Suppressive effects of PG201, an ethanol extract from herbs, on collagen-induced arthritis in mice

Abstract

Objective. PG201 has been formulated using 12 herbs known to have anti‐inflammatory and protective effects on damaged tissue and bone among other functions. The present study was done in order to assess the therapeutic effects of PG201 in collagen‐induced arthritis (CIA) in mice. Methods. DBA/1 mice were immunized with bovine type II collagen. After a second collagen immunization, mice were treated with PG201 orally at 10 mg/kg once a day for 18 days. 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. Molecular indicators related to CIA pathology were analysed by measuring the serum levels of matrix metalloproteinase 2 (MMP‐2), tissue inhibitor of matrix metalloproteinase 2 (TIMP‐2) and the anti‐inflammatory cytokines interleukin (IL)‐4 and IL‐10. Results. Administration of PG201 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 PG201. In the serum of PG201‐treated mice, the level of TIMP‐2 and the ratio of TIMP‐2 to MMP‐2 were significantly elevated, and the level of IL‐4, but not of IL‐10, was increased. Conclusion. Administration of PG201 has therapeutic effects on CIA. Protection of cartilage was particularly prominent. PG201 is a potential therapy for rheumatoid arthritis.