Inhibitory effects of Cnidium officinale Makino and Tabanus fulvus Meigan on the high glucose-induced proliferation of glomerular mesangial cells

This study describes a potent activity of Cnidium officinale Makino (Cnidii rhizoma) and Tabanus fulvus Meigan (Tabanus) as an inhibitor of high glucose-induced proliferation of glomerular mesangial cells (GMCs). Raising the ambient glucose concentration from 5.6 to 25 mM for 24 h caused a dramatic increase in [3H]thymidine incorporation, and these increases were attenuated by treatment of GMCs with the extracts of Cnidii rhizoma and Tabanus (2.5-20 μg/ml) in a dose-dependent manner. In contrast, extracts of Cnidii rhizoma or Tabanus (20 μg/ml) did not change the growth of GMCs cultured under normal glucose condition. To clarify the mechanism involved in anti-proliferative activity of these medicines, this study examined the effects of Cnidii rhizoma and Tabanus on high glucose-stimulated extracellular matrix (ECM) protein accumulation and transforming growth factor-β1 (TGF-β1) production. Exposure of GMCs to high glucose significantly stimulated the ECM protein, collagen and fibronectin, accumulation and TGF-β1 secretion, and these changes were dramatically diminished by treatment of GMCs with extracts of Cnidii rhizoma or Tabanus (10 μg/ml). Taken together, these results indicate that Cnidii rhizoma and Tabanus inhibit the high glucose-induced GMC proliferation partially through suppressing the ECM accumulation and TGF-β1 production, suggesting that these medicines may be a promising agent for treating the development and progression of diabetic glomerulopathy.