Effect of Cordyceps sinensis and Tripterygium wilfordii polyglycosidium on podocytes in rats with diabetic nephropathy.

Li Hao,Meng-Shu Pan,Rui-Feng Wang,Yun Zheng

doi:10.3892/etm.2014.1670

Abstract

The aim of the present study was to investigate the effects of Cordyceps sinensis (CS) and Tripterygium wilfordii polyglycosidium (TWP) on podocytes in rats with diabetic nephropathy (DN). DN rat models were established and divided randomly into normal control (group A), DN (group B), CS (group C), TWP (group D) and CS and TWP groups (group E). After 12 weeks, levels of 24-h urinary protein, blood urea nitrogen (BUN), serum creatinine (SCR), white blood cells, blood glucose (GLU), aspartate aminotransferase, alanine aminotransferase and kidney weight (KW)/body weight (BW) were determined. Renal pathological changes were evaluated using hematoxylin and eosin staining, whereas the structural changes in the podocytes were observed under a transmission electron microscope. The expression levels of nephrin and podocin were evaluated using immunofluorescence staining. Compared with group A, the SCR and BUN levels in group B were higher (P<0.05) and the GLU, KW/BW and the 24-h urine protein were markedly higher (P<0.01). Moreover, incidences of glomerular disorders, chronic tubulointerstitial damage and glomerular podocyte lesions in groups B, C, D and E were observed, compared with group A. The high cortical expression of nephrin and podocin protein decreased. Compared with group B, the KW/BW and 24-h urinary protein level in groups C, D and E were lower (P<0.01). The glomeruli, tubules and podocytes exhibited pathomorphological improvements and the nephrin and podocin protein expression levels were higher in the nephridial tissue. A decrease in KW/BW and the 24-h urinary protein level, as well as improvements in glomerular disorder, chronic tubulointerstitial damage and glomerular podocyte lesions, were observed in groups C, D and E. Therefore, the results demonstrated that CS and TWP exhibited a protective effect on the podocytes of rats with DN. Moreover, CS combined with TWP increased this protective effect.

Highlights

Diabetic nephropathy (DN), one of the serious complications of diabetes mellitus (DM), is the primary cause of mortality in patients with DM
CS was purchased from Jimin Pharmaceutical Co., Ltd., (Jiangxi, China), Tripterygium wilfordii polyglycosidium (TWP) was puchased from Fudan Fuhua Pharmaceutical Co., Ltd., (Shanghai, China), HAO et al: Cordyceps sinensis AND Tripterygium wilfordii streptozotocin was obtained from Sigma
MO, USA), rat urine albumin EIA assay kit was obtained from R&D Systems (Minneapolis, MN, USA), rabbit anti-rat nephrin antibodies, rabbit anti-rat podocin antibodies and goat anti-rabbit antibodies were purchased from Boster (Wuhan, China), Accuchek Blood glucose meter was obtained from Roche Diagnostics GmbH (Mannheim, Germany)

Summary

Introduction

Diabetic nephropathy (DN), one of the serious complications of diabetes mellitus (DM), is the primary cause of mortality in patients with DM. CS functions as a growth factor, antagonizes ischemia and toxic injury to the kidneys, improves metabolism and other multi‐target, multi‐link mechanisms, reduces proteinuria and improves renal function and renal pathological changes [6,7]. Previous studies have demonstrated that DN is closely associated with podocyte injury [8,9,10,11,12]. The mechanism of action of CS in protecting the kidneys via improving lesions of glomerular podocytes in DN has not been confirmed. Numerous studies have shown that Tripterygium wilfordii polyglycosidium (TWP) exhibits immunosuppressive effects and a therapeutic effect on podocyte injury.

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