis by regulating the Nrf2 pathway

Galectin-1 (Gal-1), a member of a highly conserved family of animal lectins, plays a crucial role in controlling inflammation and neovascularization. However, the potential role of Gal-1 in preventing myocarditis remains uncertain. We aimed to explore the functions and mechanisms of Gal-1 in preventing myocarditis. In vivo, C57/BL6 mice were pre-treated with or without Gal-1 and then exposed to lipopolysaccharide (LPS) to induce myocarditis. Subsequently, cardiac function, histopathology, inflammation, oxidative stress, and apoptosis of myocardial tissues were detected. Following this, qRT-PCR and Western blotting were applied to measure iNOS, COX2, TXNIP, NLRP3 and Caspase-1 p10 expressions. In vitro, H9c2 cells pre-treated with different doses of Gal-1 were stimulated by LPS to induce myocarditis models. CCK8, flow cytometry and reactive oxygen species (ROS) assay were then employed to estimate cell viability, apoptosis and oxidative stress. Furthermore, Nrf2 and HO-1 protein expressions were evaluated by Western blotting in vivo and in vitro. The results showed that in vivo, Gal-1 pre-treatment not only moderately improved cardiac function and cardiomyocyte apoptosis, but also ameliorated myocardial inflammation and oxidative damage in mice with myocarditis. Furthermore, Gal-1 inhibited TXNIP-NLRP3 inflammasome activation. In vitro, Gal-1 pre-treatment prevented LPS-induced apoptosis, cell viability decrease and ROS generation. Notably, Gal-1 elevated HO-1, total Nrf2 and nuclear Nrf2 protein expressions both in vivo and in vitro. In conclusion, pre-treatment with Gal-1 exhibited cardioprotective effects in myocarditis via anti-inflammatory and antioxidant functions, and the mechanism may relate to the Nrf2 pathway, which offered new solid evidence for the use of Gal-1 in preventing myocarditis.

Advances in health-promoting effects of natural polysaccharides: Regulation on Nrf2 antioxidant pathway

Natural polysaccharides (NPs) possess numerous health-promoting effects, such as liver protection, kidney protection, lung protection, neuroprotection, cardioprotection, gastrointestinal protection, anti-oxidation, anti-diabetic, and anti-aging. Nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway is an important endogenous antioxidant pathway, which plays crucial roles in maintaining human health as its protection against oxidative stress. Accumulating evidence suggested that Nrf2 antioxidant pathway might be one of key regulatory targets for the health-promoting effects of NPs. However, the information concerning regulation of NPs on Nrf2 antioxidant pathway is scattered, and NPs show different regulatory behaviors in their different health-promoting processes. Therefore, in this article, structural features of NPs having regulation on Nrf2 antioxidant pathway are overviewed. Moreover, regulatory effects of NPs on this pathway for health-promoting effects are summarized. Furthermore, structure-activity relationship of NPs for health-promoting effects by regulating the pathway is preliminarily discussed. Otherwise, the prospects on future work for regulation of NPs on this pathway are proposed. This review is beneficial to well-understanding of underlying mechanisms for health-promoting effects of NPs from the view angle of Nrf2 antioxidant pathway, and provides a theoretical basis for the development and utilization of NPs in promoting human health.

Regulatory effects of Auricularia cornea var. Li. polysaccharides on immune system and gut microbiota in cyclophosphamide-induced mice

The immuno-regulating potential of edible fungus polysaccharides has gained more and more attention. However, there is little information about the study of Auricularia cornea var. Li. polysaccharides regulating immunomodulatory activity. The objective of this work to analyze the immunomodulatory activity and the mechanism of A. cornea var. Li. polysaccharides supplementation in an immunosuppressed mice model induced by cyclophosphamide. The effects of A. cornea var. Li. polysaccharides on immune system including immune organ indices, immunoglobulin contents, and inflammation cytokines in immunosuppressed mice were determined. In addition, the regulatory effects of A. cornea var. Li. polysaccharides on the gut microbiota and their metabolites were analyzed. Results showed that A. cornea var. Li. polysaccharides significantly elevated immune organ indexes, remarkably enhanced the levels of immunoglobulin A (IgA), IgG and IgM in serum and secretory IgA (sIgA) in the intestinal mucosa, conspicuously stimulated the levels of tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), IL-4, and IL-10 in the serum. A. cornea var. Li. polysaccharides also could restore gut microbiota to the pattern that is similar with that of the control group with increase of the relative abundances of short-chain fatty acids (SCFAs)-producing bacteria. Furthermore, the content of SCFAs were increased after A. cornea var. Li. polysaccharides supplementation. This study provides useful information for applications of A. cornea var. Li. polysaccharides in immune-regulated foods and medicine.

A Water-Soluble Polysaccharide from the Fibrous Root of Anemarrhena asphodeloides Bge. and Its Immune Enhancement Effect in Vivo and in Vitro

Background

The fibrous roots of Anemarrhena asphodeloides Bge. (FRAAB) are byproducts of the rhizome of Anemarrhena asphodeloides. Some studies have revealed secondary metabolic small molecules in FRAAB, but there are few reports on the polysaccharides of FRAAB (PFRAAB). Aim of the Study. The present study aimed to investigate the preliminary characterization and underlying mechanism of immune stimulation of PFRAAB.

Materials and Methods

The crude polysaccharide of FRAAB was obtained by hot water extraction and alcohol precipitation, and PFRAAB was purified by a diethylaminoethyl-52 (DEAE-52) cellulose chromatographic column and graphene dialysis membrane. The preliminary characterization of PFRAAB was studied by ultraviolet (UV) scanning and Fourier Transform Infrared Reflection (FTIR). The molecular weight and composition of PFRAAB were analysed by high-performance gel permeation chromatography (HPGPC) and high-performance liquid chromatography (HPLC), respectively. The immune stimulation of PFRAAB was investigated by using cyclophosphamide- (CCP-) treated mice and RAW264.7 cells.

Results

A water-soluble PFRAAB was obtained with a molecular weight of 115 kDa and was mainly composed of arabinose (ara), galactose (gal), glucose (glc), and mannose (man). Compared with CCP-induced mice, PFRAAB significantly (p < 0.05 or p < 0.01) increased the spleen and thymus index, ameliorated injury to the spleen and thymus, and evaluated immunoglobulin levels. In addition, PFRAAB also increased the secretion of nitric oxide (NO), interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), and IL-6 in RAW264.7 cells and upregulated the expression of toll-like receptor 4 (TLR4), Myd88, nuclear factor kappa-B (NF-κB) P65, p–NF–κB P65, IKB-α, and p-IKB-α.

Conclusion

PFRAAB possesses immune stimulation activity and can be used as a potential resource for immune-enhancing drugs. Our present study provides a scientific basis for the comprehensive development of Anemarrhena asphodeloides medicinal plant resources.

The Protective Effect of Polysaccharide SAFP from Sarcodon aspratus on Water Immersion and Restraint Stress-Induced Gastric Ulcer and Modulatory Effects on Gut Microbiota Dysbiosis

Sarcodon aspratus is a popular edible fungus for its tasty flavour and can be used as a dietary supplement for its functional substances. This study was conducted to evaluate the potential health benefits of Sarcodon aspratus polysaccharides (SAFP) on water immersion and restraint stress (WIRS)-induced gastric ulcer in rats. The results indicated that SAFP could decrease myeloperoxidase (MPO) activity and plasma corticosterone levels, as well as enhance Prostaglandin E2 (PGE2) and Nitrate/nitrite (NOx) concentration in rats. Furthermore, SAFP significantly attenuated the stress damage, inflammation, pathological changes and gastric mucosal lesion in rats. Moreover, high-throughput pyrosequencing of 16S rRNA suggested that SAFP modulated the dysbiosis of gut microbiota by enhancing the relative abundance of probiotics, decreasing WIRS-triggered bacteria proliferation. In summary, these results provided the evidence that SAFP exerted a beneficial effect on a WIRS-induced gastric ulcer via blocking the TLR4 signaling pathway and activating the Nrf2 signaling pathway. Notably, SAFP could modulate the WIRS-induced dysbiosis of gut microbiota. Thus, SAFP might be explored as a natural gastric mucosal protective agent in the prevention of gastric ulcers and other related diseases in the food and pharmaceutical industries.

Docosahexaenoic acid activates the Nrf2 signaling pathway to alleviate impairment of spleen cellular immunity in intrauterine growth restricted rat pups

Intrauterine growth retardation (IUGR) impairs immune function in children. IUGR is associated with an imbalance of oxidative stress and abnormal apoptosis. Therefore, an IUGR rats model was established to determine the antioxidant capacity and apoptosis in newborn IUGR rats and explored whether these effects were regulated after Docosahexaenoic acid (DHA) supplementation to rat pups. First, eight normal-birth-weight (NBW) and eight IUGR neonatal rats (a 10% low-protein diet) were used to obtain the antioxidant capacity and apoptosis in IUGR rat pups. Then, 32 newborn rats were randomly assigned to the normal birth weight (NBW), DHA supplementation for NBW (ND), IUGR, and DHA supplementation for IUGR (ID) groups. Starting from the 7th day after birth, DHA was given to the experimental group and the same volume of distilled water was given to the control group for 21 days. (1) DHA improved the serum and spleen CD4/CD8 ratios and IL-4 and IFN-γ mRNA expression. (2) DHA decreased the level of MDA, but increased T-AOC in serum and spleen. (3) DHA increased the protein expression of Bcl-2 while decreased Bax. (4) DHA increased protein expression of the Nrf2 signaling pathway and the downstream antioxidant genes GSH-PX and CAT. DHA may alleviate the impairment of spleen cellular immunity in IUGR rat pups by inhibiting oxidative stress and apoptosis related to the activation of Nrf2 signaling pathway.

Immunomodulatory activity of puerarin in RAW264.7 macrophages and cyclophosphamide-induced immunosuppression mice

CONTEXT

Puerarin, a natural isoflavone extracted from Radix puerariae, is famous for treating various cardiovascular and cerebrovascular diseases. However, little is known about its direct immunomodulatory activity.

OBJECTIVE

This study was designed to investigate the in vitro and in vivo immunomodulatory effects of Radix puerariae by using the murine monocyte-macrophage cell line RAW264.7 and immunosuppressed cyclophosphamide-induced mice.

METHODS

MTT and neutral red phagocytosis assays were conducted to evaluate the in vitro immunomodulatory activities of puerarin on cell viability and phagocytosis by measuring the proliferation, phagocytic, nitric oxide (NO) ability, and TNF-α production ability of stimulated and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Immunosuppressed cyclophosphamide-induced mice were used to evaluate the in vivo immunomodulatory activities of puerarin by measuring IL-4 and IFN-γ, the serum half hemolysis value, spleen and thymus index, and proliferation assay for splenic lymphocytes.

RESULTS AND DISCUSSION

Results showed that puerarin improves immunomodulatory activity by increasing cell proliferation, cell phagocytosis, and NO secretion in RAW264.7 macrophages and reduces the abnormal immunologic activity by decreasing cell phagocytosis and NO secretion in LPS-stimulated RAW264.7 macrophages. In addition, puerarin enhanced the immunologic activity of cyclophosphamide-induced immunosuppression mice by increasing the secretion of NO, IFN-γ, and IL-4, the serum half hemolysis value (HC₅₀), the spleen and thymus index, and proliferation for splenic lymphocytes.

CONCLUSION

Puerarin exhibited an upregulated immunomodulatory effect on RAW264.7 macrophages and immunosuppression mice. In addition, puerarin had a downregulated immunomodulatory effect on RAW264.7 macrophages. The results suggest that puerarin could be a promising immunomodulator to assist in the treatment of tumors.

Polysaccharide of Atractylodes macrocephala Koidz (PAMK) Alleviates Cyclophosphamide-induced Immunosuppression in Mice by Upregulating CD28/IP3R/PLCγ-1/AP-1/NFAT Signal Pathway

The polysaccharide of Atractylodes macrocephala Koidz (PAMK) is recognized as an immune enhancer, with anti-cancer, anti-tumour, lymphocyte-activating and lymphocytes proliferation-inducing effects. For investigating the mechanism that PAMK alleviates the decline in T cell activation induced by CTX, 24 6-week-old BALB/c female mice were randomly divided into four groups (C, PAMK, CTX, PAMK + CTX). The spleen index, splenocytes morphology and death, cytokine concentration, T cell activating factors (CD25, CD69, CD71), mRNA expression levels related to the CD28 signal pathway were detected. Furthermore, the lymphocytes of mice was isolated and cultured, and then the Th1/Th2 ratio, activating factors, mRNA levels related to the CD28 signal pathway were detected. The results showed that PAMK significantly improved the spleen index, alleviated abnormal splenocytes morphology and death, maintained the balance of Th1/Th2 cells, increased the levels of IL-2, IL-6, TNF-α, and IFN-γ, and increased the mRNA levels of CD28, PLCγ-1, IP3R, NFAT, and AP-1. In conclusion, PAMK increased cytokines levels and alleviated the decline in activation level of lymphocytes induced by CTX through CD28/IP3R/PLCγ-1/AP-1/NFAT signal pathway.

Melatonin inhibits the apoptosis of rooster Leydig cells by suppressing oxidative stress via AKT-Nrf2 pathway activation

Oxidative stress has been described as a key driver of Leydig cell apoptosis. Melatonin has antioxidative and antiapoptotic effects, but the potential effects and mechanism of melatonin on oxidative stress and apoptosis in rooster Leydig cells remain unclear. Our results showed that melatonin biosynthetic enzymes and melatonin receptors were expressed in rooster Leydig cells and their expression were locally inhibited as rooster sexual maturation. We found that melatonin inhibited H₂O₂-induced apoptosis of rooster Leydig cell by activating the melatonin receptors Mel-1a and Mel-1b. Additionally, melatonin protects mitochondria from damage by reducing the level of oxidative stress in Leydig cells. Melatonin relieved H₂O₂-induced oxidative stress by significantly reducing intracellular ROS, MDA and 8-OHdG levels and increasing SOD and GSH-Px activities. Simultaneously, melatonin significantly reduced H₂O₂-induced depolarization of ΔΨm and decreased the release of Cytochrome C and Ca²⁺. We also observed that melatonin activated the Nrf2 pathway, while Nrf2 silencing abrogated the anti-oxidative and anti-apoptotic effects of melatonin in rooster Leydig cells. Furthermore, melatonin promoted the phosphorylation of AKT, while AKT inhibitor suppressed the Nrf2 pathway activated by melatonin and alleviated the inhibitory effects of melatonin on apoptosis and oxidative stress. In conclusion, melatonin could inhibit apoptosis in rooster Leydig cells by suppressing oxidative stress via activation of the AKT-Nrf2 pathway.

The effect of Panax notoginseng saponins on oxidative stress induced by PCV2 infection in immune cells: in vitro and in vivo studies

Background

Panax notoginseng saponins (PNS) are bioactive substances extracted from P. notoginseng that are widely used to treat cardiovascular and cerebrovascular diseases and interstitial diseases. PNS have the functions of scavenging free radicals, anti-inflammation, improving blood supply for tissue and so on.

Objectives

The aim of this study was to investigate the effects of PNS on the oxidative stress of immune cells induced by porcine circovirus 2 (PCV2) infection in vitro and in vivo.

Methods

Using an oxidative stress model of PCV2 infection in a porcine lung cell line (3D4/2 cells) and mice, the levels of nitric oxide (NO), reactive oxygen species (ROS), total glutathione (T-GSH), reduced glutathione (GSH), and oxidized glutathione (GSSG) and the activities of xanthine oxidase (XOD), myeloperoxidase (MPO) and inducible nitric oxide synthetase (iNOS) were determined to evaluate the regulatory effects of PNS on oxidative stress.

Results

PNS treatment significantly reduced the levels of NO and ROS, the content of GSSG and the activities of XOD, MPO, and iNOS (p < 0.05), while significantly increasing GSH and the ratio of GSH/GSSG in infected 3D4/2 cells (p < 0.05).Similarly, in the in vivo study, PNS treatment significantly decreased the level of ROS in spleen lymphocytes of infected mice (p < 0.05), increased the levels of GSH and T-GSH (p < 0.05), significantly decreased the GSSG level (p < 0.05), and decreased the activities of XOD, MPO, and iNOS.

Conclusions

PNS could regulate the oxidative stress of immune cells induced by PCV2 infection in vitro and in vivo.

Bioactive Phytochemical Constituents of Wild Edible Mushrooms from Southeast Asia

Mushrooms have a long history of uses for their medicinal and nutritional properties. They have been consumed by people for thousands of years. Edible mushrooms are collected in the wild or cultivated worldwide. Recently, mushroom extracts and their secondary metabolites have acquired considerable attention due to their biological effects, which include antioxidant, antimicrobial, anti-cancer, anti-inflammatory, anti-obesity, and immunomodulatory activities. Thus, in addition to phytochemists, nutritionists and consumers are now deeply interested in the phytochemical constituents of mushrooms, which provide beneficial effects to humans in terms of health promotion and reduction of disease-related risks. In recent years, scientific reports on the nutritional, phytochemical and pharmacological properties of mushroom have been overwhelming. However, the bioactive compounds and biological properties of wild edible mushrooms growing in Southeast Asian countries have been rarely described. In this review, the bioactive compounds isolated from 25 selected wild edible mushrooms growing in Southeast Asia have been reviewed, together with their biological activities. Phytoconstituents with antioxidant and antimicrobial activities have been highlighted. Several evidences indicate that mushrooms are good sources for natural antioxidants and antimicrobial agents.

Acetylated Polysaccharides From Pleurotus geesteranus Alleviate Lung Injury Via Regulating NF-κB Signal Pathway

The present work investigated the anti-inflammatory, antioxidant, and lung protection effects of acetylated Pleurotus geesteranus polysaccharides (AcPPS) on acute lung injury (ALI) mice. The acetylation of AcPPS was successfully shown by the peaks of 1737 cm⁻¹ and 1249 cm⁻¹ by FTIR. The animal experiments demonstrated that lung damage can be induced by zymosan. However, the supplementation of AcPPS had potential effects on reducing lung index, remitting inflammatory symptoms (TNF-α, IL-1β, and IL-6), inhibiting NF-κB signal pathway based on up-regulating the level of IκBα and down-regulating p-IκBα level by Western blotting and immunofluorescence assay, preventing oxidative stress (ROS, SOD, GSH-Px, CAT, T-AOC, and MDA), reducing lipid accumulation (TC, TG, LDL-C, HDL-C, and VLDL-C), and alleviating lung functions by histopathologic observation. These results demonstrated that AcPPS might be suitable for natural food for prevention or remission in ALI.

Mesona chinensis Benth polysaccharides protect against oxidative stress and immunosuppression in cyclophosphamide-treated mice via MAPKs signal transduction pathways

In this study, the immune responses of Mesona chinensis Benth polysaccharides (MP) in vitro and in vivo were investigated. Results showed that MP presented immunomodulatory activities on macrophages and T lymphocytes in vitro. Compared with the cyclophosphamide (Cy)-induced immunosuppressive mice, the body weights, spleen indexes (3.45 to 4.91) and thymus indexes (0.78 to 1.04) of the mice treated with MP were increased, and the peripheral blood levels were recovered. MP treatment also increased superoxide dismutase, glutathione peroxidase and catalase activities, and reduced malondialdehyde levels to enhance the total antioxidant capacity of Cy-treated mice. In addition, MP significantly elevated IL-2, NO, and IFN-γ secretions of splenic lymphocytes and spleen, while MP mainly exerts an immune effect by regulating T lymphocytes. Furthermore, MP possessed the immunomodulatory activity by up-regulating the phosphorylation levels of proteins factors (c-Jun N-terminal kinase, extracellular regulated protein kinase and p38 kinase) in mitogen activated protein kinases signaling pathways. This study suggested that MP may be explored as a natural immune stimulant for functional food and nutraceutical industries.

Galectin-1 ameliorates lipopolysaccharide-induced acute lung injury via AMPK-Nrf2 pathway in mice

Inflammation and oxidative stress contribute to the progression of acute lung injury (ALI). Galectin-1 (Gal-1) has important anti-inflammatory properties in renal ischemia-reperfusion injury, arthritis, uveitis, and hepatitis. However, whether Gal-1 could protect against ALI is still poorly elucidated. The current study aimed to investigate the protective effects of Gal-1 against lipopolysaccharide (LPS)-induced ALI and the underlying mechanisms. Accordingly, we found that pretreatment with Gal-1 attenuated the lung tissue injury induced by LPS, with the recovery of lung function, protecting against the production of pro-inflammatory cytokines and oxidative stress. We also confirmed the therapeutic potential of Gal-1 on the survival rate of LPS-challenged mice. In vitro studies demonstrated the protective effects of exogenous Gal-1 through downregulating pro-inflammatory cytokines release and oxidative stress in primary macrophages challenged by LPS. In addition, Gal-1 suppressed TXNIP-NLRP3 inflammasome activation in ALI mice and LPS-treated primary macrophages partly through directly binding to the NLRP3 protein. Gal-1 alleviated LPS-induced lung injury via activation of Nrf-2, which may be associated with AMPK phosphorylation. Collectively, our experimental results firstly provided the support that Gal-1 effectively protected against LPS-induced ALI via suppression of inflammation response and oxidative stress, which were largely dependent on the upregulation of the Nrf2 pathway via phosphorylation of AMPK. These results suggest that Gal-1 could be a valuable therapeutic candidate in the treatment of ALI.

Dehydroepiandrosterone resisted E. Coli O157:H7-induced inflammation via blocking the activation of p38 MAPK and NF-κB pathways in mice

Dehydroepiandrosterone (DHEA), a critical metabolite in cholesterol metabolism, can regulate the inflammatory responses in humans or animals. However, the precise mechanisms of these beneficial actions remains poorly understood. Present study aims to clarify the anti-inflammatory function of DHEA and its possible mechanisms in the E. coli O157:H7-stimulated mice. The results indicated that DHEA reduced the mortality of mice and bacterial concentration in the peritoneal fluid in the E. coli-stimulated mice. DHEA increased the spleen index, the activity of lactate dehydrogenase and acid phosphatase; while it decreased the nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in mice. The mRNA levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and interferon gamma (IFN-γ) were decreased, whereas the interleukin-4 (IL-4) and interleukin-10 (IL-10) mRNA levels were increased in the E. coli-stimulated mice treated with DHEA. Moreover, DHEA treatment reversed the increasing of IFN-γ/IL-4 ratio in mice caused by E. coli infection. Importantly, DHEA blocked the nuclear translocation of p65 through down-regulation the IκB-α protein phosphorylation level in the mice stimulated with E. coli O157:H7. No statically changes were showed on the phospho (p)-ERK1/2 and p-JNK1/2 protein level, while DHEA significantly suppressed the p-p38 protein level in mice. The above results indicated that DHEA alleviated inflammatory responses by suppressing NO secretion and promoting Th2-associated anti-inflammatory cytokines production in mice; and this action might relate to the blocking of p38 MAPK and NF-κB signaling pathways activation. All the above results provide substantial information for understanding the anti-inflammatory function of DHEA and further support it as a potential immunomodulatory in prevention inflammatory and bacterial infection diseases.

Water-soluble polysaccharides from Grifola Frondosa fruiting bodies protect against immunosuppression in cyclophosphamide-induced mice via JAK2/STAT3/SOCS signal transduction pathways

Grifola Frondosa, the king of mushrooms, is one of the most valued traditional medicines and has been used as a health food for a long time in China, Japan, and other Asian countries. The present study was designed to evaluate the immune-modulating effects of water-soluble polysaccharides from the Grifola Frondosa fruiting body (GFP) by using mouse peritoneal macrophage and cytoxan (CTX) induced immunosuppression models. Compared with CTX-induced immunosuppressive mice, the spleen and thymus indexes in mice with GFP orally administrated were significantly increased, body weight loss was alleviated, and the natural killer (NK) cytotoxicity and the proliferative activities of lymphocytes were elevated. Furthermore, levels of interleukin-2 (IL-2), interferon-6 (IL-6) and tumor necrosis factor-α (TNF-α) were notably reduced by CTX, while GFP abolished these effects. GFP also effectively increased total antioxidant capacity and superoxidase dismutase, catalase and glutathione peroxidase activities, and inhibited an increase in the malondialdehyde level. Histopathological analysis of spleens revealed the protective effect of GFP against CTX-induced immunosuppression. Western blotting results showed that GFP possessed immunomodulatory activity by up-regulating transcription factors (p-JAK2/JAK2, p-STAT3/STAT3 and SOCS3) in JAK2/STAT3/SOCS signaling pathways. This study suggested that GFP may provide an alternative strategy for lessening chemotherapy-induced immunosuppression.