侧柏总黄酮的抗炎作用及机制

目的　研究侧柏总黄酮的抗炎作用及其作用机制。方法　以二甲苯致炎小鼠耳片肿胀及角叉菜胶诱发大鼠足爪肿胀模型分别探讨侧柏总黄酮对小鼠耳片肿胀及大鼠足爪肿胀的抑制作用。高效液相色谱法测定角叉菜胶致炎的大鼠中性粒细胞花生四烯酸代谢产物白三烯B4(LTB4)及 5 羟廿碳四烯酸 (5 HETE) ,荧光法测定 β 葡糖苷酸酶释放。结果　黄酮为 12 5,2 5 0 ,50 0mg·kg- 1,氢化可的松为3 5 0mg·kg- 1的剂量对二甲苯诱导的小鼠耳肿胀抑制率分别为 2 5 2 % ,3 5 1% ,47 7%和 66 5%。 2 5～ 50mg·kg- 1剂量能抑制大鼠足爪肿胀 ,2 5mg·kg- 1的总黄酮作用强于 2mg·kg- 1的地塞米松。浓度为 5 0～ 12 5 0mg·L- 1总黄酮对大白鼠中性粒细胞花生四烯酸代谢产物 5 HETE及LTB4生物合成的抑制率分别为 3 0 5%～ 87 3 %和 2 7 8%～84 3 %。 5 0 ,2 5 0 ,45 0mg·L- 1的总黄酮对A2 3 187诱导的 β 葡糖苷酸酶释放抑制率分别为 13 4% ,2 6 2 %和3 2 2 %。结论　侧柏总黄酮具有较强的抗炎作用 ,其对中性粒细胞花生四烯酸代谢产物LTB4 、5 HETE生物合成及 β 葡糖苷酸酶释放的抑制作用可能与其抗炎作用有关。     

广西甜茶提取物的抗炎作用研究

目的:研究广西甜茶提取物的抗炎作用。方法:观察广西甜茶提取物对巴豆油诱发小鼠急性耳肿胀和对血管通透性的抑制作用及角叉菜胶引起小鼠足跖肿胀的影响。利用Griess化学法检测小鼠腹腔巨噬细胞NO含量,RT-PCR检测一氧化氮合酶(iNOS)的表达。结果:广西甜茶提取物能显著抑制由巴豆油诱发的小鼠耳肿胀及血管通透性的增高,并对角叉菜胶引起的足跖肿胀也显示一定的抑制作用。广西甜茶提取物可抑制巨噬细胞NO生成和iNOSmRNA表达。结论:广西甜茶具有抗炎作用,其作用机制可能与抑制巨噬细胞NO生成和iNOSmRNA表达有关。     

红曲抗炎作用的实验研究

目的：研究红曲的抗炎作用。方法：急性抗炎模型采用巴豆油致小鼠耳肿胀模型和角叉菜胶致大鼠足肿胀模型，慢性抗炎模型采用棉球植入小鼠腹腔致肉芽肿模型。以布洛芬作阳性对照，并设洛伐他汀高、低剂量组。比较红曲与洛伐他汀的抗炎作用。结果：红曲对巴豆油致小鼠耳肿胀、角叉菜胶致大鼠足肿胀和棉球致小鼠腹腔肉芽肿均有显著的抑制作用，与洛伐他汀的抗炎作用相近。结论：红曲具有显著的抗炎作用。     

引流熊胆的抗炎免疫抑制作用

引流熊胆Ｉｇ能明显地抑制二甲苯、巴豆油所致小鼠耳壳肿胀．抑制小鼠腹腔毛细血管通透性．抑制角叉菜胶所致大鼠足肿胀及Ｐｒｅｕｎｄ完全性剂所致大鼠关节炎；对肾上腺、胸腺、脾脏及淋巴结重量无明显影响。抑制小鼠棉球肉芽肿增生，抑制小鼠单核巨噬细胞吞噬功能。表明引流熊胆具有抑制急、慢性及免疫性炎症作用和免疫抑制作用。引流熊胆还抑制大鼠热烫足肿胀．减少大鼠炎症部位ＰＧＥ２含量。提示引流熊胆的抗炎作用与抑制炎症部位的激肽类和ＰＧＥ２的合成与释放有关。     

土牛膝在急性炎症动物模型中的抗炎作用

目的 研究土牛膝水提取物的抗炎效应.方法 采用鸡蛋清诱导大鼠足跖肿胀、二甲苯致小鼠耳廓肿胀、1％冰醋酸致小鼠腹腔渗出模型和热板法等4种急性炎症模型,观察土牛膝提取物的抗炎作用.结果 土牛膝提取物对二甲苯致小鼠耳廓肿胀、鸡蛋清引起的大鼠足跖肿胀以及急性炎症导致的腹腔毛细血管通透性均有不同程度的抑制作用,其中,土牛膝提取物低、高剂量组与模型组比较有显著性差异(P＜0.05或P＜0.01).结论 土牛膝水提取物具有较强的抗炎效应.     

淫羊藿总黄酮的抗炎作用

淫羊藿总黄酮对巴豆油所致小鼠耳肿胀、醋酸所致小鼠腹腔毛细血管通透性增加、角叉菜胶所致大鼠足肿胀及巴豆油所致肉芽组织增生具有显著抑制作用．对佐剂关节炎大鼠的原发性足肿胀和继发性足肿胀均有显著抑制作用．初步机理研究表明：淫羊藿总黄酮能显著降低炎症渗出物中前列腺素Ｅ和丙二醛的含量,提高小鼠红细胞过氧化氢酶的活力．对去肾上腺小鼠耳肿胀仍然有抑制作用,对大鼠肾上腺重量和肾上腺内维生素Ｃ含量无明显影响     

清喉口含片抗炎作用实验研究

目的：研究清喉口含片的抗炎作用。方法通过考察高、中、低剂量清喉口含片对巴豆油所致小鼠耳廓肿胀度的抑制作用,组织胺所致小鼠腹腔毛细血管通透性改变的影响及角叉菜胶所致大鼠足跖肿胀度的抑制作用,研究清喉口含片对不同炎症模型的抗炎作用。结果与空白对照组及阳性药对照组相比,清喉口含片高、中、低剂量均能够降低小鼠毛细血管通透性,抑制角叉菜胶致大鼠足跖肿胀及巴豆油致小鼠耳廓肿胀。结论清喉口含片具有较明显的抗炎作用。     

百蕊草野生苗与组培苗抑菌抗炎实验比较的研究

通过观察百蕊草野生苗和组培苗提取物的体外抑菌和对二甲苯致小鼠耳肿胀的急性炎症、大鼠棉球肉牙肿的慢性炎症和蛋清所诱发的大鼠足肿胀炎症的影响。研究百蕊草野生苗和组培苗的抗炎抑菌作用。结果表明：百蕊草野生苗与组培苗提取物在体外对大肠杆菌、金葡萄球菌、苏云金杆菌均有一定的抑制作用；两组百蕊草提取物对几种炎症均有明显的抑制作用。其抗炎抑菌作用具有等效性。     

吲哚美辛锌的抗炎,镇痛及胃刺激性研究

动物实验表明，吲哚美辛锌对大鼠由角叉菜胶诱发的足跖肿胀急性炎症、大鼠棉球肉芽肿慢性炎症、大鼠佐剂关节炎及腹腔注射０．７％醋酸诱发的小鼠急性渗出性炎症，都有明显的抑制作用。吲哚美辛锌在小鼠热板试验中有明显的镇痛作用，其抗炎、镇痛作用与吲哚美辛均无显著差异。胃刺激性实验表明，吲哚美辛锌对胃刺激性比吲哚美辛小。     

磷酸二酯酶选择性抑制剂Piclamilast的抗炎作用

目的:观察磷酸二酯酶(PDE4)选择性抑制剂Piclamilast对致炎小鼠炎症的影响,评价其作用强度.方法:采用角叉菜胶诱导小鼠腹腔中性粒细胞聚集以及小鼠足趾肿胀模型,观察腹腔灌洗液白细胞总数,中性粒细胞数量,以及足趾肿胀程度来评价药物的抗炎作用.结果:腹腔炎症模型组和足趾肿胀模型组与正常小鼠比较,白细胞总数和中性粒细胞数量以及足趾重量增值明显增高.Piclamilast 1,3,10 mg·kg-1灌胃给药均呈剂量依赖性抑制小鼠的炎症反应.结论:新型PDE4选择性抑制剂Piclamilast对炎症反应有抑制和治疗作用,具有进一步开发的价值.     

Tumour necrosis factor-alpha and leukotriene B(4) mediate the neutrophil migration in immune inflammation.

1. We investigated the mediators responsible for neutrophil migration induced by ovalbumin (OVA) in immunized mice and the mechanisms involved in their release. 2. OVA administration promoted dose- and time-dependent neutrophil migration in immunized, but not in non-immunized mice, which was mediated by leukotriene B(4) (LTB(4)) and tumour necrosis factor (TNF)alpha, since it was inhibited by LTB(4) synthesis inhibitor (MK 886) or by LTB(4) receptor antagonist (CP 105,696), by dexamethasone and by antiserum to TNFalpha (82, 85, 63 and 87%, respectively). Confirming TNFalpha involvement, OVA challenge in immunized p55 TNF receptor deficient mice (p55(-/-)) did not promote neutrophil migration (control: 2.90 +/- 0.68; p55(-/-): 0.92+/-0.23 x 10(6) neutrophils cavity(-1)). 3. OVA-stimulated peritoneal cells from immunized mice released a neutrophil chemotactic factor which mimicked, in naive mice, neutrophil migration induced by OVA. 4. Supernatant chemotactic activity is due to TNFalpha and LTB(4), since its release was inhibited by MK 886 (93%) and dexamethasone (90%), and significant amounts of these mediators were detected. 5. TNFalpha and LTB(4) released by OVA challenge seem to act through a sequential mechanism, since MK 886 inhibited (88%) neutrophil migration induced by TNFalpha. Moreover, peritoneal cells stimulated with TNFalpha released LTB(4). 6. CD(4)(+) T cells are responsible for TNFalpha release, because the depletion of this subset prevented the release of TNFalpha (control: 400 +/- 25; immunized: 670 +/- 40; CD(4)(+) depleted: 435 +/- 18 pg ml(-1)). 7. In conclusion, neutrophil migration induced by OVA depends on TNFalpha released by CD(4)(+) cells, which acts through an LTB(4)-dependent mechanism.     

Effect of endothelins on human neutrophil activation by immune complexes

Neutrophils are important effector cells of tissue injury in several pathological conditions, among them, immune complexes (IC)-induced inflammation and tissue injury. There is evidence that endothelins modulate IC-induced tissue injury in experimental models in vivo. In the present study we investigated the effect of endothelins on neutrophil activation by IC in vitro. To this purpose, pre-formed insoluble immune complexes were used to stimulate human neutrophils and production of leukotriene B(4) (LTB(4)) and hydrogen peroxyde (H(2)O(2)) were measured as indicative of phospholipase A(2) and oxidative burst activation and myeloperoxidase (MPO) release as indicative of cell degranulation. The effect of endothelins (ETs) in these events induced by IC was then examined. We found that IC stimulated all three events in human neutrophils. Addition of ET-1 but not ET-2 or ET-3 to the IC-stimulated neutrophils potentiated LTB(4) but not H(2)O(2) production. The endothelins added to resting neutrophils did not induce LTB(4) production but they were effective to stimulate H(2)O(2) production. The increased MPO activity induced by IC was not affected by endothelins nor did they stimulate the release of this enzyme in resting cells. These results show that endothelins are able to activate some neutrophil functions and to upregulate the IC-induced production of the pro-inflammatory molecule LTB(4). These data indicate that products of endothelial cells, such as endothelins, can be involved in the potentiation of neutrophil-dependent tissue injury.     

Characterization and pharmacological modulation of antigen-induced peritonitis in actively sensitized mice.

1. The intraperitoneal (i.p.) injection of 1 or 10 micrograms ovalbumin to sensitized Balb/c mice led to an acute histamine release, firstly evidenced 1 min after the challenge and returning to basal levels 30 min thereafter. This phenomenon was unaccompanied by protein extravasation. A dose-dependent increase in the amounts of immunoreactive leukotriene (LT) C4 and LTB4 was observed in the peritoneal washing from sensitized mice 6 h after 1 or 10 micrograms ovalbumin administration. In separate experiments, the i.p. administration of 1 mg activated zymosan to non-immunized mice was followed by a marked protein extravasation, and by immunoreactive LTC4 and LTB4, but not histamine, release in mouse peritoneum 1 h after its injection. 2. Mediator release in the mice peritoneal cavity was concomitant with a transient neutrophil infiltration, which peaked at 6 h and returned to basal levels therefore. An intense eosinophil accumulation starting at 24 h, peaking at 48 h and returning to basal values at 164 h, was also observed. 3. Ovalbumin (1 microgram)-induced eosinophilia, observed at 24 h, was reduced by the pretreatment of the animals with dexamethasone (1 mg kg-1, s.c.) or with the 5-lipoxygenase inhibitor, BWA4C (20 mg kg-1, s.c.), whereas indomethacin (2 mg kg-1, s.c.) and the platelet-activating factor (PAF)-antagonist SR 27417 (10 mg kg-1, s.c.) were ineffective. These results indicate that metabolites of arachidonic acid of lipoxygenase pathway, but not cyclo-oxygenase derivatives or PAF, mediate antigen-induced eosinophil accumulation in the mouse peritoneum.(ABSTRACT TRUNCATED AT 250 WORDS)     

Inhibition of LTB4 binding to human neutrophils by nordihydroguaiaretic acid

Nordihydroguaiaretic acid (NDGA) was investigated for its ability to interact with leukotriene B4 receptors on human polymorphonuclear leukocytes (hPMNs). 3H-LTB4 binding to specific receptors was reduced in a dose-dependent manner with maximal reduction at 100 microM NDGA and an IC50 of about 50 microM. Binding of another inflammatory stimulus. N-formyl-norleucyl-leucyl-phenylalanine (FNLP) was not affected by similar treatment. Chemotaxis and enzyme release stimulated by LTB4 and oligopeptide were inhibited by NDGA. In addition, LTB4-triggered inflammation in vivo in mice was inhibited by systemic administration of NDGA. These data suggest that LTB4 receptor antagonism may contribute to inhibition of inflammation by NDGA.     

Role of neutrophil elastase in LTB4-induced neutrophil transmigration in vivo assessed with a specific inhibitor and neutrophil elastase deficient mice

BACKGROUND AND PURPOSE: The serine protease neutrophil elastase (NE) appears to regulate inflammatory responses at multiple levels but its role in leukocyte transmigration in vivo remains unclear. The present study aimed to address this issue by using both an NE inhibitor (ONO-5046) and NE deficient (NE(-/-)) mice. EXPERIMENTAL APPROACH: A number of inflammatory mediators (LTB(4), KC and PAF) were investigated in vitro for their ability to stimulate the release and the surface expression of NE by neutrophils. In addition, the role of NE in leukocyte migration elicited by topical LTB(4) was investigated in vivo in mouse cremasteric venules as observed by intravital microscopy. KEY RESULTS: Amongst the mediators tested in vitro, LTB(4) was found to be a highly potent and efficacious inducer of NE cell surface expression on murine neutrophils. Furthermore, in wild-type mice (WT), LTB(4)-induced leukocyte transmigration was reduced by intravenous ONO-5046 (66% inhibition), an effect that appeared to occur at the level of the perivascular basement membrane. Interestingly, LTB(4)-induced responses were normal in NE(-/-) mice and, while ONO-5046 had no inhibitory effect in these animals, the broad-spectrum serine protease inhibitor aprotinin suppressed leukocyte transmigration in both WT and NE(-/-) mice. CONCLUSIONS AND IMPLICATIONS: The findings demonstrate the potent ability of LTB(4) to induce cell-surface expression of NE and provide evidence for the involvement of NE in LTB(4)-induced neutrophil transmigration in vivo. The results also suggest the existence of compensatory mechanisms in NE(-/-) mice, highlighting the added value of investigating pharmacological blockers in parallel with genetic deletion.     

Effects of auranofin on leukotriene production and leukotriene stimulated neutrophil function

Arachidonic acid is metabolized in neutrophils by lipoxygenase to leukotrienes, which are suggested to play a central role in inflammation. The antirheumatic drug auranofin (4 micrograms/ml) was found not to inhibit neutrophil production of the lipoxygenase products 5-HETE-, 15-HETE and LTB4, in vitro when stimulated with the calcium ionophore A23187. Auranofin, however, modulated neutrophil aggregation, enzyme release and chemotaxis induced by LTB4. The results suggest that auranofin may exert some of its antirheumatic effects through affecting neutrophil responses to leukotrienes.     

A mechanistic approach to the in vivo anti-inflammatory activity of sesquiterpenoid compounds isolated from Inula viscosa.

The present study was designed to examine the anti-inflammatory activity of the sesquiterpenoids ilicic acid and inuviscolide, isolated from Inula viscosa, on cell degranulation, leukotriene biosynthesis, neurogenic drive and glucocorticoid-like interactions. Swiss female mice were used to measure the ear oedema induced by phorbol esters or ethyl phenylpropiolate (EPP), and the paw oedema induced by phospholipase A(2) (PLA(2)) or serotonin. Drug treatment consisted of one topically-applied dose in the ear models and a subcutaneous or intraperitoneal injection in the paw models. Quantitative analysis of leukotriene B(4) (LTB(4)) formation was performed on rat peritoneal neutrophils by high performance liquid chromatography (HPLC). The lactone inuviscolide reduced the PLA(2)-induced oedema (ID(50): 98 micromol/kg). The effect on serotonin-induced oedema was not changed by modifiers of the glucocorticoid response. Ilicic acid showed minor in vivo effects, but was slightly more potent than inuviscolide on the 12-O-tetradecanoylphorbol 13-acetate (TPA) acute oedema test (ID(50): 0.650 micromol per ear). Inuviscolide reduced LTB(4) generation in intact cells, with an IC(50) value of 94 microM. On the basis of the reported results, inuviscolide is the main anti-inflammatory sesquiterpenoid from Inula viscosa, and may act by interfering with leukotriene synthesis and PLA(2)-induced mastocyte release of inflammatory mediators.     

Dapsone inhibits LTB4 binding and bioresponse at the cellular and physiologic levels

Radioligand binding studies using human neutrophils exposed to 10-100 microM dapsone indicated that this anti-inflammatory compound antagonized association of LTB4 (leukotriene B4) with its specific receptor sites. Binding inhibition was manifested in reduced biologic response of the neutrophils as determined in LTB4-stimulated chemotaxis. In addition, a physiologic model of LTB4-dependent inflammation in mice was antagonized by systemic administration of dapsone. These data suggest that inhibition of LTB4 binding may represent the cellular mechanism of action responsible for the anti-inflammatory effects of dapsone.     

Evaluation of Tenidap (CP-66,248) on human neutrophil arachidonic acid metabolism, chemotactic potential and clinical efficacy in the treatment of rheumatoid arthritis

Ten patients with rheumatoid arthritis (RA) were evaluated in a placebo-controlled, double-blind study examining the clinical efficacy of a novel nonsteroidal anti-inflammatory agent: Tenidap (CP-66,248). RA patients receiving active drug therapy (n = 6) demonstrated clinically significant improvements in observer assessment of pain (p less than 0.025), painful joint count (p less than 0.010), and overall clinical assessment as based on a modified rheumatoid activity index, MRAI (p less than 0.025). In parallel laboratory assays, Tenidap was found to exhibit a significant in vitro dose-dependent inhibition of ionophore-stimulated neutrophil production of the 5-lipoxygenase product: [3H]leukotriene B4 (LTB4). Although more importantly, Tenidap was also found to exhibit an in vitro dose-dependent inhibition (IC50 20 microM) of the ionophore-stimulated release (deacylation) of the precursor [3H]arachidonic acid (AA) from membrane phospholipids. In further studies, Tenidap did not have any effect on fMLP-induced neutrophil chemotactic response. These results suggest that one of the possible mechanisms for the clinical effectiveness of this agent, may be through its effect at inhibiting the release of free AA from membrane phospholipids and therefore limiting its further metabolism into certain biologically-active inflammatory lipids.     

Biochemical and biological characterization of the venoms of Bothriopsis bilineata and Bothriopsis taeniata (Serpentes: Viperidae).

Snake venom is a complex mixture containing diverse protein components with different structures and functions that are used for prey immobilization and death. Snake venoms from the family Viperidae cause pronounced local and systemic effects, such as pain, edema, hemorrhage and necrosis. Here, we investigated the enzymatic and biological activities of venoms from two Amazonian snakes, Bothriopsis bilineata and Bothriopsis taeniata. Both venoms presented high enzymatic activities for proteases kallikrein, thrombin and plasmin, low levels of trypsin, cathepsin C and leucine aminopeptidase activities, while lacked acetylcholinesterase activity. B. taeniata and B. bilineata crude venoms caused inflammation inducing neutrophil recruitment into peritoneal cavity of mice 4h after injection. Neutrophil recruitment induced by B. taeniata venom was accompanied by hemorrhage. EDTA treatment profoundly impaired neutrophil recruitment, suggesting the involvement of a metalloproteinase on venoms-induced neutrophil recruitment. Pretreatment with dexamethasone and zileuton, a 5-lipoxygenase inhibitor, significantly reduced neutrophil migration, but indomethacin and montelukast, a cysteinyl leukotriene receptor antagonist, had no effect, suggesting the involvement of lipoxygenase-derived metabolites, probably LTB(4). Together, these results show that B. bilineata and B. taeniata venoms induce a marked inflammatory reaction, with leukocyte recruitment, and hemorrhage, which parallels to a high proteolytic activity found in these venoms.