Effect of Oral Supplementation With Curcumin in Patients With Proteinuric Diabetic Kidney Disease

The purpose of this study is to determine if the oral supplementation with curcumin reduces proteinuria, improves the redox and pro-inflammatory state in patients with chronic kidney disease associated to Diabetes mellitus.

Diabetic Kidney Disease (DKD) represents the fist cause of end-stage kidney disease in Mexico and the world, and it is characterized by the presence of hyperfiltration, glomerular hypertrophy, tubular albuminuria and mesangial matrix expansion, mainly by the oxidative stress and the pro-inflammatory state. Current treatments are limited on controlling proteinuria and delay progression of the disease, but even with an optimal management, a significant number of patient progress to end-stage renal disease. Curcumin, found in the extracts of the rhizome of the plant Curcuma longa L., has a wide spectrum of biological and pharmacological activities, such as anti-oxidant, anti-inflammatory, anti-carcinogenic and anti-diabetic effects. It has the capacity to act directly with highly reactive oxygen species, induce the expression of various cytoprotective proteins through Keap1/Nrf2/ARE pathway and reducing inflammatory transcription factors such as NF-κB and TNF-α. Curcumin could be an adjuvant treatment in the management of DKC due to his pleiotropic nature, low cost and few side effects.

Each patient of this group will receive 1.67 grams of curcumin ( 7 capsules of 231 mg) divided in 3 doses daily for 6 months.

The control group will receive 7-capsules/ day identical in color and size, containing placebo for 6 months.

Free radical scavenging activity in plasma using DPPH, a purple-colored stable free radical is reduced to the yellow-colored diphenyl picryl-hydrazine, and the absorbance will be measure at 518 nm. The results were expressed as percentage of DPPH inhibition.

Malondialdehyde (MDA) in plasma. We will measure the reaction with 1-methyl-2- phenylindole at 586 nm, using a standard curve of tetrame- thoxypropane.

Enzyme-linked immunoassay (ELISA) will be use to the measurement of serum TGF-b, IL-10, IL-6 and TNF-a.

Inclusion Criteria: Diagnosis of Diabetes Mellitus type 2 and proteinuric kidney disease with 1000 mg of more proteins in daily recollection Glomerular filtration rate between 15-60 mL/min/ 1.73 m2 calculated by CKD-EPI Patients taking Angiotensin II Receptor Blocker or ACE inhibitors Exclusion Criteria: Renal replacement therapy Autoimmune disease or malignancy Pregnancy Hepatic damage Congestive heart failure classification III or IV (NYHA) History of organ transplantation History of chemotherapy or immunosuppression within 2 years prior to screening

National Kidney Foundation. K/DOQI clinical practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Am J Kidney Dis. 2002 Feb;39(2 Suppl 1):S1-266. No abstract available.

de Zeeuw D, Remuzzi G, Parving HH, Keane WF, Zhang Z, Shahinfar S, Snapinn S, Cooper ME, Mitch WE, Brenner BM. Proteinuria, a target for renoprotection in patients with type 2 diabetic nephropathy: lessons from RENAAL. Kidney Int. 2004 Jun;65(6):2309-20. doi: 10.1111/j.1523-1755.2004.00653.x.

Trujillo J, Chirino YI, Molina-Jijon E, Anderica-Romero AC, Tapia E, Pedraza-Chaverri J. Renoprotective effect of the antioxidant curcumin: Recent findings. Redox Biol. 2013 Sep 17;1(1):448-56. doi: 10.1016/j.redox.2013.09.003.

Khajehdehi P, Pakfetrat M, Javidnia K, Azad F, Malekmakan L, Nasab MH, Dehghanzadeh G. Oral supplementation of turmeric attenuates proteinuria, transforming growth factor-beta and interleukin-8 levels in patients with overt type 2 diabetic nephropathy: a randomized, double-blind and placebo-controlled study. Scand J Urol Nephrol. 2011 Nov;45(5):365-70. doi: 10.3109/00365599.2011.585622. Epub 2011 May 31.

Jimenez-Osorio AS, Garcia-Nino WR, Gonzalez-Reyes S, Alvarez-Mejia AE, Guerra-Leon S, Salazar-Segovia J, Falcon I, Montes de Oca-Solano H, Madero M, Pedraza-Chaverri J. The Effect of Dietary Supplementation With Curcumin on Redox Status and Nrf2 Activation in Patients With Nondiabetic or Diabetic Proteinuric Chronic Kidney Disease: A Pilot Study. J Ren Nutr. 2016 Jul;26(4):237-44. doi: 10.1053/j.jrn.2016.01.013. Epub 2016 Feb 22.