Glutathione in Diabetic Nephropathy (CGDN)

• Change from baseline in urinary alpha-1 microglobulin excretion [ Time Frame: 3-month ] [ Designated as safety issue: No ]
• Change from baseline in urinary C-C-chemokines excretion [ Time Frame: 3-month ] [ Designated as safety issue: No ]
• Change from baseline in peripheral blood monocyte glutathione content [ Time Frame: 3-month ] [ Designated as safety issue: No ]
• adverse events [ Time Frame: 1-month ] [ Designated as safety issue: Yes ]
• Change from baseline in hemoglobin level [ Time Frame: 1-month ] [ Designated as safety issue: Yes ]
• Change from baseline in serum electrolytes [ Time Frame: 1-month ] [ Designated as safety issue: Yes ]
• Change from baseline in estimated glomerular filtration rate [ Time Frame: 1-month ] [ Designated as safety issue: Yes ]
• Change from baseline in measured glomerular filtration rate [ Time Frame: 3-month ] [ Designated as safety issue: Yes ]
• Change from baseline in hemoglobin-A1c [ Time Frame: 1-month ] [ Designated as safety issue: Yes ]

The study is done to find out whether the combined use of the nutritional supplements N-acetylcysteine and Siliphos (milk thistle extract) corrects the shedding of urine protein and oxidative damage (damage to cells and organs often compared to fast aging) in patients with Type 2 Diabetes Mellitus (T2DM) and diabetic kidney disease.

Oxidative stress and glutathione (GSH) imbalance are major contributors to the pathogenesis of diabetic nephropathy. Current options for the treatment of oxidative stress in diabetic nephropathy are limited and only partially effective, thus interest in the development of new strategies is high.

The study intends to test the hypothesis that combined oral supplementation of the antioxidants N-acetylcysteine (NAC) and milk thistle flavonolignan silibin (as silibin-phosphatidylcholine) will reduce proteinuria and urinary and systemic manifestations of oxidative stress and inflammation, which are characteristically observed in patients with T2DM and related nephropathy. We expect these effects to be achieved with minimal or no side effects, and with good patient tolerance.

The trial is designed as a two-center, double-blind, placebo-controlled, randomized, modified-factorial dose-ranging design, five-arm pilot study in patients with Type 2 diabetes mellitus and advanced diabetic nephropathy with proteinuria.

Intervention consists of three-month oral administration of NAC, silibin, and/or respective placebos for three months. Subjects are randomized to the following five intervention arms: (A) placebo; (B) NAC; (C) silibin; (D) NAC + silibin; and (E) NAC + double-dose silibin.

The primary outcome measure is urinary excretion of albumin, a marker of glomerular injury. Secondary outcome measures are alpha-1 microglobulin, a marker of tubular injury, and urinary excretion of inflammatory cytokines and C-C chemokines, i.e. markers of renal inflammation. In addition, peripheral blood monocytes from the same patients are analyzed for GSH content and activity of GSH metabolizing enzymes. All outcome measures are monitored in relation to both treatment allocation and prevalent blood and urine levels of the active treatment. Safety and tolerability of this combination treatment are monitored throughout the trial.

• Diabetic Nephropathy
• Proteinuria
• Oxidative Stress

• Drug: N-acetylcysteine placebo + silibin placebo
  Dietary Supplement: N-acetylcysteine placebo excipient orally twice daily for three months
  Other Name: NAC placebo Dietary Supplement: silibin placebo excipient orally twice daily for three months Or silibin-phosphatidylcholine placebo, Siliphos placebo
• Drug: N-acetylcysteine active + silibin placebo
  Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months
  Other Name: NAC Dietary Supplement: silibin placebo excipient orally twice daily for three months Or Silibin-phosphatidylcholine placebo, Siliphos placebo
• Drug: N-acetylcysteine placebo + silibin active

  Dietary Supplement: silibin 480 mg orally twice daily for three months

  • (Other Name) Silibin-phosphatidylcholine placebo, Siliphos placebo
  • (Other Name) NAC placebo Dietary Supplement: silibin placebo excipient orally twice daily for three months
  Other Name: Silibin-phosphatidylcholine, Siliphos Dietary Supplement: N-acetylcysteine placebo excipient orally twice daily for three months
• Drug: N-acetylcysteine active + silibin active

  Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months

  • (Other Name): NAC Dietary Supplement: silibin 480 mg orally twice daily for three months Silibin-phosphatidylcholine, Siliphos Dietary Supplement: silibin placebo excipient orally twice daily for three months
  • (Other Name): Silibin-phosphatidylcholine, Siliphos Dietary Supplement: silibin placebo excipient orally twice daily for three months
  Other Name: Silibin-phosphatidylcholine placebo, Siliphos placebo
• Drug: N-acetylcysteine active + high-dose silibin active
  Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months
  Other Name: NAC Dietary Supplement: high-dose silibin 960 mg orally twice daily for three months Or Other Name: Silibin-phosphatidylcholine, Siliphos

• Placebo Comparator: Arm 1
  N-acetylcysteine placebo + silibin placebo Dietary Supplement: N-acetylcysteine placebo excipient orally twice daily for three months Other Name: NAC placebo Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
  Intervention: Drug: N-acetylcysteine placebo + silibin placebo
• Experimental: Arm 2
  N-acetylcysteine active + silibin placebo Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months Other Name: NAC Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
  Intervention: Drug: N-acetylcysteine active + silibin placebo
• Experimental: Arm 3
  N-acetylcysteine placebo + silibin active Dietary Supplement: silibin 480 mg orally twice daily for three months Other Name: silibin-phosphatidylcholine, Siliphos Dietary Supplement: N-acetylcysteine placebo excipient orally twice daily for three months Other Name: NAC placebo Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
  Intervention: Drug: N-acetylcysteine placebo + silibin active
• Experimental: Arm 4
  N-acetylcysteine active + silibin active Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months Other Name: NAC Dietary Supplement: silibin 480 mg orally twice daily for three months Other Name: silibin-phosphatidylcholine, Siliphos Dietary Supplement: silibin placebo excipient orally twice daily for three months Other Name: silibin-phosphatidylcholine placebo, Siliphos placebo
  Intervention: Drug: N-acetylcysteine active + silibin active
• Experimental: Arm 5
  N-acetylcysteine active + high-dose silibin active Dietary Supplement: N-acetylcysteine 600 mg orally twice daily for three months Other Name: NAC Dietary Supplement: high-dose silibin 960 mg orally twice daily for three months Other Name: silibin-phosphatidylcholine, Siliphos
  Intervention: Drug: N-acetylcysteine active + high-dose silibin active

• Khazim K, Giustarini D, Rossi R, Verkaik D, Cornell JE, Cunningham SE, Mohammad M, Trochta K, Lorenzo C, Folli F, Bansal S, Fanti P. Glutathione redox potential is low and glutathionylated and cysteinylated hemoglobin levels are elevated in maintenance hemodialysis patients. Transl Res. 2013 Jan 17. doi:pii: S1931-5244(12)00450-1. 10.1016/j.trsl.2012.12.014. [Epub ahead of print]
• Debnath S, Thameem F, Alves T, Nolen J, Al-Shahrouri H, Bansal S, Abboud HE, Fanti P. Diabetic nephropathy among Mexican Americans. Clin Nephrol. 2012 Apr;77(4):332-44.

Inclusion Criteria:

• Males or females age 18-76 years old
• Type 2 diabetes mellitus

• Diabetic nephropathy, as defined by:

  • estimated GFR between 60 and 15 ml/min
  • presence of proteinuria
• Current medical treatment with low dose aspirin

• Treatment of hypertension with (but not limited to):

  • one diuretic
  • one beta-blocker
  • and one medication from the classes Angiotensin Receptor Blockers (ARBs) or Angiotensin Converting Enzyme inhibitors (ACE-I)
• Treatment of hyperglycemia with (but not limited to) glipizide and the medication class insulin
• Treatment of hypercholesterolemia with (but not limited to) one medication from the class statins

Exclusion Criteria:

• Type 1 diabetes mellitus
• Glycosylated hemoglobin (HbA1C) > 10%
• >20% variation in estimated GFR, during last 6 months
• Systolic Blood Pressure >170 mmHg or Diastolic Blood Pressure >100 mmHg on medications
• Other secondary forms of hypertension (endocrine, renovascular)

• History of intolerance to:

  • Both ACE-I and ARBs
  • The investigational supplements
  • Iodinated radiologic contrast material
• Known non diabetic renal disease
• or history of solid organ transplantation
• Hepatitis virus or Human Immunodeficiency virus infections

• Use of one of the following medications within 2 months prior to enrollment in the study:

  • Metformin
  • Thiazolidinediones (pioglitazone or rosiglitazone)
  • Phenytoin
  • Warfarin
  • Prescription-grade vitamin E, vitamin C, systemic steroids, and/or non-steroidal anti-inflammatory agents
  • Over-the-counter vitamin E, vitamin C, and/or non-steroidal anti-inflammatory agents

  • Over-the-counter antioxidants supplements including:

    • Lipoic acid
    • Coenzyme Q10
    • N-acetyl-cysteine (NAC)
    • Glutathione (GSH)
    • Chromium
    • Fish-oil extracts (omega-3 fatty acids)
    • Soy extracts (isoflavones)
    • Milk thistle extract (silymarin)
    • Green-tea preparations
    • Pomegranate extracts
    • Grape extracts
    • Prickly pear extract
• Active coronary artery disease or cerebral vascular disease within 3 months prior to signing the informed consent
• Hepatic dysfunction as defined by abnormal total bilirubin or liver enzymes (ALT, AST) >2 times upper limit of normal range
• Active malignancy
• History of drug or alcohol dependency
• Psychiatric or neurological condition, preventing aware consent to the study and/or adherence to the study protocol
• Unwillingness to practice birth control throughout the study
• Participation to another clinical study within 1 month prior to signing the informed consent form
• Planned move to outside the study area, surgery or radiographic studies utilizing iodine-based contrast material within the next one year