Rehmannia glutinosa ameliorates the progressive renal failure induced by 5/6 nephrectomy

Rehmannia glutinosa, the steamed root of the Scrophulariaceae family, has been widely used in Asian countries for the treatment of renal diseases. In this study, we evaluated the renoprotective effect of aqueous extract of Rehmannia glutinosa in progressive renal failure. The effects of Rehmannia glutinosa on renal function, 24-h proteinuria, and the expression of angiotensin II, angiotensin II type 1 (AT 1) receptor, TGF-β1, and type IV collagen in renal cortex were analyzed in progressive renal failure rats induced by 5/6 nephrectomy. Rehmannia glutinosa reduced the serum creatinine level, 24-h urinary protein excretion, and glomerulosclerosis, and it also inhibited the expression of angiotensin II, AT 1 receptor, TGF-β1 and type IV collagen in the renal cortex. These results suggest that the renoprotective effect of Rehmannia glutinosa might be mediated by suppressing the expression of angiotensin II and AT 1 receptor and by regulating TGF-β1 and type IV collagen expression.