Schisandrin B promotes TH1 cell differentiation by targeting STAT1.

Schisandrin B (Sch B) is the major active ingredient of the traditional Chinese medicine Schisandra chinensis and has antitumor activity, anti-inflammatory activity. CD4+ Th subsets orchestrate immune responses to plenty of pathogen infections and participate in the pathogenesis of many immune-related diseases. However, little is known about the relationship between Sch B and T cell differentiation. Here, we showed that Sch B might participate in T cell receptor signaling pathway by using the TCMIO database. Importantly, Sch B promoted TH1 cell differentiation. Furthermore, Sch B did not affect TH2 cell and Treg differentiation. Mechanismly, Sch B increased the level of IFN-γ of CD4+ T cells by upregulating the phosphorylation of STAT1 protein. Then, STAT1 promoted T-bet expression in CD4+ T cells. In conclusion, Sch B modulates the differentiation of naïve CD4+ T cells into TH1 subset by STAT1/T-bet signaling, which may have the potential for the treatment of T cell-mediated-immune diseases.

Grape seed proanthocyanidin extract ameliorates murine autoimmune arthritis through regulation of TLR4/MyD88/NF-κB signaling pathway.

BACKGROUND/AIMS: Grape seed proanthocyanidin extract (GSPE) has been reported to have a beneficial effect on regulating inf lammation. However, the anti-inflammatory mechanism of GSPE remains unclear. The aim of this study was to verify the influence of GSPE on the Toll-like receptor 4 (TLR4)-mediated signaling pathway in the regulation of murine autoimmune arthritis. METHODS: Collagen-induced arthritis (CIA) was induced in dilute brown non-agouti (DBA)/1J mice. The mice were treated with GSPE (0 or 100 mg/kg) intraperitoneally. The severity of arthritis was assessed clinically, biochemically, and histologically. Immunostaining for TLR4 was performed. The expressions of TLR4 and downstream signaling molecules were analyzed by Western blot. The effect of GSPE on lipopolysaccharide (LPS)-induced TLR4 activation was also evaluated using RAW264.7 cells and fibroblast-like synoviocytes (FLSs) from patients with rheumatoid arthritis and from those with osteoarthritis. RESULTS: GSPE attenuated the clinical severity of arthritis and decreased histological damage. GSPE treatment reduced the number of TLR4-stained cells in the synovium of mice with CIA. GSPE also downregulated the expression of TLR4, myeloid differentiation factor 88 (MyD88) and phosphorylated IκBα synovial protein in CIA mice. Concurrently, GSPE inhibited the nuclear translocation of nuclear factor-κB (NF-κB) subunits (p65 and p50). LPS-induced TLR4 activation was suppressed by GSPE in human FLS as well as in murine macrophages in vitro. CONCLUSIONS: Our results demonstrated that GSPE ameliorated CIA by regulating the TLR4-MyD88-NF-κB signaling pathway.

INHIBITORY EFFECT OF EMODIN ON RAW 264.7 ACTIVATED WITH DOUBLE STRANDED RNA ANALOGUE POLY I:C.

BACKGROUND: Emodin (3-methyl-1, 6, 8-trihydroxyanthraquinone) is a compound which can be found in Polygoni Multiflori Radix (PMR). PMR is the root of Polygonum multiflorum. PMR is used to treat dizziness, spermatorrhea, sores, and scrofula as well as chronic malaria traditionally in China and Korea. The anti-tumor property of emodin was already reported. However, anti-viral activity of emodin on macrophages are not fully reported. MATERIALS AND METHODS: Effects of emodin on RAW 264.7 mouse macrophages induced by polyinosinic-polycytidylic acid (poly I:C), a synthetic analog of double-stranded RNA, were evaluated. RESULTS: Emodin restored the cell viability in poly I: C-induced RAW 264.7 at concentrations of up to 50 µM. Emodin significantly inhibited the production of nitric oxide, IL-1α, IL-Ιß, IL-6, GM-CSF, G-CSF, M-CSF, MCP-1, MIP-1a, MIP-Ιß, MIP-2, RANTES, and IP-10 as well as calcium release and mRNA expression of signal transducer and activated transcription 1 (STAT1) in poly I:C-induced RAW 264.7 (P < 0.05). CONCLUSION: This study shows the inhibitory effect of emodin on poly I: C-induced RAW 264.7 via calcium-STAT pathway.

In Vitro and In Vivo Anti-Allergic and Anti-Inflammatory Effects of eBV, a Newly Developed Derivative of Bee Venom, through Modulation of IRF3 Signaling Pathway in a Carrageenan-Induced Edema Model.

BACKGROUND: Bee venom (BV), a type of toxin extracted from honeybees (Apis mellifera), has been empirically and widely used to treat inflammatory diseases throughout Asia. Essential BV (eBV) was developed by removing phospholipase A2 (PLA2) and histamine to lower occurrence of allergic reaction. This study investigated the anti-allergic and anti-inflammatory activities of eBV in vitro and in vivo and its underlying mechanism of action. METHODS: The anti-inflammatory potential of eBV was assessed in vivo using a carrageenan-induced paw edema model. To further investigate the mechanism by which eBV exerts anti-allergic and anti-inflammatory effects, compound 48/80-stimulated RBL-2H3 cells and lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage cells were studied in vitro. RESULTS: Release of ß-hexosaminidase and histamine was increased by eBV in a dose-dependent manner, but these levels were lower in eBV compared to original BV at the same concentration. In addition, eBV suppressed compound 48/80-induced expression of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in RBL-2H3 cells. eBV was also shown to suppress nitric oxide (NO) production by down-regulating mRNA expression and subsequent protein expression of inflammatory mediators in LPS-induced RAW 264.7 cells. Phosphorylation of activators and signal transducers of transcription 1/interferon regulatory factor 3 (STAT1/IRF3) was attenuated by eBV treatment. eBV significantly inhibited carrageenan-induced acute edema in vivo. Serum levels of prostaglandin E2 (PGE2), TNF-α, and IL-1ß were also down-regulated by eBV. CONCLUSIONS: These results demonstrate that eBV inhibits allergic and inflammatory response by reducing inflammatory mediator production via regulation of the STAT1/IRF3 signaling pathway, suggesting that eBV is a feasible candidate for regulation of allergic-inflammatory response in complementary and alternative medicine.

Platycodon grandiflorum root-derived saponins attenuate atopic dermatitis-like skin lesions via suppression of NF-κB and STAT1 and activation of Nrf2/ARE-mediated heme oxygenase-1.

PURPOSE: The consequences of precipitously rising allergic skin inflammation rates worldwide have accelerated the risk of atopic dermatitis (AD). Natural product-based agents with good efficacy and low risk of side effects offer promising prevention and treatment strategies for inflammation-related diseases. We have already reported that Platycodon grandiflorum root-derived saponins (Changkil saponins, CKS) have many pharmacological effects, including anti-inflammatory and anti-allergic effects, but its influence on AD remains unclear. Therefore, we evaluated the inhibitory effect of CKS, mainly platycodin D, on AD-like skin symptoms in mice and the possible mechanisms in cells. METHODS: Mice were sensitized and challenged with 2,4-dinitrochlorobenzene (DNCB). Four weeks after challenge, mice were treated with oral administration of CKS for 4 weeks. In addition, cells were used to evaluate the effect of CKS, mainly platycodin D, on the TARC expression regulated mechanism. RESULTS: CKS attenuated DNCB-induced dermatitis severity, serum levels of IgE and TARC, and mRNA expression of TARC, TNF-α, IFN-γ, IL-4, IL-5, and IL-13 in mice. Histopathological examination showed reduced thickness of the epidermis/dermis and dermal infiltration of inflammatory cells and mast cells in the ears. Moreover, CKS and platycodin D inhibited TNF-α/IFN-γ-induced TARC expression through the suppression of NF-κB and STAT1 and induction of Nrf2/ARE-mediated hemeoxygenase-1 (HO-1) expression in cells. CONCLUSION: We suggest that CKS and platycodin D inhibited the development of AD-like skin symptoms by regulating cytokine mediators and may be an effective alternative therapy for AD-like skin symptoms.

Anti-inflammatory effects and the underlying mechanisms of action of daidzein in murine macrophages stimulated with Prevotella intermedia lipopolysaccharide.

BACKGROUND AND OBJECTIVE: Host modulatory agents directed at inhibiting specific proinflammatory mediators could be beneficial in terms of attenuating periodontal disease progression and potentially enhancing therapeutic responses. The aim of this study was to investigate whether daidzein could modulate the production inflammatory mediators in macrophages stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen implicated in periodontal disease, and to delineate underlying mechanisms of action. MATERIAL AND METHODS: LPS was extracted from P. intermedia ATCC 25611 cells by the standard hot phenol-water method. The amounts of nitric oxide (NO) and interleukin-6 (IL-6) secreted into the culture medium were assayed. A real-time PCR was performed to quantify inducible nitric oxide synthase (iNOS) and IL-6 mRNA expression. We used immunoblot analysis to characterize iNOS protein expression, phosphrylation of c-Jun N-terminal kinase (JNK) and p38, degradation of inhibitory κB-α (IκB-α), nuclear translocation of nuclear factor-κB (NF-κB) subunits and phosphorylation of signal transducer and activator of transcription 1 (STAT1). The DNA-binding activity of NF-κB was assessed by using ELISA-based kits. RESULTS: Daidzein significantly inhibited the production of NO and IL-6, as well as their mRNA expression, in P. intermedia LPS-treated RAW264.7 cells. The JNK and p38 pathways were not involved in the regulation of LPS-induced NO and IL-6 release by daidzein. Daidzein inhibited the degradation of IκB-α induced by P. intermedia LPS. In addition, daidzein suppressed NF-κB transcriptional activity via regulation of the nuclear translocation and DNA-binding activity of NF-κB p50 subunit and blocked STAT1 phosphorylation. CONCLUSION: Although additional studies are required to dissect the molecular mechanism of action, our results suggest that daidzein could be a promising agent for treating inflammatory periodontal disease. Further research in animal models of periodontitis is necessary to better evaluate the potential of daidzein as a novel therapeutic agent to treat periodontal disease.

(+)-Vitisin A inhibits influenza A virus-induced RANTES production in A549 alveolar epithelial cells through interference with Akt and STAT1 phosphorylation.

Airway epithelial cells are the initial sites of influenza virus infection. They participate in the airway inflammatory response by expressing various chemokines such as regulated on activation, normal T cell expressed and secreted (RANTES). In the present investigation, the effects of five stilbenes previously isolated from the roots of Vitis thunbergii on RANTES produced by influenza A virus (H1N1)-infected A549 alveolar epithelial cells were studied. We identified (+)-vitisin A, a tetramer of resveratrol, as a potent agent that inhibits RANTES secretion (EC (50): 0.27 microM). However, resveratrol exhibited a much smaller effect (EC (50): 28.37 microM). H1N1 infection increased the time-dependent phosphorylation of the transcription factor STAT (1) and of Akt (a downstream effector protein of PI3K). When the PI3K-Akt pathway was blocked by wortmannin, H1N1-stimulated STAT (1) phosphorylation and RANTES production were both abrogated, demonstrating that the PI3K-Akt pathway is necessary for STAT (1) activation and RANTES production in A549 cells. Furthermore, H1N1-stimulated phosphorylation of Akt and STAT (1) were also significantly attenuated by (+)-vitisin A. These results suggested that (+)-vitisin A might be a potent anti-inflammatory agent that inhibits influenza A virus-induced RANTES production by interfering with Akt- and STAT (1)-related signal pathways.

Comparative anti-inflammatory characterization of wild fruiting body, liquid-state fermentation, and solid-state culture of Taiwanofungus camphoratus in microglia and the mechanism of its action.

Taiwanofungus camphoratus (syn. Antrodia camphorata), a medicinal mushroom in Taiwan, is reputed to provide several therapeutic benefits, but the wild fruiting body is very rare. In this study, we used Taiwanofungus camphoratus extracts from wild fruiting bodies and two types of artificial cultivation (solid-state culture and liquid-state fermentation) to examine their anti-inflammatory effects in microglia cells and their possible roles in protection against neurodegenerative diseases. First, EOC13.31 microglia was treated with various kinds of Taiwanofungus camphoratus extracts and lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) to evaluate the iNOS expression. Western blot and RT-PCR analysis showed that among the various kinds of extracts from wild fruiting bodies, methanol extracts were the most potent inhibitors of iNOS expression. Secondly, the potency of methanol extracts could be ranked as follows: extracts of wild fruiting body>solid-state culture>liquid-state fermentation. To clarify the mechanisms involved, methanol extracts from fruiting body were found to inhibit the phosphorylation of extracellular signal-regulated protein kinases (ERK), c-Jun NH2-terminal protein kinases (JNK) and signal transducer and activator of transcription-1 (STAT-1) induced by LPS/IFN-gamma. Methanol extracts from fruiting body also inhibited NF-kappaB activation through the prevention of inhibitor kappaB (IkappaB) degradation. Moreover, methanol extracts from wild fruiting body inhibited both the iNOS and cyclooxygenase-2 (COX-2) expression induced by beta-amyloid in microglia in a dose-dependent manner. In an animal model, we confirmed that methanol extracts from fruiting bodies were able to suppress ear edema, indicating that they have anti-inflammatory activity in vivo. These results suggest that Taiwanofungus camphoratus exhibits an anti-inflammatory activity that might contribute to the prevention of neurodegenerative diseases.