SMAD3 and Ureteral obstruction: In addition, Meng et al. demonstrated that only naringenin treatment markedly alleviated renal fibrosis in vitro and in a mouse model of unilateral ureteral obstruction (UUO) by blocking Smad3 signaling directly, and the combination of naringenin with asiatic acid, a triterpene from Centella Asiatica, demonstrated to be a Smad7 agonist, produced a better inhibitory effect on renal fibrosis by suppressing Smad3 while inducing Smad7 [114].