3',4'-Dihydroxyflavonol prevents diabetes-induced endothelial dysfunction in rat aorta

Area of Science:

• Biochemistry
• Physiology
• Pharmacology

Background:

• Diabetes mellitus is associated with increased oxidative stress.
• Oxidative stress impairs endothelium-dependent relaxation in blood vessels.

Purpose of the Study:

• To investigate the effects of the antioxidant 3',4'-dihydroxyflavonol (DiOHF) on superoxide release and endothelial function in diabetic rat aortae.

Main Methods:

• Type-1 diabetes was induced in rats using streptozotocin (STZ).
• Vascular reactivity and superoxide generation were assessed in aortic rings using organ bath techniques and lucigenin-enhanced chemiluminescence.

Main Results:

• Diabetic rats exhibited elevated blood glucose and increased aortic superoxide generation compared to controls.
• Acetylcholine-induced relaxation was impaired in diabetic aortae, while relaxation to sodium nitroprusside was unaffected.
• Acute exposure to DiOHF reduced superoxide generation and enhanced acetylcholine-induced relaxation in diabetic aortae.
• One-week in vivo treatment with DiOHF also reduced superoxide generation and improved endothelial function in diabetic rats.

Conclusions:

• The antioxidant DiOHF effectively reduces oxidant stress in diabetic rat aortae.
• DiOHF preserves endothelium-dependent relaxation in the vasculature of diabetic rats, both acutely and after short-term in vivo treatment.