Suppressive effects of a water extract of Ulmus davidiana Planch (Ulmaceae) on collagen-induced arthritis in mice

Ulmus davidiana Planch (Ulmaceae) has long been known to have anti-inflammatory and protective effects on damaged tissue, inflammation and bone resorption. Therefore, this study was undertaken to address (1) whether the water extract of the bark of Ulmus davidiana Planch (Ulmaceae) (UD) can modulate the expression of inducible inflammatory cytokines in mice; (2) in order to assess the therapeutic effects of UD in collagen-induced arthritis (CIA) in mice. DBA/1 mice were immunized with bovine type II collagen. After a second collagen immunization, mice were treated with UD orally at 100 mg/kg once a day for 3 weeks. Paws were evaluated macroscopically for redness, swelling and deformities. The levels of TNF-α and IL-1β in the ankle were examined. The severity of arthritis within the knee joints was evaluated by histological assessment of cartilage destruction and pannus formation. Administration of UD significantly suppressed the progression of CIA and inhibited the production of TNF-α and IL-1β in the paws. The erosion of cartilage was dramatically reduced in mouse knees after treatment with UD. In the serum of UD-treated mice, the levels of IL-4 and IL-10, anti-inflammatory cytokines, were increased. From the results, it was concluded that administration of UD has therapeutic effects on CIA including protection of cartilage and RA for a potential therapy.