Full Length Research Paper

Effects of curcumin and tetrahydrocurcumin on diabetes induced endothelial dysfunction

Natchaya Wongeakin¹, Pattarin Sridulyakul², Amporn Jariyapongskul³, Apichart Suksamrarn⁴ and Suthiluk Patumraj⁴*

¹Department of Physiology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, Thailand.

²Faculty of Science, Srinakharintaraviroj University, Bangkok, Thailand. ³Department of Physiology, Faculty of Medicine, Srinakharintaraviroj University, Bangkok, Thailand.

⁴Department of Chemistry, Faculty of Science, Ramkamhang University, Bangkok, Thailand.

*Corresponding author. E-mail: suthilukp@yahoo.com.Tel.: +66 2 252-7854. Fax: +66 2 252-7854.

Accepted 17 April, 2009

 Abstract

Diabetes-induced endothelial dysfunction has been well recognized for its underlining causes of oxidative stress. Therefore, several studies have worked on testing active antioxidant agents such as vitamin C and E against diabetes induced oxidative stress to preserve endothelial cells. In the present study, we assessed the effects of plant-derived antioxidant, curcumin and its analog, tetrahydrocurcumin (THC) and also its preventive qualities. Using an animal model, assessment for endothelial-dependent vasodilatation and the behavior of leukocytes were accomplished by using streptozotocin-induced diabetic rats and its mesenteric microcirculation parameters. The results indicated that both antioxidants, curcumin and THC, could significantly inhibit those abnormalities typically seen in endothelial dysfunctions (P < 0.05) in relation to their hypoglycemic and hypolipidemic properties. Unfortunately, curcumin has a poor absorption quality and as a result of this, a higher dose is needed to prevent abnormal endothelial functions. On the other hand, THC was found to be a more potent antioxidant and good therapeutic agent for diabetic patients in preventing diabetes vascular abnormalities.

Key words: Curcumin, tetrahydrocurcumin, endothelial dysfunction, diabetes.