Dihydroartemisinin alleviates bile duct ligation-induced liver fibrosis and hepatic stellate cell activation by interfering with the PDGF-βR/ERK signaling pathway

• DHA attenuated liver fibrosis in vivo.
• DHA had no cytotoxic effects on hepatocytes in vitro.
• DHA inhibited HSC proliferation and induced cell cycle arrest at the S checkpoint in vitro.
• DHA inhibited HSC activation in vitro.
• DHA reduced the expressions of fibrotic marker proteins by interfering with the PDGF-βR/ERK signaling in HSCs.

Liver fibrosis represents a frequent event following chronic insult to trigger wound healing responses in the liver. Activation of hepatic stellate cells (HSCs), which is a pivotal event during liver fibrogenesis, is accompanied by enhanced expressions of a series of marker proteins and pro-fibrogenic signaling molecules. Artemisinin, a powerful antimalarial medicine, is extracted from the Chinese herb Artemisia annua L., and can inhibit the proliferation of cancer cells. Dihydroartemisinin (DHA), the major active metabolite of artemisinin, is able to attenuate lung injury and fibrosis. However, the effect of DHA on liver fibrosis remains unclear. The aim of this study was to investigate the effect of DHA on bile duct ligation-induced injury and fibrosis in rats. DHA improved the liver histological architecture and attenuated collagen deposition in the fibrotic rat liver. Experiments in vitro showed that DHA inhibited the proliferation of HSCs and arrested the cell cycle at the S checkpoint by altering several cell-cycle regulatory proteins. Moreover, DHA reduced the protein expressions of a-SMA, α1 (I) collagen and fibronectin, being associated with interference of the platelet-derived growth factor β receptor (PDGF-βR)-mediated ERK pathway. These data collectively revealed that DHA relieved liver fibrosis possibly by targeting HSCs via the PDGF-βR/ERK pathway. DHA may be a therapeutic antifibrotic agent for the treatment of hepatic fibrosis.