The effect of natural polyphenols on the oxidative stress markers in patients with diabetic nephropathy

Free Radic Biol Med. 2014 Oct;75 Suppl 1:S42. doi: 10.1016/j.freeradbiomed.2014.10.795. Epub 2014 Dec 10.


Background: Nephropathy remains a significant cause of morbidity and mortality in the diabetic population and is the leading cause of end-stage renal failure, hence kidney transplantations. As a result of the diabetic milieu, increased generation of reactive oxygen species is thought to play a key role in the progression of diabetic nephropathy. Aim of this study was to evaluate the effect of Pycnogenol (Pyc), the extract from Pinus pinaster, on the level of glucose, advanced glycation end products (AGE) and oxidative stress markers in patients with Diabetic nephropathy (DN).

Subject and methods: To double blind randomised placebo controlled exploratory study were enrolled 20 men with DN received daily Pyc (120mg) or a placebo. Patients were investigated before, one and three months after Pyc administration and after termination of drugs supplementation.

Results: The level of glucose, AGEs, malondialdehyde (MDA), 8-isoprostanes (8-Iso), as well as protein carbonyls (PC) were increased in comparison to control group. We have found lower level of glucose, AGEs, MDA and 8-Iso after 3 months of Pyc administration in comparison to the beginning state and to placebo group, but these results did not reach significance. CP and TAS were not affected.

Conclusion: Our data allow us to conclude that Pycnogenoladministration reduces oxidative damage to lipids rather through the decreased glucose level than through the influence of antioxidant capacity of plasma. This study was supported by grant Ministry of Health 2012/8-ukba-8.