Efecto antioxidante sobre niveles plasmáticos de grelina/leptina y daño oxidativo hipotalámico en ratas con diabetes.

Abstract

The hormones ghrelin and leptin are important signal regulators of energy homeostasis from the periphery to the hypothalamus. Diabetic hyperphagia is the result of the intracellular energy imbalance that leads to a state of constant hyperglycemia resulting in the generation of reactive oxygen species (ROS) and deficiency of antioxidant defenses, causing oxidative stress states and damage to lipids, proteins and DNA, leading to long-term complications. The objective of this study was to evaluate the effect of treatment with the antioxidants aged garlic extract (EAE), resveratrol (RVS) and curcumin (CUR) on DNA damage in the arcuate nucleus of diabetic rats and its relationship with the level of leptin and ghrelin in circulation. Ghrelin and leptin levels were evaluated using plasma samples from rats treated with EAE, SVR and CUR for 4 weeks. In addition, brain slices were used to evaluate the expression of DNA damage (8-oxoguanine) in neurons of the arcuate nucleus (ARC) by immunofluorescence. Diabetic animals without treatment did not show changes in ghrelin concentration in plasma but showed a decrease in leptin levels (p <0.05). Treatments with EAE and CUR caused a 20% and 18% increase, respectively, in ghrelin levels (p <0.05) and a 12.4% increase in leptin levels in plasma. On the other hand, the expression of 8-oxoguanine in the ARC was higher in the group of diabetic rats compared to the non-diabetic group. The group treated with EAE and RVS showed tendency to decrease the expression of the immunofluorescence signal. Treatment with CUR induces a greater decrease of 8-oxoguanine compared to the diabetic group. Antioxidant treatment does not have a significant effect on the concentration of ghrelin and leptin in plasma; the decreased in DNA damage after CUR treatment suggests that prolonged use of this antioxidant can improve the oxidative damage in diabetes.