SMAD3 and renal fibrosis: The results of the study showed that exogenous supplementation with EC and ECF successfully reduced creatinine and urea nitrogen levels; down-regulated the expression levels of TGF-β1, α-SMA, Smad3, and phospho-Smad3 in the TGF-β1/Smad signaling pathway; and ameliorated renal fibrosis.