Comparison of Anti-Renal Fibrosis Activity of <i>Eucommiae cortex</i> Extract and Its Microbial Fermentation Products

<b>Background:</b> Renal fibrosis is a common pathological feature of all progressive chronic kidney disease (CKD). <i>Eucommiae cortex</i> (EC) is a valuable economic tree species endemic to China. The microbial fermentation of Chinese medicines can release their active ingredients as effectively as possible or produce new active ingredients with enhanced efficacy and reduced toxic side effects; <b>Methods:</b> The microbial fermentation of EC can produce pinoresinol (Pin) and dehydrodiconiferyl alcohol (DA). In this study, C57 BL/6 mice were fed a diet containing 0.2% adenine, resulting in a model of chronic kidney disease. The effects of EC and EC ferment (ECF) on CKD were explored by the exogenous supplementation of EC and ECF; <b>Results:</b> The results of the study showed that exogenous supplementation with EC and ECF suc-cessfully 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; <b>Conclusions:</b> Both EC and ECF may have reno-protective effects and provide a reference for relevant clinical drug development.