Inhibitory effects of anthocyanin‐rich purple corn extract on diabetes‐associated glomerular angiogenesis

Abstract

Diabetic nephropathy (DN) is one of the major diabetic complications and the leading cause of end‐stage renal disease. Abnormal angiogenesis results in new vessels that are often immature and play a pathological role in DN, contributing go renal fibrosis and disrupting glomerular failure. Purple corn has been utilized as a daily food and exerts disease‐preventive activities. This study was designed to investigate whether the anthocyanin‐rich purple corn extract (PCE) prevented glomerular angiogenesis under hyperglycemic condition. Human endothelial cells were treated in conditioned media of mesangial cells exposed to 33 mM high glucose (HG‐HRMC). PCE decreased endothelial expression of the angiogenesis markers VEGF and HIF‐1α induced by HG‐HRMC‐ conditioned media. PCE attenuated angiogenic endothelial marker PECAM‐1 and integrin β3 enhanced in HG‐HRMCconditioned media. In the in vivo study, db/db mice were treated with 10 mg/kg PCE for 8 weeks. It was revealed that PCE alleviated glomerular angiogenesis of diabetic kidney by attenuating the induction of VEGF and HIF‐1α. In addition, PCE diminished plasma level of soluble VEGF. These results demonstrate that PCE antagonized glomerular angiogenesis due to chronic hyperglycemia. Therefore, PCE may be a potent therapeutic agent targeting abnormal angiogenesis in DN leading to kidney failure.