Anti-inflammatory mechanisms, pharmacokinetics of novel metabolites of vitamin E

描述(由申请人提供)：维生素E补充剂通常被用作补充和替代医学(CAM)。关于维生素E的临床研究一直集中在1-生育酚(1T)上，但在潜在的健康益处方面，他们得出了令人失望的结果。然而，我们和其他人已经证明，其他形式的维生素E，特别是它们的新代谢物具有1T所不具备的独特的抗炎特性。特别是，我们已经证明，由4-生育酚(4T)衍生的长链代谢物13‘-羧基色甘醇(4-13’-COOH)对环氧合酶(COX-1和COX-2)和5-脂氧合酶(5-LOX)的抑制作用分别与常用的非类固醇抗炎药布洛芬(NSAID)和齐留通(临床使用的5-LOX抑制剂)相似。同时，3-生育酚(3T)和4T(而不是1T)通过阻断钙内流，抑制COX-2介导的前列腺素E_2的产生，并抑制5-LOX介导的中性粒细胞产生白三烯B4。在一项初步研究中，我们发现4T具有良好的抗关节炎作用。由于这些维生素E形式和代谢产物同时抑制COXS和5-LOX介导的促炎途径，我们认为这些化合物作为抗炎和抗关节炎的常用NSAIDs可能优于常用的NSAIDs，因为大多数NSAIDs只抑制COX催化的途径。此外，由于对Coxs和5-LOX的抑制作用更强，我们认为13‘-COOH可能比非代谢维生素更有效。为了验证这些假设，我们将1)在基于细胞和酶的研究中探讨长链羧基铬醇对COX-1/-2和5-LOX催化反应的影响和机制，2)建立一种新的维生素E代谢物的LC-MS-MS分析方法，并表征4-13‘-COOH、3T和4T的药代动力学，3)将体外观察到的4-13’-COOH和维生素E独特的抗炎活性转化为大鼠炎症模型，并将其抗炎效果与已建立的非甾体抗炎药进行比较。4)通过观察4-13‘-COOH、3T和4T对大鼠佐剂性关节炎模型的抗炎作用，将抗炎作用转化为疾病相关模型。我们对这些维生素E形式及其新的代谢物的研究可能会导致发现一类新的抗炎药，它可能比一些常用的抗炎药更安全，但具有类似或更好的疗效。拟议的研究将阐明抗炎作用的机制，并产生重要的临床前数据，这些数据是确保对这些化合物进行最大限度地提供信息的临床疗效研究所必需的。 公共卫生相关性：这一应用将检验特定的维生素E形式及其新的代谢物--长链羧基铬醇--可能是有效的新型抗炎和抗关节炎药物的假设。这项研究可能会发现治疗炎症性疾病的方法比常用的非类固醇抗炎药更好，因此可能会在关节炎和疼痛治疗中用维生素E代谢物或它们与非类固醇抗炎药的组合来替代非类固醇抗炎药，这是一个临床上重要的领域。

DESCRIPTION (provided by applicant): Vitamin E supplementation has been commonly used as a CAM (Complementary and Alternative Medicine). Clinical studies on vitamin E have focused exclusively on 1-tocopherol (1T), but they have yielded disappointing results regarding potential health benefits. However, we and others have shown that other vitamin E forms and especially their novel metabolites have unique anti-inflammatory properties that are not possessed by 1T. In particular, we have demonstrated that 13'-carboxychromanol (4-13'-COOH), a long-chain metabolite derived from 4- tocopherol (4T), inhibits cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX) with potency similar to ibuprofen (a commonly used non-steroid anti-inflammatory drugs - NSAID) and zileuton (a clinically used 5-LOX inhibitor), respectively. Meanwhile, 3-tocopherol (3T) and 4T, but not 1T, inhibited COX-2-mediated prostaglandin E2 generation in cells and suppressed 5-LOX-mediated leukotriene B4 production in neutrophils by blocking calcium influx. In a preliminary study, we have found that 4T exhibited promising anti-arthritis effects. Since these vitamin E forms and metabolites inhibit both COXs- and 5-LOX-mediated pro-inflammatory pathways, we propose that these compounds may be superior to commonly used NSAIDs as anti-inflammatory and anti-arthritis agents because most NSAIDs only inhibit COX- catalyzed pathway. In addition, due to stronger inhibition of COXs and 5-LOX, we propose that 13'-COOH may be more effective than un-metabolized vitamins. To test these hypotheses, we will 1) investigate the effect and mechanism of long-chain carboxychromanols on COX-1/-2 and 5-LOX-catalyzed reactions in cell- and enzyme-based studies, 2) develop a new LC-MS-MS assay for vitamin E metabolites and characterize the pharmacokinetics of 4-13'-COOH, 3T and 4T, 3) translate the unique anti-inflammatory activity of 4-13'-COOH and vitamin E forms observed in vitro to a rat inflammation model and compare their anti-inflammatory efficacy to established NSAIDs, and 4) translate the anti-inflammatory actions to a disease relevant model by investigating anti-arthritis efficacy of 4-13'-COOH, 3T and 4T in the rat adjuvant-induced arthritis model. Our studies on these vitamin E forms and their novel metabolites may lead to discovery of a new class of anti-inflammatory agents that may be safer than some commonly used anti-inflammatory drugs and yet have similar or superior efficacy. The proposed studies will elucidate mechanisms of anti-inflammatory action and generate important preclinical data that are needed to insure maximally informative clinical efficacy studies on these compounds. PUBLIC HEALTH RELEVANCE: This application will test the hypothesis that specific vitamin E forms and their novel metabolites, long-chain carboxychromanols, may be effective novel anti-inflammatory and anti-arthritis agents. This study may lead to discovery of superior therapy for treatment of inflammatory diseases over commonly used NSAIDs and therefore may result in NSAID replacement with vitamin E metabolites or their combination with NSAIDs in arthritis and pain management, a clinically important area.