Aqueous extract of P. vulgaris block the TGF-β1/Smad signaling pathway, reduces the expression of TGF-β and Smad2/4, increases Smad7 levels, thereby inhibiting the formation of the fibrosis markers CTGF and collagen IV and ameliorating renal fibrosis in STZ-induced diabetic rats (102). Here, TGFB1 is linked to renal fibrosis.