Beneficial effects of gymnemic acid on three-dimensional vascular architecture and expression of vascular endothelial growth factor of intrarenal segmental and interlobar arteries in diabetic rat kidney

Background: A high prevalence of atherosclerotic vascular lesions has been associated with renal disease and diabetes and is a major cause for increasing deaths from cardiovascular disease. The present study aimed to determine the beneficial effects of gymnemic acids on the kidney microvasculature and to establish their anti-angiogenic properties that are related to the expression of vascular endothelial growth factor (VEGF) protein of segmental and interlobar arteries in induced diabetic rats. Methods: Rats were divided into five groups including the control group (C), control treated with gymnemic acid (CGM), diabetic animals (DM group) that were rendered diabetic by a single dose [60 mg/kg body weight (BW)] of a streptozotocin (STZ) injection, diabetic rats treated with gymnemic acid (400 mg/kg BW) (GM), and diabetic rats treated with glibenclamide (4 mg/kg BW) (GR). After 8 weeks, kidney tissues were collected for histological analysis. In rats with DM, the segmental arteries exhibited increased wall thickness. The kidney microvasculature was examined using the vascular corrosion casting method. Results: Rats with DM presented a decreasing diameter of segmental and interlobar arteries. They were evidently redeveloped and restored in the GM and GR groups. As determined by immunofluorescence, the expression of VEGF was significantly reduced in both the GM and GR groups. Conclusions: The present study demonstrated that gymnemic acid from Gymnemasylvestre may be a promising medical herb for use in the treatment of diabetes and kidney disease.Keywords: diabetes mellitus, segmental artery, interlobar artery, gymnemic acid, vascular architecture