Hydatidosis is a widely endemic helminthic disease vectored in human by the larval stage of the metacestode Echinococcus granulosus. It is characterized by the long-term coexistence of chronic infection with detectable humoral and cellular responses against the macroparasite. Previous studies demonstrated interferon-gamma (IFN-gamma) and nitric oxide (NO) production (in vivo and in vitro) during hydatidosis. In this study, we tested the hypothesis that NO production after IFN-gamma induction may constitute a host defense against E. granulosus. We also investigated the IFN-gamma effect on protoscolices (larval form of the parasite) viability in coculture with hydatid patients' peripheral blood mononuclear cells (PBMC). PBMCs from hydatic patients incubated with IFN-gamma (100 U/mL) alone are effective in the killing of protoscolices. This scolicidal activity is concomitant with elevation of nitrite levels. NO release and cytotoxic activity are inhibited by N-monomethyl-L-arginine (L-NMMA), a specific inhibitor of the NO pathway and increased by L-arginine, an NO precursor, and tetrahydrobiopterin (BH4), a nitric oxide synthase (NOS) cofactor. Our results indicate that IFN-gamma mediated iNOS induction as one of host defense mechanism against human E. granulosus infection.
Uveitis is one of the major manifestations of Behçet Disease, a systemic inflammatory vasculitis. Our aim is to investigate in vivo and in vitro production of interferon (IFN)-γ and nitric oxide (NO) during Behçet uveitis (BU). Moreover, we evaluated the implication of IFN-γ and interleukin (IL)-10 in the regulation of NO production in vitro. Cytokines' concentrations were measured by ELISA, and NO levels were assessed by modified Griess's method. Our results showed that patients with active disease had significant elevation of IFN-γ and NO concentrations in both plasma and peripheral blood mononuclear cell culture supernatants compared with controls (P<0.01) or to patients with inactive disease (P<0.05). Further, IFN-γ induced significantly higher production of NO in cell culture supernatants, whereas IL-10 significantly reduced it (P<0.05). In conclusion, the elevated levels of IFN-γ in vivo and in vitro in patients with BU reflect the implication of this cytokine in the disease physiopathology. These results suggest that IFN-γ, through the induction of NO synthase 2 and the production of NO, is implicated in the genesis of the inflammatory process during active BU; whereas IL-10 seems to have protective properties.
Sjögren's syndrome (SS) is an autoimmune epithelitis characterized by mononuclear cell (MNC) infiltration of the lacrimal and salivary glands (SG), as well as the presence of serum autoantibodies. This condition is a growing public health concern in Algeria. Herein, we sought to determine if the levels of interleukin (IL)-6, IL-17A, and nitric oxide (NO), were correlated with the extent of MNC infiltration. The expression of inducible NO synthase (NOS2) and CD68 was measured in the SG of all patients, but not in those of the normal controls (NCs). We included 44 primary Sjögren's syndrome (pSS) patients and 15 NCs in this study; we found that the expression of NOS2 and CD68 was elevated in all of the SG of SS patients. Additionally, the serum and saliva levels of IL-6, IL-17A, and NO were higher in the pSS patients, compared with the NCs. Furthermore, the NOS2-induced excess NO was associated with the extent of the MNC infiltration, and thereby with tissue injury. It is also important to note that there were correlations between the levels of IL-6, IL-17A, and NO. Such findings indicate that through the effects of NO, IL-17A participates in the pathophysiology of the disease. With the purpose of improving both the diagnosis and prognosis, IL-6, IL-17A, and NO should be assayed in the serum and saliva of patients suspected of SS.
BackgroundAdamantiades-Behçet's disease (ABD) is a chronic multisystemic inflammation with unknown pathophysiology. This disorder is associated with a dysregulation of the cytokine network that hyperactivates neutrophils and macrophages. In this study, we investigate the modulatory effects of flavonoïd compounds extracted from Algerian medicinal plant Artemisia herba alba on Th1 and Th2 cytokines and nitric oxide production.MethodsThe modulatory effects of flavonoïds extracted from Artemisia herba alba on cytokines and nitric oxide production by peripheral blood mononuclear cells isolated from Algerian ABD patients and healthy controls were respectively measured by means of ELISA assays and Griess modified method.ResultsOur results show that flavonoïds significantly reduce the production of interleukin-12, the key effector of T helper 1 (Th1) cells and nitric oxide in a dose-dependent manner in Adamantiades-Behçet's disease. In contrast, the production of IL-4, the key marker of Th2 cells was increased.ConclusionThis study suggests that in vitro supplementation with flavonoïds extracted from Artemisia herba alba could have potential immuno-modulatory effects characterised by a down-regulation and up-regulation of Th1 and Th2 cytokines, respectively. Moreover, flavonoïds may prevent nitric oxide induced damages.
Pterygium is a common ocular surface disease observed in humans. Chronic ultraviolet (UV) exposure is extensively recognized as an aetiological factor in the pathogenesis of this disease. This hypothesis is sustained by epidemiological and histopathological data in relation to UV injured skin. Although some findings have indicated that genetic factors, anti-apoptotic and immunological mechanisms are involved in the pathogenesis of pterygium, the mechanism by which it develops remains poorly understood. In this study, we analysed the in vivo production of IL-17A, IL-6, IL-10 and nitric oxide (NO) in the tears and sera from Algerian patients. Interestingly, we observed that IL-6, IL-17A and NO production in the tears and sera of all patients was strongly associated with inflammatory infiltration, NOS2, NF-κB and Bcl2 expression in pterygia biopsies. Collectively, our results indicate a relationship between local inflammation and anti-apoptotic processes in pterygium disease, leading to both tissue damage and enhanced cellular proliferation.
In this study, we evaluated the preventive and curative effects of ethanolic extract of Propolis (EEP) during α-Tropomyosin-induced uveitis in an experimental model using Wistar rats, through the regulation of inducible nitric oxide synthase (NOS2) and arginase-1. In this context, rats received daily injection of EEP (100 mg/kg) for 5 days prior to immunization or for 9 days commencing 5 days post immunization with α-Tropomyosin extract, then were sacrificed at day 14. Histological examination, NOS2, arginase-1, and nuclear factor-κB (NF-κB) expression were evaluated in the retinas. Plasmatic production of nitric oxide (NO), urea, IL-4, and TNF-α was assessed. We have found that treatment with EEP substantially reduced the retinal histological damages induced by α-Tropomyosin. In the same context, a significant decrease of NO and TNF-α levels was noticed. Interestingly, EEP down-modulated NOS2 and NF-κB expression in retina. Also, an increase in urea and IL-4 levels was concomitant to an up-modulation of arginase-1 expression. Hence, it appears that EEP attenuated retinal damages through the induction of Th2 response and the inhibition of NF-κB/NOS2 pathway.
Celiac Disease (CeD) is a chronic immune-mediated enteropathy, in which dietary gluten induces an inflammatory reaction, predominantly in the duodenum. Propolis is a resinous hive product, collected by honeybees from various plant sources. Propolis is well-known for its anti-inflammatory, anti-oxidant and immunomodulatory effects, due to its major compounds, polyphenols and flavonoids. The aim of our study was to assess the ex vivo effect of ethanolic extract of propolis (EEP) upon the activity and expression of iNOS, along with IFN-γ and IL-10 production in Algerian Celiac patients. In this context, PBMCs isolated from peripheral blood of Celiac patients and healthy controls were cultured with different concentrations of EEP. NO production was measured using the Griess method, whereas quantitation of IFN-γ and IL-10 levels was performed by ELISA. Inducible nitric oxide synthase (iNOS) expression, NFκB and pSTAT-3 activity were analyzed by immunofluorescence assay. Our results showed that PBMCs from Celiac patients produced high levels of NO and IFN-γ compared with healthy controls (HC). Interestingly, EEP reduced significantly, NO and IFN-γ levels and significantly increased IL-10 levels at a concentration of 50 µg/mL. Importantly, EEP downmodulated the iNOS expression as well as the activity of NFκB and pSTAT-3 transcription factors. Altogether, our results highlight the immunomodulatory effect of propolis on NO pathway and on pro-inflammatory cytokines. Therefore, we suggest that propolis may constitute a potential candidate to modulate inflammation during Celiac Disease and has a potential therapeutic value.
Behçet's disease (BD) is an inflammatory multisystemic disorder associated with orogenital ulcers, uveitis and skin lesions with unpredictable episodes of exacerbations and remissions. Even though several immunological and environmental factors contribute to BD progression, its ethiopathogenesis remains uncertain and elusive. Considered as one of the potent environmental factors that can increase prevalence of some autoimmune and inflammatory disorders, vitamin D deficiency has been linked to several diseases as BD. The aim of this study is to assess vitamin D status in Algerian BD patients and its relationship with disease activity. Immunomodulatory effect of this vitamin on nitric oxide (NO), inflammatory mediator, was also undertaken. Serum 25(OH) vitamin D levels were measured in healthy controls (HC), active and inactive BD patients with an electrochemiluminescence method. After treatment of HCs' and patients' peripheral blood mononuclear cells with different concentrations of vitamin D3, NO production was evaluated with Griess method, while inducible nitric oxide synthase (iNOS) and NF-κB expression with immunofluorescence test. A high decrease of vitamin D levels was noted in active BD patients compared to those of inactive stage and HC. However, a higher NO production was observed during active stage of BD compared to inactive one. In inactive BD, vitamin D levels correlates negatively with NO. Interestingly, vitamin D3 inhibits ex vivo NO production, iNOS and NF-κB expression in BD patients. In conclusion, vitamin D deficiency was associated with active BD. This vitamin down-modulates NO production in BD patients, suggesting that it may be considered as promising therapy modulating inflammation during BD.
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