TGFB1 and diabetic kidney disease: This extract (3, 6, or 12 g kg−1) inhibited SMAD2 phosphorylation, reduced TGF-β1 expression, ameliorated the expansion of the mesangial area in glomerular tissue, reduced the levels of serum creatine and BUN, and reduced the total SOD activity in the streptozotocin-induced diabetic nephropathy rats.