Impact of quercetin on inflammatory and oxidative stress markers in COPD

慢性阻塞性肺疾病（COPD）是美国死亡率和发病率的主要原因，也是全球慢性病的增长原因。目前，COPD的治疗选择有限，需要新的治疗方法来治疗/预防COPD的进展。环境因素和宿主反应导致氧化剂与抗氧化剂以及蛋白酶与抗蛋白酶的比例失衡，导致慢性炎症和组织破坏，被认为在COPD的发生和进展中起关键作用。 槲皮素是一种植物类黄酮，具有有效的抗氧化和抗炎特性。补充槲皮素可降低另一种慢性肺病肺结节病患者血浆中的氧化应激和炎症标志物。在慢性阻塞性肺疾病（COPD）的临床前模型中，槲皮素还可降低氧化应激和肺部炎症。然而，槲皮素在改变COPD受试者的生物特征方面的影响尚未确定。 拟定研究分两个阶段进行，R61/R33，以定义和确认槲皮素在COPD中的生物学效应、生物利用度、安全性，以及确定反映COPD临床结局的适当生物学特征。这项研究还将确定有利地改变生物特征所需的槲皮素的最佳剂量。这些信息对于将来在COPD患者中进行槲皮素的临床试验是必要的。 在R61阶段，将有15名中度COPD研究受试者，FEV 1范围为预测值的45 - 70%，他们将随机接受安慰剂或槲皮素2000 mg/天治疗6个月。在R33阶段，将有35例COPD受试者，随机接受安慰剂或3种槲皮素剂量（500、1000或2000 mg/天）之一。 R61阶段的结果将决定R33阶段的可行性。 在R61和R33阶段，将使用经验证的症状问卷、用药和吸烟史、合并症分析和体格检查对所有受试者进行表征。要求所有受试者在开始补充槲皮素或安慰剂前7天进行低槲皮素饮食，直至试验结束。将在7天洗脱期（导入期）和研究药物治疗后采集血液和支气管肺泡灌洗（BAL）。还将在研究药物治疗3个月时采集血液。将测量血浆和BAL槲皮素水平、血液和BAL中炎症和氧化应激的标志物。将在导入期以及研究药物治疗3个月和6个月时进行肺功能和血液特征（CBC和CMP），以评估安全性。这些研究的结果将提供有关生物学终点、安全性、生物利用度和槲皮素剂量的信息，以进行大型临床试验，检查槲皮素在COPD患者中的疗效。

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity in the United States and growing cause of chronic disease globally. At present the treatment options for COPD are limited and new therapies are needed to treat/prevent progression of COPD. Environmental factors and host response leading to imbalance in the ratio of oxidants to antioxidants, and proteases to antiproteases leading to chronic inflammation and tissue destruction is thought to play crucial role in development and progression of COPD. Quercetin is a plant flavonoid and has potent antioxidant and anti-inflammatory properties. Quercetin supplementation decreased markers of oxidative stress and inflammation in the plasma of patients with another chronic lung disease, pulmonary sarcoidosis. Quercetin also decreased both oxidative stress and lung inflammation in a preclinical model of chronic obstructive pulmonary disease (COPD). However the impact of quercetin in altering biological signatures in COPD subjects is yet to be determined. The proposed study is conducted in two phases, R61/R33 to define and confirm the biological effects of quercetin in COPD, bioavailability, safety, identification of the appropriate biological signatures which reflect clinical outcomes in COPD. This study will also define the optimal dose of quercetin required for altering biological signatures favorably. This information is necessary to conduct the future clinical trials with quercetin in COPD patients. In R61 Phase, there will be 15 study participants with moderate COPD with FEV1 ranging between 45 and 70 % of predicted and they will be randomized to receive either placebo or quercetin 2000 mg/day for 6 months. In R33 phase there will be 35 COPD subjects, who will be randomized to receive placebo, or one of the 3 quercetin doses, 500, 1000 or 2000 mg/day. Outcome of R61 phase will determine the feasibility of R33 Phase. In both R61 and R33 phases, all subjects will be characterized using a validated symptom questionnaire, medication and smoking histories, analysis of co-morbidities, and physical examination. All subjects will be asked to go on a low quercetin diet 7 days prior to start of quercetin or placebo supplementation to until the end of trial. Blood and bronchoalveolar lavage (BAL) will be collected after 7 days washout period (run-in) and after study drug treatment. Blood will also be collected at 3 months of study drug treatment. Plasma and BAL quercetin levels, markers of inflammation and oxidative stress in blood and BAL will be measured. Pulmonary function, and blood profiles (CBC and CMP) will be performed at run-in and at 3 and 6 months of study drug treatment to assess the safety. Results from these studies will provide information on biological endpoints, safety, bioavailability, and quercetin dosage required to carry out large clinical trials examining the efficacy of quercetin in COPD patients.