Beneficial Effects of Quercetin in Chronic Obstructive Pulmonary Disease (COPD)

• Determine the plasma quercetin levels in COPD patients following supplementation with quercetin [ Time Frame: four weeks ] [ Designated as safety issue: No ]
  Eligible COPD subjects will be supplemented with quercetin for 4 weeks and plasma quercetin levels will be measured prior to and after supplementation with quercetin or placebo.
  
  

• Determine the effects of quercetin supplementation on the markers of oxidative stress in COPD subjects [ Time Frame: 4 weeks supplementation ] [ Designated as safety issue: Yes ]

  Oxidative stress markers will be measured prior to and after quercetin or placebo supplementation

  • Protein carbonyls and nitrotyrosines
  • reduced glutathione
  • malondialdehyde.
  
  
• Determine the effects of quercetin supplementation on the markers of inflammation in COPD subjects [ Time Frame: 4 Weeks supplementation ] [ Designated as safety issue: Yes ]

  Sputum and blood levels of markers of inflammation will be measured prior to and after supplementation with placebo or quercetin

  • IL-6
  • IL-8
  • sICAM-1
  • CD40L
  • CC16
  • PARC/CCL18
  • surfactant D protein
  • C-reactive protein in blood only
  
  

• Determine the effects of quercetin supplementation on lung function [ Time Frame: 4 weeks ] [ Designated as safety issue: Yes ]
  To determine the overall effect of quercetin supplementation in COPD subjects we will also measure lung function by performing pre and post bronchodialator spirometry
  
  

In our preclinical study, we have demonstrated that 4 fold increase in plasma quercetin levels significantly decreased lung inflammation and prevented progression. Clinical studies in healthy volunteers 4 fold increase in plasma quercetin levels (0.22 to 1 µM) could be achieved by supplementing with 500mg of quercetin/day. However, safety of quercetin supplementation and quercetin dose required to achieve 4 fold increases in plasma qurecetin levels in 'at-high-risk' COPD population is yet to be established. This study involves two phases; the first phase examines the safety of quercetin supplementation in subjects with chronic obstructive pulmonary disease (COPD) and the second phase determines the efficacy of quercetin in COPD patients. In this study, we will enroll COPD patients with mild to moderate disease between the age group of 40 to 65 years. During the first phase, we will enroll a total of 9 patients to examine the tolerance and safety of three doses of quercetin (500, 1000 and 2000 mg/day) in a dose escalation manner. First cohort consisting of three subjects will receive placebo or 500 mg of quercetin per day for one week and the safety of quercetin supplementation will be assessed by monitoring adverse events and any changes in outcomes of blood test that include complete blood counts (CBC)and comprehensive metabolic panel prior to after supplementation. If this dose is safe and tolerated, second cohort of 3 subjects will receive placebo or 1000 mg of quercetin per day quercetin for one week and again safety will be assessed. If the dose is safely tolerated, the third cohort will receive either placebo or 2000m mg of quercetin per day for a week and the safety will be assessed. Based on this initial study, we will choose the highest quercetin dose tolerated with no adverse events and the dose (500 mg of quercetin per day) that was found to increase plasma quercetin levels by 4 fold over baseline in healthy volunteers to examine the efficacy of quercetin in reducing inflammatory and oxidative stress markers and improving lung function in COPD subjects. In the second phase, we will enroll a total of 75 subjects and randomized into three arms; placebo (15 subjects) or one of the two doses of quercetin (30 subjects per arm). All enrolled subjects will be asked to avoid quercetin rich foods throughout the study period. One week after enrollment (run-in), subjects will be either supplemented with either placebo or one of the two doses of quercetin for 4 weeks. All participants will be blinded for study agents. Plasma and sputum quercetin levels, lung function, and markers of oxidative stress and inflammation will be determined at the start of the study (following run-in period), at the end of 4 weeks treatment period.