Abstract
Diabetic retinopathy is one of the most common and severe complications of diabetes
mellitus. Arctiin, a bioactive compound isolated from the dry seeds of Arctium lappa L., has been reported to have antidiabetic activity. In this study, we investigated
the effect of arctiin on the serum glucose and HBA1c levels, the blood viscosity,
and VEGF expression in the retinal tissues of rats with diabetic retinopathy. We first
extracted arctiin from Fructus Arctii and then investigated its chemopreventive effect
on streptozotocin-induced diabetic retinopathy in male Sprague-Dawley rats. After
the induction of diabetes using streptozotocin (30 mg/kg, i. p.), the rats were randomly
divided into five groups (n = 20 per group) and treated with intragastric doses of
30, 90, or 270 mg/kg/d wt of arctiin, 100 mg/kg/d wt of calcium dobesilate, or 0.5 %
CMC-Na. Twenty nondiabetic sham-treated rats were treated with 0.5 % CMC-Na. The occurrence
of diabetic retinopathy did not differ dramatically among the groups. However, at
week 16, the glycosylated haemoglobin (HBA1c) level was significantly decreased in
all of the arctiin-treated groups when compared with the control group, and the serum
glucose level was also decreased in the rats treated with the highest dose of arctiin.
In addition, treatment with arctiin ameliorated retinal oedema, detachment of the
retina, and VEGF expression in the retina, as detected using histological and immunochemical
examinations. Finally, arctiin increased the viability of retinal microvascular endothelial
cells in vitro. Together, these findings demonstrate that arctiin decreases the severity of diabetic
complications, demonstrating the importance of this compound as an inhibitor of diabetic
retinopathy.
Key words
arctiin - diabetic retinopathy - HBA1c - retina - retinal microvascular endothelial
cell
