The liver and kidney fibrosis model was established by thioacetamide(TAA) and unilateral ureteral obstruction(UUO) in SD rats. The rats were randomly divided into three groups: model group, low and high-dose groups of C21 steroidal glycosides of Cynanchum auriculatum. Another blank control group was set. Four weeks later, serum was taken to detect the biochemical indexes of liver and kidney function. Urine protein and urine creatinine were detected by kits. Liver and kidney tissue samples were stained with HE and Masson staining, and hydroxyproline content was detected. Western blot was used to detect expressions of fibrotic proteins, inflammatory factors and TLR4 signaling pathways, so as to observe the preventive and therapeutic effects of C21 steroidal glycosides from C. auriculatum on hepatic and renal fibrosis and explore its molecular mechanism. Four weeks later, serum biochemical results showed that liver and kidney functions were seriously damaged, and pathological sections showed that inflammatory cell infiltration, decrease of parenchymal cells, and increase of interstitial fibrosis in liver and kidney tissues. The results showed that low and high doses(150, 300 mg·kg~(-1)) of C21 steroidal glycosides could significantly reduce the collagen deposition and the pathological changes of liver and kidney fibrosis compared with the model group. At the same time, we found that the expression levels of TLR4 and MyD88 signaling pathway proteins were significantly increased in the liver and kidney tissues of the model group, and a large number of NF-κB signaling pathway proteins migrated into the nucleus. On the contrary, the expression levels of TLR4, MyD88 signaling pathway proteins and the nuclear migration of NF-κB were significantly inhibited in the low and high dose groups of C21 steroidal glycosides from C. auriculatum. Therefore, it was speculated that the mechanism of C21 steroidal glycoside for preventive and therapeutic effect on hepatic and renal fibrosis was related to inhibit TLR4/MYD88/NF-κB inflammatory pathway, thus preventing hepatic and renal fibrosis.
Keywords: C21 steroidal glycosides of Cynanchum auriculatum; TLR4 pathway; collagen deposition; inflammatory factors; liver and kidney fibrosis.