Protective effect of yacon leaves decoction against early nephropathy in experimental diabetic rats

► Leaves decoction of Smallanthus sonchifolius (yacon) is a protective agent against renal damage during diabetes. ► Altered renal parameters were normalized in yacon decoction-treated diabetic rats. ► Yacon decoction alleviates early glomerulosclerosis in diabetes through TGF-β/Smad inhibition. ► The results might promote a better understanding for the molecular mechanisms of yacon decoction actions during diabetes.