International immunopharmacology
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Int. Immunopharmacol. · Jun 2010
Lactic acid bacteria enhance autophagic ability of mononuclear phagocytes by increasing Th1 autophagy-promoting cytokine (IFN-gamma) and nitric oxide (NO) levels and reducing Th2 autophagy-restraining cytokines (IL-4 and IL-13) in response to Mycobacterium tuberculosis antigen.
Control of the intracellular Mycobacterium tuberculosis (Mtb), mainly requires an appropriate ratio of Th1/Th2 cytokines to induce autophagy, a physiologically, and immunologically regulated process that has recently been highlighted as an innate defense mechanism against intracellular pathogens. Current vaccines/adjuvants induce both protective Th1 autophagy-promoting cytokines, such as IFN-gamma, and immunosuppressive Th2 autophagy-restraining cytokines, such as IL-4 and IL-13. TB infection itself is also characterized by relatively high levels of Th2 cytokines, which down-regulate Th1 responses and subsequently subvert adequate protective immunity, and a low ratio of IFN-gamma/IL-4. Therefore, there is a need for a safe and non-toxic vaccine/adjuvant that will induce Th1 autophagy-promoting cytokine (IFN-gamma) secretion and suppress the pre-existing subversive Th2 autophagy-restraining cytokines (IL-4 and IL-13). As lactic acid bacteria (LAB) belonging to the natural intestinal microflora and their components have been shown to shift immune responses against other antigens from Th2-type cytokines toward Th1-type cytokines like IFN-gamma, we investigated whether LAB can improve the polarization of Th1/Th2 cytokines and autophagic ability of mononuclear phagocytes in response to Mtb antigen. ⋯ Our study implies that LAB may reinforce the response of the mononuclear phagocytes to Mtb antigen by inducing production of the autophagy-promoting factors IFN-gamma and NO, while decreasing the Th2 autophagy-restraining cytokines IL-4 and IL-13. Hence, combination of Mtb antigen and LAB may perhaps be safer in more efficacious TB vaccine formulation.
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Int. Immunopharmacol. · Jun 2010
Icariin attenuates lipopolysaccharide-induced microglial activation and resultant death of neurons by inhibiting TAK1/IKK/NF-kappaB and JNK/p38 MAPK pathways.
Microglia in the central nervous system (CNS) play an important role in the initiation of neuroinflammatory response. Icariin, a compound from Epimedium brevicornum Maxim, has been reported to have anti-inflammatory effect on the macrophage cell line RAW264.7. However, it is currently unknown what anti-inflammatory role icariin may play in the CNS. ⋯ Further mechanism studies revealed that icariin blocked TAK1/IKK/NF-kappaB and JNK/p38 MAPK pathways. It was also found that icariin reduced the degeneration of cortical neurons induced by LPS-activated microglia in neuron-microglia co-culture system. Taken together these findings provide mechanistic insights into the suppressive effect of icariin on LPS-induced neuroinflammatory response in microglia, and emphasize the neuroprotective effect and therapeutic potential of icariin in neuroinflammatory diseases.
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Int. Immunopharmacol. · Apr 2010
Anti-inflammatory effect of lucidone in mice via inhibition of NF-kappaB/MAP kinase pathway.
Here, we investigated the anti-inflammatory activity of lucidone, a phytocompound isolated from the fruits of Lindera erythrocarpa Makino, against lipopolysaccharide (LPS)-induced acute systemic inflammation in mice. Male ICR mice were injected intraperitoneally with LPS (5 microg/kg), and the effects of pretreatment with various concentrations of lucidone (50-200 mg/kg) for 12h on the formation of nitric oxide (NO), prostaglandin-E(2) (PGE(2)) and tumor necrosis factor (TNF-alpha) were analyzed. Lucidone inhibited the production of NO, PGE(2) and TNF-alpha production in LPS-induced mice, and also induced mRNA and protein levels of inducible nitric oxide synthase (iNOS), and cyclooxigenase-2 (COX-2). ⋯ Moreover, lucidone decreased the expression and phosphorylation of c-Jun N-terminal kinase (JNK) protein thereby causing the subsequent inhibition of AP-1 activity. Finally, our results indicated that lucidone was able to block mitogen-activated protein kinases activity and its downstream signaling activation of NF-kappaB and AP-1. We thus conclude that lucidone exerts its anti-inflammatory effects in mice by inhibiting the expression of pro-inflammatory factors and their related signaling pathways.
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Int. Immunopharmacol. · Apr 2010
A phenolic acid phenethyl urea compound inhibits lipopolysaccharide-induced production of nitric oxide and pro-inflammatory cytokines in cell culture.
We previously used the Curtius rearrangement to synthesize various phenolic acid phenethyl urea compounds from phenolic acids and demonstrated their beneficial anti-oxidant and anti-cancer effects. Here, we investigated the effects of one of these synthetic compounds, (E)-1-(3,4-dihydroxystyryl)-3-(4-hydroxyphenethyl)urea (DSHP-U), on nitric oxide (NO) production, inducible nitric oxide synthase (iNOS) expression, and cytokine secretion in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. DSHP-U suppressed LPS-induced NO production and iNOS expression at a concentration of 50 microM and inhibited LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 kinase. ⋯ Furthermore, DSHP-U decreased the production of tumor necrosis factor-alpha, interleukin (IL)-1beta, and IL-6 in LPS-treated macrophages. However, the LPS-stimulated expression of LPS receptors, such as Toll-like receptor 4, myeloid differentiation factor-2, and CD14, was unchanged after DSHP-U treatment at significantly high levels. Our data suggest that DSHP-U blocks NO and inflammatory cytokine production in LPS-stimulated macrophages and that these effects are mainly mediated through the inhibition of the ERK/p38- and NF-kappaB signaling pathways.
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Int. Immunopharmacol. · Apr 2010
Pharmacological profile of AW-814141, a novel, potent, selective and orally active inhibitor of p38 MAP kinase.
The p38 mitogen activated protein kinase (MAPK) is a key signaling molecule that plays a crucial role in the progression of various inflammatory diseases such as rheumatoid arthritis (RA), asthma and chronic obstructive pulmonary disease. The objective of the present study was to evaluate the anti-inflammatory activity of a p38 MAPK inhibitor, AW-814141. AW-814141 inhibited enzymatic activity of recombinant p38-alpha and beta isoforms with IC(50) value of 100nM and 158nM, respectively. ⋯ In a carrageenan-induced rat paw edema model and collagen-induced arthritis model (CIA), AW-814141 dose dependently inhibited paw swelling. In different in vivo efficacy models, efficacy of AW-814141 was found to be better as compared to the reference compounds (Vx-745 and BIRB-796). This study demonstrated that AW-814141 is a novel p38 MAPK inhibitor and it displays promising in vitro and in vivo anti-inflammatory activities and can be used for the treatment of rheumatoid arthritis.