SMAD3 and renal fibrosis: To further validate whether nodakenin function against fibrosis by inhibiting the Smad3/Snail1 signal pathway, we constructed Snail1 overexpression cells by lentivirus transduction and found that nodakenin failed to decrease the levels of fibrotic genes in Snail1 overexpression cells, suggesting that the inhibition of renal fibrosis by nodakenin may at least partially function through Snail1 signal pathway in the obstructed kidneys.