Effects of astragalosides from Radix Astragali on high glucose-induced proliferation and extracellular matrix accumulation in glomerular mesangial cells

Diabetic nephropathy (DN) exhibits a deteriorating course that may lead to end-stage renal failure. Astragalosides have been clinically tested for the treatment of DN, but the mechanism is unclear at present. In this study, the effects of astragalosides were investigated on high glucose-induced proliferation and expression of transforming growth factor-beta(1) (TGF-beta(1)), connective tissue growth factor (CTGF), type IV collagen (colIV) and fibronectin (FN) in glomerular mesangial cells (MCs). Cell proliferation was determined by 5-bromo-2'-deoxyuridine assay, and the expression of TGF-beta(1), CTGF, colIV and FN mRNA and proteins in MCs was detected by reverse transcription-polymerase chain reaction and ELISA assay, respectively. The results showed that high glucose clearly induced the proliferation of MCs and increased the expression of TGF-beta(1), CTGF, colIV and FN. Treatment with 50, 100, 200 mu g/ml astragalosides inhibited cell proliferation and the expression of TGF-beta(1), CTGF, colIV and FN induced by high glucose. Thus, it is concluded that astragalosides inhibit the increased cell proliferation and expression of major extracellular matrix proteins that are induced by high glucose, indicating their value for the prophylaxis and therapy of DN.