Kerrie
tegen hartproblemen bij diabetici.*
Als
gevolg van diabetes ontstaat in het lichaam meer oxidatieschade met mogelijke
hartproblemen als gevolg. Uit een studie met ratten blijkt nu dat curcumine, de
gele bioactieve stof in kerrie, deze oxidatieschade te lijf gaat en hierdoor de
mogelijke hartproblemen kan voorkomen.
Differential
effects of curcumin on vasoactive factors in the diabetic rat heart
Nutrition & Metabolism 2006, 3:27 doi:10.1186/1743-7075-3-27
Abstract (provisional)
The
complete article is available as a provisional
PDF. The fully
formatted PDF and HTML versions are in production.
Background
Increased
oxidative stress has been associated with the pathogenesis of chronic diabetic
complications, including cardiomyopathy. Recent studies indicate that curcumin,
a potent antioxidant, may be beneficial in preventing diabetes-induced oxidative
stress and subsequent secondary complications. We have investigated the effects
of curcumin on the nitric oxide (NO) pathway in cardiac tissues and cultured
cells.
Methods
Streptozotocin-induced
diabetic rats were treated with curcumin for a period of one month. Heart
tissues were then analyzed for endothelial NO synthase (eNOS) and inducible NO
synthase (iNOS) mRNA expression. Oxidative protein and DNA damage were assessed
by immunohistochemical analysis of nitrotyrosine and 8-hydroxy-2'-deoxyguanosine
(8-OHdG). Heart tissues were further subjected to endothelin-1 (ET-1) mRNA
expression. In order to further characterize the effects of curcumin, we assayed
microvascular endothelial cells (MVECs). Cultured MVECs, exposed either to
glucose or glucose and varying concentrations of curcumin, were assessed for
alterations of NOS expression and activation of nuclear factor-kappa B (NF-kB)
and activating protein-1 (AP-1). Oxidative stress and ET-1 expression levels
were also assayed.
Results
Our
results indicate that one month of diabetes causes an upregulation of both eNOS
and iNOS mRNA levels, and nitrotyrosine and 8-OHdG immunoreactivity in the heart.
Treatment of diabetic rats with curcumin reduced eNOS and iNOS levels in
association with reduced oxidative DNA and protein damage. Interestingly,
curcumin further increased vasoconstrictor ET-1 in the heart. Exposure of MVECs
to high glucose increased both eNOS and iNOS levels and oxidative stress.
Curcumin prevented NOS alteration and oxidative stress in a dose-dependent
manner which was mediated by NF-kB and AP-1. Exposure to curcumin also increased
ET-1 levels in the MVECs.
Conclusions
Our
studies indicate the differential effects of curcumin in vasoactive factor
expression in the heart and indicate the importance of tissue microenvironment
in the treatment of diabetic complications. (
Juli 2006)