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Sirtuins are enzymes that catalyze NAD+ dependent protein deacetylation. The natural polyphenolic compound resveratrol received renewed interest when recent findings implicated resveratrol as a potent SIRT1 activator capable of mimicking the effects of calorie restriction. However, resveratrol directly interacts with fluorophore-containing peptide substrates. It was demonstrated that the SIRT1 activation of resveratrol is affected by the amino acid composition of the substrate. Resveratrol did increase the enzyme activity in cases in which hydrophobic amino acids are at the +1 position to the acetylated lysine in the substrate. Alkylresorcinols (ARs) are compounds that belong to the family of phenolic lipids, and they are found in numerous biological species. Here we show that the natural activators ARs increased the Vmax of recombinant SIRT1 for NAD+ and peptide substrate, and that ARs decreased acetylated histone in human monocyte cells by stimulating SIRT1-dependent deacetylation of substrates. ARs also extended the lifespan of Drosophila melanogaster, which was shown to be dependent on functional Sir2. Our results demonstrated that ARs are natural catalytic activators for sirtuin.

The present study was performed to investigate the immune-modulating activities of extracts from green soybean (Glycine max) in a 2,4-toluene diisocyanate (TDI)-inducing guinea pig rhinitis model and a human trial study for allergic rhinitis. Hot water extracts of green soybean were chosen for animal experimentation on the basis of their ability to regulate the production of B cell-activating factor of the TNF family and a proliferation-inducing ligand in mouse spleen cells. Green soybean extracts significantly decreased the levels of ovalubumin (OVA)-specific IgE in mice and significantly suppressed the TDI-induced nasal mucosa secretion. An open-label human pilot study was performed on 16 subjects, using Japanese cedar pollinosis. The symptom scores for Japanese cedar pollinosis were better in the long-term green soybean extracts intake group than in the withdrawal short-term intake group. Green soybean extracts had great potential as an orally active immune modulator for the treatment of various allergic diseases.

Inflammation is an immune response against both internal and external antigens in organisms, particularly in mammals, and includes both uncontrolled chronic and low-grade inflammations. Uncontrolled chronic inflammation often leads to severe diseases such as vascular disease, arthritis, cancer, diabete, allergy, and autoimmunity. On the other hand, low-grade inflammation is recognized as a relationship between obesity and risk of metabolic syndrome. Elevated production of pro-inflammatory cytokines and mediators is commonly observed in patients with uncontrolled or low-grade inflammation-associated diseases. Plants have been generated phytochemicals to overcome inflammations and infections through evolution. Phytochemicals belong to alkaloids, polyphenols, flavonoids, coumarins, and terpenoids. The consumption of soybeans plays a role in immune modulation through their components such as isoflavones, saponins, and anthocyanins. Recently, it was reported that the application of phytochemicals into patients with inflammatory diseases improves their symptoms. Therefore, it is important to identify novel phytochemicals with immunomodulatory activities. This review introduces and discusses recent advances and patents regarding soybean or processed soy food compounds which exhibit immunomodulatory activity in immune diseases, particularly allergy, by mediating the suppression of inflammatory pathways.

To elucidate the bioavailability of luteolin and its glycosides in Chrysanthemum morifolium flowers, the absorption and metabolism of luteolin from them was investigated in rats and Caco-2 cells using HPLC and LC-MS. After oral administration of C. morifolium extract (1.7 g/kg body weight (bw), equivalent to 22.8 and 58.3 μmol/kg bw of luteolin and luteolin-7-O-glucoside, respectively) to rats, luteolin and its glycosides were quickly absorbed and luteolin, luteolin monoglucoside, and luteolin monoglucuronide were detected in the plasma. Their levels were highest at 1 h after administration (0.76 ± 0.27 μM). These compounds were also detected in media on the basolateral side from Caco-2 cells treated with the C. morifolium extract. These results suggest that luteolin and luteolin monoglucoside are rapidly absorbed after administration of C. morifolium flower extract and that luteolin, luteolin monoglucoside, and luteolin monoglucuronide may circulate in humans.

Immune responses to parasitic helminth are usually characterized by quite mysterious phenomena: dominance of Th2-like immunity and antigen-nonspecific IgE secretion. We previously purified a factor from Dirofilaria immitis that induces antigen-nonspecific IgE in rats and named it DiAg. In the presence of IL-4, DiAg induces mouse B cells to secrete IgE, which is antigen-nonspecific polyclonal antibody. We investigated the biochemical characteristics of DiAg as a factor of inducing IgE in this study. Recombinant DiAg (rDiAg) with interleukin (IL)-4 induced IgE synthesis in highly purified human normal B cells in vitro cell culture systems. The addition of recombinant human soluble CD40 IgG fusion protein (rsCD40-Ig) inhibited induction of IgE synthesis by rDiAg with IL-4. Monocyte cells were stimulated with rDiAg and recombinant human soluble CD40L (rsCD40L); IL-12 and TNF-alpha were induced. The addition of rsCD40-Ig to THP-1 cells activated with rDiAg and rsCD40L inhibited the production of IL-12. rDiAg bound to the monocyte cell membrane fraction and recombinant human soluble CD40; this binding of rDiAg was competitively inhibited by addition of rsCD40L. Moreover, in CD40-deficient mice, IgE production and MLN-B cell proliferation by rDiAg were completely absent. Based on these results, we concluded that DiAg is an agonist of CD40.

Parasitic helminth infections are characterized by eosinophilia and markedly elevated levels of circulating antigen-nonspecific immunoglobulin E (IgE), responses from which concern helminth protection. We previously purified a factor from Dirofilaria immitis that induces antigen-nonspecific IgE in mice and rats. Recombinant DiAg (rDiAg) has various biological activities. It is also known that parasitic helminth infection generates tremendous Th2 responses. The nonobese diabetic (NOD) mouse spontaneously develops Th1 cell-dependent autoimmune diabetes. Here we investigated the effects of rDiAg on the initiation and progression of this disease. rDiAg treatment of 6-week-old NOD females (the age at which insulitis typically begins) completely prevented insulitis and diabetes. Thus, rDiAg impaired the islet Ag-specific Th1 cell response in vivo, and the prevention of diabetes by rDiAg was associated with switching of the response from a Th1 to a Th2 profile. Since rDiAg clearly prevented insulitis by inhibiting the development and further accumulation of pathogenic Th1 cells to islets of Langerhans, we conclude that DiAg is a native Th2 inducer in filarial helminth and that Th1 responses are required for early events in the development of spontaneous autoimmune diabetes. In conclusion, the presence of parasitic helminth infections may play an important role as an immunomodulator in some autoimmune diseases or allergies.

Indoleamine 2,3-dioxygenase (IDO) 1, that catalyzes the first and rate-limiting step in the degradation of L-tryptophan, has an important immunomodulatory function. The activity of IDO1 increases in various inflammatory diseases, including tumors, autoimmune diseases, and different kinds of inflammation. We evaluated the suppressive effect of plant extracts or phytochemicals on IDO1 induction and activity; sixteen kinds of plants extracts and fourteen kinds of phytochemicals were examined. As a result, the methanol extracts of Myoga flower buds, which are traditional Japanese foods, and labdane-type diterpene galanal derived from Myoga flowers significantly suppressed IDO1 activity. The Lineweaver-Burk plot analysis indicated that galanal is a competitive inhibitor. Galanal attenuated L-kynurenine formation with an IC50 value of 7.7 µM in the assay system using recombinant human IDO1, and an IC50 value of 45 nM in the cell-based assay. Further, mechanistic analysis revealed that galanal interfered with the transcriptional function of the nuclear factor-κB and the interferon-γ signaling pathway. These effects of galanal are important for immune response. Because the inhibitory effect of galanal on IDO1 activity was stronger than that of 1-methyl tryptophan, a tryptophan analog, galanal may have great potential as the novel drug for various immune-related diseases.

We conducted a preliminary investigation of the effects of visible light irradiation on plant extracts and we observed a strong suppressive effect on interleukin (IL) 2 expression with the inhibition of c-Jun amino-terminal kinase (JNK) phosphorylation in Jurkat cells by visible light irradiation to ethanol extract from green soybeans (LIEGS). This effect was produced only by extracts from green soybeans (Glycine max) and not other-color soybeans. LIEGS suppressed the lipopolysaccharide-induced IL-6, IL-12 and TNF-α expression levels in human monocyte THP-1 cells in a concentration-dependent manner. LIEGS was applied for 8 weeks to NC/Nga mice. LIEGS suppressed the development of atopic dermatitis (AD)-like skin lesions and reduced the dermatitis scores of the mice. The light irradiation changed the various types of small-molecule compounds in extracts. Visible light irradiation to daidzein with chlorophyll b induced a novel oxidative product of daidzein. This product suppressed IL-2 expression in Jurkat cells.

Green tea has been shown to have many beneficial health effects. We have previously reported that dietary (-)-epigallocatechin-3-O-gallate (EGCG), the major polyphenol in green tea, reduced gene expressions of gluconeogenic enzymes, glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK), in the normal mouse liver. In the present study, we examined the effects of intragastrical administration of EGCG on the expression of gluconeogenesis-related genes in the mouse intestine. The results of experiments with the semi-quantitative reverse transcription-polymerase chain reaction indicated that EGCG at 0.6 mg/head caused a reduced expression of G6Pase, PEPCK, hepatocyte nuclear factor 1α (HNF1α), and HNF4α. Experiments using the quantitative real-time polymerase chain reaction confirmed these effects. We then examined the effects of EGCG using human colon carcinoma Caco-2 cells stimulated with dexamethasone and dibutyryl cAMP. The results were generally consistent with those from the experiments in vivo. The present findings suggest EGCG to contribute to the beneficial effects of green tea on diabetes, obesity, and cancer by modulating gene expression in the intestine.

The mammalian fetuses are semi-allograft for mothers. Therefore the failure of immunological tolerance often causes pregnancy loss. Recently, the effects of helminthes therapy for immune mediated diseases have been reported. In the present study we employed the murine model to examine the therapeutic potential of the recombinant antigen from a nematoda parasite, Dirofilaria immitis for immune mediated pregnancy loss. Recombinant D. immitis polyproteins (rDiAg) had been cloned and selected by us for the strongest immuno-regulatory activities in parasite antigens. Female CBA/J mice were injected with sterilized rDiAg or PBS solution using micro-osmotic pumps before mating. Pregnant CBA/J mice were sacrificed on day 13.5 for scoring the number of resorbed and viable fetuses for histological and immunological analysis. The serum cytokine concentrations were measured using suspension array system. The resorption rate of mock-treated mice was 42.9% (resorbed fetus 12/total fetus 28). The resorption rate was decreased to 11.1% (resorbed fetus 3/total fetus 27) with rDiAg treatments. The IL-4, IL-23 and TNF-α concentrations in serum were significantly lower in rDiAg-treated mice than mock-treated mice. The serum IL-17 level was also reduced in rDiAg-treated mice but the difference was not significant. The rDiAg treatment reduced the resorption rates of CBA/J×DBA/2J mouse model, which mimic human pregnancy failures with allo-immune backgrounds. Our observations suggest as the first time of therapeutic potentials of the rDiAg for pregnancy loss.

BACKGROUND: Lectins are proteins that bind specifically to the carbohydrate moiety of glyco-conjugates. Japanese mistletoe lectin given intragastrically affected cytokine gene expression in the mouse intestine. This study examines the actions of Lens culinaris agglutinin (LCA) on the gene expression of gluconeogenic enzymes in the intestine. RESULTS: The results of quantitative real-time reverse transcription–polymerase chain reaction indicated that LCA caused an up-regulation of the gene expression of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK). This change was correlated with an increase in the expression of two transcription factors, HNF1α and HNF4α. Experiments using human colonic cancer Caco-2 cells demonstrated that LCA up-regulated the gene expression of G6Pase and PEPCK whereas insulin had the opposite effect. In addition, the observed up-regulation of HNF4α gene expression in the duodenum raises the possibility that the lectin promotes the colorectal cancer. CONCLUSION: Lentil beans should be cooked well to avoid unfavourable effects of LCA. Copyright © 2011 Society of Chemical Industry

We have previously reported that in peripheral blood mononuclear cells (PBMC), the augmented expression of the beta isoform of the human glucocorticoid receptor (hGRbeta), as a putative dominant negative regulator of glucocorticoid action, is associated with glucocorticoid (GC) unresponsiveness of UC patients. In this study, we quantified the levels and serial changes of hGR transcripts in PBMC of IBD patients by a real-time fluorescence monitoring of PCR. As results, relative hGRbeta mRNA expression was significantly higher in the active stage of UC than in inactive periods of UC or CD patients. Longitudinal analysis revealed that hGRbeta mRNA expression in UC was increased after the relapse of inflammation, suggesting that the overproduction of cytokines during inflammation may be responsible. In in vitro culture experiments of human lymphoid cell (CEM) and human PBMC, IL-7, and IL-18 increased hGRbeta mRNA expression in these cells but GC itself did not. Through these analyses, it is indicated that the inflammatory cytokines altered the splicing condition of the primary transcript of hGR gene in IBD patients.

Background & Aims: Recently, the glucocorticoid receptor β (hGRβ) was suggested to play a role as a dominant negative regulator for determining glucocorticoid response. The aim of this study was to clarify whether reverse-transcription polymerase chain reaction (RT-PCR) analysis of hGRβ messenger RNA (mRNA) can predict the response to glucocorticoids in patients with ulcerative colitis. Methods: Total RNA obtained from peripheral blood mononuclear cells (PBMCs) of 23 patients with ulcerative colitis and 20 healthy volunteers was reverse transcribed; the resulting complementary DNA was amplified using specific primers for hGRα and hGRβ. Protein expression of hGR in PBMCs was confirmed by immunoprecipitation–Western blot analysis. Results: The expression of hGRα mRNA (477 base pairs) was detected in all patients and all healthy volunteers. In contrast, a hGRβ mRNA (366 base pairs) was detected in 1 (9.1%) of 11 glucocorticoid-sensitive patients, 10 (83.3%) of 12 glucocorticoid-resistant patients, and 2 (10%) of 20 healthy volunteers. The positive rate of hGRβ mRNA in the resistant group was significantly higher than that in the sensitive group ( P = 0.0019). The hGRβ band could be detected by immunoprecipitation–Western blotting in hGRβ mRNA–positive patients. Conclusions: The results show that the expression of hGRβ mRNA in PBMCs examined by RT-PCR may serve as a novel predictor of glucocorticoid response in ulcerative colitis. GASTROENTEROLOGY 2000;118:859-866