Chemical Constituents of the Underground Parts of Iris florentina and their Cytotoxic Activity.

Three new isoflavonoid glycosides (1, 5, and 9) and 10 known compounds (2-4, 6-8, and 10-13) were isolated from the underground parts of Iris florentina (Iridaceae). The structures of the new compounds were determined based on extensive spectroscopic data and the results of hydrolytic cleavage. The isolated compounds and the aglycones were evaluated for cytotoxic activity against HL-60 human promyelocytic leukemia cells. Compound 12 induced apoptotic cell death in the HL-60 cells.

A new therapeutic approach using a schizophyllan-based drug delivery system for inflammatory bowel disease.

Antisense technologies for the targeted inhibition of gene expression could provide an effective strategy for the suppression of inflammation. However, the effective use of antisense oligonucleotides (ODN) has been limited because of several problems. Therefore, a delivery system for antisense ODNs that enhances antisense stability, while maintaining the specificity of antisense for its target RNA or DNA is needed. We have developed a delivery system for antisense ODN using schizophyllan (SPG), a polysaccharide that belongs to the ß-(1-3) glucan family. This system has several advantages enabling the effective suppression of targeted RNA or DNA: the SPG complex is stable in vivo and does not dissolve in the presence of deoxyribonuclease, and the SPG complex is effectively taken up into macrophages by phagocytosis through Dectin-1. Macrophage-migration inhibitory factor (MIF), which is mainly produced by macrophages has been shown to have a pathogenetic role in inflammatory bowel disease (IBD). We developed a technique to create an SPG complex that highly conformed to the antisense MIF. The administration of antisense MIF/SPG complex effectively suppressed MIF production and significantly ameliorated intestinal inflammation. Our result demonstrated a possible new therapeutic approach, i.e., the administration of antisense MIF/SPG complex, for the treatment of IBD.

Thioredoxin suppresses airway inflammation independently of systemic Th1/Th2 immune modulation.

Oxidative stress plays an important role in the pathogenesis of asthma via the upregulation of local inflammatory mediators and/or promoting Th2-skewing during Ag sensitization. Thioredoxin (TRX), a 12 kDa redox-active protein with antioxidative property, has been recently shown to play a protective role in various inflammatory diseases. Using a mouse model of asthma, we show here that IL-13 and eotaxin production are decreased in TRX-Tg mice leading to reduced eosinophils recruitment and mucus metaplasia. The reduction in airway inflammation occurs without the attenuation of systemic Th2 immunity in that comparable levels of Th2-type cytokines and Ig were detected in LN and serum, respectively, from TRX-Tg and WT mice. Likewise, CD4(+) T cells from both strains of mice developed similar Th1 and Th2 responses in vitro. Asthmatic lungs of TRX-Tg and WT mice contained similar amounts of GATA-3(+) and Foxp3(+) T cells. Finally, production of MIF, an upstream modulator of airway inflammation, was significantly reduced in the lungs of TRX-Tg mice. Our data suggest that TRX suppresses airway inflammation by inhibiting MIF production thereby limiting the downstream recruitment of eosinophils to the lung independently of modulating systemic Th1/Th2 immunity.

DNA vaccination against macrophage migration inhibitory factor improves atopic dermatitis in murine models.

BACKGROUND: Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that has been implicated in the pathogenesis of AD. Recently, we developed a novel DNA vaccine that generates neutralizing endogenous anti-MIF antibodies. OBJECTIVE: This study explores the preventive and therapeutic effects of this MIF-DNA vaccine in mouse models of AD. METHODS: Two different AD model mice (DS-Nh and NC/Nga) received MIF-DNA vaccination to analyze preventive and therapeutic effects, as assessed by clinical skin scores, histologic findings, and serum IgE levels. RESULTS: In murine models of AD, MIF-DNA vaccination prevented the occurrence of the AD skin phenotype. Furthermore, administration of MIF-DNA vaccine to mice that had already developed AD produced a rapid improvement in AD skin manifestation. There were reduced histologic signs of inflammation and lower serum IgE levels in treated mice compared with those seen in control animals. Finally, passive transfer of IgG from MIF-DNA vaccinated mice to AD mice also produced a significant therapeutic effect. These results demonstrate that MIF-DNA vaccination not only prevents the development of AD but also improves the symptoms of pre-existing AD. CONCLUSION: Taken together, the induction of an anti-MIF autoantibody response using MIF-DNA vaccination appears to be a useful approach in the treatment of AD.

Regulation of cellular contractile force in response to mechanical stretch by diphosphorylation of myosin regulatory light chain via RhoA signaling cascade.

Fibroblasts regulate their contractile force in response to external stretch; however, the detailed mechanism by which the force is regulated is unclear. Here, we show that diphosphorylation and dephosphorylation of myosin regulatory light chain (MRLC) are involved in the stretch-induced force response. Cellular stiffness, which reflects the cellular contractile force, under external stretch was measured by mechanical-scanning probe microscopy. Fibroblasts (NIH-3T3) expressing green fluorescent protein (GFP)-tagged mutant-type MRLC (MRLC(T18A)-GFP), which cannot be diphosphorylated, did not show any stretch-induced stiffness response, whereas the stiffness in cells expressing GFP-tagged wild-type MRLC (MRLC(WT)-GFP) increased immediately after the stretch and subsequently decreased after 1-2 h. Urea-PAGE western blot analysis showed that the proportion of diphosphorylated MRLC (PP-MRLC) transiently increased after the stretch and decreased after 1-2 h. Dominant-negative RhoA (RhoA(N19))-expressing cells did not show the stiffness response to the stretch, whereas wild-type RhoA-expressing cells did. It was concluded that the cellular force response originates in the stretch-induced diphosphorylation and dephosphorylation of MRLC and is regulated via the RhoA signaling cascade.

Active immunization against macrophage migration inhibitory factor using a novel DNA vaccine prevents ovariectomy-induced bone loss in mice.

Previous studies have demonstrated that mice deficient in the macrophage migration inhibitory factor (MIF) gene are protected from ovariectomy (OVX)-induced bone loss. We developed a novel MIF-deoxyribonucleic acid (DNA) vaccine by introducing oligonucleotides encoding a helper T epitope into the cDNA sequence of murine MIF. Mice given the MIF-DNA vaccine produced high titers of autoantibody against MIF, and were protected from OVX-induced bone loss. Our results further support the hypothesis that MIF is involved in the pathomechanism of OVX-induced bone loss, and also show that active immunization against MIF using a DNA vaccine may be useful for the prophylactic treatment of postmenopausal osteoporosis.

A novel DNA vaccine targeting macrophage migration inhibitory factor protects joints from inflammation and destruction in murine models of arthritis.

OBJECTIVE: Previous studies have demonstrated that neutralization of macrophage migration inhibitory factor (MIF) by anti-MIF antibodies decreases joint inflammation and destruction in a type II collagen-induced arthritis model in mice. The aim of this study was to develop and describe a simple and effective method of active immunization that induces anti-MIF autoantibodies, which may neutralize MIF bioactivity. METHODS: We developed a MIF DNA vaccine by introducing oligonucleotides encoding a tetanus toxoid (TTX) Th cell epitope into the complementary DNA sequence of murine MIF. Mice were injected with this construct in conjunction with electroporation. The ability of this immunization to inhibit the development of collagen antibody-induced arthritis (CAIA) in BALB/c mice and spontaneous autoimmune arthritis in interleukin-1 receptor antagonist (IL-1Ra)-deficient mice was then evaluated. RESULTS: Mice that received the MIF/TTX DNA vaccine developed high titers of autoantibodies that reacted to native MIF. Compared with unvaccinated mice, vaccinated mice also produced less serum tumor necrosis factor alpha after receiving an intravenous injection of lipopolysaccharide. In addition, vaccination with MIF/TTX DNA resulted in significant amelioration of both CAIA in BALB/c mice and symptoms of autoimmune arthritis in IL-1Ra-knockout mice. CONCLUSION: These results suggest that MIF/TTX DNA vaccination may be useful for ameliorating the symptoms of rheumatoid arthritis.

Inhibition of nuclear factor-kappa B activation attenuates hydrogen peroxide-induced cytotoxicity in human lens epithelial cells.

AIMS: Hydrogen peroxide (H(2)O(2)) is the major oxidant involved in cataract formation. Lens epithelial cells have been suggested to be the first site of oxidative damage. The authors investigated the relationship between H(2)O(2)-induced cytotoxicity and activation of nuclear factor kappa B (NF-kappaB) in human lens epithelial (HLE) cells. METHODS: HLE B-3 cells were stimulated by various concentrations of H(2)O(2) in the presence or absence of pyrrolidine dithiocarbamate (PDTC), a potent inhibitor of NF-kappaB. H(2)O(2)-induced cytotoxicity was measured by lactate dehydrogenase cytotoxicity assay. Translocation of NF-kappaB was examined by Western blot and immunocytochemistry using anti-p65 antibody. RESULTS: H(2)O(2)-induced cytotoxicity increased in a concentration-dependent manner. PDTC treatment significantly suppressed the cytotoxicity induced by H(2)O(2). After stimulated with H(2)O(2), NF-kappaB was found translocated from cytoplasm into the nuclei. PDTC treatment also inhibited the translocation of NF-kappaB. CONCLUSIONS: NF-kappaB signal pathway may be important in the development of H(2)O(2)-induced damage in HLE cells that is involved in cataractogenesis.

Phosphorylation of p27(KIP1) in lens epithelial cells after extraction of fiber cells.

Opacification of the posterior capsule depends on replication of the residual lens epithelial cells lining the capsule. However, the mechanisms in the regulation of lens cell proliferation have not been determined. The purpose of this study is to examine the expression of p27(KIP1), a cyclin-dependent kinase inhibitor, and its phosphorylation, and cyclin D1 in lens epithelial cells after extraction of fiber cells. C57Bl6 mice (12 weeks old) were anesthetized, and the lens fiber cells were surgically extracted. Eyeballs were collected and fixed at 15 min and 24 h after extraction with and without injection of a specific phosphorylated extracellular signal-regulated kinase (pERK) 1/2 inhibitor (PD98059) to the anterior chamber. Collected tissues were analyzed using immunohistochemistry with anti-p27(KIP1), anti-phosphorylated p27(KIP1) on serine 10 (s10-phospho-p27) and cyclin D1 antibodies. Human lens epithelial cells were cultured, and then were treated with and without 40 ng/ml human recombinant basic fibroblast growth factor (bFGF), which was analyzed by Western blot analysis. In the untreated lens, p27(KIP1) was not phosphorylated in the lens epithelial cells, although p27(KIP1)-positive nuclei were detected in the lens cells of the equatorial region. Immunoreactivity for cyclin D1 was hardly detected in the lens. Nuclear immunoreactivity for p27(KIP1) and s10-phospho-p27 was observed in several lens cells of the equatorial region 15 min after extraction of fiber cells. Western blotting demonstrated that the p27(KIP1) phosphorylation form was upregulated 15 min after bFGF treatment in cultured lens epithelial cells. Many cyclin D1-positive nuclei were noted 24 h after the surgery. p27(KIP1) phosphorylation and cyclin D1 induction were inhibited by PD98059. s10-phospho-p27 and p27(KIP1) immunoreactivity was undetected in the lens cells 24 h after the extraction of fiber cells. It is possible that the phosphorylation of p27(KIP1), and cyclin D1 expression are regulated by the ERK pathway in lens cells after the extraction of fiber cells.

Diphosphorylation of the myosin regulatory light chain enhances the tension acting on stress fibers in fibroblasts.

Regulation of the contractile force is crucial for cell migration, cell proliferation, and maintenance of cell morphology. Phosphorylation of the myosin II regulatory light chain (MRLC) is involved in these processes. To show whether the diphosphorylation of MRLC increases the tension acting on stress fibers, changes in the stiffness of fibroblasts expressing wild-type MRLC and a mutant type, which cannot be diphosphorylated, on treatment with lysophosphatidic acid (LPA) were examined by a mechanical-scanning probe microscope (M-SPM). The LPA treatment increased cellular stiffness in the wild-type MRLC expressing cells, while it had no effect on the mutated cells. Immunostaining showed that LPA stimulation induced the diphosphorylation of MRLC. These results suggest that the diphosphorylation of MRLC enhances the tension acting on stress fibers.

Transgenic mice overexpressing macrophage migration inhibitory factor (MIF) exhibit high-turnover osteoporosis.

UNLABELLED: The bone phenotype of mice overexpressing MIF was studied. These mice showed decreased trabecular bone, increased bone formation rate, and increased MMP-3, -9, and -13 mRNA expression in the femora and tibias. This model provides evidence of the role played by MIF in bone remodeling and balance in vivo. INTRODUCTION: The role of macrophage migration inhibitory factor (MIF) in in vivo bone remodeling remains unelucidated. We describe disordered bone metabolism in transgenic mice overexpressing MIF. MATERIALS AND METHODS: For in vivo study, muCT, bone histomorphometry, blood and urine biochemical data, and gene expression of MIF transgenic (MIF Tg) mice and littermate wildtype (WT) mice were examined. For in vitro study, osteoclastogenesis in the co-culture of bone marrow cells and osteoblasts from MIF Tg and WT were assessed. RESULTS: muCT analyses revealed a significant reduction in the trabecular bone of distal femur in MIF Tg at 8-12 weeks of age. Histomorphometric analysis revealed increase in several measures of bone formation. Osteoclastogenesis was not influenced by the origin of bone marrow cells or osteoblasts. Urine level of deoxypyridinoline/creatinine and the mRNA levels of matrix metalloproteinase (MMP) -3, -9, and -13 in femurs were elevated in MIF Tg. CONCLUSIONS: Overexpression of MIF causes high-turnover osteoporosis in mice. The increased expression of MMPs in bone was suggested, at least in part, as one cause of this phenotype, because MMPs plays important roles for bone resorption without affecting the formation of osteoclasts. This model provides evidence of the role played by MIF in bone remodeling and balance.

Inhibitory effects of lutein on endotoxin-induced uveitis in Lewis rats.

PURPOSE: Lutein deposits in the macula and lens of human eyes with high concentration and is well known as an eye-protective nutrient for its beneficial effects on eye disease such as age-related macular degeneration and cataract. The purpose of the present study was to investigate the effects of lutein on endotoxin-induced uveitis (EIU) in rats. METHODS: EIU was induced in male Lewis rats by subcutaneous injection of 200 microg lipopolysaccharide. Lutein or dexamethasone was administered intravenously at 30 minutes before, at the same time as, and at 30 minutes after LPS treatment. The aqueous humor was collected at 24 hours after LPS injection, the number of infiltrating cells, the protein concentration, and the levels of nitric oxide (NO), tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, prostaglandin (PG)-E2, monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein (MIP)-2 in the aqueous humor were determined. Immunohistochemical staining with a monoclonal antibody against activated nuclear factor (NF)-kappaB was performed to evaluate the effect of lutein on NF-kappaB activation in the iris-ciliary body (ICB) of rats. A mouse macrophage cell line (RAW264.7 cells) was stimulated with LPS in the presence or absence of lutein. Expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and degradation of inhibitor kappaB (IkappaB) were analyzed by Western blot analysis. RESULTS: Lutein suppressed the development of EIU in a dose-dependent fashion. The anti-inflammatory effect of 100 mg/kg lutein was as strong as that of 1 mg/kg dexamethasone. Treatment with lutein reduced the concentrations of NO, TNF-alpha, IL-6, PGE2, MCP-1, and MIP-2 in aqueous humor. Lutein also suppressed the activation of NF-kappaB in the ICB as well as iNOS and COX-2 expression and IkappaB degradation in RAW cells. CONCLUSIONS: These findings indicate that lutein has anti-inflammatory effects on EIU by inhibiting the NF-kappaB dependent signaling pathway and the subsequent production of proinflammatory mediators.

Decreased prostaglandin E2 production by inflammatory cytokine and lower expression of EP2 receptor result in increased collagen synthesis in keloid fibroblasts.

We investigated the metabolism of arachidonic acid in normal skin-derived fibroblasts (NF) as well as in keloid-derived fibroblasts (KF) in response to macrophage migration inhibitory factor (MIF), a pluripotent cytokine. We found that MIF enhanced cyclooxygenase-2 activity in NF more than in KF. Consistent with this finding, prostaglandin E(2) (PGE(2)), an antifibrogenic molecule, was more significantly increased in NF than in KF by MIF treatment. As regarding E prostanoid receptor 2, the level of expression was significantly lower in KF than in NF. On the other hand, Forskolin, a direct activator of adenylcyclase, decreased collagen synthesis in both NF and KF, which indicates that cAMP plays an important role in regulating collagen synthesis. As PGE(2) induces cAMP production, it is conceivable that increased collagen synthesis in KF might be owing to decreased PGE(2) and cAMP production. These findings may aid in the development of a therapeutic strategy for the regulation of collagen synthesis in keloid fibroblasts.

Macrophage migration inhibitory factor-deficient mice are resistant to ovariectomy-induced bone loss.

A link between macrophage migration inhibitory factor (MIF) and estrogen has recently emerged. We examined the involvement of MIF in osteoporotic changes in bone after ovariectomy (OVX), and revealed that MIF-deficient mice (MIF-KO) were completely protected from this phenomenon. The increase in osteoclast number per bone surface and serum IL-1beta levels, which were observed in wild-type mice after OVX, did not occur in MIF KO. Our data suggest that MIF plays an important role in the pathogenesis of postmenopausal osteoporosis, and could be a novel target for the treatment of this disease.

Suppressive effects of astaxanthin against rat endotoxin-induced uveitis by inhibiting the NF-kappaB signaling pathway.

We investigated the effects of astaxanthin (AST), a carotenoid, on endotoxin-induced uveitis (EIU), and over the course of the disease measured the expression of inflammatory cytokines and chemokines in the presence or absence of AST. EIU was induced in male Lewis rats by footpad injection of lipopolysaccharide (LPS). The animals were randomly divided to 12 groups with eight animals in each. Immediately after the inoculation, AST (1, 10, or 100 mg kg(-1)) was injected intravenously. Aqueous humour was collected at 6, 12 and 24 hr after LPS inoculation and the number of infiltrating cells in the anterior chamber was counted. In addition, we assayed the concentration of protein, nitric oxide (NO), tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E2 (PGE2). Immunohistochemical staining with a monoclonal antibody against activated NF-kappaB was performed in order to evaluate the effects of AST on NF-kappaB activation. Rats injected with AST showed a significant decrease in the number of infiltrating cells in the anterior chamber and additionally there was a significantly lower concentration of protein, NO, TNF-alpha and PGE2 in the aqueous humour. Moreover, even early stages of EIU were suppressed by injection of AST. The number of activated NF-kappaB-positive cells was lower in iris-ciliary bodies treated with 10 or 100 mg kg(-1) AST at 3 hr after LPS injection. These results suggest that AST reduces ocular inflammation in eyes with EIU by downregulating proinflammatory factors and by inhibiting the NF-kappaB-dependent signaling pathway.

Effects of blue honeysuckle (Lonicera caerulea L.) extract on lipopolysaccharide-induced inflammation in vitro and in vivo.

The aim of the present study was to investigate the effects of blue honeysuckle extract (BHE), which contains high level of phenolic compounds, on endotoxin-induced uveitis (EIU). Male Lewis rats were randomly divided into 5 groups with 14 rats in each (eight rats for collection of aqueous humor, six rats for histologic examination). EIU was induced by a footpad injection of lipopolysaccharide (LPS). 1, 10, or 100 mg of BHE was injected intravenously immediately after LPS injection. The aqueous humor was collected at 24 h after LPS injection, the number of infiltrating cells, protein concentration, nitric oxide (NO), tumor necrosis factor (TNF)-alpha, and prostaglandin (PG)-E2 levels in the aqueous humor were determined. Some eyes were enucleated for histologic examination and immunohistochemical analysis. Immunohistochemical staining with a monoclonal antibody against activated nuclear factor (NF)-kappaB was performed to evaluate the effect of BHE on NF-kappaB activation. To further clarify the anti-inflammatory effect, RAW264.7 cells (a mouse macrophage cell line) were stimulated with LPS in the presence or absence of BHE and its major phenolics, cyanidin 3-glucoside (C3G), cyanidin 3-rutinoside (C3R), chlorogenic acid (CA). Expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) were analyzed by Western blot method. BHE treatment significantly reduced the inflammatory cell infiltration, the protein concentration, the levels of NO, TNF-alpha and PGE2 in the aqueous humor and improved histologic status of the ocular tissue. The number of activated NF-kappaB-positive cells was lower in the iris-ciliary body treated with BHE at 3 h after LPS injection. BHE significantly suppressed the production of NO, PGE2 and TNF-alpha in the culture medium as well as the expression of iNOS and COX-2 by LPS-stimulated RAW264.7 cells in a dose-dependent fashion. C3G, C3R and CA showed no or weak inhibitory effects on the level of inflammatory mediators and the expression of iNOS and COX-2. These results suggest that BHE attenuates the degree of inflammation in eyes with EIU by inhibiting the NF-kappaB dependent signaling pathway and the subsequent production of proinflammatory mediators.

Tissue regeneration using macrophage migration inhibitory factor-impregnated gelatin microbeads in cutaneous wounds.

Migration inhibitory factor (MIF) responds to tissue damage and regulates inflammatory and immunological processes. To elucidate the function of MIF in cutaneous wound healing, we analyzed MIF knockout (KO) mice. After the excision of wounds from the dorsal skin of MIF KO and wild-type (WT) mice, healing was significantly delayed in MIF KO mice compared to WT mice. Lipopolysaccharide treatment significantly increased [(3)H]thymidine uptake in WT mouse fibroblasts compared to MIF KO mouse fibroblasts. Furthermore, there was a significant reduction in fibroblast and keratinocyte migration observed in MIF KO mice after 1-oleoyl-2-lysophosphatidic acid treatment. We subsequently examined whether MIF-impregnated gelatin slow-release microbeads could accelerate skin wound healing. Injection of more than 1.5 microg/500 microl of MIF-impregnated gelatin microbeads around a wound edge accelerated wound healing compared to a single MIF injection without the use of microbeads. MIF-impregnated gelatin microbeads also accelerated skin wound healing in C57BL/6 mice and diabetic db/db mice. Furthermore, incorporating MIF-impregnated gelatin microbeads into an artificial dermis implanted into MIF KO mice accelerated procollagen production and capillary formation. These findings suggest that MIF is crucial in accelerating cutaneous wound healing and that MIF-impregnated gelatin microbeads represent a promising treatment to facilitate skin wound healing.

Effects of fucoxanthin on lipopolysaccharide-induced inflammation in vitro and in vivo.

The aim of the present study was to investigate the efficacy of fucoxanthin on endotoxin-induced uveitis (EIU) in rats. The effects of fucoxanthin on endotoxin-induced leucocyte and protein infiltration, nitric oxide (NO), prostaglandin (PG)-E2 and tumour necrosis factor (TNF)-alpha concentrations in rat aqueous humour, as well as on the cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) protein expression in a mouse macrophage cell line (RAW 264.7 cells) were studied. EIU was induced in male Lewis rats by a footpad injection of lipopolysaccharide (LPS). Immediately after the LPS injection, either 0.1, 1 or 10mgkg(-1) of fucoxanthin was injected intravenously. The aqueous humour was collected 24hr later from both eyes, and both the number of cells infiltrating into the aqueous humour and the aqueous humour protein concentration were measured. The levels of PGE2, NO and TNF-alpha were determined by enzyme-linked immunosorbent assay. The RAW 264.7 cells were pretreated with various concentrations of fucoxanthin for 24hr and subsequently incubated with LPS for 24hr. COX-2 and iNOS protein expression was analysed by the Western blotting method. Levels of PGE2, NO and TNF-alpha production were determined. Fucoxanthin suppressed the development of EIU in a dose-dependent fashion. Treatment with fucoxanthin resulted in a reduction in PGE2, NO and TNF-alpha concentrations in the aqueous humour. The expression of COX and iNOS protein in the fucoxanthin treated RAW264.7 cells decreased significantly compared to that the LPS group. It also significantly reduced the concentration of PGE2, NO and TNF-alpha production in the medium of cells. The present result indicate fucoxanthin suppresses the inflammation of EIU by blocking the iNOS and COX-2 protein expression and its anti-inflammatory effect on eye is comparable with the effect of predinisolone used in similar doses.

Anti-inflammatory effects of aronia extract on rat endotoxin-induced uveitis.

PURPOSE: Aronia crude extract (ACE) with high levels of polyphenol compounds has been reported to have antioxidative effects in vitro and in vivo. In this study, attention was focused on the antioxidant effect of ACE. The purpose of the present study was to investigate the effect of ACE on endotoxin-induced uveitis (EIU) in rats. In addition, the endotoxin-induced expression of the inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 proteins was investigated in a mouse macrophage cell line (RAW 264.7) treated with ACE in vitro, to clarify the anti-inflammatory effect. METHODS: EIU was induced in male Lewis rats by a footpad injection of lipopolysaccharide (LPS). Immediately after the LPS inoculation, 1, 10, or 100 mg ACE or 10 mg prednisolone was injected intravenously. After 24 hours, the aqueous humor was collected from both eyes, and the number of infiltrating cells, protein concentration, nitric oxide (NO), prostaglandin (PG)-E2, and TNF-alpha levels in the aqueous humor were determined. RAW 264.7 cells treated with various concentrations of ACE were incubated with 10 mug/mL LPS for 24 hours. Levels of NO, PGE2, and TNF-alpha were determined by an enzyme-linked immunosorbent assay. The expression of iNOS and COX-2 proteins was analyzed by Western blot analysis. RESULTS: The number of inflammatory cells, the protein concentrations, and the levels of NO, PGE2, and TNF-alpha in the aqueous humor in the groups treated with ACE were significantly decreased in a dose-dependent manner. In addition, the anti-inflammatory effect of 100 mg ACE was as strong as that of 10 mg prednisolone. The anti-inflammatory action of ACE was stronger than that of either quercetin or anthocyanin administered alone. ACE also suppressed LPS-induced iNOS and COX-2 protein expressions in RAW 264.7 cells in vitro in a dose-dependent manner. CONCLUSIONS: The results suggest that ACE has a dose-dependent anti-ocular inflammatory effect that is due to the direct blocking of the expression of the iNOS and COX-2 enzymes and leads to the suppression of the production of NO, PGE2, and TNF-alpha.