Oral Glutathione Supplementation on the Levels of Blood Glutathione
Condition: Healthy Adults
Study type: Interventional

Summary: 
      This trial is designed to provide evidence of the efficacy of glutathione supplementation and
      health(GSH) and includes the assessment of both short term and long term effects. Based on
      previous laboratory animal studies and clinical data, the investigators anticipate that the
      effects of oral GSH supplementation will be progressive and cumulative. The study will also
      allow for the evaluation of effects of withdrawal of the supplement on the outcome variables.
    

Detailed description: 
      This is a randomized double-blind, placebo-controlled study in which the treatment
      allocations will be kept sealed until the final statistical evaluation. The design will
      include the recruitment of 60 healthy subjects (30-79 yr of age) randomized into 3 groups. A
      total of 48 subjects, 16 per group will be required based upon power calculations and results
      from a previous clinical trial with selenium. An additional 4 subjects per group will be
      placed on trial to account for possible attrition or non-compliance. Blood, urine and
      exfoliated buccal mucosal samples will be obtained from all subjects at baseline.
      Questionnaire data on usual dietary intake will also be obtained at baseline. Eligible
      subjects will be required to have not have taken any high dose antioxidant supplements for at
      least 1 month prior to the study. Subjects will then begin supplementation according to the
      following schedule:

      Group A, GSH (500 mg, 2 times daily); Group B, GSH (125 mg, 2 times daily); Group C, placebo
      (2 times daily). Eligible participants who sign the informed consent will be randomly
      assigned to either placebo or high or low dose Glutathione groups. Participants will be asked
      not to consume any other high-dose vitamin, multi-vitamin, or mineral supplements containing
      glutathione throughout the study in order to prevent variation in dose of supplemental GSH
      between subjects. Supplementation will continue for 6 months with biological samples
      collected at 1, 3 and 6 months after baseline. At 6 months, supplementation will be
      discontinued. A final collection of biological samples will occur 1 month afterwards.
      Compliance will be monitored by pill count.

      Levels of glutathione will be measured in plasma, lymphocytes, and red blood cells as well as
      in exfoliated buccal mucosal cells. Biomarkers of oxidative stress will include blood levels
      of glutathionylated proteins and 8-isoprostanes and urine levels of 8-hydroxydeoxyguanosine.
      Glutamylcystine ligase and GST activities, and C-reactive protein will be determined in
      blood. Immune function biomarkers will be analyzed including t-natural killer cell
      cytotoxicity, lymphoproliferation, neutrophils phagocytosis, neutrophil respiratory burst
      assays.
    

Intervention name(s): Glutathione supplementation; Gluthathione peroxidases; Placebo
Intervention type(s): Drug; Drug; Other
Intervention description(s): 500 mg, two times daily; 125 mg, two times daily; 2 times daily
Other intervention name(s): Gluthathione Peroxidates; GSH; Glutathione supplementation; GSH; Gluthathione peroxidases; GSH
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: glutathione; gluthathione peroxidases; GSH