Polyphyllin VII induces fibroblasts apoptosis via the ERK/JNK pathway

Hypertrophic scar (HS) is a pathological scar that often occurs in burn patients. Its histology is characterized by the excessive proliferation of fibroblasts (FB) and excessive accumulation of extracellular matrix (ECM). Inhibition of proliferation and activation of FB is essential for the treatment of HS. The crude extracts of traditional Chinese medicines have beneficial therapeutic effects on HS besides possessing fewer side effects and being easily available. Polyphyllin VII (PP7) is an isoprene saponin isolated from Rhizoma paridis. It has a pro-apoptotic effect on cancer cells. In the present study, we demonstrate that PP7 exerts a significant inhibitory effect on hypertrophic scar fibroblasts (HSFs) in vitro. We also demonstrate that PP7 considerably induces the apoptosis of HSFs and inhibits their activity. Our data show that the PP7-induced HSFs cell apoptosis was mainly due to the enhanced expression of apoptotic genes (Bax, Caspase-3, Caspase-9) and decreased expression of Bcl-2. Moreover, PP7 treatment also enhances the expression of JNK, but that of extracellular protein kinases (ERK) was reduced, and induces apoptosis through ERK/JNK pathways. Thus, PP7 can be used as a drug to prevent the formation of HS.