The effects of dihydroartemisinin on inflammatory bowel disease-related bone loss in a rat model.

Bone loss is one of the important extra-intestinal manifestations in patients with inflammatory bowel diseases (IBDs). Compounds derived from natural products have been used to treat IBDs. However, the role of natural products on IBD-induced bone loss is not completely clarified. In the present study, we observed the effects of dihydroartemisinin (DHA), an antimalaria drug, on IBD and IBD-induced bone loss in a rat model. Chronic IBD model was established in Sprague-Dawley rats by giving them 2.5% dextran sodium sulfate in drinking water. DHA was given by intraperitoneal injection. Blood, colon, and bone samples were collected for biomarker assay and histological analysis. There was an obvious increase in tumor necrotic factor (TNF) α and receptor activator of nuclear factor (NF)-kB ligand (RANKL), and decrease in procollagen type 1 N-terminal propeptide (P1NP) level in IBD groups compared with the normal control (p < 0.05). The disease activity score of IBD rats was significantly higher than the control (p < 0.01). Obvious decrease in disease activity score, TNFα, and RANKL level and increase in P1NP were observed in DHA-treated IBD rats. Bone loss, shown as the decrease in bone mineral density, bone volume fraction, and trabecular number and increase in trabecular separation were observed in IBD rats compared with control (p < 0.01). DHA treatment obviously abolished the bone loss, in particular in the high-dose group (p < 0.05). DHA treatment also inhibited the excessive osteoclast formation; RANKL protein expression; and RANK, TRAF6, Fra-1, NFATc1 mRNA expression induced by IBD. Our data indicated that DHA may be a potential therapeutic agent for IBD and IBD-induced bone loss. Impact statement Bone loss is one of the important extra-intestinal manifestations in patients with inflammatory bowel diseases (IBDs). Studies have shown that compounds derived from natural products are useful in the treatment of IBDs. However, few studies have investigated the role of compounds derived from natural products in treatment of osteoporosis in IBDs. The current study aimed to show the effects of dihydroartemisinin (DHA), antimalaria drug, on bone loss in a rat model of IBD. The findings showed that DHA intervention dose dependently protected against bone loss in IBD rats by inhibiting tumor necrotic factor α production and osteoclast formation. These findings highlights that DHA may be beneficial for bone health in those patients with IBD.