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Effects of a Water-Soluble Curcumin Protein Conjugate vs. Pure Curcumin in a Diabetic Model of Erectile Dysfunction


Hanan H. Fouad, MD, Medical Biochemistry Department, Unit of Biochemistry and Molecular Biology, Faculty of Medicine, Cairo University, POB 11562, Cairo 11562, Egypt. Tel: (202) 23632297; Fax: (202) 23632297; E-mail:


Introduction.  Curcumin is involved in erectile signaling via elevation of cyclic guanosine monophosphate (cGMP).

Aim.  Assessment of the effects of water-soluble curcumin in erectile dysfunction (ED).

Methods.  One hundred twenty male white albino rats were divided into: 1st and 2nd control groups with or without administration of Zinc protoporphyrin (ZnPP), 3rd and 4th diabetic groups with or without ZnPP, 5th diabetic group on single oral dose of pure curcumin, 6th diabetic group on pure curcumin administered daily for 12 weeks, 7th and 8th diabetic groups on single dose of water-soluble curcumin administered with or without ZnPP, 9th and 10th diabetic groups on water-soluble curcumin administered daily for 12 weeks with or without ZnPP. All curcumin dosage schedules were administered after induction of diabetes.

Main Outcome Measures.  Quantitative gene expression of endothelial nitric oxide synthase (eNOS), neuronal NOS (nNOS), inducible NOS (iNOS), heme oxygenase-1 (HO-1), nuclear transcription factor-erythroid2 (Nrf2), NF-Кβ, and p38. Cavernous tissue levels of HO and NOS enzyme activities, cGMP and intracavernosal pressure (ICP).

Results.  Twelve weeks after induction of diabetes, ED was confirmed by the significant decrease in ICP. There was a significant decrease in cGMP, NOS, HO enzymes, a significant decrease in eNOS, nNOS, HO-1 genes and a significant elevation of NF-Кβ, p38, iNOS genes. Administration of pure curcumin or its water-soluble conjugate led to a significant elevation in ICP, cGMP levels, a significant increase in HO-1 and NOS enzymes, a significant increase in eNOS, nNOS, HO-1, and Nrf2 genes, and a significant decrease in NF-Кβ, p38, and iNOS genes. Water-soluble curcumin showed significant superiority and more prolonged duration of action. Repeated doses regimens were superior to single dose regimen. Administration of ZnPP significantly reduced HO enzyme, cGMP, ICP/ mean arterial pressure (MAP), HO-1 genes in diabetic groups.

Conclusion.  Water-soluble curcumin could enhance erectile function with more effectiveness and with more prolonged duration of action. Abdel Aziz MT, Motawi T, Rezq A, Mostafa T, Fouad HH, Ahmed HH, Rashed L, Sabry D, Senbel A, Al-Malki A, and El-Shafiey R. Effects of a water-soluble curcumin protein conjugate vs. pure curcumin in a diabetic model of erectile dysfunction. J Sex Med 2012;9:1832–1850.