Sanguinarine ameliorates DSS induced ulcerative colitis by inhibiting NLRP3 inflammasome activation and modulating intestinal microbiota in C57BL/6 mice.

BACKGROUND: Sanguinarine (SAN) is an important natural anti-inflammatory constitutes and dietary supplementation with SAN could improve the relative length of the intestine, alter gut microbiota, and enhance growth performance of pigs, broiler chickens, and cattle. However, it is unclear whether it has the therapeutic effect on ulcerative colitis (UC). PURPOSE: This study aimed to investigate the therapeutic effect of SAN on UC and explore its mechanisms of action. STUDY DESIGN AND METHODS: Several efficacy indexes of SAN on dextran sulfate sodium (DSS)-induced C57BL/6 mice were evaluated. ELISA kit and western blot analysis were used to evaluate it's anti-inflammatory effect and the mechanism of action. 16S rDNA sequencing detection was used to determine the impact of SAN on gut microbiota. RESULTS: SAN and Sulfasalazine could significantly improve the colon length, the weight loss, the symptoms and the pathological injury of colon in DSS-induced mice. Meanwhile, SAN could decrease the levels of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1ß, IL-6, IL-13 and IL-18) and increase the levels of anti-inflammatory cytokines (IL-4 and IL-10) in colon, and suppress DSS-induced high expressions of NLRP3, caspase-1 and IL-1ß. In addition, SAN (0.5, 1 µM) could inhibit the expression level of NLRP3 and the activation of caspase-1 and IL-1ß in lipopolysaccharide-stimulated THP-1 cells in non-cytotoxic doses, which was similar to that of MCC950, a specific inhibitor of NLRP3 inflammasome activation. The abundance changes of many genera such as Muribaculaceae_unclassified, Escherichia-Shigella, Lachnospiraceae_NK4A136_group and Helicobacter were also closely related to the improvement of SAN on intestinal inflammatory response. CONCLUSION: SAN exhibited therapeutic effect on DSS-induced colitis by blocking NLRP3-(Caspase-1)/IL-1ß pathway and improving intestinal microbial dysbiosis. SAN might be developed to treat UC and other disorders associated with microbial dysbiosis.

Higher immune response induced by vaccination in Houhai acupoint relates to the lymphatic drainage of the injection site.

Houhai acupoint (HA) is a site for acupuncture stimulation, located in the fossa between the anus and tail base in animals. To evaluate HA as a potential immunization site, the immune responses were compared when HA and the conventional site nape were vaccinated in rats. The results showed that injection of a porcine epidemic diarrhea virus (PEDV) vaccine in HA induced significantly higher IgG, IgG1, IgG2, splenocyte proliferation and mRNA expression of IL-2, IL-4 and IFN-γ than in the nape. To search for the underlying mechanisms, the draining lymph nodes for HA and the nape were investigated. When rats were injected in HA with Indian ink, 11 lymph nodes including caudal mesenteric lymph node and bilateral gluteal lymph nodes, posterior inguinal lymph nodes, lumbar lymph nodes, internal iliac lymph nodes and popliteal lymph nodes were visibly stained with the ink and injection of a model antigen ovalbumin (OVA) in HA resulted in detection of OVA by western blotting while in the same lymph nodes only a pair of lymph nodes (central brachial lymph nodes) were observed when Indian ink or OVA was injected in the nape. IL-2 mRNA expression was detected in all the lymph nodes when PEDV vaccine was injected. Therefore, the enhanced immune response elicited by vaccination in HA may be attributed to more lymphocytes activated.

Protective effects of Panax notoginseng saponins on PME-Induced nephrotoxicity in mice.

Polymyxin E (PME) plays an important role in fighting against Gram-negative bacterial infections; however, it causes nephrotoxicity, which limits its clinical use. The aim of this study was to investigate the protective effects of a plant extract Panax notoginseng saponins (PNS) on PME-induced nephrotoxicity in mice. In vivo studies showed that PNS significantly reduced blood urea nitrogen (BUN), serum creatinine (CRE) and number of apoptotic cells in kidney, as well as renal histopathological damage which increased in the presence of PME, and suppressed PME-induced oxidative stress in kidney, as shown by the up-regulation of superoxide dismutase (SOD) and the down-regulation of malondialdehyde (MDA) levels. Furthermore, PNS inhibited the expression of Bax, while increased the expression of Bcl-2 compared to the PME-treated group. In vitro studies showed that PNS decreased intracellular reactive oxygen species (ROS) and MDA levels, increased glutathione (GSH) levels, and enhanced the activity of SOD and glutathione peroxidase (GSH-Px) in murine renal tubular epithelial cells (TCMK-1 cells). In addition, PNS enhanced cell viability and the expression of Bcl-2, restored the mitochondrial membrane potential, inhibited the expression of Bax, inhibited the activity of caspase-3 and caspase-9, and reduce apoptotic rate in PME-treated TCMK-1 cells. PNS could reduce PME-induced nephrotoxicity. The protective effects could result from inhibition of oxidative stress, and prevention of cell apoptosis via the mitochondrial pathway. These findings highlight the potential of PNS as a safe adjunct for ameliorating the nephrotoxicity.

Signaling pathway underlying splenocytes activation by polysaccharides from Atractylodis macrocephalae Koidz.

Previous study demonstrated that total polysaccharides isolated from Atractylodis macrocephalae Koidz. (RAMPtp) were effective to eliminate intramammary infection in cows. The present study was designed to investigate the immunomodulatory activity of RAMPtp in mouse splenocytes. Splenocyte proliferation, natural killer (NK) cytotoxicity, productions of NO and cytokines, transcription factor activity as well as the signal pathways and receptor were examined. The results showed that RAMPtp significantly promoted splenocyte proliferation and made the cells enter S and G2/M phases, increased ratios of T/B cells, boosted NK cytotoxicity, enhanced transcriptional activities of nuclear factor of activated T cells (NFAT), nuclear factor κB (NF-κB) and activator protein 1 (AP-1), and stimulated secretions of NO, immunoglobulin G (IgG) and multiple cytokine families (IL-1α, IL-1ß, IL-2, IL-3, IL-4, IL-6, IL-10, IL-12p40, IL-12p70, IL-13, IFN-γ, TNF-α, G-CSF, GM-CSF, KC, MIP-1α, MIP-1ß, RANTES and Eotaxin). In addition, all the specific inhibitors against the mitogen-activated protein kinases (MAPKs) and NF-κB significantly suppressed the IL-6 production induced by RAMPtp. Moreover, splenocytes from Toll-like receptor 4 (TLR4) deficient mouse responded equally to RAMPtp stimulation as the wild-type. Therefore, RAMPtp might induce splenocytes activation at least in part via the TLR4-independent MAPKs and NF-κB signaling pathways. The present results would be useful to further understand the immunomodulatory mechanisms of RAMPtp in elimination of intramammary infection in cows.

Soybean oil containing ginseng saponins as adjuvants promotes production of cytokines and enhances immune responses to foot-and-mouth disease vaccine.

In the present study, the adjuvant effect of soybean oil containing ginseng root saponins (SO-GS-R) on the immune response to foot-and-mouth disease vaccine (FMDV) in mice was investigated. When immunized with FMDV antigen emulsified in an SO-GS-R formulation, mice generated remarkably higher serum antibody and cytokine responses than mice immunized with FMDV antigen alone. To elucidate the mechanisms underlying the adjuvant effect of SO-GS-R, we measured cytokines in serum and muscle tissue after intramuscular injection of SO-GS-R. The results showed that injection of SO-GS-R significantly increased the levels of IL-1ß, IL-5, IL-6, G-CSF, KC, MCP-1, MIP-1α, and MIP-1ß in both serum and muscle. These results suggested that SO-GS-R recruits neutrophils, eosinophils, T cells and macrophages, causing immune cell recruitment at the injection site, driving antigen-presenting cells to actively participate in the onset of immunity, and amplifying the immune responses. Considering its adjuvant activity and plant-derived properties, SO-GS-R should be further studied for its adjuvant effect on vaccines used in food animals.

Ginsenoside Rg1 attenuates the inflammatory response in DSS-induced mice colitis.

Ginsenoside Rg1 is a major active constituent of Panax ginseng and possesses anti-inflammatory effects. It has been reported to have therapeutic effects on various diseases. In the present study, we investigated the role of ginsenoside Rg1 in dextran sodium sulfate (DSS)-induced mouse colitis. Our results showed that ginsenoside Rg1 markedly reduces proinflammatory cytokines release upon DSS stimulation of mouse dendritic cells, that ginsenoside Rg1 suppresses IL-1ß (Interleukin 1 beta) and TNF-α (Tumor necrosis factor alpha) release via up-regulation of NLRP12 (NACHT, LRR and PYD domains-containing protein 12) expression, and that ginsenoside Rg1 significantly decreases the inflammatory response to DSS-induced mouse colitis, as evidenced by increased body weight, reduced colonic damage scores and disease activity index (DAI), and lowered proinflammatory cytokines levels. These results highlight the potential therapeutic use of ginsenoside Rg1 as an anti-inflammatory agent in the treatment of colitis.