Curcumin prevents diabetes-associated abnormalities in the kidneys by inhibiting p300 and nuclear factor-kappaB

Diabetic nephropathy is a debilitating disease that leads to end-stage renal failure in the Western world. Hyperglycemia is the initiating factor in several chronic diabetic complications which mediates increased oxidative stress and eventually the increased production of vasoactive factors and extracellular matrix proteins. We hypothesized that curcumin, a potent antioxidant, might be beneficial in preventing the development of diabetic nephropathy because this compound has been shown to inhibit p300, a histone acetyltransferase that plays a role in regulating gene expression through its interaction with the transcription factor nuclear factor-kappaB.

To test this hypothesis, male Sprague-Dawley rats were injected with streptozotocin to induce diabetes. These animals were subsequently treated with curcumin for a period of 1 mo.

Real-time reverse transcriptase polymerase chain reaction analyses showed that diabetes-induced upregulation of vasoactive factors (endothelial nitric oxide synthase and endothelin-1), transforming growth factor-beta1 and extracellular matrix proteins (fibronectin and extradomain-B-containing fibronectin) in the kidneys. These changes were associated with increased oxidative stress, mesangial expansion, and p300 and nuclear factor-kappaB activity that were prevented with curcumin treatment.

These beneficial effects of curcumin were mediated through the inhibition of p300 and nuclear factor-kappaB.