Allergic rhinitis induced by intranasal sensitization and challenge with trimellitic anhydride but not with dinitrochlorobenzene or oxazolone in A/J mice.

Allergic airway diseases induced by low molecular weight (LMW) chemicals, including trimellitic anhydride (TMA), are characterized by airway mucus hypersecretion and an infiltration of eosinophils and lymphocytes. Many experimental models have linked LMW chemical-induced allergic airway disease to Th2 cytokines. Most murine models, however, use dermal exposure to sensitize mice. The present study was designed to test the hypothesis that intranasal sensitization and challenge with the known chemical respiratory allergen TMA, but not the nonrespiratory sensitizers dinitrochlorobenzene (DNCB) and oxazolone (OXA), will induce characteristic features of LMW chemical-induced allergic airway disease in the nasal and pulmonary airways. A/J mice were intranasally sensitized and challenged with TMA, DNCB, or OXA. Only mice that were intranasally sensitized and challenged with TMA had a marked allergic rhinitis with an influx of eosinophils, lymphocytes, and plasma cells, increased intraepithelial mucusubstances, and a regenerative hyperplasia. Cytokine mRNA levels in the nasal airway of TMA treated mice also revealed an increase in the mRNA levels of the Th2 cytokines IL-4, IL-5, and IL-13, but no change in the level of the Th1 cytokine IFN-gamma. No lesions were found in the nasal airways of mice exposed to DNCB or OXA. TMA increased lung-derived IL-5 mRNA while DNCB and OXA caused no change in lung-derived cytokine mRNA levels. Both TMA and DNCB caused increases in total serum IgE, unlike OXA-exposed mice. However, no adverse alterations were found microscopically in the lungs of mice treated with TMA, DNCB, or OXA. This study is the first to demonstrate that intranasal administration of a known chemical respiratory allergen is an effective method of sensitization resulting in the hallmark features of allergic rhinitis after challenge with a concomitant increase in nasal airway-derived Th2 cytokine mRNA, lung-derived IL-5 mRNA, and total serum IgE. In contrast, DNCB and OXA failed to elicit the pathologic changes in the nasal airways and cytokine changes in the lung. This model may be useful for identifying other chemical respiratory allergens.     

Tripterygium glycosides suppress production of interleukin‐4 by splenocytes in oxazolone‐induced murine colitis

OBJECTIVE: To investigate the in vitro effect of Tripterygium glycosides (TG) on cytokine production by splenocytes in oxazolone (OXZ)‐induced colitis in mice. METHODS: Oxazolone (6 mg in 50% ethanol) was administered to male SJL/J mice intrarectally to induce colitis and the mice were killed 3 days later. Isolated splenocytes were cultured for 24 h in the presence of phorbol myristate acetate and ionomycin. A preparation of Tripterygium glycosides at a concentration of either 0.1 mg/mL or 0.01 mg/mL was added to the culture medium of splenocytes. Production of interferon gamma (IFN‐γ) and interleukin‐4 (IL‐4) in the supernatant were measured by ELISA. RESULTS: Production of IFN‐γ in the normal control group was suppressed by TG at both concentrations (0.01 and 0.1 mg/mL; 1.24 ± 0.13 pg/mL (samples without TG) → 0.97 ± 0.26 pg/mL (0.01 mg/mL TG) → 0.87 ± 0.18 pg/mL (0.1 mg/mL TG); P < 0.02) in a dose dependent manner. In the OXZ‐induced colitis group, the basic level of IFN‐γ was significantly lower than that of the normal control group (1.24 ± 0.13 pg/mL vs 0.65 ± 0.08 pg/mL; P < 0.01); but IL‐4 production was significantly increased in the OXZ‐induced colitis without TG group (7.83 ± 0.69 pg/mL vs 5.65 ± 0.48 pg/mL, P < 0.01). In both groups, TG suppressed IL‐4 production in a dose‐dependent manner (normal control group: 5.65 ± 0.48 pg/mL (samples without TG) → 4.97 ± 0.38 pg/mL (0.01 mg/mL TG) → 3.98 ± 0.32 pg/mL (0.1 mg/mL TG), P < 0.01; OXZ group: 7.83 ± 0.69 pg/mL (samples without TG) → 7.07 ± 0.47 pg/mL (0.01 mg/mL TG) → 6.35 ± 0.48 pg/mL (0.1 mg/mL TG), P < 0.01). CONCLUSION: Oxazalone‐induced IL‐4 overproduction by splenocytes was significantly suppressed by TG in a dose dependent manner and the beneficial effects of TG on ulcerative colitis might be related to the suppression of the Th2 type (e.g. IL‐4) mediated immunological response of splenocytes.     

Control of racemization in peptide chain elongation with an unprotected amino acid

The racemization of the penultimate residue of the tripeptide prepared from Boc-d -Phe-d -Phe and free glycine in an aqueous mixed solvent system was examined. An HPLC method was developed to quantitate the amount of product with inverted stereochemistry, starting material, and other biproducts of the reaction. Depending on coupling conditions, the amount of inversion varied from less than 0.5 to nearly 25%. Using near optimal conditions (20% aqueous dioxane, 0.05 m reactants, 5°) two peptides were successfully synthesized in good yield with an acceptable extent of racemization. After recrystallization these peptides contained 0.1-0.2% diastereomer and were recovered in 70-74% yield. Such a prodedure could be useful for the incorporation of radiolabeled amino acids at the carboxyterminus of a peptide where minimal handling of radiolabeled intermediates is desirable.     

Pathway analysis of gene expression in local lymph nodes draining skin exposed to three different sensitizers

Genomic analysis in the local lymph node assays (LLNAs) is useful for assessing skin sensitization of chemicals and providing insights into mechanisms of sensitization. In this study, we collected 1406 genes from previous microarray findings, validated changes in their expression by RT‐PCR analysis in local lymph nodes draining skin exposed to different sensitizers, and interpreted their biological function through pathway‐based genomic analysis, in which 468 genes were identified as being in the KEGG pathway database. The top‐ranked functions (P < 0.01) identified as being affected by the sensitizers were associated with aspects of cell growth, such as DNA replication, cell cycle regulation and pyrimidine metabolism. All the sensitizers tested (DNCB, OXA and TDI) induced significant up‐regulation of Psme4, which is associated with DNA replication; Tfdp1, which is related to cell cycle regulation; and Dut, which is involved in pyrimidine metabolism. Specific changes were also shown in functional categories related to the immune response, including cytokines and their receptors. Genes identified in these functional categories, such as Ccl21c, Cxcl9, Cxcl10, Ifng and Il12rb1, were found to have functional relevance. These findings may enhance our understanding and assessment of chemical sensitizers, and enable us to distinguish sensitizers from irritants and to classify chemicals as contact sensitizers. Copyright © 2011 John Wiley & Sons, Ltd.     

八味锡类散对小鼠恶唑酮结肠炎的治疗作用及其机制

目的：观察八味锡类散对小鼠恶唑酮结肠炎的治疗作用,并探讨其作用机制。 方法：32只雄性BALB/c小鼠随机分为空白对照组、模型组、氢化可的松灌肠液组和八味锡类散组。除空白对照组外,各组小鼠均以3%恶唑酮（溶于50%乙醇）灌肠诱导结肠炎。灌肠后第2天开始,空白对照组和模型组以0.15 mL 0.9%羧甲基纤维素钠溶液灌肠,八味锡类散组以0.15 mL八味锡类散灌肠（0.2 mg/g）,氢化可的松灌肠液组以0.15 mL氢化可的松灌肠液灌肠（0.02 mg/g）,每日1次,连续给药5 d。每日进行疾病活动指数（disease activity index,DAI）评分,5 d后处死小鼠,进行结肠大体和组织学损伤的评估,免疫组织化学法检测结肠组织中occludin、Toll样受体4（Toll-like receptor 4,TLR4）和核转录因子κB（nuclear factor-κB,NF-κB）的表达情况,酶联免疫吸附测定法检测结肠组织中肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）的含量。 结果：八味锡类散组DAI和结肠大体、组织学损伤计分的改善较模型组显著（P〈0.05）,八味锡类散组和氢化可的松灌肠液组比较,差异无统计学意义（P＞0.05）。八味锡类散组结肠组织中TLR4、NF-κB表达和TNF-α含量较模型组减少（P〈0.05）,occludin表达较模型组增加（P〈0.05）,八味锡类散组和氢化可的松灌肠液组比较,差异无统计学意义（P＞0.05）。 结论：八味锡类散能有效缓解恶唑酮诱导的小鼠结肠炎,疗效与氢化可的松相似。其作用机制可能与上调紧密连接蛋白occludin的表达,增强结肠黏膜屏障功能,下调异常增高的TLR4表达,减少NF-κB的激活,最终下调炎性细胞因子TNF-α的表达并改善结肠黏膜屏障功能有关。     

Gabapentin and pregabalin inhibit the itch-associated response induced by the repeated application of oxazolone in mice

We investigated the effects of gabapentin and pregabalin on the itch-associated response in a mouse model of chronic dermatitis induced by the repeated application of 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (oxazolone). Challenging the mice with oxazolone-induced chronic dermatitis with the oxazolone evoked severe and transient scratching behavior until 1 h after the application of oxazolone. Thereafter, a more mild and continuous scratching behavior was also observed for at least 8 h. Both severe and continuous scratching behaviors were suppressed by systemic injection of gabapentin and pregabalin. This effect of these compounds was correlated with its affinity for the α₂δ subunit of voltage-gated Ca²⁺ channels. Intrathecal injection, but not peripheral treatment, with gabapentin inhibited the scratching behavior in this model. Gabapentin failed to suppress the scratching behavior induced by the intradermal injection of compound 48/80 in normal mice. The expression of the α₂δ-1 subunit in dorsal root ganglion (DRG) from mice following repeated application of oxazolone was significantly higher than that from normal mice. These results suggest that gabapentin and pregabalin show an anti-pruritic activity through α₂δ-subunit binding, and the up-regulation of the α₂δ-1 subunit in DRG may therefore play an important role in its anti-pruritic activity.     

Pharmacological activities of flavonoids (III) structure-activity relationships of flavonoids in immunosuppression

Effects of twenty-one different flavonoids and their related compounds on the phagocytosis of colloidal carbon by macrophages in liver and spleen, humoral immune responses against bacterial α-amylase and cellular immune responses against oxazolone and dinitrofluorobenzene were studiedin vivo andin vitro. It was shown that most of the flavonoids accelerated significantly the phagocytosis, and they suppressed significantly not only humoral and cellular immune responses but also the development of immunological memory after the antigenic stimulation. Especially, malvin was the most active in phagocysis, and disodium cromoglycate and morin were the most active in humoral and cellular immunosuppression, respectively. Daidzein had the most potent inhibitory activity in the development of memory cells. The structure-activity relationships of the flavonoids in immunosuppression became apparant from these results: 1. The presence of C_2–3 double bond and C₄ ketone group in C-ring was important for their immunosuppressive activity. 2. Flavonoids with benzene ring at 2 or 3 position in C-ring showed the almost same activities. 3. The opening of C-ring did not affect their immunosuppressive activity. 4. The glycosylated flavonoids at 3 position in C-ring were less potent than their aglycones. 5. Di- or tri-hydroxylated flavonoids in B-ring were more potent than mono-hydroxylated. 6. Chromanochromanone also had the immunosuppressive activity.     

Effect of the smell of Seirogan, a wood creosote, on dermal and intestinal mucosal immunity and allergic inflammation

Seirogan, a wood creosote, has been used as an antidiarrhetic drug in Asian countries including Japan for many years. This antidiarrhetic has recently been used as a sugar-coated pill because Seirogan has a strong smell. The strong smell of the uncoated form of Seirogan may modulate the defense systems of animals because the sense of smell is important for the detection of toxic metabolites in foods contaminated with pathogens. This study examined the effect of the sugar-coated and uncoated forms of this antidiarrhetic on the immunological response and inflammatory reactions in mice that had been sensitized with either fluorescein isothiocyanate or oxazolone. The sensitization of mice with either FITC or oxazolone markedly increased the plasma levels of tumor necrosis factor-α and mucosal IgA and elicited severe inflammation in the colon by a mechanism that could be suppressed by exposure of animals to the smell of uncoated Seirogan as effectively as the oral administration of the agent. Dermal inflammation in the FITC- and oxazolone-sensitized mice was also suppressed effectively either by the exposure to the smell or oral administration of the agent. Biochemical and histochemical analyses revealed that the elevated levels of plasma tumor necrosis factor-α and mucosal IgA were significantly decreased by exposure to the smell of uncoated Seirogan as well as by oral administration of the agent. Exposure of mice to the smell of Seirogan but not oral administration of the agent selectively increased plasma levels of adrenocorticotropic hormone and cortisol, particularly in the sensitized animals. These observations suggest that exposing the animals to the smell of Seirogan per se activated the hypothalamo-pituitary-adrenal axis and systemically modulated immunological reactions to suppress the allergic reactions.     

性别对两种溃疡性结肠炎模型的影响

目的：分别建立由噁唑酮（oxazolone,OXZ）及2,4,6-三硝基苯磺酸（2,4,6-trinitrobenzene sulfonic acid,TNBS）诱导的小鼠溃疡性结肠炎模型,并探讨性别因素对小鼠模型的影响。方法：30只健康成年昆明种小鼠,雌雄各半,随机分为6组,正常雌性对照组（A组,n=5）,正常雄性对照组（B组,n=5）,OXZ雌性模型组（C组,n=5）,OXZ雄性模型组（D组,n=5）,TNBS雌性模型组（E组,n=5）和TNBS雄性模型组（F组,n=5）。OXZ模型组（n=10）给予皮肤涂抹2.4% OXZ （100%乙醇溶剂）0.2 mL 2 d,5 d后以0.8% OXZ （40%乙醇溶剂） 0.1 mL灌肠;TNBS模型组（n=10）于d 1及d 6给予1.8 mg TNBS（40%乙醇溶剂）灌肠,灌肠之前均进行禁食不禁水24 h处理,正常组不作处理。造模24 h之后记录小鼠精神状态、毛色、进食、大便情况并检测小鼠疾病活动指数（disease activity index,DAI）值。造模后d 2处死,分离结肠,测定小鼠结肠组织大体评分（Colon Macroscopic Damage Index,CMDI）值以及结肠湿重指数（Colon Index,CI）,并取病变部位检测HPS（histopathological score,HPS）指标以及白细胞介素-4（interleukin 4,IL-4）、肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）的水平。结果：两种溃疡性结肠炎小鼠模型诱导成功,OXZ模型组IL-4及TNF-α 水平与正常组均有显著性差异,但TNBS模型组差异较小。除OXZ雌性组结肠指数与正常组没有显著差异外,模型组小鼠各项指标与正常组均有显著性差异。结论：性别对于小鼠溃疡性结肠炎模型的诱导有着重要的影响。